Hybrid quantitative H215O PET/CT imaging for the detection of coronary artery disease

Objectives Accurate noninvasive assessment of coronary artery disease (CAD) and its functional consequences is a challenging task. CT coronary angiography (CTCA) accurately rules out obstructive CAD while functional assessment is needed in the presence of obstructive CAD. Combining coronary anatomy and perfusion can yield complementary information and may reduce the number of diagnostic invasive coronary angiographies (ICA). The present study evaluates the accuracy of quantitative hybrid H215O PET/CT imaging compared to stand alone imaging in patients suspected of CAD.

Methods A total of 120 patients (mean age 61 ± 10 years, 77 men) with a predominantly intermediate pre-test likelihood (55 % ± 30) for CAD underwent both hybrid quantitative PET/CT imaging and ICA. A stenosis ≥50% at ICA was considered significant.

Results Obstructive CAD was diagnosed in 49 patients (41%). On a per patient basis, sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and diagnostic accuracy of CTCA were 100, 34, 100, 51, and 61%, respectively, as compared to 76, 83, 83, 76, and 80%, respectively, for H215O PET with a cut-off value of 1.86 mL/min/g. Quantitative hybrid PET/CT reduced the number of false positive CTCA studies from 47 to 6, although 12 out of 49 true positive CTCAs were incorrectly reclassified as false negative hybrid scans based on (presumably) sufficient MBF. Diagnostic accuracy for hybrid imaging was significantly improved (85%) compared to CTCA (61%) or PET (80%) alone (both p<0.05). Sensitivity, specificity, NPV, and PPV were 76, 92, 84, and 86%, respectively, for hybrid PET/CT.

Conclusions Diagnostic accuracy of quantitative hybrid PET/CT is superior to either H215O PET or CTCA alone for detection of obstructive CAD