Ultrasonography and computed tomography in pseudomyxoma peritonei.

Three patients with pseudomyxoma peritonei were found to have quite different sonographic and CT features from those described previously. Ultrasound (US) revealed (a) a large, highly echogenic mantle consisting of numerous tiny cysts, (b) echogenic "ascites" which was actually gelatinous in nature, or (c) multiple indentations of the bowel by semi-solid masses. On CT, the large masses appeared as spaces resembling ascites but containing mottled densities, while the regions which resembled echogenic "ascites" on US had an attenuation value slightly higher than water.