Incidental findings in brain computed tomography scans of 3000 head trauma patients.

Background: Limited reports exist about intracranial incidental findings on computed tomography (CT) imaging. We studied the frequency of incidental findings on 3000 brain CT scans of trauma patients.
Methods: Three thousands standard brain CT scans of trauma patients were evaluated for some incidental findings. Cisterna magna was evaluated in 1500 CT scans.
Results: In this study we found 30 incidental abnormalities that include 8 cases of tumor: 3 meningioma, 2 craniopharyngioma, 1 oligodendroglioma, 1 low-grade astrocytoma, and 1 medulloblastoma. Suspect osteoma was found in 3 cases. In 3 cases, abnormal calcification was found in pineal region, basal ganglia, and temporal horn area. Three suspect lipomas were found in midline and near midline of the brain. Arachnoid cyst was found in 7 cases and hydrocephaly in 3 cases. Large cisterna magna (>10 cm(3)) was found in 11 cases.
Conclusion: Cisterna magna enlargement was the most common incidental finding and brain tumor and arachnoid cyst were next in frequency.