Unenhanced Velocity-Selective MR Angiography (VS-MRA): Initial Clinical Evaluation in Patients With Peripheral Artery Disease

Taehoon Shin; Rajiv G Menon; Rahul B Thomas; Armando U Cavallo; Rajabraka Sarkar; Robert S Crawford; Sanjay Rajagopalan

doi:10.1002/jmri.26268

Unenhanced Velocity-Selective MR Angiography (VS-MRA): Initial Clinical Evaluation in Patients With Peripheral Artery Disease

J Magn Reson Imaging. 2019 Mar;49(3):744-751. doi: 10.1002/jmri.26268. Epub 2018 Sep 13.

Authors

Taehoon Shin^{1

2}, Rajiv G Menon^{2

3}, Rahul B Thomas⁴, Armando U Cavallo^{4

5}, Rajabraka Sarkar⁶, Robert S Crawford⁶, Sanjay Rajagopalan^{4

7}

Affiliations

¹ Division of Mechanical and Biomedical Engineering, Ewha Womans University, Seoul, South Korea.
² Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, Maryland, USA.
³ Department of Radiology, New York University, New York, New York, USA.
⁴ Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA.
⁵ Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiation Therapy, Policlinico "Tor Vergata", Rome, Italy.
⁶ Division of Vascular and Endovascular Surgery, University of Maryland, Baltimore, Maryland, USA.
⁷ Division of Cardiovascular Medicine, University of Maryland, Baltimore, Maryland, USA.

Abstract

Background: Safe and accurate imaging of the peripheral arterial system is important for diagnosis and treatment planning of patients with peripheral artery disease (PAD).

Purpose: To evaluate image quality and diagnostic performance of unenhanced magnetic resonance angiography (MRA) based on velocity-selective (VS) magnetization preparation (termed VS-MRA).

Study type: Prospective.

Population: Thirty-one symptomatic PAD patients underwent VS-MRA. Twenty-four of them underwent clinical digital subtraction angiography (DSA) examination, 18.8 ± 5.2 days after the MR scans.

Field strength/sequence: 1.5T MRI that included VS-MRA (homemade research sequence) and phase-contrast flow imaging (clinical sequence).

Assessment: Image quality (0: nondiagnostic, 3: excellent) and stenosis severity (0: normal, 3: occlusion) of VS-MRA images were assessed independently by three reviewers. Arterial signal-to-noise-ratio (SNR) and artery-to-muscle contrast-to-noise ratio (CNR) were calculated.

Statistical tests: The sensitivity and specificity of VS-MRA were calculated for the detection of significant stenosis (>50%) with DSA as the reference standard. Interobserver agreement among the three reviewers was evaluated by using Cohen κ-statistics.

Results: The image quality score of VS-MRA was 2.7 ± 0.5 for Reader 1, 2.8 ± 0.5 for Reader 2, and 2.8 ± 0.4 for Reader 3; SNR and CNR were 37.8 ± 12.5 and 30.5 ± 11.8, respectively. Segment-based analysis revealed that VS-MRA had sensitivities of 85.3%, 74.5%, and 78.4%, respectively, for the three reviewers, and specificities of 93.5%, 96.8%, and 95.2%. The interobserver agreement for the stenosis grading was good, as demonstrated by Cohen κ values of 0.76 (Reader 1 vs. Reader 2), 0.82 (Reader 1 vs. Reader 3), and 0.79 (Reader 2 vs. Reader 3).

Data conclusion: Unenhanced VS-MRA allows clear depiction of the peripheral arteries and accurate stenosis grading, as evidenced by high image quality scores and strong agreement with DSA.

Level of evidence: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:744-751.

Keywords: peripheral artery disease; unenhanced MRA; velocity-selective magnetization preparation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Angiography, Digital Subtraction*
Contrast Media / chemistry
Female
Humans
Image Processing, Computer-Assisted / methods*
Magnetic Resonance Angiography*
Male
Middle Aged
Peripheral Arterial Disease / diagnostic imaging*
Prospective Studies
Reproducibility of Results
Sensitivity and Specificity

Substances

Contrast Media

Abstract

Publication types

MeSH terms

Substances

Grants and funding