Jane P Ko, M.D.

Dual-energy Computed Tomography: Concepts, Performance, and Thoracic Applications
Ko, Jane P; Brandman, Scott; Stember, Joseph; Naidich, David P
2012 Jan;27(1):7-22, Journal of thoracic imaging
Advances in multidetector technology have made dual-energy computed tomography (CT) imaging possible. Dual-energy CT imaging enables tissue characterization in addition to morphologic evaluation of imaged regions. This article reviews current and potential CT technology, technical and workflow considerations when performing dual-energy CT, and clinical applications in the thorax, with an emphasis on the knowledge gained so far
— id: 147706, year: 2012, vol: 27, page: 7, stat: Journal Article,

Comparison of three-dimensional versus intensity-modulated radiotherapy techniques to treat breast and axillary level III and supraclavicular nodes in a prone versus supine position
Sethi RA; No HS; Jozsef G; Ko JP; Formenti SC
2012 Jan;102(1):74-81, Radiotherapy & oncology
BACKGROUND AND PURPOSE: To determine the optimal method of targeting breast and regional nodes in selected breast cancer patients after axillary dissection, we compared the results of IMRT versus no IMRT, and CT-informed versus clinically-placed fields, in supine and prone positions. MATERIALS AND METHODS: Twelve consecutive breast cancer patients simulated both prone and supine provided the images for this study. Four techniques were used to target breast, level III axilla, and supraclavicular fossa in either position: a traditional three-field three-dimensional conformal radiotherapy (3DCRT) plan, a four-field 3DCRT plan using a posterior axillary boost field, and two techniques using a CT-informed target volume consisting of an optimized 3DCRT plan (CT-planned 3D) and an intensity-modulated radiotherapy (IMRT) plan. The prescribed dose was 50Gy in 25 fractions. RESULTS: CT-planned 3D and IMRT techniques improved nodal PTV coverage. Supine, mean nodal PTV V50 was 50% (3-field), 59% (4-field), 92% (CT-planned 3D), and 94% (IMRT). Prone, V50 was 29% (3-field), 42% (4-field), 97% (CT-planned 3D), and 95% (IMRT). Prone positioning, compared to supine, and IMRT technique, compared to 3D, lowered ipsilateral lung V20. CONCLUSIONS: Traditional 3DCRT plans provide inadequate nodal coverage. Prone IMRT technique resulted in optimal target coverage and reduced ipsilateral lung V20
— id: 145493, year: 2012, vol: 102, page: 74, stat: Journal Article,

Increasing dyspnea due to an anterior mediastinal mass
Alpert, Jeffrey B; Nonaka, Daisuke; Chachoua, Abraham; Pass, Harvey I; Ko, Jane P
2011 Jan;139(1):217-223, Chest
— id: 117359, year: 2011, vol: 139, page: 217, stat: Journal Article,

Pulmonary nodule detection, characterization, and management with multidetector computed tomography
Brandman, Scott; Ko, Jane P
2011 May;26(2):90-105, Journal of thoracic imaging
Pulmonary nodule detection and characterization continue to improve with technological advancements. The noninvasive methods available for assisting in nodule detection and for characterizing nodules as benign, malignant, or indeterminate will be discussed. Evidence-based guidelines will be reviewed to help guide the appropriate management of pulmonary nodules
— id: 131807, year: 2011, vol: 26, page: 90, stat: Journal Article,

Lung pathologic findings in a local residential and working community exposed to world trade center dust, gas, and fumes
Caplan-Shaw, Caralee E; Yee, Herman; Rogers, Linda; Abraham, Jerrold L; Parsia, Sam S; Naidich, David P; Borczuk, Alain; Moreira, Andre; Shiau, Maria C; Ko, Jane P; Brusca-Augello, Geraldine; Berger, Kenneth I; Goldring, Roberta M; Reibman, Joan
2011 Sep;53(9):981-991, Journal of occupational & environmental medicine
OBJECTIVE: : To describe pathologic findings in symptomatic World Trade Center-exposed local workers, residents, and cleanup workers enrolled in a treatment program. METHODS: : Twelve patients underwent surgical lung biopsy for suspected interstitial lung disease (group 1, n = 6) or abnormal pulmonary function tests (group 2, n = 6). High-resolution computed axial tomography and pathologic findings were coded. Scanning electron microscopy with energy-dispersive x-ray spectroscopy was performed. RESULTS: : High-resolution computed axial tomography showed reticular findings (group 1) or normal or airway-related findings (group 2). Pulmonary function tests were predominantly restrictive. Interstitial fibrosis, emphysematous change, and small airway abnormalities were seen. All cases had opaque and birefringent particles within macrophages, and examined particles contained silica, aluminum silicates, titanium dioxide, talc, and metals. CONCLUSIONS: : In symptomatic World Trade Center-exposed individuals, pathologic findings suggest a common exposure resulting in alveolar loss and a diverse response to injury
— id: 137445, year: 2011, vol: 53, page: 981, stat: Journal Article,

Endovascular repair of the thoracic aorta: preoperative and postoperative evaluation with multidetector computed tomography
Godoy, Myrna C B; Cayne, Neal S; Ko, Jane P
2011 Feb;26(1):63-73, Journal of thoracic imaging
Endovascular techniques have emerged as a minimally invasive alternative for the repair of the descending thoracic aorta, especially in high-risk patients. Multidetector computed tomography has a pivotal role, specifically in determining the candidacy or exclusion of patients for thoracic endovascular aortic repair and preoperative planning. In addition, multidetector computed tomography is used for follow-up assessment of the postsurgical aorta, so that potentially fatal complications can be correctly diagnosed and treated in a timely manner. In this pictorial review, we focus on the preoperative assessment of the pathologic aorta and evaluation after thoracic endovascular aortic repair
— id: 138216, year: 2011, vol: 26, page: 63, stat: Journal Article,

From the guest editors
McComb, Barbara L; Ko, Jane P
2011 May;26(2):83-84, Journal of thoracic imaging
— id: 131806, year: 2011, vol: 26, page: 83, stat: Journal Article,

