corrected coronary opacification decrease from coronary computed tomography angiography: validation with quantitative 13n-ammonia positron emission tomography

To assess the functional relevance of a coronary artery stenosis, corrected coronary opacification (cco) decrease derived from coronary computed tomography angiography (ccta) has been proposed. the present study aims at validating cco decrease with quantitative 13n-ammonia positron emission tomography (pet) myocardial perfusion imaging (mpi). this retrospective study consists of 39 patients who underwent hybrid ccta/pet-mpi. from ccta, attenuation in the coronary lumen was measured before and after a stenosis and corrected to the aorta to calculate cco and its decrease. relative flow reserve (rfr) was calculated by dividing the stress myocardial blood flow (mbf) of a vessel territory subtended by a stenotic coronary by the stress mbf of the reference territories without stenoses. rfr was abnormal in 11 vessel territories (27%). cco decrease yielded a sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for prediction of an abnormal rfr of 73%, 70%, 88%, 47%, and 70%, respectively. ccta-derived cco decrease has moderate diagnostic accuracy to predict an abnormal rfr in pet-mpi. however, its high negative predictive value to rule out functional relevance of a given lesion confer clinical implications in the diagnostic work-up of patients with a coronary stenosis.