Potential Influence of Acute CT on Inpatient Costs in Patients with Ischemic Stroke 1 Suzanne Gleason, PhD, Karen L. Furie, MD, Michael H. Lev, MD, Joan O’Donnell, RN, CNRN Pamela M. McMahon, BS, Molly T. Beinfeld, MPH, Elkan Halpern, PhD, Mark Mullins, MD, PhD Gordon Harris, PhD, Walter J. Koroshetz, MD, G. Scott Gazelle, MD, MPH, PhD Rationale and Objectives. Patients presenting with ischemic brain symptoms have widely variable outcomes dependent to some degree on the pathologic basis of their stroke syndrome. The purpose of this study was to determine the cost impli- cations of the emergency use of a computed tomographic (CT) protocol comprising unenhanced CT, head and neck CT angiography, and whole-brain CT perfusion. Materials and Methods. By using a retrospective patient database from a tertiary care facility and publicly available cost data, the authors derived the potential savings from the use of CT angiography, CT perfusion, or both at hospital arrival by means of a cost model. The cost of the CT angiography–CT perfusion protocol was determined from Medicare reim- bursement rates and compared with that of traditional imaging protocols. Cost savings were estimated as a decrease in the length of stay for most stroke patients, whereas the most benign (lacunar) strokes were assumed to be managed in a non- acute setting. Misdiagnosis cost (erroneously not admitting a patient with nonlacunar stroke) was calculated as the cost of a severe complication. Sensitivity testing included varying the percentage of misdiagnosed patients and admitting patients with lacunar stroke. Results. The nationwide net savings that would result from the adoption of the CT angiography–CT perfusion protocol are in the $1.2 billion range (-$154 million to $2.1 billion) when patients with lacunar strokes are treated nonacutely and $1.8 billion when those patients are admitted for acute care. Conclusion. The results demonstrate the potential effect of implementing a CT angiography–CT perfusion protocol. In particular, prompt CT angiography–CT perfusion imaging could have an effect on the cost of acute care in the treatment of stroke. Key Words. Brain, CT; brain, ischemia; computed tomography (CT), angiography; efficacy study, CT. Recent advances in neurologic imaging, particularly with computed tomography (CT) and magnetic resonance (MR) imaging, have made feasible the use of diagnostic imaging tests in triage decisions for patients suspected of having acute ischemic stroke. The use of a single diag- nostic study at arrival to the hospital— one that combines axial unenhanced CT, CT angiography of the head and neck vessels, and CT perfusion mapping of cerebral per- fused blood volume— can help physicians diagnose the extent and mechanism of stroke more rapidly. If patients with potentially disabling large-artery ischemic strokes could be identified at presentation, they could be treated in a more aggressive acute manner to prevent severe long-term neurologic disability. Patients with stroke mechanisms of a more benign natural history (ie, small- vessel or lacunar strokes) could be identified and treated with safer, less invasive, and less resource-intensive strat- Acad Radiol 2001; 8:955–964 1 From the Department of Economics, Trinity College, 600 Summit St, Hart- ford, CT 06106 (S.G.); the Stroke Service, Department of Neurology (K.L.F., J.O., W.J.K.), Center for Innovated Minimally Invasive Therapy (K.L.F., P.M.M., M.T.B., W.J.K., E.H., G.S.G.), Decision Analysis and Technology Assessment Group (P.M.M., M.T.B., E.H., G.S.G.), Department of Radiology (M.H.L., M.M.), and Computer-aided Diagnostics Laboratory (G.H.), Massa- chusetts General Hospital, Boston; and the Department of Health Policy and Management, Harvard School of Public Health, Boston, Mass (G.S.G.). Received April 4, 2001; revision requested April 25; revision received May 31; accepted June 4. Address correspondence to S.G. © AUR, 2001 955