[Comparison of acceptance tests for SPECT systems in Tehran]

Acceptance test is a necessary procedure after SPECT system installation. The goal of this test is to reveal system's present condition, to compare it with manufacturer's specifications and also as a base for later tests. This study investigated four SPECT systems in Tehran. All of the quality control tests are performed on the basis of NEMA and IAEA recommendations and by a same group. These tests include intrinsic spatial resolution, intrinsic energy resolution, temporal resolution, intrinsic linearity, maximum count rate, pixel size, intrinsic and extrinsic uniformity, sensitivity, reconstruction spatial resolution with and without scatter and centre of rotation. Results of this investigation show that three systems have minimum acceptance conditions, but the fourth one due to it's suboptimal energy resolution and spatial resolution lacked the required specifications for acceptance. It was shown during the next six months after installation that this system showed frequent impairments and even had been out of service for a while. However, other systems did not show any considerable problems. The acceptance test is an essential step after installation of any SPECT system. If there is no considerable deficits at the initial acceptance test of a SPECT system, it won't become troublesome for a long time

Correlation of semiquantitative Tc99m- pyrophosphate myocardial SPECT with the quantities of LVEF in determining the extent and intensity of acute MI

This study was performed to evaluate the Tc-pyp SPECT role in determination of AMI severity and extension. Pyp SPECT imaging was done for 54 patients with AMI, who met the WHO criteria. SPECT findings were correlated with LVEF measurements. The abnormal scan was graded according to the intensity and was compared with the activity of the sternum in the same image. In addition, a segmental myocardial model was used for location determination of abnormal tracer uptake. Resting LVEF was determined by 2D echocardiography in each patient 2 weeks after onset of pain. 79 patients had positive pyp SPECT scans. According to pyp uptake intensity, good correlation between severity and extension of pyp uptake and LVEF was seen. These factors can be considered suitable for prognosis estimation in early post AMI period