High resolution MR perfusion imaging of the kidneys at 3 Tesla without administration of contrast media.

PURPOSE: The feasibility of high-resolution arterial spin labeling (ASL) perfusion imaging of the kidneys was tested and proven at 3 Tesla using a flow-sensitive alternating inversion recovery (FAIR) true fast imaging in steady precession (TrueFISP) technique.
MATERIALS AND METHODS: Kidney perfusion maps of six healthy volunteers and two patients were acquired using a clinical 3-Tesla whole-body scanner. An ASL sequence with FAIR spin preparation and a TrueFISP signal detection strategy was adapted for high-resolution perfusion imaging of the kidneys at 3 Tesla. To avoid banding artifacts in TrueFISP images, which are generally prominent at 3 Tesla, a frequency scout was implemented. Perfusion maps with an in-plane resolution of 1.5 mm were recorded in transverse and coronal orientation. For fast mapping of whole-kidney perfusion, an in-plane resolution of 2 mm was applied.
RESULTS: In all volunteers and patients, high-resolution perfusion images with excellent image quality were able to be obtained in a measuring time of approximately 10 minutes. The whole kidney was able to be mapped with good image quality in less than 10 minutes. For all slices, a suitable frequency offset made it possible to reproduce the kidneys without TrueFISP artifacts. Perfusion values of the renal cortex ranged from 250 ml/100 g/min up to 400 ml/100 g/min (mean cortical perfusion right kidney 316 +/- 43, left 336 +/- 40).
CONCLUSION: High-resolution ASL perfusion images of the whole kidney were able to be obtained with good image quality by means of a 3 Tesla MR setting within a clinically applicable measuring time, thus providing an alternative to conventional perfusion imaging involving potentially nephrotoxic contrast media.