A dynamic method for automated lung nodule morphology characterization
Stember J.; Naidich D.; Ko J.; Rusinek H.
2011 ;6:S342-S342, International journal of computer assisted radiology & surgery
Purpose: Many potential lung cancers start out as small pulmonary nodules showing up as incidental findings on chest radiograph or computed tomography (CT) scans. Diagnosis is confirmed via biopsy, usually involving broncoscopy or CT-guided biopsy. However, these are invasive procedures that expose patients to additional risks. An alternative mode of tumor detection lies in administering successive chest CT scans. This has the advantage of avoiding those risks associated with biopsy. Overall, there is growing evidence for the effectiveness of low-dose CT for lung cancer screening. Morphology is an important indicator of malignant potential for lung nodules detected at CT. Automated methods for morphology assessment have previously been described for breast cancer visualized on mammography [1]. The most common measure of nodule shape is area-to-perimeter-length ratio (APR), low APR values being associated with spiculated or lobulated shape. APR is a static measure and thus highly susceptible to alterations by random noise and artifacts in image acquisition. We introduce and analyze the self-overlap (SO) method as a dynamic automated morphological detection scheme. SO measures the rate of change of nodule masks as a function of the radius of the blurring kernel. In other words, SO measures the degree to which a nodule's shape changes or stays intact upon successive pixel averaging that blurs the original image. Irregularities at the surface mean that a significant number of high-attenuation pixels (representing solid nodular tissue) are surrounded by low-attenuation pixels (representing air). Averaging each pixel with its neighboring pixels thus serves to trim back lobulations and spiculations from a nodule image. Hence, comparedto smooth nodules, lobulated and spiculated nodules are subject to more of this trimming upon successive averaging, so that their shape changes more, resulting in lower SO values. Due to its dynamical nature, we hypothesized that SO is more resilient to random image noise than APR. Methods: In experiment 1 we compare our algorithm with APR for nodules simulated using a spherical harmonic model (degree = 0-7) rasterized and contaminated with random noise. In experiment 2 we compare the new measure with a consensus of two expert morphology ratings of 119 nodules from clinical CT exams. Results: Experiment 1 shows that both methods display the desired trend in that APR and SO both decrease with increasing spherical harmonic degree-meaning more lobulations. As such both methods serve as measures of surface smoothness. However, SO displays significantly greater robustness to CT image noise; for both methods, we calculate variability as standard deviation over mean. We find that APR's variability in the face of random noise is on the order of ten times that of SO. This finding suggests that SO is much more robust than APR to the effects of random noise. Using a logistic regression model, in experiment 2 we achieved 89.9% agreement with the consensus assessment of two expert radiologists, versus 87.4% for APR. Conclusion: Simulation nodules show that both our dynamic method (SO) and a representative static method (APR) for automated lung nodule surface morphology determination yield clear trends as functions of surface smoothness. Hence both methods can, with proper fitting and cutoff selection, yield faithful predictions that have over 80% agreement with expert assessment. However, when the simulation nodules are subjected to random noise, SO yields much more consistent and reproducible results than APR. Overall, we conclude that our method, due to its robustness to the random noise and CT artifacts that can plague nodule images, is well suited for clinical application
— id: 136629, year: 2011, vol: 6, page: S342, stat: Journal Article,

Ground-glass centrilobular nodules on multidetector CT scan: incidental diagnosis in a patient with pneumonia
Godoy, Myrna C B; Nonaka, Daisuke; Lowy, Joseph; Ko, Jane P
2010 Aug;138(2):427-433, Chest
— id: 111824, year: 2010, vol: 138, page: 427, stat: Journal Article,

Automated CT scoring of airway diseases: preliminary results
Odry, Benjamin L; Kiraly, Atilla P; Godoy, Myrna C B; Ko, Jane; Naidich, David P; Novak, Carol L; Lerallut, Jean-Francois
2010 Sep;17(9):1136-1145, Academic radiology
RATIONALE AND OBJECTIVES: The aim of this study was to retrospectively evaluate an automated global scoring system for evaluating the extent and severity of disease in a known cohort of patients with documented bronchiectasis. On the basis of a combination of validated three-dimensional automated algorithms for bronchial tree extraction and quantitative airway measurements, global scoring combines the evaluation of bronchial lumen-to-artery ratios and bronchial wall-to-artery ratios, as well as the detection of mucoid-impacted airways. The result is an automatically generated global computed tomographic (CT) score designed to simplify and standardize the interpretation of scans in patients with chronic airway infections. MATERIALS AND METHODS: Twenty high-resolution CT data sets were used to evaluate an automated CT scoring method that combines algorithms for airway quantitative analysis that have been individually tested and validated. Patients with clinically documented atypical mycobacterial infections with visually assessed CT evidence of bronchiectasis varying from mild to severe were retrospectively selected. These data sets were evaluated by two independent experienced radiologists and by computer scoring, with the results compared statistically, including Spearman's rank correlation. RESULTS: Computer evaluation required 3 to 5 minutes per data set, compared to 12 to 15 minutes for manual scoring. Initial Spearman's rank tests showed positive correlations between automated and readers' global scores (r = 0.609, P = .01), extent of bronchiectasis (r = 0.69, P = .0004), and severity of bronchiectasis (r = 0.61, P = .01), while mucus plug detection showed a lesser extent of positive correlation between the scoring methods (r = 0.42, P = .07) and wall thickness a negative weak correlation (r = -0.10, P = .40). Further retrospective review of 24 lobes in which wall thickness scores showed the highest discrepancy between manual and automated methods was then performed, using electronic calipers and perpendicular cross-sections to reassess airway measurements. This resulted in an improved Spearman's rank correlation to r = 0.62 (P = .009), for a global score of r = 0.67 (P = .001). CONCLUSION: Automated computerized scoring shows considerable promise for providing a standardized, quantitative method, demonstrating overall good correlation with the results of experienced readers' evaluation of the extent and severity of bronchiectasis. It is speculated that this technique may also be applicable to a wide range of other conditions associated with chronic bronchial inflammation, as well as of potential value for monitoring response to therapy in these same populations
— id: 112028, year: 2010, vol: 17, page: 1136, stat: Journal Article,

