The authors represent a cooperative group of 15 institutions that examined the feasibility of using metabolic fea tures observed in vivo with 'H-magnetic resonance (MR) spectroscopy to characterize brain tumors of the glial type.The institutions provided blinded, centralized MR spectroscopy data processing along with independent central review of MR spectroscopy voxel placement, composition and contamination by brain, histopathological typing using current World Health Organization criteria, and clinical data, Proton 'H-MR spectroscopy was performed using a spin-echo technique to obtain spectra from 8-cc voxels in the tumor and when feasible in the contralateral brain. Eighty-six cases were assessable, 41 of which had contralateral brain spectra. Glial tumors had significantly elevated intensities of choline signals, decreased intensities of creatine signals, and decreased intensities of N-acetyl asp art ate compared to brain. Choline signal intensities were highest in astrocytomas and anaplastic astrocytomas, and creatine signal intensi ties were lowest in glioblastomas. However, whether expressed relative to brain or as intratumoral ratios, these meta bolic characteristics exhibited large variations within each subtype of glial tumor. The resulting overlaps precluded diagnostic accuracy in the distinction of low-and high-grade tumors. Although the extent of contamination of the ]H-MR spectroscopy voxel by brain had a marked effect on metabolite concentrations and ratios, selection of cases with minimal contamination did not reduce these overlaps. Thus, each type and grade of tumor is a metabolically hetero geneous group. Lactate occurred infrequently and in all grades. Mobile lipids, on the other hand, occurred in 41% of high-grade tumors with higher mean amounts found in glioblastomas. This result, coupled with the recent demonstra tion that intratumoral mobile lipids correlate with microscopic tumor cell necrosis, leads to the hypothesis that mobile lipids observed in vivo in E H-MR spectroscopy may correlate independently with prognosis of individual patients. W. G. Negendank, et ciL rylcholine), one primarily from creatines (creatine and phosphocreatine), and one primarily from acetyl aspar tate (NAA), In disease, signals from lactate and mobile lipids may also be observed.Studies of extracts of surgical specimens of human as trocytic tum ors using ]H -N M R spectroscopy indicated an increase in the ratio o f cholines to creatines, and a decrease in the ratio of N A A to creatines, with increas ing histopathological grades of m alignancy.16,45'61 Studies in patients using !H-N M R spectroscopy, referred to as MR spectroscopy, indicated sim ilar correlations betw een m etabolic features in vivo and the histopathological grades of astrocytic tum ors. 4'11'14'21,32,43'57'58'61 Other MR spectroscopy studies indicated that lactate is more likely to be present in high-than in low-grade tumors4, 14,15'20'21 and that the am ount of lactate may correlate with the extent of hyperm etabolic glucose consumption sho...

ABSTRACT. Objective. Despite the frequent occurrence of head injury in children, there is no agreement about clinical screening criteria that indicate the need for imaging studies. This study was undertaken to provide information relevant to the choice of imaging modalities in children with acute head trauma.Methodology. A prospective cohort of 322 children seeking care consecutively in an urban pediatric emergency department for nontrivial head injury was assembled. Skull radiographs, head computed tomography, and data forms including mechanism of injury, symptoms, and physical findings were completed for each child.Results. Intracranial injury occurred in 27 children (8%), whereas 50 (16%) had skull fractures. Of those with intracranial injury, 16 (59%) had normal mental status and no focal abnormalities, and 1 of those 16 required surgery for evacuation of an epidural hematoma. Six (38%) of the 16 were younger than 1 year, 5 of whom had scalp contusion or hematoma without other symptoms. Findings not significantly associated with intracranial injury were scalp contusion, laceration, hematoma, abrasion, headache, vomiting, seizure, drowsiness, amnesia, and loss of consciousness for less than 5 minutes. Findings associated with intracranial injury were skull fracture, signs of a basilar skull fracture, loss of consciousness for more than 5 minutes, altered mental status, and focal neurologic abnormality.Conclusions. Intracranial injury may occur with few or subtle signs and symptoms, especially in infants younger than 1 year. The relative risk for intracranial injury is increased almost fourfold in the presence of a skull fracture, although the absence of a skull fracture does not rule out intracranial injury. The significance of nonsurgical intracranial injury in neurologically normal children needs further study. Pediatrics 1997;99(5). URL: http://www.pediatrics.org/cgi/content/full/99/5/e11; brain injuries, head injuries, skull fractures, computed tomography, radiography.

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