Clinical application of diffusion-weighted MR imaging in malignant brain tumors

The purpose of this study was to evaluate the clinical usefulness of diffusion-weighted magnetic resonance (MR) imaging (DWI) in the assessment of intracerebral malignant tumors. This study included 33 patients (10 with glioblastomas, 1 with anaplastic astrocytomas, 19 with brain metastases and 3 with malignant lymphomas) during the last 1.5 years. DWI was acquired using the diffusion-weighted, single-shot, multislice, echo planar SE sequence. In high-grade gliomas, malignant lymphomas and brain metastases, areas of tumors that showed significant enhancement on T1-weighted MR images after administration of contrast material were hyperintense on DWI. Furthermore, on DWI the edema surrounding glioblastomas produced higher signals than edema surrounding metastases. DWI is a clinically useful technique for studying malignant tumors. It enables us to differentiate various aspects of tumors (e.g., enhancing, nonenhancing, cystic, necrotic, or recurrence). Further investigations of pathological features of these areas are needed. (author)