Endoleak detection after endovascular aneurysm repair using unenhanced MRI with flow suppression technique: Feasibility study in comparison with contrast-enhanced CT

To evaluate the feasibility of unenhanced motion-sensitized-driven equilibrium (MSDE)-prepared balanced turbo field echo (BTFE) sequences for detecting endoleaks after endovascular aneurysm repair (EVAR). Forty-six patients treated with EVAR for aortic and/or iliac arterial aneurysms underwent contrast-enhanced CT and MSDE-prepared BTFE sequences with and without flow suppression. Two independent observers reviewed these sequences and their subtraction images and assigned confidence levels for detecting endoleaks. Relative contrast values were calculated by dividing signal intensities by those of paraspinal muscles. CT provided the reference standard. CT showed types I and II endoleaks in one and ten patients, respectively. Areas under receiver operating characteristic curves were 0.92 and 0.97 for observers 1 and 2, respectively. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of both observers were 91 (10/11), 91(32/35), 91 (42/46), 77 (10/13) and 97 % (32/33), respectively. Relative contrast values of endoleaks and flowing blood significantly decreased by flow suppression on MSDE-prepared BTFE images (P = 0.002 and P < 0.0001 respectively), and were significantly higher than those of the excluded aneurysms on subtraction images (P = 0.003 and P = 0.001, respectively). Unenhanced MSDE-prepared BTFE sequences are feasible for detecting endoleaks. aEuro cent Flow suppression significantly reduces endoleak signals on MSDE-prepared BTFE images. aEuro cent Subtraction images of MSDE-prepared BTFE sequences +/- flow suppression demonstrate endoleaks. aEuro cent MSDE-prepared BTFE sequences indicate high diagnostic values (> 90 %) except PPV (77 %). aEuro cent MSDE-prepared BTFE sequences need further refinement to reduce false positives. aEuro cent Endoleaks can be detected without contrast injection using MSDE-prepared BTFE sequences.