Thoracic aorta: Acute syndromes
Shiau M.C.; Godoy M.C.B.; Groot P.M.D.; Ko J.P.
2010 ;39(1-2):6-16, Applied radiology
— id: 108914, year: 2010, vol: 39, page: 6, stat: Journal Article,

Understanding chest radiographic anatomy with MDCT reformations
Sussmann, A R; Ko, J P
2010 Feb;65(2):155-166, Clinical radiology
Chest radiograph interpretation requires an understanding of the mediastinal reflections and anatomical structures. Computed tomography (CT) improves the learning of three-dimensional (3D) anatomy, and more recently multidetector CT (MDCT) technology has enabled the creation of high-quality reformations in varying projections. Multiplanar reformations (MPRs) of varying thickness in the coronal and sagittal projections can be created for direct correlation with findings on frontal and lateral chest radiographs, respectively. MPRs enable simultaneous visualization of the craniocaudal extent of thoracic structures while providing the anatomic detail that has been previously illustrated using cadaveric specimens. Emphasis will be placed on improving knowledge of mediastinal anatomy and reflections including edges, lines, and stripes that are visible on chest radiographs
— id: 106504, year: 2010, vol: 65, page: 155, stat: Journal Article,

Computer-Assisted Detection for Lung Nodule Detection Using Compressed CT Data: Benefit to Readers on Thick-Section Images
Sussmann, A; Ko, J; Girvin, F; Naidich, D; Babb, J; Shah, M; Brusca-Augello, G; Anand, V
2010 MAY ;194(5):-, American journal of roentgenology
— id: 111949, year: 2010, vol: 194, page: , stat: Journal Article,

Multidetector CT of solitary pulmonary nodules
Truong, Mylene T; Sabloff, Bradley S; Ko, Jane P
2010 Feb;20(1):9-23, Thoracic surgery clinics
With the increasing use of MDCT, more solitary pulmonary nodules are being detected. Although the majority of these lesions are benign, lung cancer constitutes an important consideration in the differential diagnosis of solitary pulmonary nodules. The goal of management is to correctly differentiate malignant from benign nodules to ensure appropriate treatment. Stratifying patients' risk factors for malignancy, including patient age, smoking history, and history of malignancy, is essential in the management of solitary pulmonary nodules. In terms of radiologic evaluation, obtaining prior films is important to assess for nodule growth. The detection of certain patterns of calcification and stability for 2 years or more have historically been the only useful findings for determining whether a nodule is or is not benign. However, recent technological advances in imaging, including MDCT and PET/CT, have improved nodule characterization and surveillance. For solid nodules, CT enhancement of less than 15 HU and hypometabolism on PET (SUVmax <2.5) favor a benign etiology. Potential pitfalls in nodule enhancement and PET evaluation of solitary pulmonary nodules include infectious and inflammatory conditions. Stratified according to patient risk factors for malignancy and nodule size, recent guidelines for the management of incidentally detected small pulmonary nodules have been useful in decision analysis. An important exception to these guidelines is the evaluation and management of the subsolid nodule. These lesions are not suitable for CT enhancement studies and may show low metabolic activity on PET imaging. Due to their association with bronchioloalveolar carcinoma and adenocarcinoma, subsolid nodules require a more aggressive approach in terms of reassessing serial imaging and/or obtaining tissue diagnosis. As data from the low-dose CT lung cancer screening trials are analyzed and further studies with new imaging techniques are performed, management strategies for the imaging evaluation of the solitary pulmonary nodule will continue to evolve
— id: 112029, year: 2010, vol: 20, page: 9, stat: Journal Article,

Multidetector CT of solitary pulmonary nodules
Truong, Mylene T; Sabloff, Bradley S; Ko, Jane P
2010 Jan;48(1):141-155, Radiologic clinics of North America
With the increasing use of multidetector CT, small nodules are being detected more often. Although most incidentally discovered nodules are benign, usually the sequelae of pulmonary infection and malignancy, either primary or secondary, remains an important consideration in the differential diagnosis of solitary pulmonary nodules. This article reviews the role of imaging in the detection and characterization of solitary pulmonary nodules. Strategies for evaluating and managing solitary pulmonary nodules are also discussed
— id: 112030, year: 2010, vol: 48, page: 141, stat: Journal Article,

Coverage of axillary lymph nodes in supine vs. prone breast radiotherapy
Alonso-Basanta, Michelle; Ko, Jane; Babcock, Melissa; Dewyngaert, J Keith; Formenti, Silvia C
2009 Mar 1;73(3):745-751, International journal of radiation oncology biology physics
PURPOSE: To compare the dosimetry of target and normal tissue when tangents with the breast tissue were applied in a subset of breast cancer patients who had undergone computed tomography (CT) planning both supine and prone. METHODS AND MATERIALS: The CT images of 20 patients who had undergone simulation in supine and prone positions were used for planning. The axillary lymph node regions (level I-III), breast tissue, tumor bed, heart, and bilateral lungs were manually contoured. Standard tangent fields were designed for the whole breast to deliver a prescribed dose of 50 Gy. Dose-volume histograms were compared between the two sets. RESULTS: In each patient, coverage of breast tissue and tumor bed was readily achieved by either technique. In either position, treatment of the nodal regions was inadequate. On average, the mean dose to the nodal regions for levels I-III was approximately 50% less in the prone as compared with the supine position. The mean ipsilateral lung volume receiving 95% of the prescribed dose was 6.3% in the supine position compared to 0.43% in the prone position. When planned supine, the mean heart volume receiving 30 Gy was 0.56% compared with 0.30% in the prone position. CONCLUSIONS: Planning in either position was found to achieve adequate coverage of the breast tissue and tumor bed for all patients. Lung was better spared prone. Coverage of axillary nodes was inadequate in either position, but further reduced in the prone vs. supine position. The choice of optimal setup should take into considerations stage and risk of nodal recurrence
— id: 93548, year: 2009, vol: 73, page: 745, stat: Journal Article,

