- Thallium shows myocardial perfusion (or blood flow to the heart muscle). In addition,
- the thallium scan can show the function of the heart (the left ventricular ejection
- fraction- LVEF- or the percentage of blood the heart pumps out to the body with each
- heart beat). This is done by "gating" the stress images with the electrocardiogram.
- The resulting images can be displayed in real time to see left ventricular wall motion
- and the LVEF can be calculated from the end diastolic (ED) image and the end
- systolic image (ES). Viewing wall motion in junction with the perfusion images
- can help the interpreter decide whether a fixed defect is due to myocardial
- infarction (there will be lack of wall motion in the infarcted wall) or artifact (there
- will be normal wall motion in the affected wall).
-
|
 Normal |
- This example shows the vertical long axis end diastolic (ED) image at the upper left,
- the horizontal long axis ED image at upper right, the vertical long axis end systolic (ES)
- image at lower left and the horizontal long axis ES image at lower right. Compared to
- the ED images, the ES images are thicker and brighter in the anterior, apical,
- lateral and inferior walls, signifying normal wall motion and LVEF (the LVEF in
- this case was 66%).
|
 Apical Myocardial Infarction |
- This is an example of apical akinesis. The anterior, lateral and inferior walls
- all thicken and brighten in systole. There is no activity (no yellow) in the
- apex, both with diastole and systole signifying myocardial infarction.
|
 Inferior Myocardial Infarction |
- This is an example of an inferior myocardial infarction. The anterior, apical
- and lateral walls all thicken and brighten with systole. There is no activity in
- the inferior wall, an inferior MI.
|
| |
| |
