Simultaneous Highly Efficient Contrast-Free Lumen and Vessel Wall MR Imaging for Anatomical Assessment of Aortic Disease

Abstract

Background: Bright-blood lumen and black-blood vessel wall imaging are required for the comprehensive assessment of aortic disease. These images are usually acquired separately, resulting in long examinations and potential misregistration between images.Purpose: To characterize the performance of an accelerated and respiratory motion-compensated three-dimensional (3D) cardiac MRI technique for simultaneous contrast-free aortic lumen and vessel wall imaging with an interleaved T2 and inversion recovery prepared sequence (iT2Prep-BOOST).Study Type: Prospective. Population: A total of 30 consecutive patients with aortopathy referred for a clinically indicated cardiac MRI examination (9 females, mean age +/- standard deviation: 32 +/- 12 years).Field Strength/Sequence: 1.5-T; bright-blood MR angiography (diaphragmatic navigator-gated T2-prepared 3D balanced steady-state free precession [bSSFP], T2Prep-bSSFP), breath-held black-blood two-dimensional (2D) half acquisition single shot turbo spin echo (HASTE), and 3D bSSFP iT2Prep-BOOST.Assessment: iT2Prep-BOOST bright-blood images were compared to T2prep-bSSFP images in terms of aortic vessel dimensions, lumen-to-myocardium contrast ratio (CR), and image quality (diagnostic confidence, vessel sharpness and presence of artifacts, assessed by three cardiologists on a 4-point scale, 1: nondiagnostic to 4: excellent). The iT2PrepBOOST black-blood images were compared to 2D HASTE images for quantification of wall thickness. A visual comparison between computed tomography (CT) and iT2Prep-BOOST was performed in a patient with chronic aortic dissection. Statistical Tests: Paired t-tests, Wilcoxon signed-rank tests, intraclass correlation coefficient (ICC), Bland-Altman analysis. A P value < 0.05 was considered statistically significant.Results: Bright-blood iT2Prep-BOOST resulted in significantly improved image quality (mean +/- standard deviation 3.8 +/- 0.5 vs. 3.3 +/- 0.8) and CR (2.9 +/- 0.8 vs. 1.8 +/- 0.5) compared with T2Prep-bSSFP, with a shorter scan time (7.8 +/- 1.7 minutes vs. 12.9 +/- 3.4 minutes) while providing a complementary 3D black-blood image. Aortic lumen diameter and vessel wall thickness measurements in bright-blood and black-blood images were in good agreement with T2PrepbSSFP and HASTE images (< 0.02 cm and 0.96) and interreader (ICC > 0.94) agreement was observed for all measurements.