Mohsen Saghari - Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Tehran, Iran
Mohammad Taghavi - Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Tehran, Iran
Armaghan Fard-Esfahani - Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Tehran, Iran
Babak Fallahi - Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Tehran, Iran
Mohammad Eftekhari - Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Tehran, Iran

Fixed myocardial defects in both stress and rest images, could be artifactual as a result of soft tissue attenuation. To increase specificity and identify the false positive results, we used gated technique to evaluate the wall motion and wall thickening as an index to differentiate real ischemic lesions from artifactual defects. ۹۳ patients were studied. In ۴۶ patients (۴۸.۸%) fixed perfusion defects were identified. Of these patients ۱۰ (۲۱.۷%) had definite evidence of previous MI, ۶ of whom (۶۰%) showed abnormal gated SPECT findings. Among ۳۶ patients without history of MI, ۱۱ cases (۳۰%) showed abnormal ventricular function (Probably due to silent MI) and ۲۵ patients (۷۰%) had normal function. The latter group was comprised of ۱۳ females (۵۲%) with fixed perfusion defects seen in the anterior, septal and apical segments of the myocardium. He results of the investigation indicate that using gated SPECT method with ۹۹mTc-MIBI myocardial perfusion studies increases specificity of the fixed myocardial defects and is highly recommended.

Gated SPECT, Fixed defect