Kidney transplant: functional assessment with diffusion-tensor MR imaging at 3T.

Area of Science:

• Medical Imaging
• Nephrology
• Transplant Surgery

Background:

• Renal allograft assessment is crucial for patient outcomes.
• Noninvasive functional evaluation of transplanted kidneys remains a challenge.

Purpose of the Study:

• To evaluate the feasibility of diffusion-tensor imaging (DT imaging) at 3 Tesla for functional assessment of transplanted kidneys.
• To determine the correlation between DT imaging parameters and allograft function.

Main Methods:

• Prospective study of 40 renal transplant recipients using a 3-T MR imager.
• Echo-planar DT imaging sequence with five b values and 20 diffusion directions.
• Analysis of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in renal cortex and medulla, correlated with estimated glomerular filtration rate (eGFR).

Main Results:

• Significantly higher mean FA and ADC values in the renal medulla and cortex of patients with good allograft function (eGFR > 30 mL/min/1.73 m(2)) compared to those with impaired function (eGFR ≤ 30 mL/min/1.73 m(2)).
• Lower medullary FA in patients with non-recovered renal function.
• Significant positive correlations found between eGFR and medullary FA, cortical ADC, and medullary ADC.

Conclusions:

• DT imaging is a promising noninvasive technique for the functional assessment of renal allografts.
• Medullary FA values demonstrate a strong correlation with renal function, indicating its potential as a biomarker.