IRM de diffusion et tumeurs annexielles

Advances in ultrafast MRI techniques have made it possible to overcome many motion-related problems and obtain reliable DW images of pelvis organs. b1000 signal intensity within solid component should help radiologists characterize these masses. Therefore, DW images have to be interpreted in accordance with traditional morphological sequences (T2, T1 with dynamic injection of gadolinium). Diffusion MRI optimizes the characterization of complex adnexal masses: the absence of b1000 signal intensity within solid component has an excellent positive predictive value for benignity (PLR: 10.9) whereas the presence of high b1000 signal intensity within solid component is less useful. In our experience, every invasive malignant tumors display a high b1000 signal intensity within solid component but many numerous benign tumors also because of their high cellularity (ovarian fibroma, cystadnofibroma). This technique has also shown interest in staging of ovarian cancer by improving the detection of peritoneal implants, which is a major prognosis factor in ovarian cancer and optimizing the characterization of lymphadenopathy using apparent diffusion coefficient (ADC) measurements.