Diffusion-weighted imaging of skull lesions

Diffusion-weighted imaging can increase the conspicuity of skull lesions and be applied toward noninvasive differentiation of malignant from benign lesions. Malignant skull lesions generally display lower diffusivity than benign lesions, although there are exceptions, and clinical parameters and conventional imaging modalities should also be considered in the evaluation of skull lesions. Nevertheless, in some instances diffusion-weighted imaging (DWI) can be used for problem solving when conventional imaging features are indeterminate, such as with skull base involvement by nasopharyngeal carcinoma versus osteomyelitis. In addition, DWI may be useful for monitoring treatment effects. The use of readout segmented technique, parallel imaging, multishot acquisition, turbo spin-echo DWI, diffusion tensor imaging, and higher field strengths can improve image quality. The feasibility of implementing DWI for characterizing skull lesions, the DWI findings of benign and malignant skull lesions, and technical considerations are discussed in this article.