Comparison of Free-Breathing Versus Navigator-Controlled Diffusion-Weighted MR Imaging of the Kidneys: Effects on ADC Statistics.

Neil Peter Jerome¹, Matthew Orton¹, James d'Arcy¹, David J. Collins¹, Dow-Mu Koh², Martin O. Leach¹

Discussions about the optimum breathing modality for acquiring abdominal diffusion-weighted MR images include consideration of navigator-controlled acquisition to reduce motion blurring, but this is dependent on repeatability of respiratory cycle and is inevitably time-inefficient. Adopting a free-breathing strategy allows greater averaging for the same acquisition time; we show that fitted pefusion-insensitive ADC parameters from the kidneys of a volunteer cohort are not significantly different between navigator-controlled and free-breathing modalities. Global statistics are reported, as well as for renal cortex and pyramid ROIs, and distibutions of ADCs and of signal intensities at each b-value are shown to be not significantly different.