Revealing the Decrease of Renal Cortical Perfusion in Primary Glomerular Disease and Renal Aging by Arterial Spin Labeling

Abstract

Objectives: To reveal the change of renal cortical blood perfusion in primary glomerular disease (PGD) and renal aging by flow-sensitive alternating inversion recovery (FAIR) arterial spin labeling (ASL) technique. Patients and Methods: Renal cortical perfusion was estimated in 24 PGD patients and 30 healthy volunteers using FAIR-ASL in this case-control study. MRI examination was repeated after one week in six randomly selected healthy volunteers. In PGD patients, we regard estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m2 as mild PGD and eGFR < 60 mL/min/1.73 m2 as moderate-late PGD. The correlations between ASL perfusion values and eGFR in healthy volunteers, mild and moderate-late PGD patients were assessed. Results: In healthy volunteers, the perfusion values between the twice ASL scanning with one week-interval showed an excellent agreement by Bland-Altman analysis. The mean perfusion value of the bilateral kidneys decreased with age increase (25 - 72 years) (r = -0.496, P = 0.012). There were significant differences in ASL perfusion values among healthy volunteers, mild and moderate-late PGD patients (P < 0.0001). Perfusion values correlated strongly with eGFR in all PGD patients (r = 0.868, P < 0.0001), but not in healthy volunteers (r = 0.156, P = 0.405). The correlation coefficient of perfusion values with eGFR in mild and moderate-late PGD patients were 0.749 (P = 0.008) and 0.809 (P = 0.010), respectively. Conclusion: FAIR-ASL technique represents a feasible approach to monitor the renal perfusion variations in PGD patients. It is a noninvasive technique to discover the early abnormality of renal function, and assess the degree of renal aging.