| Patient History Patient
is a 45 year old male who presented with mild chest pain following low
level exertion. The patient had no risk factors for cardiac disease (normal
cholesterol, exercises, non-smoker, no family history of cardiac events).
Height: 69 inches; weight: 175 lbs.
Imaging Procedure
The Two Day Cardiolite Protocol was used, and rest imaging was performed
first. Imaging was done on a GE Millennium Dual Head Camera with
36 stops/detector, 180 degrees.
Acquisition Parameters:
| |
Type of Acquisition |
Time per stop |
Agent |
Dose |
Injection-Image Interval |
| Rest |
Ungated SPECT |
25 seconds |
99m Tc Sestamibi |
25.8 mCi |
45 minutes after-injection |
| Stress |
Gated SPECT |
25 seconds |
99m Tc Sestamibi |
26.9 mCi |
40 minutes after-injection |
Target heart rate (85% of maximum heart rate): 149 bpm. Maximal heart rate
achieved on treadmill: 121 bpm.
|
Imaging Analysis |
| |
This data was reconstructed and reformatted using the ECToolbox.
Slices were reviewed in the Planar/ Slice review. Slices were automatically
aligned (since the data had already been processed with CEqual) and normalized
to the maximum in the myocardium. There is a handy button on this review
“change map” which makes it easy to switch maps from color
to black and white as needed to review the slices.
|
|
If the color map of the projection images is changed to inverse,
the rest projection images clearly show the hotter counts on the lower border
of the heart to come from a loop of bowel behind the heart (views 15 and
39).
Note: Reconstruction and reformatting could have been done by QGS/QPS,
Cardiac SPECT, or the ECToolbox (they all use the same format)
or by the MyoSPECT protocol.
|
|
| This data was processed with the CEqual option of the ECToolbox.
The reversible nature of the defect is clearly seen in the CEqual plots
and SSS scores, and is affirmed in the Perfex results available on the Plot
review. |
|
The deep teal color in the standard deviation polar plots emphasizes the
severity of this defect (7-8 SD below normal); the extent scores show the
size of the defect as well as the total per cent of the myocardium affected.
The blackout 3D with superimposed arteries visually reaffirms the location
and extent of the defect.
|
|
| This data was further processed with QGS to give additional gated
and 3D information. QGS will use as input the slices created in the ECToolbox.
There is no need to reconstruct the data in QGS. The totally automatic wire
mesh surfaces give a good global impression of the heart's motion. The reference
static and beating 3D surfaces in Views are also helpful. The QGS beating
slices and wire mesh surfaces show moderate wall motion.
|
|
The reversible nature of the defect can be seen on the 2D and 3D perfusion
surfaces.
|
|
| MyoSPECT was then used to show all three sets of slices at one
time - rest, stress, and stress gated. Since the slices were already
created, there was no need to reconstruct them in MyoSPECT. The slices can
easily be aligned in MyoSPECT by dragging the appropriate dataset. The number
of slices to be viewed can be selected right in the work area. Contours
and beating slices can be shown on this review. 3D surfaces and plots can
be added, and they visually reinforce the reversible nature of the defect.
EKG Results
The EKG showed 2.2 mm of ST depression in AVF, and 1.8 mm of ST elevation
in V2. Findings were consistent with inferior wall ischemia.
Findings
There was a large zone of stress-induced ischemia in the anterior wall
and septum. Left ventricular function was normal. Cardiac catheterization
revealed 95% stenosis of LAD (mid segment). A stent was placed at the
site of narrowing, and the patient now has a 0% stenosis. |
|
| |
Images courtesy of:
Oconomowoc Memorial Hospital, Oconomowoc, WI
|
