Michael Macari, M.D.

Well-differentiated Pancreatic Neuroendocrine Carcinoma in Tuberous Sclerosis-Case Report and Review of the Literature
Arva, Nicoleta C; Pappas, John G; Bhatla, Teena; Raetz, Elizabeth A; Macari, Michael; Ginsburg, Howard B; Hajdu, Cristina H
2012 Jan;36(1):149-153, American journal of surgical pathology
Neuroendocrine tumors of the pancreas are rare in children. They usually occur in the setting of genetic syndromes such as multiple endocrine neoplasia type 1, von Hippel-Lindau disease, and neurofibromatosis 1. These tumors have also been reported in the tuberous sclerosis complex (TSC), but the incidence is low in comparison with other syndromes. Only 9 cases have been described to date, and it is not yet well understood if any connection exists between TSC and pancreatic endocrine tumors. TSC is characterized by mutations in TSC1 and TSC2 genes, which activate the AKT-mTOR oncogenic cascade. Recent molecular studies in pancreatic endocrine tumors showed activation of the same pathway, which points toward a common molecular pathway between these two entities. We present a case of well-differentiated neuroendocrine carcinoma of the pancreas in a child with TSC and discuss the genetic aspects of this disease
— id: 147697, year: 2012, vol: 36, page: 149, stat: Journal Article,

Iodine Quantification With Dual-Energy CT: Phantom Study and Preliminary Experience With Renal Masses
Chandarana, Hersh; Megibow, Alec J; Cohen, Benjamin A; Srinivasan, Ramya; Kim, Danny; Leidecker, Christianne; Macari, Michael
2011 Jun;196(6):W693-W700, American journal of roentgenology
OBJECTIVE: The purpose of this study was to validate the utility of dual-source dual-energy MDCT in quantifying iodine concentration in a phantom and in renal masses. MATERIALS AND METHODS: A series of tubes containing solutions of varying iodine concentration were imaged with dual-source dual-energy MDCT. Iodine concentration was calculated and compared with known iodine concentration. Single-phase contrast-enhanced dual-source dual-energy MDCT data on 15 patients with renal lesions then were assessed independently by two readers. Dual-energy postprocessing was used to generate iodine-only images. Regions of interest were placed on the iodine image over the lesion and, as a reference, over the aorta, for recording of iodine concentration in the lesion and in the aorta. Another radiologist determined lesion enhancement by comparing truly unenhanced with contrast-enhanced images. Mixed-model analysis of variance based on ranks was used to compare lesion types (simple cyst, hemorrhagic cyst, enhancing mass) in terms of lesion iodine concentration and lesion-to-aorta iodine ratio. RESULTS: In the phantom study, there was excellent correlation between calculated and true iodine concentration (R(2) = 0.998, p < 0.0001). In the patient study, 13 nonenhancing (10 simple and three hyperdense cysts) and eight enhancing renal masses were evaluated in 15 patients. The lesion iodine concentration and lesion-to-aorta iodine ratio in enhancing masses were significantly higher than in hyperdense and simple cysts (p < 0.0001). CONCLUSION: Iodine quantification with dual-source dual-energy MDCT is accurate in a phantom and can be used to determine the presence and concentration of iodine in a renal lesion. Characterization of renal masses may be possible with a single dual-source dual-energy MDCT acquisition without unenhanced images or reliance on a change in attenuation measurements
— id: 132885, year: 2011, vol: 196, page: W693, stat: Journal Article,

Delayed presentation of splenic rupture following colonoscopy: Clinical and CT findings
Fishback S.J.; Pickhardt P.J.; Bhalla S.; Menias C.O.; Congdon R.G.; MacAri M.
2011 ;18(6):539-544, Emergency radiology
The purpose of this study is to investigate the clinical and CT findings in patients with symptomatic colonoscopy-induced splenic rupture, and to assess for common features among this cohort. Multi-center search yielded 11 adults with symptomatic splenic injury related to colonoscopy. Workup included abdominal CT in 10 (91%) cases and abdominal radiography in two patients (one patient had both). Colonoscopy findings, post-procedural course, and CT findings were systematically reviewed. Mean patient age was 62.2 years (range, 51-84 years); 8 (73%) of 11 were female. The majority (64%) of colonoscopies were for screening. No immediate complications were reported at optical colonoscopy; tortuosity/redundancy was noted in five cases. Except for a small (8 mm) polyp in one case and a large (10 mm) polyp in another, the remaining nine patients had either diminutive or no polyps. Only one patient presented with hemodynamic instability during post-colonoscopy recovery; the other ten had a delayed presentation ranging from 8 h to 8 days (mean, 2.1 days). All 11 patients presented with abdominal pain. CT was diagnostic for splenic injury with subcaspular and/or perisplenic hematoma in all ten CT cases. Hemoperitoneum was present in eight, visible splenic laceration in three cases, and splenic artery pseudoaneurysm in one case. Five patients underwent splenectomy (four emergent) and six patients were treated conservatively. Average hospital stay was 5.5 days (range, 3-10 days). Colonoscopy-induced splenic rupture characteristically presents as a delayed and often serious complication. In cases of apparent non-traumatic splenic hematoma or rupture at CT, eliciting a history of recent colonoscopy may identify the etiology. 2011 Am Soc Emergency Radiol
— id: 147752, year: 2011, vol: 18, page: 539, stat: Journal Article,

Frequency of Intraductal Papillary Mucinous Neoplasm in Patients with and without Pancreas Cancer
Macari M; Eubig J; Robinson E; Megibow A; Newman E; Babb J; Pachter HL; Hajdu C
2011 Jan 21;10(6):734-741, Pancreatology
Purpose: To determine the frequency of intraductal papillary mucinous neoplasm (IPMN) in patients with and without invasive ductal adenocarcinoma (IDAC). Methods: 82 patients underwent pancreatectomy for pancreas adenocarcinoma. 68/82 subjects underwent at least one preoperative imaging study including CT (n = 43), MRI (n = 25), or both (n = 12). Imaging studies were retrospectively evaluated to determine if IPMN was present in the gland at a location distant from IDAC. In 183 different adult patients undergoing MRI for renal mass, images were evaluated to determine the frequency of IPMN. Fisher's exact test was used to test whether the prevalence of IPMN was greater among patients with pancreas cancer than those without. Results: Five of 68 (7.3%) patients who underwent pancreatic resection for IDAC had IPMN at a site distant from the cancer. Two of 182 (1.1%) patients undergoing MRI for renal cancer had imaging evidence of IPMN. There was a significant difference (p = 0.017) in the prevalence of IPMN between patients with and without IDAC. The odds ratio for IPMN as a predictor of pancreas cancer was estimated as 7.18. Conclusion: IPMN occurs with increased frequency in patients with pancreas cancer as opposed to those without pancreas cancer. and IAP
— id: 121309, year: 2011, vol: 10, page: 734, stat: Journal Article,

CT Colonography in Senior versus Nonsenior Patients: Extracolonic Findings, Recommendations for Additional Imaging, and Polyp Prevalence
Macari M; Nevsky G; Bonavita J; Kim DC; Megibow AJ; Babb JS
2011 Jun;259(3):767-774, Radiology
Purpose: To retrospectively evaluate the frequency of recommendations for additional imaging (RAIs) for important extracolonic findings and polyp prevalence among a cohort of seniors (age >/= 65 years) and nonseniors (age < 65 years) undergoing low-dose computed tomographic (CT) colonography. Materials and Methods: Institutional review board approval was obtained for this HIPAA-compliant retrospective study. Four hundred fifty-four patients (204 nonseniors: mean age, 52 years; 250 seniors: mean age, 69 years) underwent CT colonography at an outpatient facility. Cases were prospectively reported by one of four abdominal radiologists with expertise in CT colonography. The dictated reports were reviewed to determine the frequency of polyps (>/=6 mm), the number of extracolonic findings, and the number of RAIs generated. The Fisher exact test was used to compare the percentage of seniors and nonseniors with at least one reported polyp, with at least one extracolonic finding, as well as the frequency of RAIs. Results: The percentage of patients with at least one reported polyp was 14.2% (29 of 204) for the nonsenior group and 13.2% (33 of 250) for seniors, which was not significantly different (P = .772). The percentage of patients with at least one extracolonic finding was 55.4% (113 of 204) for nonseniors and 74.0% (185 of 250) for seniors (P < .0001). The percentage of patients in which an RAI was suggested was 4.4% (nine of 204) for nonseniors and 6.0% (15 of 250) for seniors, which was not significantly different (P = .450). Conclusion: Extracolonic findings were more frequent in seniors than in nonseniors; however, there was no significant difference in the frequency of RAIs between the two groups. (c) RSNA, 2011 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11102144/-/DC1
— id: 130256, year: 2011, vol: 259, page: 767, stat: Journal Article,

Can the location of the CT whirl sign assist in differentiating sigmoid from caecal volvulus?
Macari, M; Spieler, B; Babb, J; Pachter, H L
2011 Feb;66(2):112-117, Clinical radiology
AIM: To determine whether the location of the computed tomography (CT) whirl sign can be used to help differentiate caecal from sigmoid volvulus. MATERIALS AND METHODS: Thirty-one patients (mean age 64.6 years) underwent multidetector CT and had confirmed colonic volvulus. There were 15 patients with caecal volvulus and 16 with sigmoid volvulus. Axial and coronal images were retrospectively evaluated on the picture archiving and communication system (PACS) by two reviewers in consensus without knowledge of the final diagnosis to determine whether a CT whirl sign was present and, if so, was the location to the right of midline or in the midline/left. The location of the twisting at imaging was correlated with whether the patient had caecal or sigmoid volvulus. Fisher's exact test was used to determine whether there was an association between the location of the twist (right versus mid-left) and the location of the colonic volvulus (caecal versus sigmoid). The non contrast CT (NCCT) examinations of 30 additional patients without colonic volvulus were evaluated for the presence or absence of a CT whirl sign. RESULTS: All 31 patients with colonic volvulus had a CT whirl sign. No patient who underwent NCCT for kidney stones demonstrated a CT whirl sign. According to Fisher's exact test, there was a highly significant association (p<0.0001) between the location of the twist (right versus mid-left) and the location of the colonic volvulus (caecal versus sigmoid). Using the location of the twist as a predictor of whether the volvulus was caecal or sigmoid provided a correct diagnosis for 93.3% (14/15) of the patients with caecal volvulus and 100% (16/16) of those with sigmoid volvulus, yielding an overall diagnostic accuracy of 96.8% (30/31). CONCLUSION: The location of the mesenteric twist (CT whirl sign) is a highly accurate finding in discriminating caecal from sigmoid volvulus
— id: 119233, year: 2011, vol: 66, page: 112, stat: Journal Article,

Focal Cystic Pancreatic Lesions: Variability in Radiologists' Recommendations for Follow-up Imaging
Macari, Michael; Megibow, Alec J
2011 Apr;259(1):20-23, Radiology
— id: 129324, year: 2011, vol: 259, page: 20, stat: Journal Article,

Dual-energy Computed Tomography Applications in Uroradiology
Park J; Chandarana H; Macari M; Megibow AJ
2011 Feb;13(1):55-62, Current urology reports
The introduction of dual-energy computed tomography systems (ie, scanners that can simultaneously acquire images at different energies) has significant and unique applications for urologists. Imaging data from these scanners can be used to evaluate composition of urinary calculi and, by 'removing' iodine from an image, significantly decrease radiation dose to patients referred for hematuria. Further, the ability to create a virtual noncontrast image obviates the need for repeated scanning in patients with incidentally detected renal and adrenal masses. Finally, the ability to quantify the regional concentration of iodine in a renal neoplasm may provide a method to monitor effectiveness of therapy before size changes become apparent
— id: 141866, year: 2011, vol: 13, page: 55, stat: Journal Article,

Single-Phase Dual- Energy CT Allows for Characterization of Renal Masses as Benign or Malignant
Graser, A; Becker, CR; Staehler, M; Clevert, DA; Macari, M; Arndt, N; Nikolaou, K; Sommer, W; Stief, C; Reiser, MF; Johnson, TRC
2010 JUL ;45(7):399-405, Investigative radiology
Purpose: To evaluate the diagnostic accuracy of dual-energy CT (DECT) in renal mass characterization using a single-phase acquisition. Materials and Methods: A total of 202 patients (148 males, 54 females; 63 +/- 13 years) with ultrasound-based suspicion of a renal mass underwent unenhanced single energy and nephrographic phase DECT on a dual source scanner (Siemens Somatom Definition Dual Source, n = 174; Somatom Definition Flash, n = 28). Scan parameters for DECT were: tube potential, 80/100 and 100/Sn140 kVp; exposure, 404/300 and 96/232 effective mAs; collimation, 14 x 1.2/32 x 0.6 mm. Two abdominal radiologists assessed DECT and SECT image quality and noise on a 5-point visual analogue scale. Using solely the DE acquisition including virtual nonenhanced (VNE) and color coded iodine images that enable direct visualization of iodine, masses were characterized as benign or malignant. In a second reading session after 34 to 72 (average: 55) days, the same assessment was again performed using both the true nonenhanced (TNE) and nephrographic phase scans thereby simulating conventional single-energy CT. Sensitivities, specificities, diagnostic accuracies, and interpretation times and were recorded for both reading paradigms. Dose reduction of a single-phase over a dual-phase protocol was calculated. Results were tested for statistical significance using the paired Wilcoxon signed rank test and student t test. Differences in sensitivities were tested for significance using the McNemar test. Results: Of the 202 patients, 115 (56.9%) underwent surgical resection of renal masses. Histopathology showed malignancy in 99 and benign tumors in 18 patients, in 48 patients (23.7%), follow-up imaging showed size stability of lesions diagnosed as benign, and 37 patients (18.3%) had no mass. Based on DECT only, 95/99 (96.0%) patients with malignancy and 96/103 (93.2%) patients without malignancy were correctly identified, for an overall accuracy of 94.6%. The dual-phase approach identified 96/99 (97.0%) and 98/103 (95.1%), accuracy 96.0%, P > 0.05 for both. Mean interpretation time was 2.2 +/- 0.8 minutes for DECT, and 3.5 +/- 1.0 minutes for the dual-phase protocol, P < 0.001. Mean VNE/TNE image quality was 1.68 +/- 0.65/1.30 +/- 0.59, noise was 2.03 +/- 0.57/1.18 +/- 0.29, P < 0.001 for both. Omission of the true unenhanced phase lead to a 48.9 +/- 7.0% dose reduction. Conclusion: DECT allows for fast and accurate characterization of renal masses in a single-phase acquisition. Interpretation of color coded images significantly reduces interpretation time. Omission of a nonenhanced acquisition can reduce radiation exposure by almost 50%
— id: 110856, year: 2010, vol: 45, page: 399, stat: Journal Article,

