Abstract Update

The following abstract has been replaced:
Pediatrics
095. MR Imaging Findings in Immunocompromised Children with Human Herpes Virus 6 Encephalitis
Provenzale J.M.*; Mukundan S.; White L.E.; Lewis D.V.; Radiology, Pediatrics and Physical Therapy, Duke University Medical Center, Durham, NC.

Pediatrics
NEW 095.Head CT in pediatric patients following blunt trauma: utilization, incidence of traumatic brain injury, injury progression and outcomes.
*Chaudry S.; Hollingworth W.; Vavilala M.S.; Jarvik J.G.; Wang M.C. University of Washington, Department of Radiology, Seattle, WA.

Objective: Head CT is frequently used in the evaluation of pediatric patients with traumatic brain injury. We evaluated the utilization and diagnostic yield of initial and repeat head CTs in children.
Materials and Methods: A retrospective study of patients (age <15 years) admitted to the emergency department between 1994 and 2003 following blunt trauma. Data were gathered from the trauma registry and radiology information systems. The CT reports of a subset of patients who had more than one head CT were reviewed, blinded to demographic and clinical details.
Results: 6,664 patients met our criteria of whom 2,279 (34%; mean age 7.2; 63% male; 68% admitted to hospital) had at least one head CT within 6 hours of admission. 582 (9%) of these patients also had a second head CT within one week. In patients with at least one head CT, the mean number of head CTs per patient increased by age (1.45 (0-4 yrs) vs 1.52(5-9yrs) vs 1.71(10-14yrs)) (p<0.01); this relationship remained after adjustment for mechanism, Glasgow coma score, severity of injury and polytrauma. In the subgroup of patients with more than one head CT, the initial findings were: normal (13%); epidural hematoma (14%); subdural hematoma (25%); subarachnoid hemorrhage (21%); intra-ventricular hemorrhage (6%); intraparenchymal hemorrhage (32%); edema (18%) diffuse axonal injury (9%); mass effect (13%); skull fracture (51%). Skull fractures were significantly more prevalent in the youngest age group, while the prevalence of IPH, edema, and DAI increased with age even after adjustment for injury mechanism and severity. The majority of 2nd CT reports documented interval improvement (19%) or no change (50%). Nearly 1/3 of repeat CTs showed worsening TBI (13%) or a new lesion (17%). The probability of new or worsening findings increased with age (24% vs. 30% vs. 38%; p<0.01). Hospital stay and inpatient mortality were lowest in younger patients.
Conclusion: Initial head CTs have high yields while the yield of repeat head CTs are lower. However, both are likely useful in the diagnostic work-up of TBI. Head CTs were requested less frequently in the youngest patients. Older children were more likely to have progressive and delayed brain injuries and worse outcomes.