presented with dizziness by a 2:1 ratio (Table I). There was a relatively equal number of Caucasians and Afri- can-American in the sample population. However, these data could not be compared due to the lack of readily available comparable information from the general HMO population. Of 1,028 (61.20%) patients who received a CT to evaluate their complaint, 810 patients received a CT of the head/brain specifically for dizziness or vertigo (excluding patients with syncope, stroke, and history of brain tumor, neurosurgery, or baseline underlying neuro- logical pathology). Of these 810 patients, only 50 (6.17%) had abnormal findings, with six (0.74%) which were clinically significant (Table II). Table III lists the six abnormal CT findings and the presenting symptoms.Of the 90 patients who received MRI of the brain, 16 (17.7%) had abnormal findings, 11 (12.2%) of which were clinically significant (Table IV).The charges for a single CT scan within the health system were $1,220 per study. Thus, the total amount billed for CTs obtained for dizziness in 810 cases was $988,200. The amount charged for the six cases of abnor- mal CT scans totaled $7,320. The cost incurred for a positive CT yield in ED patients with dizziness in our system over the time period studied was $164,700 ($988,200/6). Potential cost savings of unremarkable CT totaled $980,880.Charges for MRI of the brain within the health sys- tem were $2,696 per study. The total charges of MRIs performed for 90 cases of dizziness were $242,640. The amount billed for significantly abnormal MRI scans in 11 cases totaled $29,656. Therefore, the cost of a positive MRI was $22,058 ($242,640/11). Potential cost savings of unremarkable MRI totaled $212,984.For both CT and MRI, the total charges were $1,230,840. There were a total of 17 (1.49%) abnormal findings, which cost $39,976 to obtain. The potential cost savings is approximately $1.2 million.Of the factors analyzed for correlation of both imag- ing modalities, advanced age (P 1⁄4 .001) was found to be potentially associated with acquisition of in-ED CT scan. We found that for every increase of 10 years in age of a