Dual-energy computed tomography imaging of the aorta after endovascular repair of abdominal aortic aneurysm
Laks, Shaked; Macari, Michael; Chandarana, Hersh
2010 Aug;31(4):292-300, Seminars in ultrasound CT & MR
Endovascular repair is increasingly considered a less-invasive alternative to open repair of abdominal aortic aneurysm. However, there are still many potential complications of endovascular repair, including endoleaks, graft migration, thrombosis, and fistula formation. Endoleak is the most common complication for which these patients undergo long-term imaging surveillance. Most centers acquire computed tomographic (CT) data before contrast administration and during an arterial and delayed phase of aortic enhancement after the administration of intravenous contrast material to optimize detection of endoleaks. Although this technique works well, the downside is significant patient radiation exposure. Although the carcinogenic risk of ionizing radiation because of CT exposure is low, it has been linked to an increase in the lifelong risk of developing fatal cancers. Furthermore, this risk is cumulative and increases with multiple radiation exposure, as is true in surveillance after endovascular repair. As a result, considerable research is being performed to optimize CT protocols in an effort to decrease radiation dose. One such approach is to image these patients with recently introduced dual source dual-energy CT system. Using this technique, virtual noncontrast data may be generated from a postcontrast acquisition which may obviate the routine acquisition of noncontrast acquisition, thus decreasing radiation dose. In this article, we discuss the role of dual energy CT imaging in evaluation of patients after endovascular repair of abdominal aortic aneurysm
— id: 136564, year: 2010, vol: 31, page: 292, stat: Journal Article,

Comparison of a unidirectional panoramic 3D endoluminal interpretation technique to traditional 2D and bidirectional 3D interpretation techniques at CT colonography: preliminary observations
Lenhart, D K; Babb, J; Bonavita, J; Kim, D; Bini, E J; Megibow, A J; Macari, M
2010 Feb;65(2):118-125, Clinical radiology
AIM: To compare the evaluation times and accuracy of unidirectional panoramic three-dimensional (3D) endoluminal interpretation to traditional two-dimensional (2D) and bidirectional 3D endoluminal techniques. MATERIALS AND METHODS: Sixty-nine patients underwent computed tomography colonography (CTC) after bowel cleansing. Forty-five had no polyps and 24 had at least one polyp > or = 6 mm. Patients underwent same-day colonoscopy with segmental unblinding. Three experienced abdominal radiologists evaluated the data using one of three primary interpretation techniques: (1) 2D; (2) bidirectional 3D; (3) panoramic 3D. Mixed model analysis of variance and logistic regression for correlated data were used to compare techniques with respect to time and sensitivity and specificity. RESULTS: Mean evaluation times were 8.6, 14.6, and 12.1 min, for 2D, 3D, and panoramic, respectively. 2D was faster than either 3D technique (p < 0.0001), and the panoramic technique was faster than bidirectional 3D (p = 0.0139). The overall sensitivity of each technique per polyp and per patient was 68.4 and 76.7% for 2D, 78.9 and 93.3% for 3D; and 78.9 and 86.7% for panoramic 3D. CONCLUSION: 2D interpretation was the fastest overall, the panoramic technique was significantly faster than the bidirectional with similar sensitivity and specificity. The sensitivity for a single reader was significantly lower using the 2D technique. Each reader should select the technique with which they are most successful
— id: 106503, year: 2010, vol: 65, page: 118, stat: Journal Article,

Invited commentary
Macari, Michael; Graser, Anno; Katz, Douglas S
2010 Jul-Aug;30(4):1052-1055, Radiographics
— id: 111393, year: 2010, vol: 30, page: 1052, stat: Journal Article,

Dual-source dual-energy MDCT of pancreatic adenocarcinoma: initial observations with data generated at 80 kVp and at simulated weighted-average 120 kVp
Macari, Michael; Spieler, Bradley; Kim, Danny; Graser, Anno; Megibow, Alec Jeffrey; Babb, James; Chandarana, Hersh
2010 Jan;194(1):W27-W32, American journal of roentgenology
OBJECTIVE: The purpose of this study was to determine whether the conspicuity of malignant tumors of the pancreas at dual-source dual-energy CT is better with 80-kVp acquisition than with 120-kVp acquisition simulated with a weighted average. MATERIALS AND METHODS: Fifteen patients with pancreatic adenocarcinoma underwent contrast-enhanced dual-source dual-energy CT. The abdominal diameter of all patients was 35 cm or less. Data were reconstructed as a weighted average of the 140- and 80-kVp acquisitions, simulating 120 kVp, and as a pure 80-kVp data set. A region-of-interest cursor was placed within the tumor and the adjacent normal parenchyma, and attenuation differences and contrast-to-noise ratios were calculated for pancreatic tumors at 80 kVp and with the weighted-average acquisition. The 80-kVp and weighted-average images were subjectively compared in terms of lesion conspicuity, image quality, and duct visualization. An exact Wilcoxon's matched pairs signed rank test was used to test whether differences in attenuation, contrast-to-noise ratio, and subjective assessment were greater at 80 kVp. RESULTS: The mean difference in attenuation for each pancreatic tumor and adjacent portion of normal pancreas was 83.27+/-29.56 (SD) HU at 80 kVp and 49.40+/-23.00 HU at weighted-average 120 kVp. Adenocarcinoma attenuation differences were significantly greater at 80 kVp than at 120 kVp (p=0.00006). Contrast-to-noise ratio was significantly higher at 80 kVp than at 120 kVp (p=0.00147). Subjective analysis showed lesion conspicuity (p=0.001) and duct visualization (p=0.0156) were significantly better on the 80-kVp images. CONCLUSION: At portal venous phase dual-source dual-energy CT, the conspicuity of malignant tumors of the pancreas is greater at 80 kVp than with weighted-average acquisition
— id: 105989, year: 2010, vol: 194, page: W27, stat: Journal Article,

Dual source dual energy MDCT: comparison of 80 kVp and weighted average 120 kVp data for conspicuity of hypo-vascular liver metastases
Robinson, Emma; Babb, James; Chandarana, Hersh; Macari, Michael
2010 Jul;45(7):413-418, Investigative radiology
PURPOSE: To determine whether liver metastases conspicuity is improved at 80 kVp when compared with weighted average (WA) simulated 120 kVp data using dual source dual energy CT. METHODS: A total of 11 patients with 44 hypo-vascular liver metastases underwent contrast enhanced Dual Energy CT (DECT). In all cases the subject's abdominal diameter measured <or=35 cm. Data were reconstructed as a WA of the 140 kVp and 80 kVp acquisitions (simulating 120 kVp) and as a pure 80 kVp data set. A region of interest cursor was placed within the metastasis and adjacent normal parenchyma and attenuation differences and contrast to noise ratios (CNR) were calculated for the metastases at 80 kVp and on the WA acquisition. A mixed model 2-way analysis of variance was used to test whether the attenuation difference between metastases and normal liver was higher at 80 kVp than 120 kVp. An exact Wilcoxon matched-pairs signed rank test was used to test whether CNR was higher at 80 kVp. Cases were retrospectively reviewed to determine whether lesions could be seen on only one or both data sets. As the 80 kVp tube has a smaller detector than the 140 kVp tube, we also noted whether any of the liver lesions were not included on the 80 kVp dataset. Two radiologists in consensus evaluated the 80 kVp data and WA data and subjectively rated hepatic metastases conspicuity on a 4 point scale; with 1 being excellent, 2 good, 3 poor, and 4 not seen. RESULTS: The mean size of the metastases was 2.6 cm. The mean +/- SD of the attenuation difference between the metastases and the normal liver was 78.37 +/- 24.6 at 80 kVp and 56.89 +/- 17.9 at 120 kVp. The mean difference in attenuation was significantly higher at 80 kVp (P < 0.001). In 2 cases, a metastases was only seen at 80 kVp. The difference between 80 and 120 kVp in terms of CNR was statistically significant (P = 0.042). In one patient, 11 lesions were not included in the smaller field of view of the 80 kVp detector. The conspicuity scores were rated as significantly better at 80 kv than at 120 kVp (P < 0.0001). CONCLUSION: When compared with 120 kVp data, pure 80 kVp data acquired from a dual source dual energy MDCT scanner demonstrates greater attenuation differences and improved contrast to noise between metastatic disease and normal liver
— id: 110077, year: 2010, vol: 45, page: 413, stat: Journal Article,

CT diagnosis of mucocele of the appendix in patients with acute appendicitis
Bennett, Genevieve L; Tanpitukpongse, Teerath P; Macari, Michael; Cho, Kyunghee C; Babb, James S
2009 Mar;192(3):W103-W110, American journal of roentgenology
OBJECTIVE: The purpose of this study was to identify the CT features of mucocele of the appendix coexisting with acute appendicitis and to determine whether this entity can be differentiated from acute appendicitis without mucocele. MATERIALS AND METHODS: CT scans of 70 patients (12 with acute appendicitis with mucocele, 29 with acute appendicitis without mucocele, 29 with a normal appendix) were retrospectively interpreted by two readers. The appendix was evaluated for maximal luminal diameter, cystic dilatation, luminal attenuation, appendicolith, mural calcification and enhancement, periappendiceal fat stranding, fluid, and lymphadenopathy. CT findings were compared by use of Mann-Whitney U and Fisher's exact tests. Receiver operating characteristics analysis was performed to assess the diagnostic utility of appendiceal luminal diameter in differentiating acute appendicitis with from that without coexisting mucocele. RESULTS: Cystic dilatation of the appendix and maximal luminal diameter achieved statistical significance (p < 0.05) for the diagnosis of acute appendicitis with mucocele. Mural calcification achieved statistical significance for one reader (p = 0.0049) and a statistical trend for the other (p < 0.1). A maximal luminal diameter greater than 1.3 cm had a sensitivity of 71.4%, specificity of 94.6%, and overall diagnostic accuracy of 88.2% for the diagnosis of acute appendicitis with mucocele. CONCLUSION: Although there is overlap with acute appendicitis without mucocele, CT features suggestive of coexisting mucocele in patients with acute appendicitis include cystic dilatation of the appendix, mural calcification, and a luminal diameter greater than 1.3 cm
— id: 95059, year: 2009, vol: 192, page: W103, stat: Journal Article,

Pattern recognition of benign nodules at ultrasound of the thyroid: which nodules can be left alone?
Bonavita, John A; Mayo, Jason; Babb, James; Bennett, Genevieve; Oweity, Thaira; Macari, Michael; Yee, Joseph
2009 Jul;193(1):207-213, American journal of roentgenology
OBJECTIVE: The purpose of this study was to evaluate morphologic features predictive of benign thyroid nodules. MATERIALS AND METHODS: From a registry of the records of 1,232 fine-needle aspiration biopsies performed jointly by the cytology and radiology departments at a single institution between 2005 and 2007, the cases of 650 patients were identified for whom both a pathology report and ultrasound images were available. From the alphabetized list generated, the first 500 nodules were reviewed. We analyzed the accuracy of individual sonographic features and of 10 discrete recognizable morphologic patterns in the prediction of benign histologic findings. RESULTS: We found that grouping of thyroid nodules into reproducible patterns of morphology, or pattern recognition, rather than analysis of individual sonographic features, was extremely accurate in the identification of benign nodules. Four specific patterns were identified: spongiform configuration, cyst with colloid clot, giraffe pattern, and diffuse hyperechogenicity, which had a 100% specificity for benignity. In our series, identification of nodules with one of these four patterns could have obviated more than 60% of thyroid biopsies. CONCLUSION: Recognition of specific morphologic patterns is an accurate method of identifying benign thyroid nodules that do not require cytologic evaluation. Use of this approach may substantially decrease the number of unnecessary biopsy procedures
— id: 100484, year: 2009, vol: 193, page: 207, stat: Journal Article,

