Non Contrast-Enhanced MRA versus Ultrasound blood vessel assessment to determine the choice of hemodialysis vascular access

Purpose: The aim of this work was to establish the relationship between traditional blood vessel mapping for vascular access (VA) creation by B-mode ultrasound (US) and novel non contrast-enhanced magnetic resonance angiography (NCE-MRA), and to study the potential influence of the diameter assessment technique on the choice of hemodialysis vascular access. Methods: A total of 27 end-stage renal-disease patients were included. They received routine US and a NCE-MRA examination of the upper extremity. Diameters were measured manually on US and semi-automatically on NCE-MRA. These measurements were statistically compared for the arteries and veins and for each measurement location. Furthermore, sensitivity and specificity of both modalities to predict VA location was investigated by comparison with an experienced surgeon. This analysis gave insight into the potential influence of vessel mapping modality on decision-making. Results: Comparison of NCE-MRA with US for the arteries and veins, demonstrated a bias of 9% (limits -33%-78%) and 38% (limits -36%-198%), respectively. Statistically significant differences between the modalities on the individual locations were mainly found for the venous locations. The sensitivity and specificity for US to predict VA location was 1.0 and 0.74, respectively, while for NCE-MRA this was 0.88 and 0.39, respectively. Conclusions: The results obtained indicate that extreme caution should be exercised when replacing one diameter measurement modality with the other. A further need exists to improve both vessel mapping protocols to obtain a geometric description of the upper extremity vasculature regardless of acquisition modality.