Rapid High-resolution, Self-registered, Dual Lumen-contrast MRI Method for Vessel-wall Assessment in Peripheral Artery Disease:: A Preliminary Investigation

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• 作者：Michael C. Langham ; PhD^a ; Benoit Desjardins ; MD ; PhD^a ; Erin K. Englund ; BE^a ; Emile R. Mohler III ; MD^b ; Thomas F. Floyd ; MD^c ; Felix W. Wehrli ; PhD^a ; ^{wehrli@mail.med.upenn.edu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Black-blood imaging ; gray-blood imaging ; vessel-wall imaging ; calcification ; double-echo steady-state ; peripheral artery disease ; SSFP-FID ; SSFP-Echo ; angiography
• 刊名：Academic Radiology
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：23
• 期：4
• 页码：457-467
• 全文大小：2700 K

文摘

Contrast-enhanced angiographic evaluation by magnetic resonance imaging (MRI) and computed tomography (CT) is the reference standard for assessing peripheral artery disease (PAD). However, because PAD and diabetes often coexist, the prevalence of renal insufficiency is a major challenge to contrast-based angiography. The objective of this work is to describe and demonstrate a new application of three-dimensional double-echo steady-state (3D DESS) as a noncontrast vascular MRI method for evaluating peripheral atherosclerosis at 3 Tesla (3T).

Materials and Methods

A water-selective 3D DESS pulse sequence was designed to simultaneously collect two steady-state free-precession signals (free induction decay and Echo) yielding “black blood” (BB) and “gray blood” (GB) images. For completeness Bloch equation, simulations were performed to characterize DESS signals of various tissues including blood at different velocities and to assess two healthy subjects for the purpose of pulse sequence optimization. Exploratory studies were performed as an add-on protocol to an existing study involving patients with PAD. To evaluate the method's specificity for detecting calcification, images from select patients were compared against CT angiography.

Results

Simulations agreed qualitatively with in vivo images supporting DESS' potential for generating distinct lumen contrast (GB vs BB). Lesions representing calcium were easily identifiable on the basis of signal void occurring on both image types and were confirmed by CT angiography. Further, BB allowed visualization of stent restenosis, and data suggest its ability to visualize acute thrombus by virtue of T2 weighting.

Conclusion

Preliminary investigation and results suggest noncontrast 3D DESS to have the potential to improve diagnosis of PAD patients by providing detailed structural assessment of vessel-wall architecture.