Immune-reconstitution syndrome related to atypical mycobacterial infection in AIDS
Berman, Erika J; Iyer, Ramesh S; Addrizzo-Harris, Doreen; Ko, Jane P
2008 Aug;23(3):182-187, Journal of thoracic imaging
The immune-reconstitution syndrome is a paradoxical inflammatory response to a preexisting or a coexisting disease, after the initiation of highly active antiretroviral therapy for the human immunodeficiency virus. Infrequently described, the radiographic and computed tomographic findings of the immune-reconstitution syndrome, which is related to the Mycobacterium avium-intracellulare infection and to highly active antiretroviral therapy, are presented in 2 patients. Homogeneous mediastinal and hilar lymphadenopathy were present in both individuals, with one having a large mass accompanied by small nodules
— id: 92677, year: 2008, vol: 23, page: 182, stat: Journal Article,

Pulmonary nodules: detection, assessment, and CAD
Girvin, Francis; Ko, Jane P
2008 Oct;191(4):1057-1069, American journal of roentgenology
OBJECTIVE: The imaging of pulmonary nodules is an evolving and dynamic field. In this review, we discuss the detection and multitechnique characterization of pulmonary nodules, emphasizing the impact of technological advances on both noninvasive and invasive evaluation and surveillance. The potential contribution of MRI, evolving imaging-guided techniques, and computer applications are also discussed. CONCLUSION: Advances in MDCT and PET and the potential contribution of fast-imaging MRI sequences and computer applications should continue to improve our evaluation of the solitary pulmonary nodule
— id: 93370, year: 2008, vol: 191, page: 1057, stat: Journal Article,

Imaging evaluation of the solitary pulmonary nodule: self-assessment module
Ko, Jane P; Roberts, Catherine C; Berger, William G; Chew, Felix S
2007 Mar;188(3 Suppl):S1-S4, American journal of roentgenology
The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the imaging evaluation of the solitary pulmonary nodule
— id: 101377, year: 2007, vol: 188, page: S1, stat: Journal Article,

Benefit of CT venography for the diagnosis of thromboembolic disease
Rhee, Kyung Hwa; Iyer, Ramesh S; Cha, Susan; Naidich, David P; Rusinek, Henry; Jacobowitz, Glenn R; Ko, Jane P
2007 Jul-Aug;31(4):253-258, Clinical imaging
OBJECTIVE: The aim of this study was to determine the benefit of lower extremity CT venography (CTV) with pulmonary CT angiography (CTA) for diagnosing thromboembolic (TE) disease. SUBJECTS AND METHODS: Reports of all CTAs and CTVs over a 3-year interval (Group I) and CTAs, CTVs, and lower extremity Doppler ultrasounds (US) over a 1 1/2-year subset (Group II) were reviewed. Patient population was inpatients and emergency department patients who were assessed for pulmonary embolism (PE) and deep venous thrombosis (DVT) at a tertiary care hospital. Reported results for CTA or CTV were categorized as positive (CTA(P), CTV(P)), negative (CTA(N), CTV(N)), or indeterminate for PE or DVT. When CTV and US results were discrepant, medical records were reviewed for clinical management. Additional benefit of CTV was assessed by chi-square analysis. RESULTS: In Group I, 737 (81.1%) of 909 CTAs from combined CTA/CTV studies were negative. The diagnosis rate of TE disease increased from 13.0% to 17.3% with the addition of CTV(P)s (P=.01). Of the 119 cases in Group II undergoing combined CTA, CTV, and US, CTV and US were both positive in eight and both negative in 88. Of the seven discordant CTVs and USs with clinical follow-up, five CTVs were positive while USs were negative, three of which were treated clinically for TE disease, while two were considered falsely positive. As CTA also proved positive in one of the three, CTV therefore affected management in two of these five cases and increased the rate of thromboembolism diagnosis from 21.0% to 22.6%; however, this was not significant (P>.05). Two CTV(N)s were managed as false negatives. CONCLUSIONS: The combined use of CTA and CTV significantly increases the rate of TE disease over CTA alone. In cases in which ultrasound is performed, however, there is no significant advantage to performing combined CTA/CTV studies
— id: 73253, year: 2007, vol: 31, page: 253, stat: Journal Article,

Effect of blood vessels on measurement of nodule volume in a chest phantom
Ko, Jane P; Marcus, Rachel; Bomsztyk, Elan; Babb, James S; Stefanescu, Cornel; Kaur, Manmeen; Naidich, David P; Rusinek, Henry
2006 Apr;239(1):79-85, Radiology
PURPOSE: To identify, by using a chest phantom, whether vessels that contact lung nodules measuring less than 5 mm in diameter will affect nodule volume assessment. MATERIALS AND METHODS: Forty synthetic nodules (20 with ground-glass attenuation and 20 with solid attenuation) that measured less than 5 mm in diameter were placed into a chest phantom either adjacent to (n = 30) or isolated from (n = 10) synthetic vessels. Nodules were imaged by using low-dose (20 mAs) and diagnostic (120 mAs) multi-detector row computed tomography (CT). Nodules that were known to lie in direct contact with vessels were confirmed by visual inspection. Nontargeted 1.25 x 1.00-mm sections were analyzed with a three-dimensional computer-assisted method for measuring nodule volume. A mixed-model analysis of variance was used to examine the influence of several factors (eg, the presence of adjacent vessels; tube current-time product; and nodule attenuation, diameter, and location) on measurement error. RESULTS: The mean absolute error (MAE) for all nodules adjacent to vessels was 2.3 mm(3), which was higher than the MAE for isolated nodules (1.9 mm(3)) (P < .001). This difference proved significant only for diagnostic CT (2.2 mm(3) for nodules adjacent to vessels vs 1.3 mm(3) for nodules isolated from vessels) (P < .05). A larger MAE was noted for nodules with ground-glass attenuation (2.3 mm(3)) versus those with solid attenuation (2.0 mm(3)), for increasing nodule volume (1.66 mm(3) for nodules smaller than 20 mm(3) vs 2.83 mm(3) for nodules larger than 40 mm(3)), and for posterior nodule location (P < .05). CONCLUSION: The presence of a vessel led to a small yet significant increase in volume error on diagnostic-quality images. This represents less than one-third of the overall error, even for nodules larger than 40 mm(3) or approximately 4 mm in diameter. This increase, however, may be more important for smaller nodules with errors of less than 3 mm(3)
— id: 64205, year: 2006, vol: 239, page: 79, stat: Journal Article,

