Early diagnosis of cerebral fat embolism syndrome by diffusion-weighted MRI (starfield pattern)

Background-Cerebral fat embolism syndrome is a rare, but potentially lethal . complication of long bone fractures. Neurological symptoms are variable. and the clinical diagnosis is difficult. The purpose of this case study is to demonstrate the value of diffusion-weighted MRI of the brain for early d iagnosis of' fat embolism syndrome. Case Description-A non-head-injured 18-year-old woman suffered acute mental status changes 21 hours after an uncomplicated fracture of the left tibia. MRI of the brain was performed 48 hours after injury. T2-weighted images s howed multiple nonconfluent areas of high signal intensity, which, on the d iffusion-weighted scans, were revealed as bright spots on a dark background ("starfield" pattern). We suggest that this indicates areas of' restricted diffusion that are due to cytotoxic edema, resulting from multiple microem boli. Conclusions-High-intensity lesions in the brain on diffusion-weighted image s may serve as an early-appearing and more sensitive indicator of the diagn osis of fat embolism in the clinical context of long bone injury without he ad trauma.