[Characterization of hepatic tumors with contrast-enhanced ultrasound and digital grey-scale analysis]. / Charakterisierung von Lebertumoren durch kontrastverstärkte Sonographie und digitale Graustufenbestimmung.

PURPOSE: The characterization of different liver tumors is of therapeutic and prognostic relevance and has been the purpose of several studies. Although ultrasound offers the opportunity to detect hepatic tumors without ionizing radiation, its previous techniques did not lead toward a definitive differentiation of different tumor entities. The purpose of this study was the clinical evaluation of contrast enhanced ultrasound followed by quantitative digital analysis in patients with focal hepatic tumors. MATERIALS AND METHODS: In a prospective study, 50 patients (18 females, 32 males, age 28 to 83 years, mean age 59.4 years) with liver tumors previously detected by CT (n = 47) or MRI (n = 3) were examined by ultrasound of the upper abdomen using conventional technique and phase inversion technique after intravenous application of sulfur-based contrast enhancer SonoVue. At scheduled intervals after application of the contrast enhancer, a digital image was stored and the characteristic signal course of each lesion determined semiquantitatively. The gold standard was either resection (n = 17), percutaneous needle biopsy (n = 19) or the clinical course (n = 14). RESULTS: While the percentage of tumors correctly characterized by CT/MRI amounted to 78 %, the percentage increased from 60 % using conventional ultrasound to 86 % using contrast enhanced ultrasound including grey-scale analysis. Typical graphs were achieved for different tumor entities on digital grey-scale analysis. The optimal intervals for the differentiation of particular entities were 20 and 100 seconds after injection. CONCLUSION: Quantification of contrast enhanced ultrasound is an addition to the previous diagnostic procedure in hepatic tumors. It offers the possibility of an investigator-independent characterization of lesions and should be evaluated in further studies.

[Magnetic resonance tomography guided focussed ultrasound surgery (MRgFUS) in tumor therapy--a new noninvasive therapy option]. / Magnetresonanztomographiegesteuerter fokussierter Ultraschall (MRgFUS) in der Tumortherapie--eine neuartige nichtinvasive Therapieoption.

The demand for minimal or non-invasive therapies especially in tumor therapy is increasing constantly. High frequency focussed ultrasound represents an effective and safe alternative to established thermoablative procedures. In this article we report the advantages of MR-guidance for focussed ultrasound. We describe first clinical experiences in the treatment of uterine fibroids, breast cancer and fibroadenomas of the breast employing MR-guided focussed ultrasound surgery (MRgFUS). This method offers strong potential in the treatment also of other tumorentities since it provides excellent accuracy. Currently numerous efforts are undertaken to introduce MRgFUS for the therapy of liver or cerebral tumors.