Intravoxel Incoherent Motion (IVIM) MRT pelviner Lymphknoten : Stellenwert der biexponentiellen ADC-Berechnungin der Unterscheidung benigner und maligner Beckenlymphknoten beim Prostatakarzinom
Intravoxel incoherent motion (IVIM) is a model introduced by Le Bihan et al. to describe the parts diffusion and perfusion play in magnetic resonance imaging (MRI) signal intensity. The aim of this study was to examine whether diffusion-weighted MRI (DWI-MRI) can be used for distinguishing between benign and malign pelvic lymph nodes in patients with high-risk prostate cancer. I retrospectively analyzed the obtained MRI data of 43 consecutive patients who were scheduled for pre-operative imaging of the pelvic lymph nodes using histopathological finding as reference. Data was processed using the biexponential IVIM model. Mean diffusion coefficient in benign lymph nodes was significantly higher than in malign lymph nodes (1,10x10-3mm2/sec vs. 0,54x10-3mm2/sec) with p<0,001. Mean apparent diffusion coefficient (ADC) for benign and malign lymph nodes were 1,67x10-3mm2 and 0,88x10-3mm2 , respectively. It could be shown that using biexponential calculation for the ADC and diffusion coefficient D might hold an additional benefit in pre-operative imaging for evaluating the nodal status, as distinguishing benign from malign lymph nodes in the examined patients’ collective was possible with high precision.