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

The Lower Limit of Reference of Urinary Albumin/Creatinine Ratio and the Risk of Chronic Kidney Disease Progression in Patients With Type 2 Diabetes Mellitus

“…Whether early detection of renal hyperperfusion in type 2 diabetes might be a manifestation of normal urinary protein should be considered. Unfortunately, it is relative not easy to determine the early renal perfusion abnormality, further evaluation of the association of UACR levels and early abnormal renal perfusion status should be further investigated in the future ( 42 , 43 ).…”

Update on state‐of‐the‐art for arterial spin labeling (ASL) human perfusion imaging outside of the brain

“…The “unbalanced” implementation of PCASL is more robust to field inhomogeneity at the labeling location, compared to the “balanced” approach 27 although eddy current differences between label/control are minimized in balanced PCASL. Studies directly comparing PCASL and FAIR have yielded mixed results 28,29 . An exhaustive comparison between FAIR and a kidney optimized PCASL implementation is warranted.…”

“…Studies directly comparing PCASL and FAIR have yielded mixed results. 28,29 An exhaustive comparison between FAIR and a kidney optimized PCASL implementation is warranted.…”

Renal Assessment in Acute Cardiorenal Syndrome

“…Arterial spin labeling (ASL) is a technique that uses labeled water tracing for regional perfusion mapping. Although it is mostly restricted to research settings, the latest studies have stated that cortical perfusion decreases in CKD proportionally to stages of CKD and correlates to eGFR [134].…”