Pulmonary fissure segmentation on CT
Wang, Jingbin; Betke, Margrit; Ko, Jane P
2006 Aug;10(4):530-547, Medical image analysis
A pulmonary fissure is a boundary between the lobes in the lungs. Its segmentation is of clinical interest as it facilitates the assessment of lung disease on a lobar level. This paper describes a new approach for segmenting the major fissures in both lungs on thin-section computed tomography (CT). An image transformation called 'ridge map' is proposed for enhancing the appearance of fissures on CT. A curve-growing process, modeled by a Bayesian network, is described that is influenced by both the features of the ridge map and prior knowledge of the shape of the fissure. The process is implemented in an adaptive regularization framework that balances these influences and reflects the causal dependencies in the Bayesian network using an entropy measure. The method effectively alleviates the problem of inappropriate weights of regularization terms, an effect that can occur with static regularization methods. The method was applied to segment and visualize the lobes of the lungs on chest CT of 10 patients with pulmonary nodules. Only 78 out of 3286 left or right lung regions with fissures (2.4%) required manual correction. The average distance between the automatically segmented and the manually delineated 'ground-truth' fissures was 1.01mm, which was similar to the average distance of 1.03mm between two sets of manually segmented fissures. The method has a linear-time worst-case complexity and segments the upper lung from the lower lung on a standard computer in less than 5min
— id: 68531, year: 2006, vol: 10, page: 530, stat: Journal Article,

Dosimetric comparisons of supine versus prone radiation: Implications on normal tissue toxicity
Alonso-Basanta, M; MacDonald, S; Lymberis, S; Ko, J; DeRouen, M; Jozsef, G; DeWyngaert, JK; Formenti, SC
2005 NOV 16 ;63(2):S182-S183, International journal of radiation oncology biology physics
— id: 58992, year: 2005, vol: 63, page: S182, stat: Journal Article,

Lung nodule detection and characterization with multi-slice CT
Ko, Jane P
2005 Aug;20(3):196-209, Journal of thoracic imaging
The influence of MSCT on nodule detection and characterization will be discussed. The objective is to improve understanding of the clinical issues involved in nodule detection, characterization, and management in light of technological advances. Topics to be covered are noninvasive characterization techniques, such as morphologic and density inspection on CT, nodule enhancement techniques, CT-PET, temporal nodule size assessment, and computer aided diagnosis for both detection and characterization
— id: 68532, year: 2005, vol: 20, page: 196, stat: Journal Article,

Effect of CT image compression on computer-assisted lung nodule volume measurement
Ko, Jane P; Chang, Jeffrey; Bomsztyk, Elan; Babb, James S; Naidich, David P; Rusinek, Henry
2005 Oct;237(1):83-88, Radiology
PURPOSE: To evaluate the effect of two-dimensional wavelet-based computed tomographic (CT) image compression according to the Joint Photographic Experts Group (JPEG) 2000 standard on computer-assisted assessment of nodule volume. MATERIALS AND METHODS: This HIPAA-compliant study was approved by the research board at the authors' institution; patients' informed consent was not required. Fifty-one nodules in 23 patients (seven men, 16 women; mean age, 59 years; age range, 39-75 years) were selected on low-dose CT scans that were compressed to levels of 10:1, 20:1, 30:1, and 40:1 by using a two-dimensional JPEG 2000 wavelet-based image compression method. Nodules were classified according to size (< or = 5 mm or > 5 mm in diameter), location (central, peripheral, or abutting pleura or fissures), and attenuation (solid, calcified, or subsolid). Regions of interest were placed on the original images and transposed onto compressed images. Nodule volumes on original (noncompressed) and compressed images were measured by using a computer-assisted method. A mixed-model analysis of variance was conducted for statistical evaluation. RESULTS: Nodule volumes averaged 388.1 mm3 (range, 34-3474 mm3). There were three calcified, 33 solid noncalcified, and 15 subsolid nodules (13 with ground-glass attenuation). Average volume decreased with increasing compression level, to 383 mm3 (10:1), 370 mm3 (20:1), 360 mm3 (30:1), and 354 mm3 (40:1). No significant difference was identified between measurements obtained on original images and those compressed to a level of 10:1. Significant differences were noted, however, between original images and those compressed to a level of 20:1 or greater (P < .05). Compression level significantly interacted with nodule size, location, and attenuation (P < .001). The effect of compression was greater for nodules with ground-glass attenuation than for those with higher attenuation values. The difference in mean volumes between original images and those compressed to a level of 20:1 was 34.9 mm3 for nodules with ground-glass attenuation, compared with 8.3 mm3 for higher-attenuation nodules, a 4.2-fold difference. CONCLUSION: Nodule volumes measured on images compressed to a level of 20:1 differed significantly from those measured on noncompressed images, especially for nodules with ground-glass attenuation. This difference could affect the assessment of nodule change in size as measured with computer-assisted methods
— id: 58740, year: 2005, vol: 237, page: 83, stat: Journal Article,

