Online guidelineMyocardial perfusion and function single photon emission computed tomography
Section snippets
Acquisition protocols
Protocols for the various nuclear cardiology single photon emission computed tomography (SPECT) acquisition studies are presented in the following pages. For each of the protocols, the acquisition parameters are listed along with their corresponding value for exercise and rest. Implementation of these protocol acquisition parameters has been shown to provide acceptable images of good quality for routine clinical interpretation and quantitation. However, protocol parameters other than those
Processing protocols
Empty Cell Rest study Stress study Empty Cell For information, see paragraph Dose 8–12 mCi 24–36 mCi Standard 1 Position Supine Supine Standard 2 Prone Prone Optional 2 Upright/semiupright Upright/semiupright Optional Delay time (intervals) Injection → imaging 30–60 min 15 min to 1 h Standard 3 Rest → stress 30 min to 4 h Standard 3 Acquisition protocol Energy window 15%–20% symmetric Same Standard 4 Collimator LEHR Same Preferred 5 Orbit 180° (45° RAO to 45° LPO) Same Preferred 6 Orbit type Circular Same
Perfusion quantitation
The display medium and translation table employed can have a significant impact on image interpretation going as far as to make a normal perfusion scan appear abnormal or vice versa. Quantitative analysis is a direct way of measuring relative uptake of a perfusion tracer that is independent of the display medium and translation table and can thus greatly reduce variations in interpretation due to subjective analysis and inconsistent image display. Quantitative analysis also allows for the
Gated SPECT
Acquisition. The introduction of technetium-based perfusion tracers has resulted in images with sufficient count density to allow for cardiac gating adding parameters of wall motion and EF to myocardial perfusion imaging. Gating requires a stable and consistent heart rhythm as well as sufficient temporal resolution to correctly characterize the cardiac cycle. A stable heart rate and rhythm can be achieved by rejecting heartbeats that fall out of range at the expense of a slight increase in
General Comments
The interpretation of myocardial perfusion SPECT images should be performed in a systematic fashion to include (1) repeat evaluation of the raw tomographic images to determine the presence of technical sources of abnormalities and extracardiac activity; (2) acquisition of additional views when appropriate; (3) interpretation of images with respect to the extent and severity of perfusion abnormalities that are believed to be present, as well as chamber sizes and, when appropriate, pulmonary
Gated myocardial perfusion SPECT
Because of the comparatively low additional cost and substantial benefit of the information obtained, gated studies of ventricular function should be a routine part of myocardial perfusion SPECT. A systematic approach to display and interpretation of the ventricular function derived from gated SPECT is important.
- 17
Gated SPECT display. Multiple ventricular slices should be evaluated. At a minimum, a quad-screen display of apical and mid-basal short-axis, a mid-ventricular horizontal long-axis, and