Diffusion-weighted imaging has recently been incorporated into extra-neurological pediatric imaging protocols because of its various clinical advantages. Because diffusion-weighted imaging does not require intravenous contrast media, it can be safely used in patients with reduced renal function. Furthermore, diffusion-weighted imaging can be performed within several minutes by using the echo planar imaging technique. Its clinical advantages include improved tissue characterization, as well as the ability to assess organ functionality, monitor the treatment response after chemotherapy or radiation therapy and predict patient outcomes. The aims of this pictorial essay were to explain the physical principles underlying diffusion-weighted imaging, to outline the interpretation of diffusion-weighted images and apparent diffusion coefficient maps, and to list the extra-neurological applications of diffusion- weighted imaging in children.

Keywords: diffusion-weighted MRI , tumor , pediatrics