[Diffuse axonal injury manifested as corpus callosum damage on magnetic resonance imaging. Case report]

A 26-year-old male was injured in a motorcycle accident and arrived unconscious at a local general hospital. Lack of improvement despite intensive care prompted his referral to the neurosurgical department, approximately 10 hours after the accident. On neurological examination his Glasgow Coma Scale score was 8, and mild right hemiparesis and right radial nerve palsy were noted. There was no skull fracture. Computed tomography disclosed intraventricular hemorrhage and small hemorrhagic foci in the prepontine area and the border between the gray and white matter. No hemorrhage was demonstrated in the corpus callosum. Magnetic resonance imaging (MRI) was performed 3 weeks after admission with a 0.5-tesla resistive Vista magnetic resonance scanner. The inversion recovery technique was used, with a repetition time (TR) of 2100 msec, an inversion time of 500 msec, and an echo time (TE) of 40 msec, for T1-weighted images. The spin-echo technique was used, with a TR of 2000 msec and a TE of 80 msec, for T2-weighted images. In the body and splenium of the corpus callosum, T1-weighted images showed a spotty area of low signal intensity with an irregular margin; this area was of high signal intensity on T2-weighted images. On repeat MRI performed 4 months after injury, T1-weighted images showed, in the same region, granular low signal intensity, while T2-weighted images showed high signal intensity. The MRI findings in the subacute and chronic stages of diffuse axonal injury are discussed.