Reproducibility of Kidney Perfusion Measurements With Arterial Spin Labeling at 1.5 Tesla MRI Combined With Semiautomatic Segmentation for Differential Cortical and Medullary Assessment

Abstract

Magnetic resonance imaging with arterial spin labeling (ASL) is a noninvasive approach to measure organ perfusion. The purpose of this study was to evaluate the reproducibility of ASL kidney perfusion measurements with semiautomatic segmentation, which allows separate quantification of cortical and medullary perfusion.The right kidneys of 14 healthy volunteers were examined 6 times on 2 occasions (3 times at each occasion). There was a 10-minute pause between each examination and a 14-day interval between the 2 occasions. Cortical, medullary, and whole kidney parenchymal perfusion was determined with customized semiautomatic segmentation software. Coefficient of variances (CVs) and intraclass correlations (ICCs) were calculated.Mean whole, cortical, and medullary kidney perfusion was 307.26 ± 25.65, 337.10 ± 34.83, and 279.61 ± 26.73 mL/min/100 g, respectively. On session 1, mean perfusion for the whole kidney, cortex, and medulla was 307.08 ± 26.91, 336.79 ± 36.54, and 279.60 ± 27.81 mL/min/100 g, respectively, and on session 2, 307.45 ± 24.65, 337.41 ± 33.48, and 279.61 ± 25.94 mL/min/100 g, respectively (P > 0.05; R2 = 0.60/0.59/0.54). For whole, cortical, and medullary kidney perfusion, the total ICC/CV were 0.97/3.43 ± 0.86%, 0.97/4.19 ± 1.33%, and 0.96/4.12 ± 1.36%, respectively. Measurements did not differ significantly and showed a very good correlation (P > 0.05; R2 = 0.75/0.76/0.65).ASL kidney measurements combined with operator-independent semiautomatic segmentation revealed high correlation and low variance of cortical, medullary, and whole kidney perfusion.

Evaluation of Renal Blood Flow in Chronic Kidney Disease Using Arterial Spin Labeling Perfusion Magnetic Resonance Imaging

“… 13 , 28 Although only a few studies evaluating ASL MRI measurements have been performed to date, the technique has been shown to be reproducible. 29 , 30 Furthermore, ASL MRI−derived perfusion estimates correlated well with para-aminohippuric acid measurements and were able to discriminate pharmacologic changes in renal plasma flow. 31 The comparison of the ASL technique with a microsphere method in an animal model has shown that cortical perfusion measured with ASL correlated with microspheres in the expected physiologic range.…”

“…A recent report suggests a high degree of reproducibility of renal ASL MRI when repeated after 2 weeks. 29 In this study, we used longer TI for patients, assuming slower circulation compared to that of controls. 13 , 34 Although this is not ideal, it should not unduly influence the estimated flow, as the quantitation takes TI in to account.…”

Multiparametric Renal Magnetic Resonance Imaging: Validation, Interventions, and Alterations in Chronic Kidney Disease

“…By subtracting labeled images (radiofrequency magnetic labeling) from control images (no labeling applied), perfusion maps can be quantified using a kinetic model (Buxton et al, 1998 ). Renal tissue perfusion assessed by ASL has been implemented in healthy (Karger et al, 2000 ; Martirosian et al, 2004 ; Boss et al, 2005 ; Kiefer et al, 2009 ; Gardener and Francis, 2010 ; Cutajar et al, 2012 , 2014 ; Park et al, 2013 ; Gillis et al, 2014 ; Tan et al, 2014 ; Hammon et al, 2016 ), transplanted (Artz et al, 2011a , b ; Niles et al, 2016 ) and diseased (Michaely et al, 2004 ; Boss et al, 2005 ; Fenchel et al, 2006 ; Ritt et al, 2010 ; Rossi et al, 2012 ; Dong et al, 2013 ; Heusch et al, 2013 ; Tan et al, 2014 ) kidneys.…”

Renal Arterial Spin Labeling Magnetic Resonance Imaging

“…A good repeatability of the perfusion measurements (reported as coefficient of variation, CV) was found over the cortex [29,32,33,34] (CV = 4-16%) and the whole kidney [33,34] (CV = 3-7%), while the data for the renal medulla are sparse [34]. A good correlation of the cortical renal blood flow (RBF) was found for ASL and DSC MRI [29,35] in healthy volunteers.…”