Does diffusion-weighted magnetic resonance imaging help in the detection of renal parenchymal disease and staging/prognostication in chronic kidney disease?

Abstract

Purpose Diffusion-weighted imaging (DWI) in renal diseases is an upcoming modality, and its utility as an additional marker is yet to be proven. This study was intended to find the relationship between apparent diffusion coefficient (ADC) values with renal function tests and stages of chronic kidney disease (CKD) to assess renal dysfunction, and to label a cut-off for normal renal function and dysfunction. Material and methods A prospective diagnostic study was conducted on 120 patients: 60 with deranged renal function tests (RFT) and 60 with normal RFT. DWI using a 1.5-Tesla MRI (at b -values of 0 and 500 s/mm 2 ) was done. A region of interest of size 1-2 cm 2 was placed on renal parenchyma in the region of medulla, one each, over the superior, mid, and lower regions of each kidney separately. ADC values were recorded for renal parenchyma and compared. Results In patients with renal dysfunction ADC values were significantly lower than in patients with normal function (1.75 ± 0.25 vs. 2.28 ± 0.21 of right kidney and 1.79 ± 0.17 vs. 2.29 ± 0.21 of left kidney [×10 −3 mm 2 /s]; p = 0.001). ADC values of different stages of CKD showed a decreasing trend with increasing stage. Conclusions ADC values taken at all poles to get focal involvement of the kidney can be used to measure each kidney separately, and values can be individually correlated with the elevated renal parameters. The cut-off value of the mean ADC for individual kidneys was > 2.28 (×10 −3 mm 2 /s) in normal renal function and < 2.00 (×10 −3 mm 2 /s) in renal dysfunction.

The role of diffusion-weighted imaging in the diagnosis of early kidney damage

“…Moreover, Emre et al revealed significant differences between all stage groups in terms of mean ADC values. In a recent study by Arora et al [18] that compared 60 patients with CKD to 60 healthy individuals without a history of CKD and high creatinine levels, the mean ADC values significantly differed in the CKD group at different stages. In addition, they found that the mean ADC values in the CKD group were significantly lower than those in the healthy control group.…”

“…We found that individuals with normal renal function can be differentiated from patients with dysfunction with 69.7% sensitivity and 87.7% specificity for measurements above the cut-off value of 1.944 (× 10 − 3mm 2 /s). Notably, Arora et al [18] found the cutoff value of 2.000 (× 10 − 3mm 2 /s) as an indicator of renal dysfunction. They reported that with the currently used cut-off value, the sensitivity is 56% and the specificity is 91%.…”