[Dynamic changes in magnetic resonance diffusion-weighted and fluid-attenuated images of cerebral fat embolism: a case report].

Cerebral fat embolism (CFE) is serious complication of a long-bone fracture. We reported magnetic resonance (MR) diffusion-weighted (DWI) and fluid attenuated inversion recovery (FLAIR) images in a patient suffered with CFE. A 26-year-old man with a right femoral bone fracture lapsed into a semicoma eight hours later. Eighteen hours after the depressed consciousness, DWI and FLAIR images on MR imaging showed multiple high-intensity spots in corona radiata, basal ganglia, thalamus, corpus callosum, brain stem and cerebellum. Thereby, he was diagnosed as CFE. These multiple lesions were more detectable on FLAIR images than DWI, particularly in posterior fossa. Eight days after the onset, follow-up DWI, FLAIR, and T 2-weighted MR image (T 2 WI) showed most of the lesions disappeared or shrunk. The resolution of the lesions suggests that most of the lesions were brain edema as a result of the unique pathophysiological condition of CFE. The remained lesions were diagnosed as cerebral infarctions. The consciousness of the patient improved alert. Three months later, follow-up MRI showed almost complete resolution of the abnormal intensities. Follow up DWI and FLAIR images observed in the patient indicated that many small lesions occurs throughout the whole brain without a preferential region, and many of the lesions can subside or attenuate in CFE.