Optimization of the contrast dose and injection rates in whole-body MR angiography at 3.0T.

PURPOSE: To optimize the contrast agent dose and delivery rate used in a novel whole-body magnetic resonance angiography (MRA) protocol using a 3.0T MR scanner. MATERIALS AND METHODS: Six groups of 20 consenting volunteers underwent whole-body MRA, with each group receiving a different contrast dose and contrast delivery rate. The arterial tree was divided into 16 segments and the image quality at each of the anatomical locations, covering the whole body, was assessed. Qualitative analysis was carried out using a scoring assessment of image quality, and quantitative assessments were performed by measuring contrast-to-noise (CNR) and a signal-to-noise (SNR) index. RESULTS: Reducing the contrast dose from 40 mL to 25 mL was found to significantly increase the CNR in several vessels of interest in the arterial tree. There was also a significant increase in the qualitative image quality score (P < 0.001). CONCLUSION: This study demonstrates that reducing the contrast dose at 3.0T can result in an increase in the CNR in the vessels of interest without significantly affecting the SNR.