Use of Three-Dimensional Arterial Spin Labeling to Evaluate Renal Perfusion in Patients With Chronic Kidney Disease

Abstract

Background: A noninvasive method for evaluating renal blood flow (RBF) in patients with chronic kidney disease (CKD) may have clinical value in disease staging, management, and prognostication.

Purpose: To evaluate effectiveness of three-dimensional pseudocontinuous arterial spin labeling (pCASL) and pulsed arterial spin labeling (PASL) in assessment of cortex and outer medulla (cortex/OM) RBF in CKD patients and healthy volunteers (HVs).

Study type: Prospective, in a single institution.

Subjects: A total of 48 CKD patients (stage 1, 2, 3, and 4-5: N = 11, 12, 13, and 12, respectively) and 18 HVs FIELD STRENGTH/SEQUENCE: 3 T, pCASL, and PASL with a three-dimensional hybrid gradient echo/spin echo sequence.

Assessment: Quality of RBF images derived from pCASL and PASL were evaluated and RBF in cortex/OM measured. Clinical and laboratory data were recorded.

Statistical tests: Image quality differences between pCASL and PASL were evaluated with Wilcoxon signed-rank test. For both methods, analysis of variance, followed by Fisher's LSD-t test, was used to determine whether RBF differed between CKD stages and HVs. Pearson correlation coefficients were calculated to assess strength of relationships between cortex/OM RBF and data from clinical and laboratory tests.

Results: Image quality differences were significantly higher in pCASL than PASL in both patients and HVs (both P < 0.05). For pCASL, cortex/OM RBF of patients were significantly lower than those of HVs (P < 0.05). Cortex/OM RBF were higher in S1 and S2 patients than those in S3 and S4-5 (P < 0.05). For PASL, only RBF in cortex of S1 and S2 patients were significantly higher than those of S4-5 (P < 0.05). Good correlations between pCASL RBF and estimated glomerular filtration (eGFR) were found in cortex/OM of patients (rho = 0.796 and 0.798, respectively, both P < 0.05), higher than those between PASL RBF and eGFR (rho = 0.430 and 0.374, respectively, both P < 0.05).

Data conclusion: Three-dimensional pCASL may potentially be a noninvasive technique to assess renal perfusion in CKD patients in different stages.

Level of evidence: 1 TECHNICAL EFFICACY: Stage 2.

Keywords: arterial spin labeling; chronic kidney disease; magnetic resonance imaging; perfusion; renal blood flow.