Diffusion-weighted MR imaging of kidneys in patients with chronic kidney disease: initial study.

OBJECTIVE

To prospectively evaluate the feasibility of diffusion-weighted (DW) magnetic resonance (MR) imaging in the assessment of renal function in patients with chronic kidney disease (CKD).

METHODS

Seventy-two healthy volunteers and 43 patients underwent coronal echo-planar DW MR imaging of the kidneys with a single breath-hold time of 16 s. The patients were grouped according to five stages as indicated by the K/DOQI CKD (kidney disease outcome quality initiative). The apparent diffusion coefficient (ADC) value of the kidneys was calculated with high b values (b = 500 s/mm(2)). The ADC values were compared between patients and healthy volunteers, and among different stages. For statistical analysis, Student's t tests, ANOVA, Pearson's correlation tests, and Spearman's correlation tests were used.

RESULTS

No difference between the cortex and medulla could be observed on DW images of all volunteers. Patients with CKD had significantly lower renal ADC (t = -4.383, P = 0.000) than volunteers. The ADC values of kidneys were significantly lower than normal at most stages of CKD, except CKD1. There was a negative correlation between the ADCs and serum creatinine (sCr) level (P = 0.000) amongst the patients.

CONCLUSION

Diffusion-weighted MR imaging is feasible in the assessment of renal function, especially in the detection of early stage renal failure of CKD.