Reelin and cyclin-dependent kinase 5-dependent signals cooperate in regulating neuronal migration and synaptic transmission
Beffert, Uwe; Weeber, Edwin J; Morfini, Gerardo; Ko, Jane; Brady, Scott T; Tsai, Li-Huei; Sweatt, J David; Herz, Joachim
2004 Feb 25;24(8):1897-1906, Journal of neuroscience
Neuronal migration and positioning in the developing brain require the coordinated interaction of multiple cellular signaling pathways. The extracellular signaling molecule Reelin and the cytoplasmic serine/threonine kinase Cdk5 (cyclin-dependent kinase 5) are both required for normal neuronal positioning, lamination of the neocortex, and foliation of the cerebellum. They also modulate synaptic transmission in the adult brain. It is not known, however, to what extent Cdk5 participates in Reelin signaling and whether both pathways interact on the genetic or biochemical level. We have used genetically altered mice to generate compound functional defects of Reelin and Cdk5 signaling. Differential neurohistochemical staging combined with the biochemical analysis of Reelin- and Cdk5-dependent signaling in primary embryonic neurons and electrophysiology in hippocampal slices reveals evidence for genetic and functional interaction between both pathways. Inhibition of Reelin or Cdk5 signaling had no discernible biochemical effect on each other. Taken together, these findings suggest that both pathways function together in a parallel, rather than a simple, linear manner to coordinate neuronal migration and neurotransmission in the developing and mature brain
— id: 68533, year: 2004, vol: 24, page: 1897, stat: Journal Article,

Computer-aided diagnosis and the evaluation of lung disease
Ko, Jane P; Naidich, David P
2004 Jul;19(3):136-155, Journal of thoracic imaging
— id: 43865, year: 2004, vol: 19, page: 136, stat: Journal Article,

Segmentation of nodules on chest computed tomography for growth assessment
Mullally, William; Betke, Margrit; Wang, Jingbin; Ko, Jane P
2004 Apr;31(4):839-848, Medical physics
Several segmentation methods to evaluate growth of small isolated pulmonary nodules on chest computed tomography (CT) are presented. The segmentation methods are based on adaptively thresholding attenuation levels and use measures of nodule shape. The segmentation methods were first tested on a realistic chest phantom to evaluate their performance with respect to specific nodule characteristics. The segmentation methods were also tested on sequential CT scans of patients. The methods' estimation of nodule growth were compared to the volume change calculated by a chest radiologist. The best method segmented nodules on average 43% smaller or larger than the actual nodule when errors were computed across all nodule variations on the phantom. Some methods achieved smaller errors when examined with respect to certain nodule properties. In particular, on the phantom individual methods segmented solid nodules to within 23% of their actual size and nodules with 60.7 mm3 volumes to within 14%. On the clinical data, none of the methods examined showed a statistically significant difference in growth estimation from the radiologist
— id: 43866, year: 2004, vol: 31, page: 839, stat: Journal Article,

Shape-based curve growing model and adaptive regularization for pulmonary fissure segmentation in CT
Wang, JB; Betke, M; Ko, JP
2004 OCT 14 ;3216(2):541-548, Lecture notes in computer science
This paper presents a shape-based curve-growing algorithm for object recognition in the field of medical imaging. The proposed curve growing process, modeled by a Bayesian network, is influenced by both image data and prior knowledge of the shape of the curve. A maximum a posteriori (MAP) solution is derived using an energy-minimizing mechanism. It is implemented in an adaptive regularization framework that balances the influence of image data and shape prior in estimating the curve, and reflects the causal dependencies in the Bayesian network. The method effectively alleviates over-smoothing, an effect that can occur with other regularization methods. Moreover, the proposed framework also addresses initialization and local minima problems. Robustness and performance of the proposed method are demonstrated by segmentation of pulmonary fissures in computed tomography (CT) images
— id: 98197, year: 2004, vol: 3216, page: 541, stat: Journal Article,

Landmark detection in the chest and registration of lung surfaces with an application to nodule registration
Betke, Margrit; Hong, Harrison; Thomas, Deborah; Prince, Chekema; Ko, Jane P
2003 Sep;7(3):265-281, Medical image analysis
We developed an automated system for registering computed tomography (CT) images of the chest temporally. Our system detects anatomical landmarks, in particular, the trachea, sternum and spine, using an attenuation-based template matching approach. It computes the optimal rigid-body transformation that aligns the corresponding landmarks in two CT scans of the same patient. This transformation then provides an initial registration of the lung surfaces segmented from the two scans. The initial surface alignment is refined step by step in an iterative closest-point (ICP) process. To establish the correspondence of lung surface points, Elias' nearest neighbor algorithm was adopted. Our method improves the processing time of the original ICP algorithm from O(kn log n) to O(kn), where k is the number of iterations and n the number of surface points. The surface transformation is applied to align nodules in the initial CT scan with nodules in the follow-up scan. For 56 out of 58 nodules in the initial CT scans of 10 patients, nodule correspondences in the follow-up scans are established correctly. Our methods can therefore potentially facilitate the radiologist's evaluation of pulmonary nodules on chest CT for interval growth
— id: 43867, year: 2003, vol: 7, page: 265, stat: Journal Article,

Automated assessment of small airway disease on lung CT : a preliminary study
Dittmer-Roche B; Rusinek H; Ko J; McGuiness C; Naidich D
2003 ;5030:41-50, Medical imaging (SPIE)
Air trapping is a prominent finding in small airway disease (SAD)of the lungs. To investigate the feasibility of accurate, automated assessment of air-trapping from low-dose CT, we compare visual scoring by expert radiologists to a conventional method of automated assessment as well as two novel methods. The conventional method,the markdensity maskmark method, has been reported to correlateweakly but significantly with visual scoring on normal-dose CT.While we were unable to reproduce these results on our low-dose scans, our two novel methods showed some promise. More study on larger data sets is required to determine the optimal analysis method.
— id: 44187, year: 2003, vol: 5030, page: 41, stat: Journal Article,

Lung nodule detection and characterization with multislice CT
Ko, Jane P; Naidich, David P
2003 May;41(3):575-97, vi, Radiologic clinics of North America
The ability to identify and characterize pulmonary nodules has been dramatically increased by the introduction of multislice CT (MSCT) technology. Using high-resolution sections, MSCT allows considerable improvement in assessing nodule morphology, enhancement patterns, and growth. MSCT also has facilitated the development and potential of clinical application of computer-assisted diagnosis
— id: 43868, year: 2003, vol: 41, page: 575, stat: Journal Article,

