[Clinical utility of MR FLAIR imaging for head injuries]

To study the utility of fluid attenuated inversion recovery (FLAIR)MR images in the evaluation of traumatic head injury, 56 patients with traumatic head injuries were examined with long TR/TE spin-echo(SE)sequences and FLAIR sequences. In 40 of them, long TR/short TE images were added to those sequences. Careful readings of MR images were done by two well-trained neuroradiologists. The chi square test was used for statistical evaluation of our results. The relative sensitivities of FLAIR images were significantly better than those of long TR/TE, long TR/short TE images for the detection of diffuse axonal injury (p < 0.01), cortical contusion (p < 0.01), and subdural hematoma (p < 0.01) for long TR/TE, p < 0.05 for long TR/short TE). The number of cases of epidural hematoma and brainstem injury was too small for statistical significance to be determined. In 9 patients with corpus callosum injuries. FLAIR images demonstrated the lesions as abnormally high signal intensity in the septum pellucidum and fornix. Only sagittal FLAIR images could definitely discriminate the traumatic lesions of the fornix from the surrounding CSF. In addition, FLAIR images could easily discriminate DAI of the corpus callosum from CSF of the cavum velli interpositi. MR FLAIR images were found to be useful for detecting traumatic head injuries.