Economic impact of replacing CT with MR imaging for refractory epilepsy

Purpose: To evaluate the economic costs of using computed tomography (CT) vs. magnetic resonance (MR) imaging in the preoperative evaluation of refractory epilepsy patients. Methods: Preoperative CT and MR imaging findings from 117 patients who underwent surgery for medically refractory epilepsy during a 3.5-year period were reviewed. Cost savings were based on the paradigm that intracranial electroencephalogram monitoring (costing about $50,000) would have been necessary for preoperative localization of the epileptogenic zone in those patients without positive imaging findings. Savings attributed to replacing CT with MR were based on patients with positive MR and normal CT. A similar paradigm was used to calculate savings for replacing MR with CT. National savings were based solely on patients with neoplasms or vascular lesions because paradigms for other lesions vary considerable depending on institutional philosophy. Results: Replacing CT with MR imaging would have eliminated preoperative intracranial electrode procedures in 29 of 117 patients, with potential savings of $1,450,000 at our institution. In the 37 patients with neoplastic or vascular substrates, MR would have eliminated 10 invasive electrode procedures with estimated savings of $0.5 million institutionally and $3 to $4 million per year nationally. There were no cases to support replacing MR with CT. Conclusion: Replacing CT with MR decreases health costs associated with preoperative evaluation of intractable epilepsy requiring surgical amelioration.