RSNA 2015

Abstract Archives of the RSNA, 2015


SSK08-09

Intravoxel Incoherent Motion MRI for Differentiating Renal Hypoperfusion from Increased Cellularity after Ischemia-Reperfusion

Wednesday, Dec. 2 11:50AM - 12:00PM Location: E450B



Mike Notohamiprodjo, Munich, Germany (Presenter) Nothing to Disclose
Katharina Stella Winter, Munich, Germany (Abstract Co-Author) Nothing to Disclose
Michael Staehler, MD, Munich, Germany (Abstract Co-Author) Nothing to Disclose
Andreas D. Helck, MD, Munich, Germany (Abstract Co-Author) Nothing to Disclose
Olaf Dietrich, PhD, Munich, Germany (Abstract Co-Author) Nothing to Disclose
Moritz Schneider, Munich, Germany (Abstract Co-Author) Nothing to Disclose
PURPOSE

To differentiate hypoperfusion from inflammatory hypercellularity after renal ischemia-reperfusion due to partial nephrectomy using Intravoxel Incoherent Motion MRI.

METHOD AND MATERIALS

This IRB approved prospective study was performed according to the declaration Helsinki. 15 patients with renal tumors underwent MR at 3T (Magnetom Verio, Siemens Healthcare) directly before and one week after partial nephrectomy. Diffusion weighted imaging was acquired with an EPI-sequence (10 b-values 0-800 s/mm2, 3 averages, 6 directions). IVIM-analysis was performed with home-built software (PMI 0.4, IDL) by biexponential fitting of the tissue Dslow (mm2/s*10-3) and the pseudo-diffusion Dfast (mm2/s*10-3) as well as the perfusion component f (%). Apparent diffusion coefficient (ADC; mm2/s*10-3) was derived from monoexponential analysis. To compare parameters between baseline and follow-up the paired Wilcoxon signed-rank test and to compare non-nephrectomized and partially nephrectomized kidneys the non-paired Mann-Whitney U test was used.

RESULTS

In the baseline examination prior to partial nephrectomy there were no significant differences between tumor bearing and contralateral kidney, whereas the follow-up measurement showed significant differences for ADC (p<0.001), Dfast (p=0.02) and most pronounced for f (p<0.001). Partially nephrectomized kidneys showed a significant decrease of ADC (2.5±0.3 vs. 2.3±0.2, p<0.01), Dfast (8.6±1.8 vs. 7.3±1.7, p = 0.02) and again most pronounced for f (19.2±3.0 vs. 13.7±4.4 p < 0.01). There were no significant differences for Dslow (operated kidney 2.0±0.2 vs. 2.0±0.2; contralateral kidney 2.1±0.2 vs. 2.0±0.1) Non-nephrectomized contralateral kidneys expressed a significant increase of ADC (2.5±0.2 vs. 2.7±0.3, p < 0.01), and f (19.3±2.6 vs. 21.5±4.0, p = 0.03). There was no significant correlation of the alteration of each parameter to clamping time.

CONCLUSION

IVIM detects significant changes, particularly of the perfusion fraction in the operated and contralateral kidney after partial nephrectomy suggesting that ischemia-reperfusion associated diffusion restriction is correlated to hypoperfusion rather than increasing inflammatory cellularity.

CLINICAL RELEVANCE/APPLICATION

IVIM MRI suggest that renal ischemia-reperfusion associated diffusion restriction is correlated to hypoperfusion rather than increasing inflammatory cellularity.