Dual-Energy CT in Patients Suspected of Having Renal Masses: Can Virtual Nonenhanced Images Replace True Nonenhanced Images?
Graser, A; Johnson, TRC; Hecht, EM; Becker, CR; Leidecker, C; Staehler, M; Stief, CG; Hildebrandt, H; Godoy, MCB; Finn, ME; Stepansky, F; Reiser, MF; Macari, M
2009 AUG ;252(2):433-440, Radiology
Purpose: To qualitatively and quantitatively compare virtual nonenhanced (VNE) data sets derived from dual-energy (DE) computed tomography (CT) with true nonenhanced (TNE) data sets in the same patients and to calculate potential radiation dose reductions for a dual-phase renal multidetector CT compared with a standard triple-phase protocol. Materials and Methods: This prospective study was approved by the institutional review board; all patients provided written informed consent. Seventy one men (age range, 30-88 years) and 39 women (age range, 22-87 years) underwent preoperative DE CT that included unenhanced, DE nephrographic, and delayed phases. DE CT parameters were 80 and 140 kV, 96 mAs (effective). Collimation was 14 x 1.2 mm. CT numbers were measured in renal parenchyma and tumor, liver, aorta, and psoas muscle. Image noise was measured on TNE and VNE images. Exclusion of relevant anatomy with the 26-cm field of view detector was quantified with a five-point scale (0 = none, 4 = >75%). Image quality and noise (1 = none, 5 = severe) and acceptability for VNE and TNE images were rated. Effective radiation doses for DE CT and TNE images were calculated. Differences were tested with a Student t test for paired samples. Results: Mean CT numbers (+/- standard deviation) on TNE and VNE images, respectively, for renal parenchyma were 30.8 HU +/- 4.0 and 31.6 HU +/- 7.1, P = .29; liver, 55.8 HU +/- 8.6 and 57.8 HU +/- 10.1, P = .11; aorta, 42.1 HU +/- 4.1 and 43.0 HU +/- 8.8, P = .16; psoas, 47.3 HU +/- 5.6 and 48.1 HU +/- 9.3 HU, P = .38. No exclusion of the contralateral kidney was seen in 50 patients, less than 25% was seen in 43, 25%-50% was seen in 13, and 50%-75% was seen in four. Mean image noise was 1.71 +/- 0.71 for VNE and 1.22 +/- 0.45 for TNE (P < .001); image quality was 1.70 HU +/- 0.72 for VNE and 1.15 HU +/- 0.36 for TNE (P < .0001). In all but three patients radiologists accepted VNE images as replacement for TNE images. Mean effective dose for DE CT scans of the abdomen was 5.21 mSv +/- 1.86 and that for nonenhanced scans was 4.97 mSv +/- 1.43. Mean dose reduction by omitting the TNE scan was 35.05%. Conclusion: In patients with renal masses, DE CT can provide high-quality VNE data sets, which are a reasonable approximation of TNE data sets. Integration of DE scanning into a renal mass protocol will lower radiation exposure by 35%. (C) RSNA, 2009
— id: 101609, year: 2009, vol: 252, page: 433, stat: Journal Article,

Dual energy CT: preliminary observations and potential clinical applications in the abdomen
Graser, Anno; Johnson, Thorsten R C; Chandarana, Hersh; Macari, Michael
2009 Jan;19(1):13-23, European radiology
Dual energy CT (DECT) is a new technique that allows differentiation of materials and tissues based on CT density values derived from two synchronous CT acquisitions at different tube potentials. With the introduction of a new dual source CT system, this technique can now be used routinely in abdominal imaging. Potential clinical applications include evaluation of renal masses, liver lesions, urinary calculi, small bowel, pancreas, and adrenal glands. In CT angiography of abdominal aortic aneurysms, dual energy CT techniques can be used to remove bones from the datasets, and virtual unenhanced images allow differentiation of contrast agent from calcifying thrombus in patients with endovascular stents. This review describes potential applications, practical guidelines, and limitations of dual energy CT in the abdomen
— id: 95303, year: 2009, vol: 19, page: 13, stat: Journal Article,

Differentiating pancreatic cystic neoplasms from pancreatic pseudocysts at MR imaging: value of perceived internal debris
Macari, Michael; Finn, Myra E; Bennett, Genevieve L; Cho, Kyunghee C; Newman, Elliot; Hajdu, Cristina H; Babb, James S
2009 Apr;251(1):77-84, Radiology
PURPOSE: To retrospectively evaluate the sensitivity and specificity of several morphologic findings that may be seen with cystic pancreatic lesions, in the diagnosis of pseudocyst at magnetic resonance (MR) imaging. MATERIALS AND METHODS: This study was institutional review board approved and HIPAA compliant. From January 1, 2005, to December 31, 2007, electronic radiology and pathology databases were searched to identify patients with pancreatic cystic neoplasms or pseudocysts who underwent pancreatic MR imaging. Twenty-two patients with cystic pancreatic neoplasms that were confirmed at surgical resection (n = 12) or endoscopic ultrasonography (US) with cystic fluid analysis (n = 10) were identified. Of 20 patients with pancreatic pseudocysts, seven had pseudocysts that were identified at pathologic resection and 13 had a clinical history of pancreatitis, with initial computed tomography (CT) revealing no pancreatic cyst and subsequent follow-up MR imaging depicting cystic lesions. Two abdominal radiologists independently and randomly evaluated each case for presence or absence of septa and internal dependent debris and for external cyst morphology on axial and coronal T2-weighted images and three-dimensional gradient-echo T1-weighted images obtained before and after intravenous contrast agent administration. Logistic regression for correlated data was used to assess the usefulness of internal debris, external morphology, and septa for differentiating cystic neoplasms from pseudocysts. RESULTS: The readers' assessments of the presence or absence of cystic debris were concordant for 40 (95%) of the 42 patients, with a kappa coefficient of 0.889, which indicated nearly perfect agreement. Thirteen (93%) of 14 lesions found to have debris by either or both readers were pseudocysts, and only one (4%) of the 22 cystic neoplasms had debris. Both readers were more likely to identify septa within cystic neoplasms than within pseudocysts; however, the difference was not significant for either reader. The readers were more likely to observe microlobulated morphology in cystic neoplasms than in pseudocysts, with the difference between these lesion types, in terms of prevalence of microlobulated morphology, exhibiting a trend toward-but not reaching-statistical significance (P = .0627). CONCLUSION: Presence of internal dependent debris appears to be a highly specific MR finding for the diagnosis of pancreatic pseudocyst
— id: 97865, year: 2009, vol: 251, page: 77, stat: Journal Article,

Is gadolinium necessary for MRI follow-up evaluation of cystic lesions in the pancreas? Preliminary results
Macari, Michael; Lee, Terrence; Kim, Sooah; Jacobs, Stacy; Megibow, Alec J; Hajdu, Cristina; Babb, James
2009 Jan;192(1):159-164, American journal of roentgenology
OBJECTIVE: The purpose of our study was to determine whether gadolinium is necessary in the follow-up evaluation of pancreatic cystic lesions. MATERIALS AND METHODS: Fifty-six patients with pancreatic cystic lesions detected on initial MRI and who underwent follow-up MRI were identified. Mean cyst size was 1.9 cm, and mean follow-up was 9.1 months. MRI included multiacquisition T1- and T2-weighted sequences before contrast administration and 3D fat-suppressed T1-weighted images before and after gadolinium administration. Two radiologists independently reviewed the entire initial examination and follow-up MRI using only unenhanced T1- and T2-weighted sequences from the second examination. Each radiologist made one of three recommendations: 1, no follow-up necessary or follow-up imaging in 6-12 months; 2, cyst aspiration; or 3, cyst resection. Four weeks later, imaging studies were reevaluated with the contrast-enhanced images from the second examination. A second recommendation using the same outcomes was made. Interobserver and intraobserver variations for the same patient were summarized in terms of kappa coefficients and the percentage of times the decisions were concordant. A 95% CI for the percentage of times management decisions would change without and with gadolinium was calculated. RESULTS: Concordance between the two different readers for the interpretations (when using the same MRI interpretation technique for follow-up surveillance) was 87.5% with a kappa coefficient to assess interobserver variation of 0.075, suggesting only slight agreement between the two readers. However, treatment recommendations provided by a single reader with and without information from the contrast-enhanced images were discordant only 4.5% of the time. Recommendations were concordant without and with gadolinium 95.5% (107/112; kappa=0.67) of the time, suggesting substantial agreement. A retrospective consensus review of the five cases in which gadolinium effected a change in the observer's recommendation was performed. There was nothing on the gadolinium-enhanced sequences that would specifically alter a change in a management decision, and it is likely that the changes in management decisions in these five cases were simply related to expected variations in categorizing lesions rather than to the use of gadolinium. CONCLUSION: The use of gadolinium has minimal impact in the follow-up MR assessment of pancreatic cystic lesions
— id: 92182, year: 2009, vol: 192, page: 159, stat: Journal Article,

ACR Colon Cancer Committee white paper: status of CT colonography 2009
McFarland, Elizabeth G; Fletcher, Joel G; Pickhardt, Perry; Dachman, Abraham; Yee, Judy; McCollough, Cynthia H; Macari, Michael; Knechtges, Paul; Zalis, Michael; Barish, Matthew; Kim, David H; Keysor, Kathryn J; Johnson, C Daniel
2009 Nov;6(11):756-772.e4, Journal of the American College of Radiology : JACR
PURPOSE: To review the current status and rationale of the updated ACR practice guidelines for CT colonography (CTC). METHODS: Clinical validation trials in both the United States and Europe are reviewed. Key technical aspects of the CTC examination are emphasized, including low-dose protocols, proper insufflation, and bowel preparation. Important issues of implementation are discussed, including training and certification, definition of the target lesion, reporting of colonic and extracolonic findings, quality metrics, reimbursement, and cost-effectiveness. RESULTS: Successful validation trials in screening cohorts both in the United States with ACRIN and in Germany demonstrated sensitivity > or = 90% for patients with polyps >10 mm. Proper technique is critical, including low-dose techniques in screening cohorts, with an upper limit of the CT dose index by volume of 12.5 mGy per examination. Training new readers includes the requirement of interactive workstation training with 2-D and 3-D image display techniques. The target lesion is defined as a polyp > or = 6 mm, consistent with the American Cancer Society joint guidelines. Five quality metrics have been defined for CTC, with pilot data entered. Although the CMS national noncoverage decision in May 2009 was a disappointment, multiple third-party payers are reimbursing for screening CTC. Cost-effective modeling has shown CTC to be a dominant strategy, including in a Medicare cohort. CONCLUSION: Supported by third-party payer reimbursement for screening, CTC will continue to further transition into community practice and can provide an important adjunctive examination for colorectal screening
— id: 131925, year: 2009, vol: 6, page: 756, stat: Journal Article,

Abdominal aorta: evaluation with dual-source dual-energy multidetector CT after endovascular repair of aneurysms--initial observations
Chandarana, Hersh; Godoy, Myrna C B; Vlahos, Ioannis; Graser, Anno; Babb, James; Leidecker, Christianne; Macari, Michael
2008 Nov;249(2):692-700, Radiology
PURPOSE: To evaluate the possible radiation dose reduction facilitated by using dual-energy (DE) multidetector computed tomography (CT) after endovascular repair of abdominal aortic aneurysms (AAAs). MATERIALS AND METHODS: This prospective study was HIPAA compliant and institutional review board approved. Twenty-two patients who previously had undergone endovascular repair of AAAs underwent 24 DE multidetector CT examinations, which were performed with a 64-detector scanner. Initial nonenhanced CT was followed by arterial phase and venous phase acquisitions. Virtual nonenhanced, pure 80-kVp, and weighted-average peak voltage CT data sets were generated from the venous acquisition. Two independent readers interpreted the virtual nonenhanced and DE weighted-average CT data for the presence or absence of endoleaks. These interpretations were compared with the clinical interpretations of the data performed by a different radiologist by using true nonenhanced, arterial phase, and venous phase data. Region-of-interest measurements of the abdominal aorta and of the region of the endoleaks were obtained. Effective radiation dose was calculated. RESULTS: Both independent readers' interpretations of the virtual nonenhanced and weighted-average venous CT data revealed six type II endoleaks. There were no false-positive or false-negative findings. Aortic attenuation during the arterial, 80-kVp venous, and weighted-average data acquisitions were 288, 213, and 150 HU, respectively. The attenuation of the endoleaks was higher during the 80-kVp acquisition (P < .03) than during the arterial phase and weighted-average venous phase acquisitions. The mean effective dose for DE venous phase CT was 11.1 mSv compared with 27.8 mSv for standard triple-phase CT with a single-source configuration. CONCLUSION: Preliminary observations suggest that obtaining DE multidetector CT data by using a single 60-second contrast material-enhanced acquisition may be all that is required for surveillance after endovascular repair of AAA
— id: 93372, year: 2008, vol: 249, page: 692, stat: Journal Article,

