Corrected coronary opacification decrease from coronary computed tomography angiography: Validation with quantitative 13N-ammonia positron emission tomography

Abstract

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 may confer clinical implications in the diagnostic work-up of patients with a coronary stenosis.

Added Value of Transluminal Attenuation Gradient to Qualitative CCTA Ischemia Detection as Determined by 13N-ammonia PET Quantitative Myocardial Perfusion

“…Because the study of Bom et al was performed with a 256-slice CT scanner (Brilliance iCT, Philips Healthcare, Best, The Netherlands) [ 7 ], the current study also demonstrates that their results can similarly be extrapolated to a 64-Multislice scanner and ischemia according to stress MBF measured by 13 N-ammonia PET. Benz et al has previously described the relationship between corrected coronary opacification and 13 N-ammonia PET [ 18 ]. Their results suggest that attenuation of contrast in the coronary artery may be of value in the diagnostic workup of coronary stenosis.…”

Anatomy and physiology in coronary artery disease imaging

“…17 As for CO and CCO, it is a parameter that can be calculated even without sophisticated software and the assessment is implemented into the most advanced processing software available on the market. This is the first study to compare CCO with stress Myocardial Blood Flow (MBF) and to report on its ability to predict abnormal Relative Flow Reserve (RFR) 16 ; the study shows that the presence of an abnormal CCO decrease is associated with significantly lower RFR even though with moderate diagnostic accuracy; however, the absence of CCO decrease excludes an abnormal RFR with high negative predictive value. Hence, one may elaborate that adding this parameter to conventional anatomical CCT assessment may impact significantly (i.e., reduce) the prevalence of false positives (i.e., specificity and positive predictive value).…”

“…16 Coronary Opacification (CO) difference (i.e., difference of luminal attenuation across a coronary stenosis in Hounsfield Units) was the first ''flow parameter'' derived from CCT and it was further improved into ''Corrected Coronary Opacification'' (CCO) difference; these parameters are related to abnormal resting coronary blood flow. Transluminal Attenuation Gradient (TAG) is considered as a more recent and accurate version of CO and CCO; it reflects the kinetics of iodinated contrast media within the coronary arteries and across stenosis and it seems to be a reproducible method.…”

“…The Authors of the current paper did not provide this kind of analysis, and in fact it would be quite interesting to see; from the clinical standpoint, all patients who would get a CCO evaluation would anyway get also a conventional CCT stenosis assessment. 16 CT-derived Fractional Flow Reserve (FFRct) is a computational fluid dynamics simulation of adenosinemediated hyperemia applied to CCT imaging. As for TAG, one of the main parameters is attenuation through the coronary artery associated with morphology of the vessel lumen and other parameters.…”

Fractional flow reserve as the standard of reference: All that glistens is not gold

“…16 Thanks to significant reduction in radiation exposure from coronary CT angiography, [25][26][27] coronary lesions of younger and healthier patients are now being tested by CT-FFR or other CT-derived measurements. [28][29][30] As a consequence, the interaction between lesion-specific ischemia and myocardial blood flow warrants further investigation to prevent overestimation of coronary lesions.…”