Peritoneal metastases: evaluation with contrast-enhanced ultrasound.

ABSTRACT

OBJECTIVES: The aim of this study is to evaluate the contrast-enhanced ultrasound (CEUS) features of peritoneal metastases. MATERIALS AND METHODS: Unenhanced ultrasound and CEUS were conducted in 25 patients who had confident diagnoses of peritoneal metastases after ultrasound-guided biopsies of peritoneum. B-mode sonograms, color Doppler, CEUS pattern and quantitative analysis of blood perfusion in peritoneal metastases were successively evaluated. RESULTS: Peritoneum became markedly thickened and was well seen as a heterogeneous omental cake at B-mode ultrasound. Color Doppler only detected dotted or strip-like blood flow scattered in the thickened peritoneum and no blood signal was found in any metastatic nodule. At CEUS, the thickened peritoneum enhanced diffusely and parameters of time-intensity curves did not show any significant difference among variant metastases groups. All the metastatic nodules in the peritoneum showed fast radial enhancement and became homogeneous with adjacent parenchyma. These nodules soon became hypoechoic and the contour of the nodule was clearly shown during the wash-out phase. In all the nodules, the time to peak was shorter and peak intensity was higher compared with the peripheral tissue. CONCLUSION: CEUS played a good role in the evaluation of microcirculation and angiogenesis of peritoneal metastases and metastatic nodules in thickened peritoneum.