Caecal epiploic appendagitis: an unlikely occurrence
Macari, M; Laks, S; Hajdu, C; Babb, J
2008 Aug;63(8):895-900, Clinical radiology
AIM: To determine whether epiploic appendagitis occurs in the caecum. METHODS: From 2000-2006, 58 cases with classic computed tomography (CT) features of acute epiploic appendagitis (focal round or oval fat density immediately adjacent to the colon with surrounding oedema and stranding, with or without a central area of high attenuation) were identified from a radiology information system and available for review on the picture archiving and communication system (PACS). Cases were assigned to one of six colonic segments: rectum, sigmoid, descending colon, transverse colon, ascending colon, and caecum. The Blyth-Still-Casella procedure was used to derive an exact upper bound on the likelihood of epiploic appendagitis occurring within the caecum. RESULTS: Twenty-eight cases occurred in the sigmoid colon, 16 in the descending colon, four in the transverse colon, and 10 in the ascending colon. No cases of acute epiploic appendagitis were identified in the caecum. Four cases of prospectively dictated caecal epiploic appendagitis were identified from the database. Retrospective review of these cases showed two cases to be epiploic appendagitis of the ascending colon. The third case demonstrated peritoneal thickening without evidence of an inflamed epiploic appendage. The fourth case was caecal diverticulitis. Based on these findings there is 95% confidence that no more than 4.6% of patients with epiploic appendagitis will show this condition within the caecum. CONCLUSION: In the authors' experience, epiploic appendagitis does not occur in the caecum. Therefore, it is an unlikely cause for an inflammatory process in this region and other conditions should be considered
— id: 93337, year: 2008, vol: 63, page: 895, stat: Journal Article,

"Unpredictable" late rupture of an abdominal aortic aneurysm after bifurcated Ancure endograft repair
Rosen, Noah A; Cayne, Neal S; Macari, Michael; Jacobowitz, Glenn R
2008 Feb-Mar;42(1):69-73, Vascular & endovascular surgery
The goal of endovascular repair of an abdominal aortic aneurysm is to exclude the aneurysm from systemic arterial pressure, thereby preventing rupture. However, the long-term durability of endovascular repair continues to be in question, as aneurysm rupture after endovascular repair continues to be reported. We report the case of an 89-year-old patient who underwent endovascular repair of a 7.1-cm abdominal aortic aneurysm with an Ancure endograft 5 years earlier. Despite close follow-up and a shrinking aneurysm sac on annual contrast-enhanced computed tomography, he presented with aneurysm rupture and a new proximal type I endoleak. The endoleak and rupture were successfully repaired with endovascular placement of a main body extension
— id: 78735, year: 2008, vol: 42, page: 69, stat: Journal Article,

Mucinous cancer of the appendix: challenges in diagnosis and treatment
Andreopoulou, E; Yee, H; Warycha, M A; Macari, M; Berman, R; Lowy, A; Muggia, F
2007 Aug;19(4):451-454, Journal of chemotherapy
The authors report and discuss a case of a mucinous carcinoma of the appendix, a rare entity with a distinct natural history that poses diagnostic and therapeutic challenges. Mucinous peritoneal carcinomatosis is most commonly associated with primary tumors of the appendix and colon. Typically, spread remains confined to the abdominal cavity. Imaging assessment of these mucinous lesions is difficult, while tumor markers (CEA and CA19.9) may be surrogates for extent of disease. Treatment consists of surgical debulking, sometimes coupled with intraperitoneal drug delivery, but recurrence is universal. New treatment approaches are needed. Mucin genes are regulated in part by epidermal growth factor receptor signaling. Therefore, we initiated a phase II study of cetuximab for mucinous peritoneal carcinomatosis, that was part of this patient's treatment
— id: 73927, year: 2007, vol: 19, page: 451, stat: Journal Article,

Computer-aided detection of colorectal polyps: can it improve sensitivity of less-experienced readers? Preliminary findings
Baker, Mark E; Bogoni, Luca; Obuchowski, Nancy A; Dass, Chandra; Kendzierski, Renee M; Remer, Erick M; Einstein, David M; Cathier, Pascal; Jerebko, Anna; Lakare, Sarang; Blum, Andrew; Caroline, Dina F; Macari, Michael
2007 Oct;245(1):140-149, Radiology
PURPOSE: To determine whether computer-aided detection (CAD) applied to computed tomographic (CT) colonography can help improve sensitivity of polyp detection by less-experienced radiologist readers, with colonoscopy or consensus used as the reference standard. MATERIALS AND METHODS: The release of the CT colonographic studies was approved by the individual institutional review boards of each institution. Institutions from the United States were HIPAA compliant. Written informed consent was waived at all institutions. The CT colonographic studies in 30 patients from six institutions were collected; 24 images depicted at least one confirmed polyp 6 mm or larger (39 total polyps) and six depicted no polyps. By using an investigational software package, seven less-experienced readers from two institutions evaluated the CT colonographic images and marked or scored polyps by using a five-point scale before and after CAD. The time needed to interpret the CT colonographic findings without CAD and then to re-evaluate them with CAD was recorded. For each reader, the McNemar test, adjusted for clustered data, was used to compare sensitivities for readers without and with CAD; a Wilcoxon signed-rank test was used to analyze the number of false-positive results per patient. RESULTS: The average sensitivity of the seven readers for polyp detection was significantly improved with CAD-from 0.810 to 0.908 (P=.0152). The number of false-positive results per patient without and with CAD increased from 0.70 to 0.96 (95% confidence interval for the increase: -0.39, 0.91). The mean total time for the readings was 17 minutes 54 seconds; for interpretation of CT colonographic findings alone, the mean time was 14 minutes 16 seconds; and for review of CAD findings, the mean time was 3 minutes 38 seconds. CONCLUSION: Results of this feasibility study suggest that CAD for CT colonography significantly improves per-polyp detection for less-experienced readers
— id: 95304, year: 2007, vol: 245, page: 140, stat: Journal Article,

Signal characteristic and enhancement patterns of pancreatic adenocarcinoma: evaluation with dynamic gadolinium enhanced MRI
Chandarana, H; Babb, J; Macari, M
2007 Sep;62(9):876-883, Clinical radiology
AIM: To determine the signal characteristics and enhancement patterns of proven pancreatic adenocarcinomas at 1.5 T and to compare these results with contrast enhanced computed tomography (CECT). MATERIALS AND METHODS: Twenty-five patients, mean age 73 years, with proven pancreatic adenocarcinoma were imaged at 1.5 T using in- and opposed-phase, gradient-echo (GRE), T1-weighted sequences, T2 weighting using either a short tau inversion recovery (STIR) or frequency selective, fat-suppressed turbo spin echo (TSE) sequence, and with a three-dimensional (3D), fat-suppressed, GRE T1 sequence before, during the arterial, venous, and equilibrium phases after Gadolinium administration. Fourteen of the 25 patients underwent CECT. Magnetic resonance imaging (MRI) examinations were evaluated by two observers in consensus for size, signal characteristics, and enhancement patterns, and the results were compared with CECT. RESULTS: The mean size of pancreatic adenocarcinomas was 32mm. On unenhanced T1-weighted images, 12 of 25 lesions (48%) were hypointense, 13 (52%) were isointense. On STIR/T2, 11 of 25 (44%) pancreatic adenocarcinomas were hyperintense, 14 (56%) were isointense. All 25 (100%) adenocarcinomas were hypointense during the arterial phase. Twenty (80%) and 17 (68%) remained hypointense in the venous phase and equilibrium phases, respectively. In seven of 14 (50%) cases, the pancreatic mass was iso-attenuating to the pancreatic parenchyma during both the pancreatic and venous phases of CECT. CONCLUSION: The results of the present study showed that all 25 pancreatic adenocarcinomas were hypointense to pancreatic parenchyma during the arterial phase. Moreover, MRI may be useful in patients with a high suspicion of pancreatic carcinoma that is not visualized during CECT
— id: 73893, year: 2007, vol: 62, page: 876, stat: Journal Article,

CT of jejunal diverticulitis: imaging findings, differential diagnosis, and clinical management
Macari, M; Faust, M; Liang, H; Pachter, H L
2007 Jan;62(1):73-77, Clinical radiology
AIM: To describe the imaging findings of jejunal diverticulitis as depicted at contrast-enhanced computed tomography (CT) and review the differential diagnosis and clinical management. MATERIALS AND METHODS: CT and pathology databases were searched for the diagnosis of jejunal diverticulitis. Three cases were identified and the imaging and clinical findings correlated. RESULTS: Jejunal diverticulitis presents as a focal inflammatory mass involving the proximal small bowel. A trial of medical management with antibiotics may be attempted. Surgical resection may be required if medical management is unsuccessful. CONCLUSION: The imaging findings at MDCT may allow a specific diagnosis of jejunal diverticulitis to be considered and may affect the clinical management of the patient
— id: 70314, year: 2007, vol: 62, page: 73, stat: Journal Article,

A pattern approach to the abnormal small bowel: observations at MDCT and CT enterography
Macari, Michael; Megibow, Alec J; Balthazar, Emil J
2007 May;188(5):1344-1355, American journal of roentgenology
OBJECTIVE: Imaging of the vast array of pathologic processes occurring in the small bowel has been facilitated by recent advances, including the use of MDCT scanners that acquire isotropic data and neutral oral contrast agents that improve small-bowel distention. CONCLUSION: This review shows how a systematic pattern approach can be used to narrow the differential diagnosis when an abnormal small-bowel loop is detected on MDCT
— id: 71932, year: 2007, vol: 188, page: 1344, stat: Journal Article,

Assessment of low signal adjacent to the falciform ligament on contrast-enhanced MRI
Macari, Michael; Yeretsian, Rita; Babb, James
2007 Dec;189(6):1443-1448, American journal of roentgenology
OBJECTIVE: Geographic low signal in the medial segment of the liver seen on contrast-enhanced MRI has been attributed to focal fatty infiltration. Using in- and opposed-phase gradient-recalled echo (GRE) T1-weighted MRI, we attempted to determine if this finding represents focal fatty infiltration. MATERIALS AND METHODS: From a radiology information system, we identified 174 consecutive patients who underwent contrast-enhanced abdominal MRI. Subjects with diffuse liver disease were excluded. The presence of geographic low signal adjacent to the falciform ligament in the anterior medial aspect of the medial segment of the liver during dynamic gadolinium-enhanced imaging was assessed during the arterial, portal venous, and equilibrium phases of enhancement. If this finding was present on any contrast-enhanced sequence, in- and opposed-phase images were qualitatively evaluated to determine if signal loss occurred on opposed-phase imaging. RESULTS: Fifty-three patients were excluded because of diffuse liver disease. Twenty-one (17.4%) of the remaining 121 patients showed focal low signal during gadolinium-enhanced MRI. This finding was present in all 21 patients during the portal venous phase and in seven and five during the arterial and equilibrium phases of enhancement, respectively. Of the 21 patients, three showed signal loss on opposed-phase imaging and 18 (85.7%) did not. CONCLUSION: Although low attenuation or signal adjacent to the falciform ligament may represent focal fat, it usually does not and is likely related to anomalous venous drainage into the liver
— id: 75407, year: 2007, vol: 189, page: 1443, stat: Journal Article,

Racial/ethnic differences in patient experiences with and preferences for computed tomography colonography and optical colonoscopy
Rajapaksa, Roshini C; Macari, Michael; Bini, Edmund J
2007 Nov;5(11):1306-1312, Clinical Gastroenterology & Hepatology
BACKGROUND & AIMS: Racial/ethnic minorities are less likely than whites to undergo colorectal cancer (CRC) screening. Although computed tomography colonography (CTC) is a less invasive alternative to optical colonoscopy (OC), it is not known whether CTC will increase acceptance of CRC screening in minorities. METHODS: Patients undergoing OC for clinically indicated reasons had CTC followed by same-day OC. After the sedation from the OC had worn off, a questionnaire was administered to assess pain, discomfort, bloating, embarrassment, anxiety, and patient satisfaction using a 10-point scale (1 = least, 10 = greatest). RESULTS: Of the 272 patients enrolled, there were 134 whites, 71 blacks, 53 Hispanics, and 14 who self-identified their race/ethnicity as other. Although the proportion of subjects who preferred CTC over OC was not significantly different (52.9% vs 47.1%, P = .36), racial/ethnic minorities were significantly less likely than whites to prefer CTC over OC (whites, 65.7%; blacks, 45.1%; Hispanics, 35.8%; and other, 35.7%; P < .001). Racial/ethnic minorities were less satisfied with CTC (whites, 8.4 +/- 1.7; blacks, 7.8 +/- 1.7; Hispanics, 7.4 +/- 1.8; and other, 7.5 +/- 2.1; P = .001) and were significantly less willing to undergo CTC again in the future (whites, 95.5%; blacks, 80.3%; Hispanics, 84.9%; and other, 85.7%; P = .006). CONCLUSIONS: Compared with white patients, OC is better tolerated and is preferred over CTC for evaluation of the colon among racial/ethnic minorities. Although CTC is less invasive than OC, our findings suggest that CTC is unlikely to overcome racial/ethnic disparities in CRC screening
— id: 75365, year: 2007, vol: 5, page: 1306, stat: Journal Article,

