The value of magnetic resonance imaging (MRI) in the diagnosis of acute non-accidental head injury (NAHI) was studied retrospectively in 12 infants and children, ages 1 to 34 months (average, 5.7 months), admitted to the Royal Hospital for Sick Children, Edinburgh, Scotland. Injuries were whiplash-shaking with impact in 4 cases and without impact in 7, and a compression injury in 1. Subdural hematomas, commonly subtemporal, were present in all cases, and MRI findings were similar in cases with and without evidence of impact. MRI is superior to CT scan in defining subtemporal hematomas, tearing of bridging veins, and demonstrating hemorrhages at the grey-white matter junction, lesions common to cases of acute NAHI involving rotational acceleration/deceleration forces. 
COMMENT. In infants with suspected non-accidental head injury, a CT scan on admission should be followed by MRI at 3 to 7 days after the acute injury, and as a guide to resolution of the hemorrhage. Whiplash-shaking injury syndrome without impact can result in MRI evidence of contusion and subdural hematomas, similar to that resulting from injury with impact.
Serial CT and MRI in outcome prediction of mild to moderate head injury. A series of 67 adults had CT on admission and MRIs within 1-3 and 6-12 months after injury. Outcome was worse in patients with edema and lesions on CT, and also in those with MRI lesions. Early MRI showing frontal lesions and late MRI with focal atrophy in frontotemporal regions, in combination with duration of amnesia, were predictive of outcome.