Purpose: To develop a robust renal arterial spin labeling (ASL) acquisition and processing strategy for mapping renal blood flow (RBF) in a pediatric cohort with severe kidney disease.
Methods: A single-shot background-suppressed 3D gradient and spin-echo (GRASE) flow-sensitive alternating inversion recovery (FAIR) ASL acquisition method was used to perform 2 studies. First, an evaluation of the feasibility of single-shot 3D-GRASE and retrospective noise reduction methods was performed in healthy volunteers. Second, a pediatric cohort with severe chronic kidney disease underwent single-shot 3D-GRASE FAIR ASL and RBF was quantified following several retrospective motion correction pipelines, including image registration and threshold-free weighted averaging. The effect of motion correction on the fit errors of saturation recovery (SR) images (required for RBF quantification) and on the perfusion-weighted image (PWI) temporal signal-to-noise ratio (tSNR) was evaluated, as well as the intra- and inter-session repeatability of renal longitudinal relaxation time (T1 ) and RBF.
Results: The mean cortical and/or functional renal parenchyma RBF in healthy volunteers and CKD patients was 295 ± 97 and 95 ± 47 mL/100 g/min, respectively. Motion-correction reduced image artefacts in both T1 and RBF maps, significantly reduced SR fit errors, significantly increased the PWI tSNR and improved the improved the repeatability of T1 and RBF in the pediatric patient cohort.
Conclusion: Single-shot 3D-GRASE ASL combined with retrospective motion correction enabled repeatable non-invasive RBF mapping in the first pediatric cohort with severe kidney disease undergoing ASL scans.
Keywords: arterial spin labeling (ASL); kidneys; motion correction; pediatric MRI; renal MRI; renal blood flow.
© 2018 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.