Abstract 389: Detection of Coronary Artery Disease With 3T Contrast-enhanced Whole Heart MR Coronary Angiography
PURPOSE Whole heart MR coronary angiography (MRCA) allows for non-invasive assessments of coronary artery disease (CAD). Recently, high diagnostic accuracy was reported by employing inversion recovery 3T MRCA. However, this approach requires continuous infusion of high dose gadolinium contrast medium. The purpose of this study was to evaluate the feasibility and accuracy of 3T whole heart MRCA performed as part of a comprehensive CMR study by acquiring MRCA after late gadolinium enhanced (LGE) MRI.
METHOD AND MATERIALS Ninety patients with suspected CAD underwent free-breathing whole heart CE-MRCA with a 3T MR scanner and 32 channel cardiac coils. MRCA was obtained using a T2-prepared, fat suppressed 3D-TFE sequence (TR/TE/FA of 4.2ms/2.1ms/20deg.) following acquisition of cine MRI and LGE MRI (0.15mmol/kg of Gd-DTPA). Acquisition window was optimized in each patient using high temporal resolution axial cine MR images in order to obtain motion-free images of the coronary arteries. Image quality was assessed on a 4-point scale (1=poor, 2=moderate, 3=good, 4=excellent). Diagnostic accuracy of CE-MRCA was evaluated in 42 patients who underwent X-ray coronary angiogram within 2 weeks from MRI.
RESULTS Whole heart CE-MRCA was successfully completed in all patients with an average acquisition window of 57±30ms and an average total scan time of 9.2±3.8 minutes. CE-MRCA was obtained during diastole in 59 and systole in 31 patients. The mean image quality score was 3.9±0.4, 3.7±0.6, and 3.3±0.8 in the proximal, middle, and distal coronary artery segments, respectively. The sensitivity, specificity, PPV, NPV and accuracy of CE-MRCA for detecting significant CAD were 89% (16/18), 92% (22/24), 89% (16/18), 92% (22/24) and 91% (38/42) by patient-based analysis. No significant difference was observed between patients with lower HR (n=24, 45– 68bpm, mean 62bpm) and those with higher HR (n=18, 70 –90bpm, mean 76bpm) in the sensitivity (91% vs 86%) and specificity (92% vs 91%).
CONCLUSION CE-MRCA performed as part of comprehensive CMR study can provide a reliable detection of coronary arterial stenoses regardless of HR. With high study success rate and negative predictive value of CE-MRCA, 3T CMR is well suited for ruling out significant CAD.