[Effects of biphasic spiral CT, conventional and iron oxide enhanced MRI on therapy and therapy costs in patients with focal liver lesions].
OBJECTIVE
Evaluation of the diagnostic efficacy and cost-benefit of contrast enhanced CT (CT) and MRI pre- and post-SPIO-particles in focal hepatic disease with consideration of therapeutic outcome.


METHODS
In 52 patients with the suspicion of primary or secondary hepatic malignancy, biphasic spiral CT and breath-hold gradient-echo T1- and fast spin-echo T2-weighted MRI pre- and post-iron oxide administration (1.5 T, body-phased-array coil) were compared. The number of hepatic lesions and the related diagnoses resulting 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 considering 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 estimated without hospitalization costs.


RESULTS
In 34/52 (65.4%) of the cases 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 the diagnosis was established only by SPIO-MRI (se. 100%, sp. 86.7%). Considering the possible therapeutic recommendation arising from each modality, CT 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 costs 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 hemangioma, 1 regenerative nodule) all modalities failed, causing unnecessary surgery in one patient.


CONCLUSIONS
In this problem-oriented scenario unenhanced and SPIO-enhanced MRI proved to be superior to CT regarding diagnostic efficacy. The cost-benefit resulted mainly due to preserving patients from unnecessary surgical procedures.
Helmberger
T
T
Institut für Klinische Radiologie, Klinikum der Ludwig-Maximillians-Universität München, Grosshadern. helmberg@ikra.med.uni-muenchen.de
Gregor
M
M
Holzknecht
N
N
Rau
H
H
Scheidler
J
J
Reiser
M
M
D018248:Adenoma, Liver Cell / Q000175:diagnosis* / Q000191:economics* / Q000628:therapy; D001706:Biopsy; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000191:economics* / Q000628:therapy; D003287:Contrast Media; D003362:Cost-Benefit Analysis; D003365:Costs and Cost Analysis; D003937:Diagnosis, Differential; D005260:Female; D005290:Ferric Compounds; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000191:economics* / Q000556:secondary / Q000628:therapy; D008279:Magnetic Resonance Imaging / Q000191:economics / Q000379:methods*; D008297:Male; D012680:Sensitivity and Specificity; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000191:economics / Q000379:methods*
D003287:Contrast Media; D005290:Ferric Compounds; C000499:ferric oxide