Purpose: To prospectively study the diagnostic performance of hybrid single-dose contrast-enhanced MRA of peripheral arterial disease (PAD), with digital subtraction angiography (DSA) as the reference standard.
Materials and methods: Hybrid MRA, combining time resolved imaging of contrast kinetics and two-station bolus-chase sequences, of lower limb was performed in 31 PAD patients (21 men, 10 women; mean age, 72 years) with two separate gadobenate dimeglumine (8 mL) injections in each sequence. Two independent blinded readers analyzed the vascular stenosis (32 segments in each limb). Sensitivity, specificity, and accuracy in all vascular segments and segments below popliteal artery were calculated. Interobserver agreements on MRA and intermodality agreements between MRA and DSA were calculated by using k statistics.
Results: Sensitivity, specificity, and accuracy of the hybrid MRA with regard to hemodynamically significant stenosis in all vascular segments were 92%, 97%, and 95% for reader 1, and 90%, 92%, and 92%, for reader 2, respectively. The interobsever agreements on MRA were good (k = 0.77-0.74) for all-grade stenosis, and excellent (k = 0.82-0.81) for hemadynamically significant stenosis. The intermodality agreements are good to excellent (k = 0.73-0.94).
Conclusion: Single-dose hybrid MRA is a safe and reliable noninvasive alternative to conventional DSA in the assessment of PAD patients.