Prospective, intraindividual comparison of MRI versus MDCT for endoleak detection after endovascular repair of abdominal aortic aneurysms

Abstract

This study compares MRI and MDCT for endoleak detection after endovascular repair of abdominal aortic aneurysms (EVAR). Forty-three patients with previous EVAR underwent both MRI (2D T1-FFE unenhanced and contrast-enhanced; 3D triphasic contrast-enhanced) and 16-slice MDCT (unenhanced and biphasic contrast-enhanced) within 1 week of each other for endoleak detection. MRI was performed by using a high-relaxivity contrast medium (gadobenate dimeglumine, MultiHance). Two blinded, independent observers evaluated MRI and MDCT separately. Consensus reading of MRI and MDCT studies was defined as reference standard. Sensitivity, specificity, and accuracy were calculated and Cohen's k statistics were used to estimate agreement between readers. Twenty endoleaks were detected in 18 patients at consensus reading (12 type II and 8 indeterminate endoleaks). Sensitivity, specificity, and accuracy for endoleak detection were 100%, 92%, and 96%, respectively, for reader 1 (95%, 81%, 87% for reader 2) for MRI and 55%, 100%, and 80% for reader 1 (60%, 100%, 82% for reader 2) for MDCT. Interobserver agreement was excellent for MDCT (k = 0.96) and good for MRI (k = 0.81). MRI with the use of a high-relaxivity contrast agent is significantly superior in the detection of endoleaks after EVAR compared with MDCT. MRI may therefore become the preferred technique for patient follow-up after EVAR.

Reporting standards for thoracic endovascular aortic repair (TEVAR)

“…45 MR imaging, especially delayed imaging with gadolinium or blood-pool contrast enhancement, has been reported to be particularly sensitive and useful as a means of detecting endoleak. 46,47 The sensitivity and specificity of available imaging methods for endoleak detection have not been characterized well, in part because some stent grafts are not MR-compatible. Dynamic CT or dynamic MR can quantify aneurysm morphology over time, and have been suggested as another means to evaluate for potential sac pressurization.…”

Magnetic Resonance Imaging with a Weak Albumin Binding Contrast Agent can Reveal Additional Endoleaks in Patients with an Enlarging Aneurysm after EVAR

“…10 As this contrast agent is available exclusively in the USA, the aim of the present study was to investigate the value of another albumin binding contrast agent. The contrast agent used in the present study, gadobenate dimeglumine, was previously used for endoleak detection by Alerci et al 9 The study by Alerci et al showed that MRI with this albumin binding contrast agent was superior to CTA for endoleak detection, mainly for type II endoleaks. 9 In contrast to Alerci et al, 9 who analyzed a series of patients under follow up after EVAR, the present study investigated a different study population by including only patients with aneurysm growth after EVAR.…”

“…The contrast agent used in the present study, gadobenate dimeglumine, was previously used for endoleak detection by Alerci et al 9 The study by Alerci et al showed that MRI with this albumin binding contrast agent was superior to CTA for endoleak detection, mainly for type II endoleaks. 9 In contrast to Alerci et al, 9 who analyzed a series of patients under follow up after EVAR, the present study investigated a different study population by including only patients with aneurysm growth after EVAR. This inclusion criterion was chosen as a detected endoleak could have consequences for treatment strategy, according to the guidelines as stated earlier, only for this group of patients.…”

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

“…On the other hand, gadoliniumenhanced magnetic resonance (MR) imaging has been reported to be more sensitive to detect endoleaks than contrastenhanced CT in three previous prospective comparative studies [8][9][10]. However, since an association between gadolinium and nephrogenic systemic fibrosis has been demonstrated [11], gadolinium is recommended to be contraindicated or used with caution in patients with renal impairment [12].…”