Abstract
Objectives The main purpose of this article is to measure the fractional anisotropy (FA) and
apparent diffusion coefficient (ADC) values of cortex and medulla of renal allograft
using 3-Tesla diffusion tensor imaging (DTI) in renal transplant patients with normal
and graft dysfunction and to assess the correlation between diffusion tensor parameters
(ADC and FA) and the estimated glomerular filtration rate (eGFR) value.
Materials and Methods Fifty renal transplant recipients who received either living or cadaveric renal allografts
were included in the study. Blood samples for serum creatinine and eGFR value were
taken on the same day prior to the magnetic resonance study and the patients were
assigned to three groups (A, B, C) according to allograft function (eGFR levels).
The mean ADC and FA values of the cortex/medulla in upper, mid, and lower poles were
calculated from the DTI sequence. Statistical analysis was performed using paired
sample Student’s t-test and one-way analysis of variance test.
Results The mean ADC values of the cortex were higher than the medulla that was statistically
significant. However, the mean FA values were significantly higher in the medulla
than the cortex. Mean ADCs and FA of the renal cortex and medulla were significantly
higher in group A patients with normal renal function than in group B and C with poor
renal functions. The corticomedullary difference in the FA values was more in group
A. However, this difference was lower in group B and more so in group C.
Conclusion ADC and FA values in the renal cortex and medulla exhibit a good correlation with
allograft function and were significantly lower in transplants with dysfunction than
those with good function. FA values appear to be more sensitive than eGFR and ADC
for detection of early pathological changes in the graft dysfunction.
Keywords
diffusion tensor imaging - functional assessment - transplant kidneys
