Greyscale and contrast enhanced ultrasonography for characterization of gastric malignant tumors.

Aims: To evaluate the utility of grey scale ultrasonography (US) and contrast enhanced ultrasonography (CEUS) for characterization of malignant gastric tumors. Material and methods: The study was conducted prospectively and it included a number of 30 patients with malignant gastric tumors diagnosed through upper tract endoscopy and biopsy: 25 adenocarcinomas, 3 lymphomas, and 2 stromal tumors. All the patients were examined by US, followed immediately by CEUS, using both oral and intravenous contrast agents. CEUS assessed the dynamics of the contrast agent during the arterial phase and the venous phase. The distribution characteristics of the contrast agent inside the region of interest (ROI) were also evaluated. Twenty four patients underwent surgery. Results: Adenocarcinomas presented heterogeneous enhancement with variable pattern, followed by a delayed wash-out in almost all of the situations. Lymphomas presented a variable pattern, intensity and homogeneity of the enhancement, followed by delayed wash-out. Stromal tumors showed early arterial intense and homogenous enhancement followed by moderate wash-out in venous phase. Conclusions: Grey scale US and CEUS are useful methods in characterizing gastric tumors and contribute to a more adequate evaluation of the lesions. The dynamics of the contrast agent may be suggestive for the anatomopathological nature of the tumor. Larger studies will be necessary in order to determine the practical value of the method.