Influence of contrast-enhanced CT and MRI with or without SPIO particles on therapy and therapy costs for patients with focal liver disease.

Purpose: Evaluation of the diagnostic efficacy and cost-benefit of contrast enhanced CT (CT) and MRI pre- and post-SPIO-particles in focal hepatic dis ease with consideration of therapeutic outcome. Methods: In 52 patients wit h the suspicion of primary or secondary hepatic malignancy, biphasic spiral CT and breathhold gradient-echo T-1- and fast spin-echo T-2-weighted MRI p re- and post-ferumoxide administration (1.5 T, body-phased-array coil) were compared. The number of hepatic lesions and the related diagnoses resultin g from each imaging modality were recorded and statistically correlated to the final diagnoses established by biopsy/OP (34/ 52), long term follow-up of 12 months (18/52), and a consensus reading of all imaging modalities con sidering all clinical imaging information. The most likely induced therapy resulting from each imaging test was correlated to the final therapy. Based on data from the hospitals accountants, the therapy-related costs were est imated without hospitalization costs. Results: In 34/52 (65.4%) of the case s the correct diagnosis was primarily stated by CT (sensitivity [se.] 85.2% , specificity [sp.] 44.0%). In additional 10/52 of the cases unenhanced MRI (se. 91.4%, sp. 75.0%) enabled correct diagnoses, and in another 6 cases t he diagnosis was established only by SPIO-MRI (se. 100%, sp. 86.7%). Consid ering the possible therapeutic recommendation arising from each modality, C T would have induced needles therapy costs of 191,042 DM, unenhanced MRI of 171,035 DM, and SPIO-MRI of 7,311 DM. In comparison to the real therapy co sts of 221,873 DM, this would have corresponded to an unnecessary increase of therapy costs of 86.1%, 77.1%, and 3.3%, respectively. In two cases (1 h emangioma, 1 regenerative nodule) all modalities failed, causing unnecessar y surgery in one patient. Discussion: In this problem-oriented scenario une nhanced and SPIO-enhanced MRI proved to be superior to CT regarding diagnos tic efficacy. The cost-benefit resulted mainly due to preserving patients f rom unnecessary surgical procedures.