Interpretations and treatment decisions based on MR angiography versus conventional arteriography in symptomatic lower extremity ischemia.

Purpose: To determine the frequency with which treatment plans based on findings at magnetic resonance angiography (MRA) match those based on findings at conventional x-ray arteriography (XRA) in the evaluation of symptomatic lower extremity ischemia.
Patients and Methods: Two-dimensional time-of-flight (TOF) MRA was performed in 42 patients undergoing XRA for evaluation of symptomatic lower extremity ischemia. The blind interpretations and treatment plans based on MRA findings were compared with those based on XRA findings, with use of XRA as the standard of reference.
Results: For identification of hemodynamically significant stenosis or occlusion, the sensitivity and specificity of MRA was 100% and 23% for iliac segments, 100% and 82% for common femoral segments, 89% and 67% for superficial femoral segments, 100% and 88% for popliteal segments, and 92% and 91% for tibioperoneal segments, respectively. The treatment plan based on MRA findings matched that based on XRA findings in 41% of patients.
Conclusion: For evaluation of symptomatic lower extremity ischemia, two-dimensional TOF MRA cannot be considered a reliable substitute for XRA in patients who lack contraindications to XRA.