Diagnostic accuracy of non-contrast quiescent-interval slice-selective (QISS) MRA combined with MRI-based vascular calcification visualization for the assessment of arterial stenosis in patients with lower extremity peripheral artery disease

• Published in: European radiology Vol. 31; no. 5; pp. 2778 - 2787
• Main Authors: Varga-Szemes, Akos, Penmetsa, Megha, Emrich, Tilman, Todoran, Thomas M., Suranyi, Pal, Fuller, Stephen R., Edelman, Robert R., Koktzoglou, Ioannis, Schoepf, U. Joseph
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2021; Springer Nature B.V
• Subjects: Accuracy; Angiography; Angiography, Digital Subtraction; Calcification; Calcification (ectopic); Cardiac; Constriction, Pathologic - diagnostic imaging; Contrast Media; Diagnostic Radiology; Diagnostic systems; Humans; Image processing; Image quality; Imaging; Internal Medicine; Interventional Radiology; Lower Extremity - diagnostic imaging; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Medical diagnosis; Medical imaging; Medicine; Medicine & Public Health; Neuroradiology; Peripheral Arterial Disease - complications; Peripheral Arterial Disease - diagnostic imaging; Proton density (concentration); Radiology; Reproducibility of Results; Sensitivity; Sensitivity and Specificity; Stenosis; Ultrasound; Vascular Calcification - complications; Vascular Calcification - diagnostic imaging; Vascular diseases; Visualization; Computed tomography angiography; Peripheral artery disease; Vascular calcification; Non-contrast magnetic resonance angiography; Magnetic resonance imaging
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-020-07386-4

Objectives
The proton density–weighted, in-phase stack-of-stars (PDIP-SOS) MRI technique provides calcification visualization in peripheral artery disease (PAD). This study sought to investigate the diagnostic accuracy of a combined non-contrast quiescent-interval slice-selective (QISS) MRA and PDIP-SOS MRI protocol for the detection of PAD, in comparison with CTA and digital subtraction angiography (DSA).
Methods
Twenty-six prospectively enrolled PAD patients (70 ± 8 years) underwent lower extremity CTA and 1.5-T or 3-T PDIP-SOS/QISS MRI prior to DSA. Two readers rated image quality and graded stenosis (≥ 50%) on QISS MRA without/with calcification visualization. Sensitivity, specificity, and area under the curve (AUC) were calculated against DSA. Calcification was quantified and compared between MRI and non-contrast CT (NCCT) using paired
t
test, Pearson’s correlation, and Bland-Altman analysis.
Results
Image quality ratings were significantly higher for CTA compared to those for MRA (4.0 [3.0–4.0] and 3.0 [3.0–4.0];
p
 = 0.0369). The sensitivity and specificity of QISS MRA, QISS MRA with PDIP-SOS, and CTA for ≥ 50% stenosis detection were 85.4%, 92.2%, and 90.2%, and 90.3%, 93.2%, and 94.2%, respectively, while AUCs were 0.879, 0.928, and 0.923, respectively. A significant increase in AUC was observed when PDIP-SOS was added to the MRA protocol (
p
 = 0.0266). Quantification of calcification showed significant differences between PDIP-SOS and NCCT (80.6 ± 31.2 mm
3
vs. 88.0 ± 29.8 mm
3
;
p
 = 0.0002) with high correlation (
r
 = 0.77,
p
 < 0.0001) and moderate mean of differences (− 7.4 mm
3
).
Conclusion
QISS MRA combined with PDIP-SOS MRI provides improved, CTA equivalent, accuracy for the detection of PAD, although its image quality remains inferior to CTA.
Key Points
• Agreement in stenosis detection rate using non-contrast quiescent-interval slice-selective MRA compared to DSA improved when calcification visualization was provided to the readers.
• An increase was observed in both sensitivity and specificity for the detection of ≥ 50% stenosis when MRI-based calcification assessment was added to the protocol, resulting in a diagnostic accuracy more comparable to CTA.
• Quantification of calcification showed statistical difference between MRI and non-contrast CT; however, a high correlation was observed between the techniques.