超常磁性体酸化鉄造影MRIを用いた大動脈ステントグラフ治療後のエドリークの検出 : 造影CTとの比較検討

Abstract

OBJECTIVE: Contrast-enhanced computed tomography (CE-CT) has been commonly used for follow-up imaging after endovascular aneurysm repair (EVAR), but it is difficult to use on patients with renal insufficiency. Superparamagnetic iron oxide (SPIO) particles, contrast medium for magnetic resonance imaging (MRI) that has been widely used for detection of the liver tumor, rarely affects renal function. The present study examined SPIO-enhanced dynamic MRI as a potential alternative to CE-CT for detection of endoleaks after EVAR. METHODS: Institutional review board approval was obtained for this prospective study. Twenty-three consecutive patients with normal renal function were evaluated using both CE-CT and SPIO-enhanced MRI within 2 weeks after EVAR. The median interval between the two modalities was 2 days. SPIO-enhanced MRI was performed at 1.5 T with T1-weighted, SPIO-enhanced dynamic, and postcontrast T1-weighted gradient echo sequences. The CE-CT protocol consisted of triple scans. Two experienced, blinded observers evaluated all images. Consensus reading of CE-CT and SPIO-MRI was defined as the reference standard. Interobserver, intraobserver, and intermodality agreement for endoleak detection was assessed by κ statistics. RESULTS: A total of 11 type II endoleaks originating from either the lumbar or inferior mesenteric artery were detected. Eight were able to be detected by CE-CT (8/11:73%) and 10 (10/11:91%) by SPIO-enhanced MRI. Interobserver (κ = 0.91; 95% CI, 0.74-1.00) and intraobserver agreement for MRI (κ = 1.00) were excellent. Intermodality agreement for endoleak detection was moderate (κ = 0.63; 95% CI, 0.32-0.94; and κ = 0.62; 95% CI, 0.29-0.95 for observers A and B, respectively). CONCLUSIONS: SPIO-enhanced MRI could represent a useful alternative to CE-CT, as it offers excellent interobserver, intraobserver agreement, and could detect more endoleaks than CE-CT.博士（医学）・乙第1379号・平成28年7月8日Copyright © 2013 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved