Cranial Cranial Computed Tomography Scan Research Articles

Accuracy of Interpretation of Cranial Computed Tomography Scans in an Emergency Medicine Residency Program

Study objectives: To determine the concordance of emergency physicians and radiologists in interpreting cranial computed tomography (CT) scans. The study also sought to determine the clinical significance of misinterpretations of cranial CT scans by emergency physicians. Design: Prospective cohort study. Setting: A county hospital emergency medicine residency program. Participants: Five hundred fifty-five patients undergoing CT scanning during emergency department evaluation. Results: Forty-nine percent (272) of the indications for CT scanning were for trauma, 14.2% (79) were for cerebrovascular accident, 25.1% (139) were for headache, 15.1% (84) were for seizure, and 13.7% (76) were for miscellaneous reasons. The radiologists interpreted 46.1% (256) of the CT scans as abnormal. The most frequent abnormalities were scalp hematoma, 15.2% (39); infarction, 14.1% (36); calcification, 6.3% (16); contusion, 6.3% (16); parenchymal hemorrhage, 5.1% (13); and mass, 5.1% (13). Nonconcordance between radiologists and emergency physicians was found in 38.7% (206) of the cases. Potentially clinically significant misinterpretations were found in 24.1% (131) of the total sample. These misinterpretations included 62 missed major findings (11.4% of total sample): 25 new infarcts, 10 mass lesions, 8 cases of cerebral edema, 8 parenchymal hemorrhages, 5 contusions, 4 subarachnoid hemorrhages, 1 epidural hematoma, and 1 subdural hematoma. However, on chart review, only three patients (0.6%) were found to have been managed inappropriately, and none had an adverse outcome. Conclusion: The misinterpretation rate of cranial CT scans by emergency physicians is of potential clinical concern. However, clinical mismanagement is rare. We recommend that more formal education in CT interpretation be included in residency training and continuing medical education programs for emergency physicians. [Alfaro D, Levitt MA, English DK, Williams V, Eisenberg R: Accuracy of interpretation of cranial computed tomography scans in an emergency medicine residency program. Ann Emerg Med February 1995;25:169-174.]

Cranial Computed Tomography Scans in Children After Minimal Head Injury With Loss of Consciousness

See related editorial, "CT for Head Trauma in Children." Study objective: To assess the need for cranial computed tomography (CT) in the emergency department evaluation of children with Glasgow Coma Scale (GCS) score of 15 after mild head injury with loss of consciousness. Design: Retrospective case series of children aged 2 to 17 years with documented loss of consciousness after head injury from January 1, 1988, to July 31, 1992. All had a GCS score of 15 on initial ED evaluation and were further categorized according to physical examination findings, neurologic status, and whether the head injury was isolated or nonisolated. Recursive partitioning was used to identify variables predictive of the presence and absence of intracranial hemorrhage. Setting: ED in two settings: a regional tertiary care trauma center and a community children's hospital. Results: Of the 185 patients who met study criteria, 17 had evidence of depressed or basilar skull fractures on physical examination or had a ventriculoperitoneal shunt in place before head injury. In the remaining 168 patients, recursive partioning identified two variables (neurologic status and head injury type) associated with intracranial hemorrhage. Overall, 12 of 168 patients (7%) had intracranial bleeding. However, none of the 49 neurologically normal children with isolated head injury had intracranial hemorrhage (95% confidence interval, 0.0 to 6.0). Conclusion: The prevalence of intracranial hemorrhage in children with mild closed-head injury appears to vary with the presence of neurologic abnormalities and other noncranial injuries. After isolated head injury with loss of consciousness, children older than 2 years who are neurologically normal and without signs of depressed or basilar skull fracture may be discharged home from the ED without a cranial CT scan after careful physical examination alone. [Davis RL, Mullen N, Makela M, Taylor JA, Cohen W, Rivara FP: Cranial computed tomography scans in children after minimal head injury with loss of consciousness. Ann Emerg Med October 1994;24:640-645.]

Limitations of neurological assessment in mild head injury.

The authors have investigated two commonly used methods of assessing neurological status in patients with mild head injury to determine whether they can predict intracranial damage. Of 686 such patients with cranial computed tomography (CT) scans, scan results were recorded, along with total and motor components of the Glasgow Coma Scale (GCS) and the Reaction Level Scale (RLS85). Despite relatively normal admission neurological examinations, 127 of the 689 patients (18.4%) had intracranial lesions, and 38 (5.5%) required surgery. There was no significant difference in distribution of the GCS in patients with and without intracranial lesions. The RLS85 was superior to the GCS in predicting intracranial pathology, and a significant association between RLS85 and lesions on CT scanning was noted. However, even this test was normal in 19 patients found to have intracranial pathology, including nine who required surgery. The authors conclude that a normal or near-normal mental status examination in a head-injured patient on arrival at the emergency room is inadequate to exclude a potentially serious intracranial lesion. It is unlikely that further refinements in the clinical evaluation will result in diagnostic accuracy comparable with that of CT scanning. Accordingly, we recommend that any patient who has suffered a loss of consciousness or amnesia following head injury have an urgent cranial CT scan.

Case Report

Cranial computed tomography (CT) in a 58-year-old man disclosed enhancing lesions in the medial right temporal lobe and the right pons. Biopsy of the sural nerve was positive for Whipple's disease, and one of the temporal lobe lesions showed unprecedented histological findings. This case, to our knowledge, is unique in its demonstration of cranial CT findings in association with Whipple's disease. It is suggested that a cranial CT scan with the use of intravenous contrast material should be performed in patients presenting with the signs or symptoms of Whipple's disease.