Small pulmonary nodules: volume measurement at chest CT--phantom study
Ko, Jane P; Rusinek, Henry; Jacobs, Erika L; Babb, James S; Betke, Margrit; McGuinness, Georgeann; Naidich, David P
2003 Sep;228(3):864-870, Radiology
Three-dimensional methods for quantifying pulmonary nodule volume at computed tomography (CT) and the effect of imaging variables were studied by using a realistic phantom. Two fixed-threshold methods, a partial-volume method (PVM) and a variable method, were used to calculate volumes of 40 plastic nodules (largest dimension, <5 mm: 20 nodules with solid attenuation and 20 with ground-glass attenuation) of known volume. Tube current times (20 and 120 mAs), reconstruction algorithms (high and low frequency), and nodule characteristics were studied. Higher precision was associated with use of a PVM with predetermined pure nodule attenuation, high-frequency algorithm, and diagnostic CT technique (120 mAs). A PVM is promising for volume quantification and follow-up of nodules
— id: 43798, year: 2003, vol: 228, page: 864, stat: Journal Article,

Wavelet compression of low-dose chest CT data: effect on lung nodule detection
Ko, Jane P; Rusinek, Henry; Naidich, David P; McGuinness, Georgeann; Rubinowitz, Ami N; Leitman, Barry S; Martino, Jennifer M
2003 Jul;228(1):70-75, Radiology
PURPOSE: To assess the effect of using a lossy Joint Photographic Experts Group standard for wavelet image compression, JPEG2000, on pulmonary nodule detection at low-dose computed tomography (CT). MATERIALS AND METHODS: One hundred sets of lung CT data ('cases') were compressed to 30:1, 20:1, and 10:1 levels by using a wavelet-based JPEG2000 method, resulting in 400 test cases. Each case consisted of nine 1.25-mm sections that had been obtained with 20-40 mAs. Four thoracic radiologists independently interpreted the test case images. Performance was measured by using area under the receiver operating characteristic (ROC) curve (Az) and conventional sensitivity and specificity analyses. RESULTS: There were 51 cases with and 49 without lung nodules. Az values were 0.984, 0.988, 0.972, 0.921, respectively, for original and 10:1, 20:1, and 30:1 compressed images. Az values decreased significantly at 30:1 (P =.014) but not at 10:1 compression, with a trend toward significant decrease at 20:1 (P =.051). Specificity values were unaffected by compression (>98.0% at all compression levels). Sensitivity values were 86.3% (176 of 204 test cases with nodules), 77.9% (159 of 204 cases), 76.5% (156 of 204 cases), and 70.1% (143 of 204 cases), respectively, for original and 10:1, 20:1, and 30:1 compressed images. Results of logistic regression model analysis confirmed the significant effects of compression rate and nodule attenuation, size, and location on sensitivity (P <.05). CONCLUSION: While no reduction in nodule detection at 10:1 compression levels was demonstrated by using ROC analysis, a significant decrease in sensitivity was identified. Further investigation is needed before widespread use of image compression technology in low-dose chest CT can be recommended
— id: 43799, year: 2003, vol: 228, page: 70, stat: Journal Article,

Thymic enlargement and FDG uptake in three patients: CT and FDG positron emission tomography correlated with pathology
Wittram, Conrad; Fischman, Allan J; Mark, Eugene; Ko, Jane; Shepard, Jo-Anne O
2003 Feb;180(2):519-522, American journal of roentgenology
OBJECTIVE: Our purpose was to describe three adult patients in whom we found increased thymic uptake of FDG on positron emission tomography and thymic enlargement with convex lateral margins on CT. Subsequent biopsy or resection showed normal thymic tissue. CONCLUSION: In three adults, we found a physiologic uptake of FDG by the thymus with standardized uptake values in the range of thymic neoplasia
— id: 43861, year: 2003, vol: 180, page: 519, stat: Journal Article,

Pulmonary aspergillosis in an immunocompetent patient
Ko, Jane P; Kim, Dennis H; Shepard, Jo-Anne O
2002 Jan;17(1):70-73, Journal of thoracic imaging
SUMMARY: A case of an immunocompetent patient with severe Aspergillus infection and radiographic findings typically described with angioinvasive aspergillosis is presented. When Aspergillus is isolated from the sputum in a patient with normal immunity, invasive aspergillosis should be considered when there are extensive radiographic findings characteristic of invasive fungal disease
— id: 43869, year: 2002, vol: 17, page: 70, stat: Journal Article,

Imaging of diaphragmatic injury: A diagnostic challenge? Invited commentary
Ko, JP; Primack, SL
2002 OCT ;22(1):S116-S118, Radiographics
— id: 32545, year: 2002, vol: 22, page: S116, stat: Journal Article,

Chest CT: automated nodule detection and assessment of change over time--preliminary experience
Ko JP; Betke M
2001 Jan;218(1):267-273, Radiology
The authors developed a computer system that automatically identifies nodules at chest computed tomography, quantifies their diameter, and assesses for change in size at follow-up. The automated nodule detection system identified 318 (86%) of 370 nodules in 16 studies (eight initial and eight follow-up studies) obtained in eight oncology patients with known nodules. Assessment of change in nodule size by the computer matched that by the thoracic radiologist (Spearman rank correlation coefficient, 0.932)
— id: 43872, year: 2001, vol: 218, page: 267, stat: Journal Article,

