Evaluation of Transplanted Kidneys and Comparison with Healthy Volunteers and Kidney Donors with Diffusion-Weighted Magnetic Resonance Imaging: Initial Experience.

OBJECTIVES: The aim of this study was to evaluate the feasibility of diffusion-weighted magnetic resonance, by comparing imaging in renal allograft recipients for functional assessment of kidney transplants versus imaging of these features in healthy volunteers and kidney donors with native kidneys.
MATERIALS AND METHODS: Seventy renal transplant recipients (group A) with stable graft function at postoperative month 1, 40 healthy volunteers (group B), and 40 kidney donors (group C) underwent diffusion-weighted magnetic resonance imaging. An echo-planar diffusion-weighted imaging sequence was performed in coronal orientation by using 6 b values (0, 200, 400, 600, 800, 1000 s/mm²). The apparent diffusion coefficients were determined for the upper and lower poles of the kidney cortex and medulla. Relations between apparent diffusion coefficients and allograft function, determined by the estimated glomerular filtration rate (comparing rates > 60 mL/min/1.73 m² [group A1] versus < 60 mL/min/1.73 m² [group A2]), were investigated in renal transplant recipients, and apparent diffusion coefficients in groups A, B, and C were compared.
RESULTS: Apparent diffusion coefficients were statistically higher in group A1 than in group A2 (P < .05) and statistically higher in group A than in groups B and C (P < .001). There were no significant differences between groups B and C (P > .05).
CONCLUSIONS: We observed that apparent diffusion coefficients of transplanted kidneys at postoperative month 1 were higher than values in native kidneys of healthy volunteers and kidney donors. In addition, apparent diffusion coefficients of transplanted kidneys with estimated glomerular filtration rates > 60 mL/min/1.73 m² were higher than transplanted kidneys with rates < 60 mL/min/1.73 m².