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Last Updated: 4/9/2002
These cases are typically performed on pediatric patients
and are often run and read by the pediatric radiologist. Patients who
are preoperative for TET with pulmonary atresia are done with the general
protocol above.
Patients will usually have an IV placed for sedation.
Typically double dose IV Gadolinium contrast (*)
is used to obtain the MRA
(2cc/10 lb instead of 1cc/10 lb) (0.1 – 0.2 mmol/kg Gd)
EKG leads
| Sequence |
Plane |
Comment |
Film # |
| DB Haste |
Ax, Cor |
Gated. |
2 |
| Cine GRE |
Ax,
Obl Cor, and
Sag |
Under WIP-cardiac fn. TR 60; 23
beat (don’t use grid tagging)
Gated. 10-14 slices; 4-10mm; Ax from above PA’s to base of
heart.
Oblique coronal slices through right and left PA.
Sagital slices through pulmonic valve and MPA (1-2 slices).
# of phases usu 7-15 based on heart rate (TR * phases < RR interval)
Acq time 24-35 sec using 2 acquisitions. Smallest FOV without wrap. |
2
(film 1st image of each
cine) |
| Flow Quant |
Perpend-icular
to MPA |
Typically 2-4 min – be sure patient
is well sedated or told not to move.
Choose VENC 150 sequence. Phases 30-32.
Done as a through plane through the MPA. Plan off the
sagital cine images.
Use a level in the area of laminar flow (non-turbulent flow). |
0 |
| 3D FLASH |
Obl Sag
or
Coronal |
1 measure. Use 3D FLASH 2b488 {fl3d_itn_2b488ykc:
NOT qfs}(System #2) or ITN 2b488 (System #1)
For pulmonary artery studies the goal is 9-15 sec acquisition.
Otherwise, 9-24 sec (but shorter is better if you can maintain resolution)
Minimum FOV; actual effective thickness 1-2mm. |
0 |
| Timing Run |
Ax |
Thru the main PA. Time to the PA.
Use 10% of the contrast dose up to 1cc and inject by power injector
at 2cc/sec(if IV and patient are large enough) followed by 10-20
cc saline at 2cc/sec or hand injection if patient and IV are too
|
0 |
| 3D FLASH |
Obl
Sag
or
Coronal |
2 measures with no gap. Contrast
at 2cc/sec with 20 cc saline flush or by hand if IV too small.
Use the standard timing formula. |
0 |
| MIP |
|
Subtract if necessary. |
2 |
Pulmonary flow calculation:
- Found in the menu system under EVALUATE > FLOW QUANT.
- Place an ROI circle over the entire MPA and press GO.
- There should be a smooth curve with an early positive peak and negative
late flow.
(*) The use of gadolinium contrast material for these
applications represents off-label usage in the U.S. Outside the U.S.,
please consult your country's regulations for local guidelines.
NOTE: These protocols apply to Siemens
Symphony (with Quantum gradients) and Sonata systems. While they reflect
the protocols used at NYU Medical Center, NYU is not responsible for their
application elsewhere.
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