Abdominal aortic aneurysm: can the arterial phase at CT evaluation after endovascular repair be eliminated to reduce radiation dose?
Macari, Michael; Chandarana, Hersh; Schmidt, Bernhardt; Lee, Julie; Lamparello, Patrick; Babb, James
2006 Dec;241(3):908-914, Radiology
PURPOSE: To retrospectively determine if arterial phase computed tomographic (CT) imaging is necessary for follow-up imaging of patients who have undergone endovascular stent-graft therapy for abdominal aortic aneurysm. MATERIALS AND METHODS: This HIPAA-compliant study was exempt from institutional review board approval; informed patient consent was waived. Eighty-five patients (66 men, 19 women; mean age, 66 years; range, 45-81 years) underwent 110 multidetector CT examinations after endovascular repair of abdominal aortic aneurysms. Nonenhanced CT images were obtained. Intravenous contrast material was then injected at 4 mL/sec, and arterial and venous phase (60 seconds) CT images were obtained. The nonenhanced and venous phase images were evaluated to determine if an endoleak was present. Subsequently, arterial phase images were analyzed. The effective dose was calculated. Ninety-five percent confidence intervals as indicators of how often arterial phase imaging would contribute to the diagnosis of endoleak were determined. RESULTS: Twenty-eight type II endoleaks were detected by using combined nonenhanced and venous phase acquisitions. Twenty-five of the 28 endoleaks were also visualized during the arterial phase. Three type II endoleaks were seen only during the venous phase. The arterial phase images depicted no additional endoleaks. Seventy-eight CT examinations performed in 67 patients revealed no endoleak during the venous phase. The arterial phase images also depicted no endoleaks at these examinations. Thus, for no more than 3.1% of all examinations, there was 95% confidence that arterial phase imaging would depict an endoleak missed at venous phase imaging. Arterial phase imaging contributed to a mean of 36.5% of the effective dose delivered. CONCLUSION: Study results indicate that arterial phase imaging may not be necessary for the routine detection of endoleaks. Radiation exposure can be decreased by eliminating this phase
— id: 69695, year: 2006, vol: 241, page: 908, stat: Journal Article,

Marked racial and ethnic differences in patient satisfaction with and preferences for CT colonography and optical colonoscopy
Rajapaksa, RC; Macari, M; Bini, EJ
2006 SEP ;101(9):S557-S557, American journal of gastroenterology
— id: 69316, year: 2006, vol: 101, page: S557, stat: Journal Article,

Computer-aided detection (CAD) for CT colonography: a tool to address a growing need
Bogoni, L; Cathier, P; Dundar, M; Jerebko, A; Lakare, S; Liang, J; Periaswamy, S; Baker, ME; MacAri, M
2005 AUG ;78(8):S57-S62, British journal of radiology
Colorectal cancer is the third most common cancer in both men and women. It is estimated that in 2004, nearly 147 000 cases of colon and rectal cancer will be diagnosed in the USA, and approximately 57 000 people would die from the disease; however, only 44% of the eligible population undergoes any type of colorectal cancer screening. Many reasons have been identified for non-compliance, with key ones being patient comfort, bowel preparation and cost. Virtual colonoscopy derived from computed tomography (CT) images is gaining broader acceptance as a screening method for colorectal neoplasia. Our research suggests that computer-aided detection (CAD) as a second reader has great potential in improving polyp detection. The ColonCAD prototype presented in this paper was developed and tested on cases representative of the variability and quality in true clinical practice. Results of this study with 150 patients demonstrate that: the developed algorithm generalises well: the sensitivity for polyps >= 6 mm is on average 90%; and the median false positive rate is a manageable 3 per volume
— id: 56296, year: 2005, vol: 78, page: S57, stat: Journal Article,

Stercoral colitis leading to fatal peritonitis: CT findings
Heffernan, Cathleen; Pachter, H Leon; Megibow, Alec J; Macari, Michael
2005 Apr;184(4):1189-1193, American journal of roentgenology
OBJECTIVE: Stercoral colitis is an inflammatory process involving the colonic wall related to fecal impaction. Our purpose was to describe the imaging findings of stercoral colitis and ulceration and to emphasize the potential serious clinical implications of the condition. CONCLUSION: Fecal impaction may lead to ischemic pressure necrosis and subsequent colonic perforation. In the appropriate clinical setting, the imaging findings that should prompt the radiologist to consider this diagnosis are the presence of fecal impaction, focal colonic wall thickening, and adjacent stranding of the fat. If the fecal impaction is not promptly relieved, the condition can lead to colonic perforation, peritonitis, and patient demise
— id: 52632, year: 2005, vol: 184, page: 1189, stat: Journal Article,

CT colonography: the real deal
Macari, M
2005 Mar-Apr;30(2):184-194, Abdominal imaging
— id: 57677, year: 2005, vol: 30, page: 184, stat: Journal Article,

CT colonography: where have we been and where are we going?
Macari, Michael; Bini, Edmund J
2005 Dec;237(3):819-833, Radiology
Over the past decade, computed tomographic (CT) colonography (also known as virtual colonoscopy) has been used to investigate the colon for colorectal neoplasia. Numerous clinical and technical advances have allowed CT colonography to advance slowly from a research tool to a viable option for colorectal cancer screening. However, substantial controversy remains among radiologists, gastroenterologists, and other clinicians with regard to the current role of CT colonography in clinical practice. On the one hand, all agree there is much excitement about a noninvasive imaging examination that can reliably depict clinically important colorectal lesions. However, this is tempered by results from several recent studies that show the sensitivity of CT colonography may not be as great when performed and the images interpreted by radiologists without expertise and training. The potential to miss important lesions exists; moreover, if polyps cannot be differentiated from folds and residual fecal matter, unnecessary colonoscopy will be performed. In this review, current issues will be discussed regarding colon cancer and the established and reimbursed strategies to screen for it and the past, current, and potential future role of CT colonography
— id: 59374, year: 2005, vol: 237, page: 819, stat: Journal Article,

Perforated duodenal diverticulitis: a report of three cases
Miller, George; Mueller, Claudia; Yim, Duke; Macari, Michael; Liang, Howard; Marcus, Stuart; Shamamian, Peter
2005 ;22(3):198-202, Digestive surgery
BACKGROUND: Duodenal diverticuli are present in up to 22% of the population. However, perforation of a duodenal diverticulum with spillage of enteric contents into the retroperitoneum is rare. METHODS: We report three cases of perforated duodenal diverticulitis. RESULTS: Clinical presentations varied widely from patients with acute abdominal findings and generalized sepsis to a patient with mild symptoms of abdominal discomfort. CT scanning was the imaging modality used to make an accurate diagnosis. Treatment approaches for the most stable patient included nonoperative management with antibiotics, bowel rest and parenteral alimentation, while the less stable patients underwent definitive surgery with complete diversion of gastric contents and biliary flow from the affected area of duodenum. CONCLUSIONS: This report highlights the salient issues in the presentation, diagnosis and modern management of patients with this potentially catastrophic disease
— id: 61257, year: 2005, vol: 22, page: 198, stat: Journal Article,

Retroperitoneal perforation of the duodenum from biliary stent erosion
Miller, George; Yim, Duke; Macari, Michael; Harris, Marsha; Shamamian, Peter
2005 Sep-Oct;62(5):512-515, Current surgery
Endoscopically placed biliary stents have supplanted surgical decompression as the preferred treatment option for patients with obstructive jaundice from advanced pancreatic cancer. An unusual complication of indewelling biliary stents is duodenal perforation into the retroperitoneum. We describe the case of a patient with end-stage pancreatic cancer who presented with an acute abdomen from erosion of a previously placed bile duct stent through the wall of the second portion of the duodenum. Although our patient presented with advanced symptoms, clinical presentations can vary from mild abdominal discomfort and general malaise to overt septic shock. Definitive diagnosis is best made with computed tomography (CT) imaging, which can detect traces of retroperitoneal air and fluid. Treatment options vary from nonoperative management with antibiotics, bowel rest, and parenteral alimentation in the most stable patients to definitive surgery with complete diversion of gastric contents and biliary flow from the affected area in patients with clinical symptoms or radiologic evidence suggesting extensive contamination. Complications of management can include duodenal fistulization, residual retroperitoneal or intrabdominal abscess, and ongoing sepsis. This report highlights the salient issues in the presentation, diagnosis, and modern management of patients with this rare complication of indwelling biliary stents
— id: 61335, year: 2005, vol: 62, page: 512, stat: Journal Article,

Comprehensive evaluation of potential right lobe liver donors: Comparison of MRI with 3D MRCP and CT with CT cholangiography
Morgan, GR; Taouli, B; Israel, GM; Macari, M; Moses, DA; Heche, E; Lee, VS; Teperman, LW
2005 MAY ;5(5):209-209, American journal of transplantation
— id: 57861, year: 2005, vol: 5, page: 209, stat: Journal Article,

Focal amyloidoma of the small bowel mimicking adenocarcinoma on CT
Saindane, Amit M; Losada, Mariela; Macari, Michael
2005 Nov;185(5):1187-1189, American journal of roentgenology
— id: 62527, year: 2005, vol: 185, page: 1187, stat: Journal Article,

Type II endoleaks after endovascular repair of abdominal aortic aneurysms: natural history
Tolia, Anuj J; Landis, Ronnie; Lamparello, Patrick; Rosen, Robert; Macari, Michael
2005 May;235(2):683-686, Radiology
PURPOSE: To retrospectively determine the natural history of type II endoleaks detected at thin-section multi-detector row computed tomographic (CT) angiography. MATERIALS AND METHODS: Neither institutional review board approval nor patient informed consent was required. Between December 1999 and December 2000, 83 patients (73 men and 10 women; mean age, 61 years; range, 55-75 years) underwent endovascular repair of an infrarenal abdominal aortic aneurysm with an endoluminal stent graft. Postprocedural abdominal CT angiography was performed every 3-12 months for the evaluation of endoleaks and the maximal sac diameter. A retrospective analysis of all postprocedural CT angiographic reports was performed until November 2003 to document the presence and development of type II endoleaks and the maximal orthogonal aneurysmal sac size. Findings at CT angiography were evaluated with regard to clinical outcomes and treatment in all patients in whom type II endoleaks were observed. The postprocedural follow-up period was 1.5-4.5 years (mean, 2.5 years). RESULTS: Twenty type II endoleaks were identified in 16 (19%) of the 83 patients. Four (20%) of the 20 endoleaks were embolized secondary to an increasing aneurysmal sac size when compared with that at preoperative CT angiography. These four leaks occurred in two patients, each with two separate endoleaks. Sixteen (80%) of the 20 endoleaks in 14 patients were managed with continued observation. In these patients, the aneurysmal sac size was stable or had decreased when compared with the size at preoperative CT angiography. Ten (62.5%) of the 16 endoleaks have sealed spontaneously during the follow-up, and six (37.5%) have persisted with stable or decreased aneurysmal sac size. None of the patients experienced aneurysmal sac rupture. CONCLUSION: Type II endoleaks with a stable or decreased aneurysmal sac size can be followed up with CT angiography secondary to the high rate of spontaneous resolution and a low risk of rupture
— id: 55605, year: 2005, vol: 235, page: 683, stat: Journal Article,

CT colonography reporting and data system: a consensus proposal
Zalis, Michael E; Barish, Matthew A; Choi, J Richard; Dachman, Abraham H; Fenlon, Helen M; Ferrucci, Joseph T; Glick, Seth N; Laghi, Andrea; Macari, Michael; McFarland, Elizabeth G; Morrin, Martina M; Pickhardt, Perry J; Soto, Jorge; Yee, Judy
2005 Jul;236(1):3-9, Radiology
— id: 95305, year: 2005, vol: 236, page: 3, stat: Journal Article,

Virtual colonoscopy
Ferrucci, Joseph; Barish, Matthew; Choi, Richard; Dachman, Abraham; Fenlon, Helen; Glick, Seth; Laghi, Andrea; Macari, Michael; Morrin, Martina; Paulson, Erik; Pickhardt, Perry J; Soto, Jorge; Yee, Judy; Zalis, Michael
2004 Jul 28;292(4):431-432, JAMA
— id: 95306, year: 2004, vol: 292, page: 431, stat: Journal Article,

Positional change in colon polyps at CT colonography
Laks, Shaked; Macari, Michael; Bini, Edmund J
2004 Jul;231(3):761-766, Radiology
PURPOSE: To determine the frequency with which polyps change positions with respect to the bowel surface and the cause of this movement. MATERIALS AND METHODS: From December 2001 to March 2003, 113 patients underwent computed tomographic (CT) colonography prior to colonoscopy. For all confirmed polyps that were 5 mm and larger, images obtained with CT colonography were retrospectively analyzed by one author to determine if the polyp was present on both data sets or on only one data set. Retrospective evaluation of these polyps for ventral or dorsal location within the colonic lumen was performed for data sets obtained with patients in the prone and the supine position. The data sets were further reviewed by another author to determine the cause of positional change, when present. RESULTS: Twenty-six patients had a total of 49 histologically proved colorectal polyps that were 5 mm and larger. Eight of 49 colorectal polyps were depicted only on images obtained with the patient in the supine or prone position. Of the remaining 41 polyps that were depicted on images obtained with the patient in the supine and the prone position, 11 moved from a dorsal to a ventral location or vice versa relative to the colonic surface when the patient changed position. Five of these polyps were pedunculated on a stalk. Six were sessile; two were located in the sigmoid colon, two in the transverse colon, one in the ascending colon, and one in the cecum. In these cases, polyp mobility was related to positional changes of the colon in the mesentery, as opposed to true mobility of the polyp. CONCLUSION: In this series, 27% of polyps moved from a ventral location to a dorsal location relative to the colonic surface when the patient was turned from the supine to the prone position; thus, polyps appeared to be mobile. Thus, a mobile filling defect cannot be assumed to be residual fecal material at CT colonography
— id: 46179, year: 2004, vol: 231, page: 761, stat: Journal Article,

