Blood flow quantification in haemodialysis fistulae by phase contrast MR angiography (PC-MRA) in comparison to duplex sonography.

Purpose: Aim of this study was to evaluate whether phase contrast MR angiography (PC-MRA) could provide additional functional information besides morphology in the assessment of haemodialysis fistulae. Material and method: Twenty-two patients (11 male, 11 female), aged 22-77 years, were examined. MR images were obtained with a 1.5 T Gyroscan(R) ACS-NT (Philips, Best, Netherlands) using a high-resolution wrap-around coil. In addition to MRA blood-flow measurements were performed with a gradient-echo sequence (T-R 14 ms, T-E 5-5.5 ms, flip-angle 15 degrees, 6 mm slice thickness, retrospective gating, matrix 96:128) in the venous and arterial section of the fistulae. Doppler flow measurements were performed at the same position with a Sonoline Elegra(R) (Siemens AC, Erlangen) using a 7.5 MHz transducer. Results: Both methods of flow-volume measurements showed a good correlation (r = 0.94 in the arterial section, r = 0.90 in the venous section, p<0.001). The average calculated blood flow was measured 11%(arterial section) and 12.8% (venous section) higher with Pulsed Waved Doppler as compared to PC-MRA. Conclusion: PC-MRA with a high-resolution wrap-around coil is a reliable method for measuring functional parameters like flow-volume and flow velocity in haemodialysis fistulae and a useful complement to the visualisation capabilities of MRA.