Intra‐arterial magnetic resonance angiography of the iliac arteries: clinical experience using two different protocols

Abstract

Purpose: To assess the feasibility of intra‐arterial magnetic resonance angiography (iaMRA) with two different protocols. Material and Methods: Twenty patients were prospectively examined after digital subtraction angiography. Contrast‐enhanced iaMRA was performed using a 1.5T magnetic resonance imaging (MRI) system. Contrast agent (gadodiamide) was injected through a conventional angiography catheter placed in the abdominal aorta. The patients were randomized into two groups each comprising 10 patients. Group 1 was examined with a FLASH‐3D (fast low‐angle shot) sequence, allowing the center of the k‐space to be acquired 0.5 s after initiation of the measurement. Group 2 was examined with the identical sequence, but the center of the k‐space was acquired after 8.7 s. The increase in the intravascular signal intensity was determined and the diagnostic value of the angiograms was independently scored by 4 investigators using a 5‐point scale. Results: Nineteen of 20 MRAs were scored as diagnostic; only 1 was scored as non‐diagnostic by 2 observers. The diagnostic value of the angiograms of group 2 was judged superior to that of group 1 owing to a more homogeneous intravascular contrast distribution. Conclusion: Intra‐arterial MRA is feasible. The diagnostic value of angiograms using a flash sequence with center of the k‐space acquisition after 8.7 s ranged from good to excellent. This sequence is appropriate for iaMRA of iliac arteries to support MR guided intervention.