Abstract 4208: Hemodynamic Relevance of Calcified Coronary Artery Lesions -Non-Invasive Assessment Using Dual-Source CT and Magnetic Resonance Stress Imaging
Multi Detector Computed Tomography (MDCT) permits detection of coronary stenoses, but coronary segments are often unassessable in presence of calcifications. Adenosine-stress cardiac magnetic resonance imaging (cMRI) allows accurate detection of hemodynamical relevant coronary artery disease (CAD) independent from the occurrence of calcified plaques. We examined the feasibility of an combined non-invasive approach for detection of prevalence of hemodynamically relevant CAD masked by calcified plaque using Dual-Source Computed Tomography (DSCT) and adenosine-stress cMRI. 30 patients (22 male, mean age 69.5±10y) with at least one coronary segment unevaluable in coronary CTA (Siemens Somatom Definition, temporal resolution 83 ms) due to calcified plaque, but without stenoses of further segments, underwent adenosine-stress cMRI (Siemens Magnetom Sonata 1.5 Tesla) for exclusion of relevant CAD. CMRI perfusion was performed with a 3-slice TrueFisp sequence and i.v.-application of adenosine at 140μg/kgbw/min and 0.1mmol of Gd-DTPA/kgbw. DSCT and cMRI data sets were analyzed by visual assessment of two readers in consensus using the AHA 15-segment coronary model for CT- and the AHA 16-segment LV-model for MRI- perfusion analysis. Mean heart rate during CT scan was 67±7 bpm, mean Agatston score was 754±560. A total of 65 coronary segments were unevaluable due to calcifications (26 in LAD, 22 in LCX and 17 in RCA, respectively). In cMRI first-pass perfusion imaging, 27 examinations were inconspicuous, 3 patients showed perfusion deficits (one patient in LAD-related segments, one patient in segments referring to LAD and LCX and one patient with a perfusion deficite of an RCA-related segment). There were no perfusion deficiencies in cMRI not resulting from coronary segments heavily calcified in DSCT. DSCT and cMRI showed a correlation of 100 %. The overall prevalence of hemodynamically relevant CAD was 10 %. Adenosine-stress cMR perfusion imaging is a valuable tool for additional exclusion of hemodynamically relevant CAD, if coronary segments are unevaluable due to calcifications in CTA. Prevalence of hemodynamically relevant CAD caused by calcified plaque appears to be low.