Dirk Blondin MD, Presenter: Nothing to Disclose

Rotem Shlomo Lanzman MD, Abstract Co-Author: Nothing to Disclose

Philipp Bilk, Abstract Co-Author: Nothing to Disclose

Falk Roland Miese MD, Abstract Co-Author: Nothing to Disclose

Patrick Kroepil MD, Abstract Co-Author: Nothing to Disclose

Hans-Joerg Wittsack MD, Abstract Co-Author: Nothing to Disclose

Contrast-enhanced MRI is considered problematic in renal allograft recipient due to the development of nephrogenic systemic fibrosis. However, the assessment of functional information of the kidney is desirable. Therefore, we assessed the clinical value of diffusion weighted imaging (DWI) analyzed by a mono-exponential (ADCmono) and a distribution function model (ADCstat) in renal allografts.

The local ethics committee approved the study protocol. All patients provided written informed consent. A total of 23 patients were divided into three groups: (a) stable function for at least 6 month, (b) transplantation <30d with good function and (c) an acute deterioration or decreased of renal allograft function. T2w axial, T1w coronar and a paracoronar DWI sequence with 16 b-values (b = 0 – 750 s/mm2) were performed on a 1.5T MR-scanner (Magnetom Avanto, Siemens AG Healthcare, Germany ). Regional analysis of the ADC of the renal cortex was performed.

Mono-exponential analysis showed an ADCmono of 1932 ± 98, 2095 ± 246 and 1636 ± 200 10-6mm2/sec for patient group a, b, and c respectively. The distribution function revealed a mean ADCstat of 2487 ± 185, 2850 ± 325 and 2142 ± 314 for group (a),(b) and (c) respectively. The difference in between group (a,b) and (c) (p<0.005) was statistically significant for ADCmono and ADCstat. The correlation coefficient R2 yielded the best regression of mathematical fitting for ADCstat (p<0.0001).

Nonenhanced evaluation of renal allografts with DWI correlated well with renal function for both, the mono-exponential analysis and the distribution function model The ADCs resulting from both models did not show statistical significant differences, but the distribution function model showed the best regression. Therefore, larger scaled studies are mandatory.

In times of NSF our results indicate a high potential for using diffusion weighted imaging to monitor transplanted kidneys.

Blondin, D, Lanzman, R, Bilk, P, Miese, F, Kroepil, P, Wittsack, H, Diffusion Attenuated MR Signal of Renal Allografts: Comparison of Two Different Statistical Models.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9010076.html