Optimization of single shot 3D breath-hold nonenhanced MR angiography of the renal arteries (Journal of Cardiovascular Magnetic Resonance)

Background: Cardiac and navigator-gated, inversion-prepared non-enhanced magnetic resonanceangiography techniques can accurately depict the renal arteries without the need for contrastadministration. However, the scan time and effectiveness of navigator-gated techniquesdepend on the subject respiratory pattern, which at times results in excessively prolongedscan times or suboptimal image quality. A single-shot 3D magnetization-prepared steadystatefree precession technique was implemented to allow the full extent of the renal arteriesto be depicted within a single breath-hold. Methods: Technical optimization of the breath-hold technique was performed with fourteen healthyvolunteers. An alternative magnetization preparation scheme was tested to maximize inflowsignal. Quantitative and qualitative comparisons were made between the breath-holdtechnique and the clinically accepted navigator-gated technique in both volunteers andpatients on a 1.5 T scanner. Results: The breath-hold technique provided an average of seven fold reduction in imaging time,without significant loss of image quality. Comparable single-to-noise and contrast-to-noiseratios of intra- and extra-renal arteries were found between the breath-hold and the navigatorgatedtechniques in volunteers. Furthermore, the breath-hold technique demonstrated goodimage quality for diagnostic purposes in a small number of patients in a pilot study. Conclusions: The single-shot, breath-hold technique offers an alternative to navigator-gated methods fornon-enhanced renal magnetic resonance angiography. The initial results suggest a potentialsupplementary clinical role for the breath-hold technique in the evaluation of suspected renalartery diseases.