Prompt-gamma compensation in Rb-82 myocardial perfusion 3D PET/CT

To compare the diagnostic accuracy of Rb-82 myocardial perfusion three-dimensional (3D) PET with and without prompt-gamma compensation (PGC).

Retrospective, single center study of 76 patients who had rest and adenosine stress Rb-82 myocardial perfusion 3D PET. All studies were acquired using a Siemens Biograph-40 PET/CT scanner and were reconstructed with and without PGC. Fifty-seven patients (mean age 63 ± 11 years, 26 men) had coronary angiography within 40 days of Rb-82 imaging. Nineteen patients (mean age 43 ± 7 years, 10 men) had low likelihood of coronary artery disease (CAD). All PET images were scored by consensus of two blinded readers on a standard 5-point scale using a 17-segment left ventricular model. A normal PET test was defined as a summed stress score of less than four. Obstructive CAD at coronary angiography was used as the gold-standard and was defined as luminal stenoses ≥50% in one or more major coronary arteries. The prevalence of obstructive disease at coronary angiography was 68% (39/57). The mean summed stress score was 12 ± 12 for PGC images and was 18 ± 14 for non-PGC images. Sensitivity and specificity for obstructive CAD were 90% (95% CI 88-99) and 72% (95% CI 52-93) for PGC images and 95% (95% CI 88-100) and 22% (95% CI 3-41) for non-PGC images.

PGC in Rb-82 3D PET improves the specificity for obstructive CAD at coronary angiography with no significant loss in sensitivity.