3D fusion of coronary CT angiography and CT myocardial perfusion imaging: Intuitive assessment of morphology and function.

BACKGROUND: The objective of this work was to support three-dimensional fusion of coronary CT angiography (coronary CTA) and CT myocardial perfusion (CT-Perf) data visualizing coronary artery stenoses and corresponding stress-induced myocardial perfusion deficits for diagnostics of coronary artery disease.

METHODS: Twelve patients undergoing coronary CTA/CT-Perf after heart transplantation were included (56 ± 12 years, all males). CT image quality was rated. Coronary diameter stenoses >50% were documented for coronary CTA. Stress-induced perfusion deficits were noted for CT-Perf. A software was implemented facilitating 3D fusion imaging of coronary CTA/CT-Perf data. Coronary arteries and heart contours were segmented automatically. To overcome anatomical mismatch of coronary CTA/CT-Perf image acquisition, perfusion values were projected on the left ventricle as visualized in coronary CTA. Three resulting datasets (coronary tree/heart contour/perfusion values) were fused for combined three-dimensional rendering. 3D fusion was compared with conventional analysis of coronary CTA/CT-Perf data and to results from catheter coronary angiography.

RESULTS: CT image quality was rated good-excellent (3.5 ± 0.5, scale 1-4). 3D fusion imaging of coronary CTA/CT-Perf data was feasible in 11/12 patients (92%). One patient (8%) was excluded from further analysis due to severe motion artifacts. 2 of 11 remaining patients (18%) showed both stress-induced perfusion deficits and relevant coronary stenoses. Using 3D fusion imaging, the ischemic region could be correlated to a culprit coronary lesion in one case (1/2 = 50%) and diagnostic findings could be rectified in the other case (1/2 = 50%). Coronary CTA was in full correspondence with catheter coronary angiography.

CONCLUSION: A method for 3D fusion of coronary CTA/CT-Perf is introduced correlating relevant coronary lesions and corresponding stress-induced myocardial perfusion deficits.