Factors influencing pneumothorax rate at lung biopsy: are dwell time and angle of pleural puncture contributing factors?
Ko JP; Shepard JO; Drucker EA; Aquino SL; Sharma A; Sabloff B; Halpern E; McLoud TC
2001 Feb;218(2):491-496, Radiology
PURPOSE: To study factors that may influence pneumothorax and chest tube placement rate, especially needle dwell time and pleural puncture angle. MATERIALS AND METHODS: In 159 patients, 160 coaxial computed tomography (CT)-guided lung biopsies were performed. Dwell time, the time between pleural puncture and needle removal, was calculated. The smallest angle of the needle with the pleura ('needle-pleural angle') was measured. These and other variables were correlated with pneumothorax and chest tube rates. RESULTS: One hundred fifty biopsies were included. There were 58 (39%) pneumothoraces (14 noted only at CT), with eight (5%) biopsies resulting in chest tube placement. Longer dwell times (mean, 29 minutes; range, 12-66 minutes) did not correlate with pneumothoraces (P =.81). Smaller needle-pleural angles (< 80 degrees) [corrected], decreased forced expiratory volume in 1 second to vital capacity ratio (<50%), lateral pleural puncture, and lesions along fissures were associated with higher [corrected] pneumothorax rates (P <.05). Emphysema along the needle path, pulmonary function tests showing ventilatory obstruction, and lesions along fissures predisposed patients to chest tube placement (P <.05). Pleural thickening and prior surgery were associated with lower pneumothorax rates (P <.05). CONCLUSION: Longer dwell times do not correlate with pneumothorax and should not influence the decision to obtain more biopsy samples. A shallow pleural puncture angle may increase the pneumothorax rate
— id: 43870, year: 2001, vol: 218, page: 491, stat: Journal Article,

Volume quantitation of small pulmonary nodules on low-dose chest
Ko, JP; Rusinek, H; Chandra, R; McGuinness, G; Betke, M; Naidich, DP
2001 NOV ;221(2):312-312, Radiology
— id: 73267, year: 2001, vol: 221, page: 312, stat: Journal Article,

Tuberculosis from head to toe
Harisinghani MG; McLoud TC; Shepard JA; Ko JP; Shroff MM; Mueller PR
2000 Mar-Apr;20(2):449-470, Radiographics
Tuberculosis can affect virtually any organ system in the body and can be devastating if left untreated. The increasing prevalence of tuberculosis in both immunocompetent and immunocompromised individuals in recent years makes this disease a topic of universal concern. Because tuberculosis demonstrates a variety of clinical and radiologic findings and has a known propensity for dissemination from its primary site, it can mimic numerous other disease entities. Primary pulmonary tuberculosis typically manifests radiologically as parenchymal disease, lymphadenopathy, pleural effusion, miliary disease, or lobar or segmental atelectasis. In postprimary tuberculosis, the earliest radiologic finding is the development of patchy, ill-defined segmental consolidation. Both computed tomography (CT) and magnetic resonance (MR) imaging are helpful in diagnosing tuberculous spondylitis and tuberculous arthritis. CT is especially useful in depicting gastrointestinal and genitourinary tuberculosis. In tuberculosis involving the central nervous system, CT and MR imaging findings vary depending on the stage of disease and the character of the lesion. A high degree of clinical suspicion and familiarity with the various radiologic manifestations of tuberculosis allow early diagnosis and timely initiation of appropriate therapy, thereby reducing patient morbidity
— id: 43873, year: 2000, vol: 20, page: 449, stat: Journal Article,

CT depiction of regional nodal stations for lung cancer staging
Ko JP; Drucker EA; Shepard JA; Mountain CF; Dresler C; Sabloff B; McLoud TC
2000 Mar;174(3):775-782, American journal of roentgenology
— id: 43874, year: 2000, vol: 174, page: 775, stat: Journal Article,

CT manifestations of respiratory syncytial virus infection in lung transplant recipients
Ko JP; Shepard JA; Sproule MW; Trotman-Dickenson B; Drucker EA; Ginns LC; Wain JC; McLoud TC
2000 Mar-Apr;24(2):235-241, Journal of computer assisted tomography
PURPOSE: The purpose of our study was to evaluate CT findings during respiratory syncytial virus (RSV) infection in lung transplant recipients and to identify sequelae. METHOD: Thirty-nine CT scans prior to, during, and following acute infection in 10 lung transplant recipients were reviewed. Abnormalities that were new from baseline observations and occurred within 4 weeks of diagnosis were defined as acute. Chronic findings were defined as those present >4 weeks after diagnosis. RESULTS: Findings in nine patients were ground-glass (seven), air-space (five), and tree-in-bud (four) opacities and acute bronchial dilatation (four) and wall thickening (four). Patients lacked pleural effusions or lymph node enlargement. Five of seven patients with follow-up exams had new air trapping (three), persistent bronchial dilatation (three), and thickening (two). Three and 2 of the 10 patients developed bronchiolitis obliterans syndrome and obliterative bronchiolitis, respectively. CONCLUSION: During acute infection, patients commonly had ground-glass opacities but lacked pleural effusions and lymph node enlargement. There can be chronic sequelae after infection
— id: 43871, year: 2000, vol: 24, page: 235, stat: Journal Article,

Magnetic resonance imaging of pericardial constriction: comparison of cine MR angiography and spin-echo techniques
Hartnell GG; Hughes LA; Ko JP; Cohen MC
1996 Apr;51(4):268-272, Clinical radiology
AIM: Spin-echo (SE) MRI detects pericardial thickening in pericardial constriction but the validity of extrapolating SE criteria to cine MRA imaging has not been tested. Pericardial thickness measured by SE and cine MRA was compared in patients with and without pericardial thickening to determine if the range of pericardial thickness measured by the two techniques is the same. PATIENT AND METHODS: Fourteen patients, investigated for possible pericardial constriction (PC), were compared with 24 subjects without evidence of pericardial disease (controls). Images were acquired using SE and cine MRA. Pericardial thickness was compared with final diagnosis. RESULTS: Pericardial thickening ( > 3.5 mm) by SE detected pericardial constriction: sensitivity = 100% specificity = 96%, kappa = 0.91. Cine MRA had a sensitivity = 86%, specificity = 63%, kappa = 0.33. Maximum differences between SE and cine MRA pericardial thickness ranged from +2.5 mm to -2/7 mm. CONClUSIONS: Spin-echo identifies pericardial thickening with little overlap between measurements in patients with and without pericardial constriction. Pericardial thickness on cine MRA usually exceeds SE thickness, but with considerable overlap of thickness measurements in patients with and without pericardial constriction. Cine MRA cannot be used alone to diagnose pericardial thickening
— id: 43875, year: 1996, vol: 51, page: 268, stat: Journal Article,