BACKGROUND: There are various physical factors that limit the
quality of the Single Photon Emission Computed Tomography (SPECT) images
such as number of frames per projection, number of projections per scan and
time per projection in gated myocardial SPECT scan.
OBJECTIVE: The aim of the present work was to evaluate physical
acquisition parameters affecting the cardiac imaging to optimize the
patient's examination time and image quality that are acquired with the
gamma camera and workers radiation protection (through reducing time of
radiation exposure) in cardiac SPECT facility. Cardiac functional parameters
like ejection fraction (EF), end diastole volume (EDV), end systole volume
(ESV) and total perfusion defect (TPD) were evaluated.
METHODS: Thirty patients were divided into three groups as follows:
1- Group (1): contains two sub-groups, one scanned with 8 frames per projection, the other with 16 frames per projection.
2- Group (2): contains two sub-groups, one scanned with 32 projections per scan, the other with 16 projections per scan.
3- Group (3): contains two sub-groups, one scanned at a time per projection of 20 s and the other scanned at 10 s per projection.
Parameters such as the Ejection Fraction (EF), End Diastole Volume (EDV),
End Systole Volume (ESV) and Total Perfusion Defect (TPD) in SPECT were
compared for each group.
RESULTS: There was insignificant difference in the EF, EDV, ESV and
TPD between the different groups concerning the number of frames per
projection, number of projections per scan and time per projection.
CONCLUSION: The reduction of scan time to half or the number of
projections per scan to half or increasing the number of frames per scan
from 8 to 16 at the same duration has insignificant effect in the cardiac
functional parameters used with gated SPECT scan.