Frequency and relevance of the "small-bowel feces" sign on CT in patients with small-bowel obstruction
Lazarus, Dawn E; Slywotsky, Chrystia; Bennett, Genevieve L; Megibow, Alec J; Macari, Michael
2004 Nov;183(5):1361-1366, American journal of roentgenology
OBJECTIVE: We sought to determine the incidence of the 'small-bowel feces' sign (SBFS) in patients with small-bowel obstruction (SBO) and whether it can be used to accurately locate the point of obstruction. SUBJECTS AND METHODS: From November 2002 until March 2003, 34 consecutive adult patients with CT findings of small-bowel obstruction were prospectively evaluated. The CT findings used to diagnose small-bowel obstruction were a dilated proximal small bowel and a collapsed distal small bowel and colon. CT scans were evaluated to determine the degree of obstruction (mild, moderate, or high-grade), the presence or absence of the SBFS (defined as particulate-type material in the dilated small bowel), the location of the SBFS in relation to the transition zone, and the cause of the obstruction. Mild obstruction was defined as a slight discrepancy between the caliber of the proximal and that of the distal small bowel; moderate SBO was defined as a discrepancy of 50% or more between the calibers of the proximal and the distal small bowel; and high-grade SBO was considered to be present if the distal small bowel and the colon had collapsed. The cause of the obstruction was determined from surgical findings or a combination of CT findings, follow-up barium studies, and clinical assessment. RESULTS: The SBFS was present in 19 (55.9%) of 34 patients with SBO. The degree of SBO was mild in six, moderate in 11, and high-grade in 17 of the patients. The SBFS was present in one of the six patients (16.6%) with mild, eight (72.7%) of the 11 with moderate, and 10 (58.8%) of the 17 with high-grade SBO. In all patients in whom the SBFS was present, the particulate material could be traced to the point of transition and was most conspicuous in the transition zone. The length of fecallike material ranged from 2 to 25 cm and was longer in moderate and high-grade SBO than in mild SBO. The cause of the SBO was an adhesion in 20 patients, a hernia in four patients, Crohn's disease in four patients, a tumor in three patients, and other miscellaneous causes in three patients. CONCLUSION: When present on CT, the SBFS can be used to help locate the transition zone in patients with SBO. The sign is present more frequently in patients with moderate and high degrees of SBO
— id: 47832, year: 2004, vol: 183, page: 1361, stat: Journal Article,

CT colonography. Current and emerging applications
Macari M; Megibow AJ
2004 ;2004(2):115-115, Azarbaycan tibb jurnali / Azarbaycan Respublikasi, Sahiyya Nazirliyi = Azerbaijan medical journal
— id: 46299, year: 2004, vol: 2004, page: 115, stat: Journal Article,

Significance of missed polyps at CT colonography
Macari, Michael; Bini, Edmund J; Jacobs, Stacy L; Lui, Yvonne W; Laks, Shaked; Milano, Andrew; Babb, James
2004 Aug;183(1):127-134, American journal of roentgenology
OBJECTIVE: Our purpose was to determine the clinical significance of polyps missed on CT colonography using histologic analysis and the natural history of colorectal polyps and to propose guidelines for follow-up colon surveillance based on CT colonographic findings. SUBJECTS AND METHODS. One hundred eighty-six men (age range, 40-87 years; mean, 62.3 years) underwent CT colonography immediately before conventional colonoscopy. All polyps detected on CT colonography were measured and imaged, and their segmental location was documented. All polyps detected on colonoscopy were measured, photographed, biopsied, and histologically analyzed. Results of CT colonography and conventional colonoscopy were compared with the final pathology reports. Conventional colonoscopy was used as the gold standard unless CT colonography showed a lesion measuring 10 mm or more that was not detected on conventional colonoscopy and had characteristics of a polyp. In these cases, follow-up conventional colonoscopy was offered. RESULTS: One hundred ninety-one polyps were detected on conventional colonoscopy. CT colonography prospectively detected 53 polyps. Histologic analysis of the polyps not detected on CT colonography showed that of those 5 mm or smaller, 58.1% were not adenomas, and of those measuring 6-9 mm, 42.8% were not adenomas. Both missed polyps at CT colonography of 10 mm or more were adenomas. Of the 22 polyps measuring 10 mm or more, three were not detected on conventional colonoscopy. Of these three, CT colonography showed a lesion having characteristics of a polyp, follow-up endoscopy confirmed the presence of the lesion, and histologic analysis showed a villous adenoma, a tubulovillous adenoma, and a tubular adenoma. CONCLUSION: If CT colonography shows no abnormality, follow-up screening in 5 years is recommended. If CT colonography detects a lesion smaller than 5 mm, follow-up imaging in 3-5 years is recommended. If CT colonography detects a lesion measuring 6 mm or more, endoscopy and polypectomy should be offered unless contraindicated
— id: 46120, year: 2004, vol: 183, page: 127, stat: Journal Article,

Colorectal polyps and cancers in asymptomatic average-risk patients: evaluation with CT colonography
Macari, Michael; Bini, Edmund J; Jacobs, Stacy L; Naik, Sanjay; Lui, Yvonne W; Milano, Andrew; Rajapaksa, Roshini; Megibow, Alec J; Babb, James
2004 Mar;230(3):629-636, Radiology
PURPOSE: To compare thin-section multi-detector row computed tomographic (CT) colonography with conventional colonoscopy in the evaluation of colorectal polyps and cancer in asymptomatic average-risk patients. MATERIALS AND METHODS: Sixty-eight asymptomatic men (age > 50 years) scheduled to undergo screening colonoscopy were enrolled in this study. CT colonography was followed by conventional colonoscopy, performed on the same day. Supine and prone CT colonography were performed after colonic insufflation with room air. A gastroenterologist measured all polyps, which were categorized as 1-5, 6-9, or over 10 mm. Biopsy and histologic evaluation were performed of all polyps. CT colonography and colonoscopy results were compared for location, size, and morphology of detected lesions. Point estimates and 95% CIs were provided for specificity and sensitivity of CT by using results at conventional colonoscopy as the reference standard. RESULTS: At colonoscopy, 98 polyps were identified in 39 patients; 21 (21.4%) of 98 were detected at CT colonography. Sensitivity was 11.5% (nine of 78) for polyps 1-5 mm, 52.9% (nine of 17) for polyps 6-9 mm, and 100% (three of three) for polyps over 10 mm. Results at colonoscopy were normal in 29 (42.6%) of 68 patients; at CT colonography, results were correctly identified as normal in 26 of these 29 patients. In one of these patients, a lesion larger than 10 mm was detected at CT colonography. The per-patient specificity of CT was 89.7% (26 of 29; 95% CI: 72.7%, 97.8%). The mean time for CT image interpretation was 9 minutes. CONCLUSION: In patients at average risk for colorectal cancer, CT colonography is a sensitive and specific screening test for detecting polyps 10 mm or larger; the sensitivity for detecting smaller polyps is decreased. Examination findings can be interpreted in a clinically feasible amount of time
— id: 42610, year: 2004, vol: 230, page: 629, stat: Journal Article,

Prevalence and impact of extracolonic findings in patients undergoing CT colonography
Rajapaksa, Roshini C; Macari, Michael; Bini, Edmund J
2004 Oct;38(9):767-771, Journal of clinical gastroenterology
BACKGROUND: CT colonography (virtual colonoscopy) is a new technique being offered to patients as a noninvasive method of imaging the colon. The aims of this study were to prospectively determine the prevalence of extracolonic findings in patients undergoing CT colonography, as well as to determine the clinical significance and consequences of these findings. METHODS: Two-hundred and fifty patients who were referred for colonoscopy for clinically indicated reasons underwent CT colonography using low-dose radiation (50 mAs) immediately prior to conventional colonoscopy. A single radiologist reviewed the CT images for extracolonic pathology, and findings were classified as having high, moderate, or low clinical significance. Electronic medical records were reviewed to assess what follow up diagnostic tests, if any, were performed. RESULTS: A total of 136 extracolonic findings were detected in 83 (33.2%) of the 250 patients. Of these 136 findings, 17 (12.5%) were highly significant, 53 (38.9%) were moderately significant, and 66 (48.5%) were of low significance. The most common highly significant lesions were solitary lung nodules in 3 patients, mesenteric lymphadenopathy in 3, adrenal masses in 2, low attenuation liver lesions consistent with metastases in 2, and bone metastases in 2 patients. Fourteen of the 17 (82.4%) highly significant findings were new findings, and in 11 the extracolonic abnormalities resulted in further diagnostic testing. None of the patients with moderate or low significance lesions underwent further testing. CONCLUSIONS: Low-dose CT colonography can detect highly significant extracolonic findings. Although extracolonic lesions were common, only a small proportion of patients required further diagnostic testing. Additional studies to determine the optimal radiation dose, cost-effectiveness, and legal implications of detecting extracolonic findings are warranted
— id: 49341, year: 2004, vol: 38, page: 767, stat: Journal Article,

CT Colonography Data Interpretation: Effect of Different Section Thicknesses--Preliminary Observations
Lui, Yvonne W; Macari, Michael; Israel, Gary; Bini, Edmund J; Wang, Hao; Babb, James
2003 Dec;229(3):791-797, Radiology
PURPOSE: To evaluate if differences exist in the interpretation of thin- and thick-section reconstructions at computed tomographic (CT) colonography. MATERIALS AND METHODS: Twenty-five patients underwent multi-detector row CT colonography prior to colonoscopy. CT images were reconstructed with two methods: 1.25-mm sections reconstructed every 1 mm (thin) and 5-mm sections reconstructed every 2 mm (thick). Two independent readers interpreted thin sections, then waited a minimum of 15 days before interpreting thick sections. With colonoscopy as the reference standard, comparisons were made between interpretation of thin and thick sections, including sensitivity, specificity, and number of false-positive observations. Interpretation times were recorded, and comparisons were made by using repeated measures analysis of variance. For all tests, P <.05 indicated a statistically significant difference. RESULTS: At colonoscopy, 10 patients had 12 polyps (</=5 mm, n = 7; 6-9 mm, n = 2; >/=10 mm, n = 3). Sensitivity for polyp detection was statistically indistinguishable for thin and thick sections. Reader 1 had three false-positive findings with thin sections and six with thick sections. Reader 2 had six false-positive findings with thin sections and 11 with thick sections. For both readers, the number of false-positive findings was significantly lower for thin sections than for thick sections (P =.035). Specificity was 93.3% with thin sections and 80.0% with thick sections for reader 1 and 80.0% with thin sections and 73.3% with thick sections for reader 2. Mean interpretation time for reader 1 was significantly longer with thin sections (P <.001). Mean interpretation time for reader 2 was 13.0 minutes for both thin and thick sections. CONCLUSION: Specificity improved for both readers with thin sections, with no difference in sensitivity.
— id: 39750, year: 2003, vol: 229, page: 791, stat: Journal Article,

Imaging intestinal manifestations of AIDS
Macari M
Textbook-atlas of intestinal infections in AIDS Milan : Springer, 2003,
— id: 3287, year: 2003, vol: , page: ?, stat: Chapter,

Virtual colonoscopy in the evaluation of colonic disease
Macari M
Colonoscopy : principles and practice Maden MA : Blackwell, 2003,
— id: 3285, year: 2003, vol: , page: ?, stat: Chapter,

Techniques for performing virtual colonoscopy
Macari M; Drachman A
Atlas of virtual colonoscopy New York : Springer, 2003,
— id: 3286, year: 2003, vol: , page: ?, stat: Chapter,

The acute right lower quadrant: CT evaluation
Macari, Michael; Balthazar, Emil J
2003 Nov;41(6):1117-1136, Radiologic clinics of North America
Acute right lower quadrant pain is a nonspecific but common clinical complaint. Appendicitis is the most common cause of acute right lower quadrant pain and CT has become the most reliable imaging method in the evaluation of these patients. Although there is controversy regarding the best way to perform CT in this setting, oral and i.v. contrast-enhanced CT remains the most commonly used technique. CT with oral and i.v. contrast material facilitates diagnosis of appendicitis and the numerous other entities that may cause right lower quadrant pain
— id: 43878, year: 2003, vol: 41, page: 1117, stat: Journal Article,

Filling defects at CT colonography: pseudo- and diminutive lesions (the good), polyps (the bad), flat lesions, masses, and carcinomas (the ugly)
Macari, Michael; Bini, Edmund J; Jacobs, Stacy L; Lange, Nick; Lui, Yvonne W
2003 Sep-Oct;23(5):1073-1091, Radiographics
Numerous filling defects may be detected in the colon during interpretation of data sets obtained with computed tomographic (CT) colonography. A series of 230 patients were evaluated with thin-section multidetector row CT colonography immediately before conventional colonoscopy. In all cases, the interpreting radiologist and gastroenterologist reviewed the imaging findings as well as the results of histologic analysis of biopsy specimens to determine the causes of filling defects. In many cases, the cause of a filling defect can be confidently determined at CT colonography by using combinations of two- and three-dimensional images. However, lesions will occasionally be indeterminate because of overlapping features and will require further evaluation with endoscopy. With knowledge of the morphologic and attenuation characteristics of the various filling defects in the colon, one should be able to differentiate those filling defects detected at CT colonography that require no further evaluation from those that require endoscopic interrogation
— id: 39751, year: 2003, vol: 23, page: 1073, stat: Journal Article,

