Combined assessment of subtended myocardial volume and myocardial blood flow for diagnosis of obstructive coronary artery disease using cardiac computed tomography: A feasibility study

Abstract

Background: This study aimed to evaluate the combined diagnostic performance of coronary artery stenosis-subtended myocardial volume (V sub ) and myocardial blood flow (MBFsub) on computed tomography (CT) for detecting obstructive coronary artery disease (CAD) assessed by invasive coronary angiography (ICA) and fractional flow reserve (FFR). Methods: Thirty-nine patients who underwent coronary CT angiography (CTA) and stress dynamic myocardial CT perfusion (CTP) prior to ICA were enrolled. Obstructive CAD was defined as severe (!70%) or moderate (30-69%) stenosis with FFR 0.8 on ICA. The V sub was semi-automatically calculated from coronary CTA data using Voronoi diagram-based myocardial segmentation. The standard CT-MBF based on the 17-segment model was calculated using dynamic stress CTP data and deconvolution analysis. The CT-MBFsub was automatically analyzed by integrating the CT-MBF and Voronoi diagram-based myocardial segmentation analyses. The diagnostic performance of combined CT-MBFsub and V sub assessment was determined using receiver operating characteristic analysis and compared with standard CT-MBF and CT-MBFsub. Results: Of 117 vessels in 39 patients, 72 vessels were suspected of significant stenosis on CTA and 33 vessels had obstructive CAD on ICA and FFR. The sensitivity and specificity for identifying obstructive CAD were 67% and 82% for standard CT-MBF, 70% and 77% for CT-MBFsub, and 85% and 82% for combined CT-MBFsub and V sub assessment. The area under the receiver operating characteristic curve of the combined CT-MBFsub and V sub assessment was significantly higher than those of standard CT-MBF and CT-MBFsub (0.89 vs. 0.75, 0.77; p < 0.05). Conclusions: The V sub may aid in increasing the diagnostic performance of CT-MBFsub for detecting obstructive CAD.

Correlation between quantification of myocardial area at risk and ischemic burden at cardiac computed tomography

“…For instance, in a study by Tanabe et al the combined diagnostic performance of coronary artery stenosis-subtended myocardial volume and myocardial blood flow (MBF) on CTP for detecting obstructive coronary artery disease was assessed. It was found that the AUC of the combined use of the subtended CTP myocardial blood flow and subtended mass was significantly higher than that of myocardial blood flow alone in the detection of hemodynamically significant stenoses (0.89 vs. 0.75, 0.77; p < 0.05) [18] .…”

Incremental value of volumetric quantification for myocardial perfusion imaging by computed tomography

“…There have been some studies that investigated the prognostic value of dynamic CTP, but none of them have analyzed volumetric ischemia assessment [20][21][22][23][24][25]. Tanabe et al [7], in a small study (39 patients), investigated the expected MBF from Voronoi-diagram-based myocardial segmentation but did not evaluate the true percentage of myocardial ischemia. As shown in the meta-analysis conducted by Pontone et al, positive stress myocardial CTP added to coronary CTA has a very high diagnostic performance in identifying a functionally significant coronary lesion in a patient-based model [26].…”

“…CT-FFR does not offer such an assessment, but volumetric ischemia assessment may theoretically be done via CTP. Despite the potential added clinical value of volumetric perfusion deficits, the previous studies on CTP have not addressed this issue [7].…”

Quantification Of Myocardial Ischemia And Subtended Myocardial Mass At Adenosine Stress Cardiac Computed Tomography. A Feasibility Study.

“…A Voronoi-based segmentation algorithm was also used for calculating subtended myocardial volume yielding an average of 42.7 mL for obstructive CAD. Our average subtended mass per lesion (36 g) is only slightly lower when taking into account average density of myocardial tissue of 1055 g/mL to convert mass to volume [21,22]. This could be due to the fact that contrary to Tanabe no ICA was used for verifying the hemodynamical significance of the relevant coronary artery lesion(s).…”