91. Nonaccidental Trauma: Comparison of Traditional Magnetic Resonance Imaging with a New High-Resolution Blood-Sensitive Magnetic Resonance Technique and Magnetic Resonance Spectroscopy

We compared the ability of conventional magnetic resonance imaging (MRI) techniques to a newer high-resolution blood-sensitive MR technique (susceptibility-weighted imaging [SWI]) and proton MR Spectroscopy (MRS) in detecting intracranial injury in 12 infants and children suspected of suffering nonaccidental trauma (NAT). Patients were clinically categorized as NAT or not-NAT. In 8 of 12 patients with a diagnosis of NAT, MRI alone suggested the diagnosis in 3 of 8 whereas MRS and SWI suggested the diagnosis in 7 of 8.Of the four not-NAT patients, MRI was positive for traumatic injury in two of four; MRS and SWI were positive in three of four. Nine of our patients demonstrated changes consistent with diffuse axonal injury (DAI) on MRS (in-creased choline; reduced NAA) whereas conventional MRI sequences including a gradient-echo sequence failed to detect any evidence of DAI. SWI was much more sensitive than gradient-echo imaging in detecting intraparenchymal hemorrhage. None of the 31 parenchymal microhemorrhages detected by SWI were identified on traditional MRI. MRS and SWI combined had a sensitivity of 88% and a specificity of 25% for detecting intracranial traumatic injury whereas conventional MRI alone had a sensitivity of 38% and a specificity of 50%. Newer imaging techniques such as SWI and MRS are more sensitive in detecting DAI associated with traumatic brain injury and should be considered in the acute evaluation of children suspected of having NAT.