Intestinal ischemia versus intramural hemorrhage: CT evaluation
Macari, Michael; Chandarana, Hersch; Balthazar, Emil; Babb, James
2003 Jan;180(1):177-184, American journal of roentgenology
OBJECTIVE: We evaluated the capability of CT to depict findings that allowed differentiation of small-bowel ischemia from intramural hemorrhage. MATERIALS AND METHODS: Findings of 35 CT examinations (19 patients with small-bowel ischemia and 16 patients with intramural hemorrhage) were analyzed by two abdominal radiologists for the degree of wall thickening, location and length of involvement (short, <or = 15 cm; medium, 16-30 cm; or long, >30 cm), presence of hemoperitoneum, and pattern of attenuation. Patency and caliber of the superior mesenteric artery and vein were noted. Diagnosis was confirmed by laboratory findings, clinical parameters, and follow-up examinations, or at surgery. A Mann-Whitney U or Fisher's exact test was used to compare the two conditions for the following features: wall thickening, location and length of involvement, presence of hemoperitoneum, and appearance of the target sign. RESULTS: Among the 35 examinations, 18 abnormal segments with intramural hemorrhage and 19 abnormal segments with ischemia were identified. (Two patients with intramural hemorrhage each had two segments involved.) Mean bowel wall thickness was 11.7 mm (range, 4-25 mm) in patients with intramural hemorrhage and 4.0 mm (range, 1-9 mm) in patients with ischemia. Length of involvement was short in 14 segments with intramural hemorrhage and medium in four segments with intramural hemorrhage; none of the segments with intramural hemorrhage had long involvement. Among the segments with ischemia, length of involvement was medium in three and long in 16; none of the ischemic segments had short involvement. Fifteen (94%) of 16 segments with intramural hemorrhage and six (32%) of 19 segments with ischemia had hemoperitoneum. Seven of the 18 segments with intramural hemorrhage and nine of the 19 with ischemia had a target sign. Segments with intramural hemorrhage exhibited a higher statistically significant degree of wall thickening (p < 0.001), a shorter length of involvement (p < 0.0001), and a higher incidence of hemoperitoneum (p < 0.001) than did segments with ischemia. The two groups were not statistically different in location of involvement (p = 0.12) or in the incidence of the target sign (p = 0.18). CONCLUSION: Although some of the CT features overlap, a short segment involvement with wall thickening of 1 cm or greater is typical of intramural hemorrhage; a long segment involvement with wall thickening of less than 1 cm is typical of ischemia
— id: 43879, year: 2003, vol: 180, page: 177, stat: Journal Article,

Duodenal diverticula mimicking cystic neoplasms of the pancreas: CT and MR imaging findings in seven patients
Macari, Michael; Lazarus, Dawn; Israel, Gary; Megibow, Alec
2003 Jan;180(1):195-199, American journal of roentgenology
OBJECTIVE: Duodenal diverticula are common and are typically asymptomatic. When filled with gas or a combination of fluid and gas, duodenal diverticula are easily recognized on CT or MR imaging. However, a duodenal diverticulum that is entirely filled with fluid may mimic a cystic neoplasm arising from the head of the pancreas. We present seven cases of patients with duodenal diverticula in whom initial findings on CT or MR imaging were suggestive of a cystic neoplasm in the head of the pancreas. In all patients, this structure was ultimately proven to be a duodenal diverticula. CONCLUSION: When filled with only fluid, a duodenal diverticulum may mimic a cystic neoplasm in the head of the pancreas. Recognizing the location in which this entity characteristically arises and identifying small amounts of intradiverticular gas when it is present may aid in establishing the correct diagnosis in patients with duodenal diverticula
— id: 43656, year: 2003, vol: 180, page: 195, stat: Journal Article,

Prospective comparison of virtual and conventional colonoscopy for colorectal cancer screening in asymptomatic average-risk patients
Bini, EJ; Naik, S; Milano, A; Babb, J; Macari, M
2002 ;122(4):M1691-M1691, Gastroenterology
— id: 108246, year: 2002, vol: 122, page: M1691, stat: Journal Article,

Colorectal neoplasms: prospective comparison of thin-section low-dose multi-detector row CT colonography and conventional colonoscopy for detection
Macari, Michael; Bini, Edmund J; Xue, Xiaonan; Milano, Andrew; Katz, Seth S; Resnick, Daniel; Chandarana, Hersh; Krinsky, Glen; Klingenbeck, Klaus; Marshall, Christopher H; Megibow, Alec J
2002 Aug;224(2):383-392, Radiology
PURPOSE: To prospectively compare thin-section low-dose multi-detector row computed tomographic (CT) colonography with conventional colonoscopy for the detection of colorectal neoplasms. MATERIALS AND METHODS: One hundred five patients underwent CT colonography immediately before colonoscopy. Supine and prone CT colonographic acquisitions to image the region during a 30-second breath hold were performed. CT colonographic images were prospectively interpreted for the presence, location, size, and morphologic features of polyps. The time of image interpretation was noted. Sensitivity, specificity, and positive and negative predictive values of CT colonography were calculated, with 95% CIs, by using colonoscopic findings as the reference standard. The weighted CT dose index was calculated on the basis of measurements in a standard body phantom. Effective dose was calculated by using commercially available software. RESULTS: Median CT data interpretation time was 12 minutes. One hundred thirty-two polyps in 59 patients were identified at colonoscopy; no polyps were detected in 46 patients. Sensitivities for detection of polyps smaller than 5 mm, 6-9 mm, and larger than 10 mm in diameter were 12% (11 of 91 polyps), 70% (19 of 27 polyps), and 93% (13 of 14 polyps), respectively. Estimated overall specificity was 97.7% (515 of 527 imaging results). The total weighted CT dose index for combined supine and prone CT colonography was 11.4 mGy. The effective doses for combined CT colonography were 5.0 mSv and 7.8 mSv for men and women, respectively. CONCLUSION: Low-dose multi-detector row CT colonography has excellent sensitivity and specificity for detection of colorectal neoplasms 10 mm and larger
— id: 32913, year: 2002, vol: 224, page: 383, stat: Journal Article,

Mesenteric adenitis: CT diagnosis of primary versus secondary causes, incidence, and clinical significance in pediatric and adult patients
Macari, Michael; Hines, John; Balthazar, Emil; Megibow, Alec
2002 Apr;178(4):853-858, American journal of roentgenology
OBJECTIVE: Our objective was to determine the clinical significance of mesenteric adentitis when detected on CT. MATERIALS AND METHODS: Mesenteric adenitis was considered present if a cluster of three or more lymph nodes measuring 5 mm or greater each was present in the right lower quadrant mesentery. If no other abnormality was detected on CT, then mesenteric adenitis was considered primary. If a specific inflammatory process was detected in addition to the lymphadenopathy, then mesenteric adenitis was considered secondary. Patients with a known neoplasm or HIV infection were excluded. Three separate groups of patients were examined for the presence and cause of mesenteric adenitis. Group 1 consisted of 60 consecutive patients prospectively identified with mesenteric adenitis on CT examinations. Group 2 consisted of 60 consecutive patients undergoing abdominal and pelvic CT for evaluation of blunt or penetrating abdominal trauma. Group 3 consisted of 60 consecutive patients undergoing abdominal and pelvic CT with acute abdominal symptoms. In all patients, the indication for imaging was documented, and the size of the largest lymph node, when present, was measured. In patients with mesenteric adenitis, the CT findings, clinical history, and clinical or surgical follow-up were subsequently evaluated to determine the cause of mesenteric adenitis. RESULTS: In the 60 patients prospectively identified with CT findings of mesenteric adenitis (group 1), 18 (30%) of 60 had primary mesenteric adenitis. The remaining 42 patients (70%) had an associated inflammatory condition that was established on CT as the likely cause of mesenteric adenitis. Mesenteric adenitis was present in none (0%) of the 60 patients in group 2 and in five (8.3%) of 60 patients in group 3. CONCLUSION: The incidence of mesenteric adenitis in patients with and those without abdominal pain is low. When evidence of mesenteric adenitis is present on CT examinations, usually a specific diagnosis can be established as its cause
— id: 43661, year: 2002, vol: 178, page: 853, stat: Journal Article,

Computed tomography diagnosis utilizing compressed image data: an ROC analysis using acute appendicitis as a model
Megibow, Alec J; Rusinek, Henry; Lisi, Virna; Bennett, Genevieve L; Macari, Michael; Israel, Gary M; Krinsky, Glenn A
2002 Jun;15(2):84-90, Journal of digital imaging
Using receiver-operating characteristic (ROC) methodology, the ability to diagnose acute appendicitis with computed tomography (CT) images displayed at varying levels of lossy compression was evaluated. Nine sequential images over the ileocecal region were obtained from 53 consecutive patients with right lower quadrant pain who were clinically suspected to have acute appendicitis. Thirty were proven surgically to have acute appendicitis, alternative diagnoses confirmed in 23. The image sets were subjected to a lossy wavelet-based compression algorithm 'Embedded Predictive Wavelet Image Coder' (EPWIC). Compression levels were: none, 8:1, 16:1, and 24:1, resulting in 4 sets of images per patient. Image sets were randomized and evaluated separately by 4 body radiologists on a 1,024 x 768-pixel SVGA color PC monitor in 512 x 512 format. The readers were aware of the clinical suspicion of appendicitis but were unaware of the positive fraction of cases. Individual and combined reader ROC and c2 analyses of sensitivity, specificity, and accuracy were determined. For all readers, sensitivity decreases at 16:1 and 24:1 levels (P <0.01, P <0.001, respectively). Accuracy decreased at 24:1 levels (P <0.01). Specificity was unaffected. By ROC analysis there was statistically significantly decreased area under the curve at 24:1 levels (P <0.02) as compared with uncompressed images. Finite levels of lossy wavelet compression may be applied to CT images without compromising diagnostic performance
— id: 43659, year: 2002, vol: 15, page: 84, stat: Journal Article,

Prevalence and impact of extracolonic findings in patients undergoing CT colonography
Rajapaksa, R; Macari, M; Bini, EJ
2002 SEP abstract #339;97(9):S111-S112, American journal of gastroenterology
— id: 32558, year: 2002, vol: 97, page: S111, stat: Journal Article,

Patient preferences and satisfaction with virtual vs. conventional colonoscopy
Rajapaksa, R; Macari, M; Weinshel, E; Bini, EJ
2002 ;55(5):468-468, Gastrointestinal endoscopy
— id: 108250, year: 2002, vol: 55, page: 468, stat: Journal Article,

Acute appendicitis: comparison of helical CT diagnosis focused technique with oral contrast material versus nonfocused technique with oral and intravenous contrast material
Jacobs JE; Birnbaum BA; Macari M; Megibow AJ; Israel G; Maki DD; Aguiar AM; Langlotz CP
2001 Sep;220(3):683-690, Radiology
PURPOSE: To compare the diagnostic accuracy of focused helical computed tomography (CT) with orally administered contrast material with that of nonfocused helical CT with orally and intravenously administered contrast material. MATERIALS AND METHODS: After receiving oral contrast material, 228 patients with clinically suspected appendicitis underwent focused appendiceal CT (5-mm section thickness, 15-cm coverage in the right lower quadrant). Immediately thereafter, helical CT of the entire abdomen and pelvis was performed following intravenous administration of contrast material (abdomen, 7-mm section thickness; pelvis, 5-mm section thickness). Studies were separated and independently interpreted by three observers who were blinded to patient names. Diagnoses were established by means of surgical and/or clinical follow-up findings. RESULTS: Fifty-one (22.4%) of 228 patients had acute appendicitis. Readers diagnosed appendicitis with 83.3%, 73.8%, and 71.4% sensitivity and 93.0%, 92.3%, and 97.9% specificity with focused nonenhanced appendiceal CT. Readers diagnosed appendicitis with 92.9%, 92.9%, and 88.1% sensitivity and 93.7%, 95.1%, and 96.5% specificity with nonfocused enhanced CT. Summary areas under the receiver operating characteristic curve estimates for focused nonenhanced and nonfocused enhanced CT were 0.916 and 0.964, respectively; the differences were statistically significant (P <.05) for two of three readers. All readers demonstrated higher sensitivities for detecting the inflamed appendix with nonfocused enhanced CT. Appendicitis was missed with focused CT in two patients whose inflamed appendix was not included in the imaging of the right lower quadrant. All readers were significantly more confident in diagnosing alternative conditions with nonfocused enhanced CT. CONCLUSION: Diagnostic accuracy of helical CT for acute appendicitis improved significantly with use of intravenous contrast material
— id: 43662, year: 2001, vol: 220, page: 683, stat: Journal Article,

Virtual colonoscopy: clinical results
Macari M
2001 Oct;22(5):432-442, Seminars in ultrasound CT & MR
CT colonography is an evolving noninvasive imaging technique that allows detection of colorectal polyps and cancers. When assessing the clinical results of this test, several points need to be emphasized. First, as computed tomography (CT) technology improves, so will clinical results. Therefore, earlier results reporting the accuracy of CT colonography may not be applicable to the current state of the art. Second, as clinical experience has grown, an understanding of the limitations and pitfalls of the technique has increased. A learning curve is involved and, with increased experience, results should improve. This article will focus on the evolving clinical results of CT colonography
— id: 26507, year: 2001, vol: 22, page: 432, stat: Journal Article,

Ct of bowel wall thickening: significance and pitfalls of interpretation
Macari M; Balthazar EJ
2001 May;176(5):1105-1116, American journal of roentgenology
— id: 20728, year: 2001, vol: 176, page: 1105, stat: Journal Article,

