The use of diffusion weighted imaging to evaluate pathology outside the brain parenchyma in neuroimaging studies.

Diffusion-weighted imaging (DWI) has transformed the radiological assessment of a variety of cerebral pathologies, in particular acute stroke. In neuroimaging studies, DWI can also be used to evaluate pathology outside the brain parenchyma, although it is sometimes underutilized for this purpose. In this pictorial review, the principles of DWI are outlined, and 13 cases of abnormal diffusion outside the brain parenchyma are illustrated in order to show DWI as a useful sequence for the evaluation of the following recommended review areas: the dural venous sinuses, internal carotid arteries, meninges, ventricles, cavernous sinus and orbits, skull base and lymph nodes.