Infrarenal abdominal aortic aneurysms at multi-detector row CT angiography: intravascular enhancement without a timing acquisition
Macari M; Israel GM; Berman P; Lisi M; Tolia AJ; Adelman M; Megibow AJ
2001 Aug;220(2):519-523, Radiology
In 70 patients referred for evaluation of aortoiliac aneurysm disease, multi-detector row computed tomography was performed with a uniform 25-second delay from the initiation of intravenous administration of a 150-mL bolus of contrast material at 4 mL/sec. In all patients, adequate enhancement (>200 HU) of the aorta and intense enhancement of iliofemoral runoff was achieved without venous contamination
— id: 26720, year: 2001, vol: 220, page: 519, stat: Journal Article,

Effect of different bowel preparations on residual fluid at CT colonography
Macari M; Lavelle M; Pedrosa I; Milano A; Dicker M; Megibow AJ; Xue X
2001 Jan;218(1):274-277, Radiology
The effect of different bowel preparations on residual fluid during computed tomographic (CT) colonography was evaluated. Forty-two patients received either a polyethylene glycol electrolyte solution preparation or a phospho-soda preparation the day prior to CT colonography. The amount of residual fluid was calculated for each patient. On average, a phospho-soda preparation provided significantly less residual fluid than a polyethylene glycol electrolyte solution preparation
— id: 21257, year: 2001, vol: 218, page: 274, stat: Journal Article,

Imaging of suspected acute small bowel obstruction
Macari M; Megibow A
2001 Apr;36(2):108-117, Seminars in roentgenology
— id: 20694, year: 2001, vol: 36, page: 108, stat: Journal Article,

Pitfalls of using three-dimensional CT colonography with two-dimensional imaging correlation
Macari M; Megibow AJ
2001 Jan;176(1):137-143, American journal of roentgenology
— id: 21259, year: 2001, vol: 176, page: 137, stat: Journal Article,

Cystic pancreatic masses: cross-sectional imaging observations and serial follow-up
Megibow AJ; Lombardo FP; Guarise A; Carbognin G; Scholes J; Rofsky NM; Macari M; Balthazar EJ; Procacci C
2001 Nov-Dec;26(6):640-647, Abdominal imaging
BACKGROUND: We retrospectively reviewed the imaging features of a series of patients with cystic pancreatic masses, the majority of whom underwent imaging surveillance. METHODS: Imaging data from 30 patients with known cystic pancreatic masses were reviewed. Nine patients had surgical and/or cytologic classification. Of the 21 who were not operated on, all underwent serial imaging surveillance. Of these, five had corroborative endoscopic retrograde cholangiopancreatography and 16 were followed by only computed tomography and/or magnetic resonance imaging. RESULTS: In the nonoperated group, mean follow-up time was 30 months (3-144 months). Two patients demonstrated growth, and the remainder remain stable. In the patients who underwent surgery, invasive carcinoma was found in those with lesions larger than 4 cm, involvement of the main pancreatic duct, or visible solid components on the imaging study. Smaller lesions were benign. CONCLUSION: In patients with suspected cystic pancreatic neoplasms, surveillance might be possible if lesions are smaller than 2.5 cm, spare the main pancreatic duct, and demonstrate no solid components
— id: 32122, year: 2001, vol: 26, page: 640, stat: Journal Article,

CT interpretation utilizing compressed image data: Acute appendicitis as a model for assessing diagnostic quality
Megibow, AJ; Rusinek, H; Lisi, V; Macari, MJ; Bennett, GL; Israel, GM
2001 NOV ;221(2):377-377, Radiology
— id: 73268, year: 2001, vol: 221, page: 377, stat: Journal Article,

Comparison of time-efficient CT colonography with two- and three-dimensional colonic evaluation for detecting colorectal polyps
Macari M; Milano A; Lavelle M; Berman P; Megibow AJ
2000 Jun;174(6):1543-1549, American journal of roentgenology
OBJECTIVE: We compared the findings of time-efficient CT colonography with complete two-dimensional (2D) and three-dimensional (3D) CT colonography and conventional colonoscopy in detecting colorectal polyps. SUBJECTS AND METHODS: Forty-two patients undergoing colonoscopy screening were examined with CT colonography before endoscopy. Data were examined following one of two methods. In method 1, axial 2D data sets were examined in a cine mode. If findings were suggestive of abnormality, focal areas were examined with 3D CT colonography. In method 2, data sets were examined exactly as in method 1, and subsequent to that review, data sets were examined with simultaneous 3D 'fly-through' CT colonography (surface-rendered images) and multiplanar reformatted images. The time required to examine CT colonography using each technique was recorded and abnormal findings were documented. Results of methods 1 and 2 were compared with findings on colonoscopy. RESULTS: Colonoscopy detected 16 polyps in 13 patients (polyp size, 2-10 mm). Ten polyps measured 5 mm or less, five measured between 6 and 9 mm, and one measured 10 mm or more. Using method 1, two of 10 polyps measuring less than 5 mm, three of five polyps measuring between 6 and 9 mm, and one polyp measuring 10 mm were detected. We noted no false-positive polyps. Average evaluation time was 16 min. With method 2, the same polyps were seen as with method 1. No additional polyps were detected, and the average evaluation time was 40 min. CONCLUSION: Axial 2D CT colonography can be performed quickly and is comparable with complete 2D and 3D CT colonography in detecting colorectal polyps
— id: 11651, year: 2000, vol: 174, page: 1543, stat: Journal Article,

The accordion sign at CT: a nonspecific finding in patients with colonic edema
Macari M; Balthazar EJ; Megibow AJ
1999 Jun;211(3):743-746, Radiology
PURPOSE: To determine whether the 'accordion sign' is a specific computed tomographic (CT) sign of Clostridium difficile colitis. MATERIALS AND METHODS: Fifty-seven patients with CT evidence of severe colitis, as judged by colonic wall thickening, an abnormal haustral pattern, the target sign, and stranding of the pericolic fat, were identified from a computerized CT database for 25 months. CT images were retrospectively evaluated for the presence of oral contrast material in the colon and for the accordion sign. The medical and laboratory records of all patients were reviewed and correlated with CT findings to establish the cause of colitis. RESULTS: Oral contrast material had reached the colon in 35 of 57 patients at the time of the CT examination. The images in 15 of these patients demonstrated the accordion sign, and those in 20 patients did not. C difficile colitis was documented in four of the 15 cases displaying the accordion sign. In the remaining 11 patients, a different cause was documented. Oral contrast material had not reached the colon in the remaining 22 patients. Within this group with findings similar to the accordion sign, five patients had documented C difficile colitis, and four had colitis from other causes. CONCLUSION: The accordion sign is indicative of severe colonic edema or inflammation, but it is not specific for C difficile colitis
— id: 6127, year: 1999, vol: 211, page: 743, stat: Journal Article,

Usefulness of CT colonography in patients with incomplete colonoscopy
Macari M; Berman P; Dicker M; Milano A; Megibow AJ
1999 Sep;173(3):561-564, American journal of roentgenology
OBJECTIVE: Our objective was to investigate the use of CT colonography in patients who have undergone incomplete colonoscopy. CONCLUSION: CT colonography is effective in evaluating portions of the colon not seen during colonoscopy and may have an adjunctive role
— id: 6189, year: 1999, vol: 173, page: 561, stat: Journal Article,

Delayed CT to evaluate renal masses incidentally discovered at contrast-enhanced CT: demonstration of vascularity with deenhancement
Macari M; Bosniak MA
1999 Dec;213(3):674-680, Radiology
PURPOSE: To determine whether delayed computed tomography (CT) can help confirm vascularity in a neoplasm and differentiate it from a high-density cyst when a well-demarcated homogeneous high-attenuating (> 30-HU) renal mass is incidentally discovered during contrast material-enhanced CT. MATERIALS AND METHODS: In 25 patients, 26 well-demarcated, homogeneous high-attenuating renal masses (mean diameter, 2.5 cm; range, 1-4 cm) detected at initial postcontrast CT were further evaluated with delayed CT (mean, 38 minutes; range, 15-240 minutes) performed with identical parameters. On both the initial postcontrast and delayed CT scans, region-of-interest measurements were obtained in renal masses and in the gallbladder or low-density renal cysts as controls. Correlation with surgical or additional imaging findings was used to determine proof of diagnosis. RESULTS: Nine of the masses demonstrated no change in attenuation between initial postcontrast and delayed CT, indicating that they represented avascular lesions consistent with high-density cysts. These cases were confirmed with prior or follow-up imaging studies that demonstrated stability. Seventeen masses (nine surgically proved neoplasms and eight neoplasms that demonstrated interval growth at follow-up or previous CT) demonstrated decreased attenuation at delayed CT compared with initial postcontrast CT, which indicates vascularity. CONCLUSION: Delayed CT of incidentally discovered well-demarcated homogeneous high-attenuating (> 30-HU) renal masses detected at postcontrast CT enables differentiation of high-density cysts from renal neoplasms by demonstrating deenhancement as a proof of vascularity and, hence, neoplasm
— id: 6251, year: 1999, vol: 213, page: 674, stat: Journal Article,

Diagnosis of familial adenomatous polyposis using two-dimensional and three-dimensional CT colonography
Macari M; Green JC; Berman P; Milano A
1999 Jul;173(1):249-250, American journal of roentgenology
— id: 6156, year: 1999, vol: 173, page: 249, stat: Journal Article,

CT diagnosis of ileal diverticulitis
Macari M; Balthazar EJ; Krinsky G; Cao H
1998 Jul-Aug;22(4):243-245, Clinical imaging
The preoperative diagnosis of ileal diverticulitis has been reported during small-bowel series when inflammatory changes are associated with ileal diverticula. Previous CT reports of this entity have failed to establish the specific diagnosis preoperatively. We report the CT findings in a patient with right lower quadrant pain that enabled the specific diagnosis of ileal diverticulitis to be made
— id: 7667, year: 1998, vol: 22, page: 243, stat: Journal Article,

Diagnosis of agenesis of the dorsal pancreas with MR pancreatography
Macari M; Giovanniello G; Blair L; Krinsky G
1998 Jan;170(1):144-146, American journal of roentgenology
— id: 7668, year: 1998, vol: 170, page: 144, stat: Journal Article,

Non-small cell lung carcinoma: usefulness of unenhanced helical CT of the adrenal glands in an unmonitored environment
Macari M; Rofsky NM; Naidich DP; Megibow AJ
1998 Dec;209(3):807-812, Radiology
PURPOSE: To evaluate routine non-contrast material-enhanced helical computed tomography (CT) of the adrenal glands in patients with non-small cell lung carcinoma to facilitate characterization of adrenal masses detected in an unmonitored environment (i.e., the radiologist on duty did not look at the acquired images before the patient left the scanner). MATERIALS AND METHODS: One hundred consecutive patients with non-small cell lung carcinoma were referred for CT evaluation of the chest; chest and abdomen; or chest, abdomen, and brain. All underwent unenhanced CT of the adrenal glands before the requested CT examination. The morphologic features, size, and attenuation values of the adrenal masses were calculated. Attenuation values of adrenal masses from prior imaging, if available, were compared with those at follow-up imaging to classify these masses. Variable unit cost increase in obtaining these additional images was estimated. RESULTS: Fifteen adrenal masses were identified in 13 patients. In one patient, bilateral ill-defined adrenal masses were present. In 12 patients, 13 masses were sharply circumscribed: Seven were less than 10 HU and six were 20 HU or greater at unenhanced CT. Nine of these 12 patients received iodinated contrast material. Without the unenhanced CT, 10 adrenal masses in these nine patients would have been indeterminate for malignancy. In six of these nine patients, the adrenal mass was the only potential site of metastatic disease. The unenhanced CT data helped classify three of these masses as benign-10 HU or less- and three as indeterminate-greater than 10 HU. CONCLUSION: Unenhanced CT of the adrenal glands can prospectively characterize adrenal masses and obviate further examination in patients with lung carcinoma
— id: 7396, year: 1998, vol: 209, page: 807, stat: Journal Article,

Intestinal ischemia in patients in whom small bowel obstruction is suspected: evaluation of accuracy, limitations, and clinical implications of CT in diagnosis
Balthazar EJ; Liebeskind ME; Macari M
1997 Nov;205(2):519-522, Radiology
PURPOSE: To determine the accuracy of computed tomography (CT) in diagnosis of intestinal ischemia in patients with possible intestinal obstruction and the limitations and clinical implications of use of CT. MATERIALS AND METHODS: In 100 patients in whom intestinal obstruction was suspected clinically, CT findings were correlated with surgical findings in 77 patients and with follow-up clinical findings after nasogastric suction in 23 patients. The interval between CT and surgical exploration in patients with ischemic bowel was 1-98 hours (mean, 13 hours). RESULTS: Correlation of CT findings of strangulation obstruction with surgical findings revealed 72 true-negative, 19 true-positive, five false-positive, and four false-negative CT results. Sensitivity was 83%, specificity was 93%, accuracy was 91%, positive predictive value was 79%, and negative predictive value was 95%. CONCLUSION: CT enables accurate detection of bowel ischemia, particularly when small bowel obstruction is present. Exploratory laparotomy should be performed when unexplained disparities exist between equivocal CT findings and a deteriorating clinical condition in patients with possible small bowel obstruction or mesenteric infarction
— id: 12235, year: 1997, vol: 205, page: 519, stat: Journal Article,