Induced pneumoperitoneum in CT evaluation of peritoneal carcinomatosis

Imaging of peritoneal carcinomatosis is a well-known problem even for technologies as recent as computed tomography (CT). The purpose of this study was to evaluate whether CT performed after induced pneumoperitoneum (CT-PP) could have a higher sensitivity in the detection of peritoneal implants over conventional CT.

Five patients with known ovarian malignancies underwent standard CT and CT-PP. Exploratory laparotomy was performed with a maximum interval of 7 days from the last imaging procedure. Results were prospectively compared with surgical findings on a compartment to compartment basis.

CT-PP was well-tolerated with no serious adverse reactions registered. The anterior and visceral peritoneum, the paracolic gutters and subphrenic areas were particularly well depicted but not the pelvis which was poorly evaluated in all cases. CT-PP detected all the three cases where peritoneal carcinomatosis was present even when metastatic nodules were smaller than 2 mm; it also showed intraabdominal adhesions in two patients, an important finding that precludes the use of intraperitoneal chemotherapy.

With CT-PP there seems to be a reduction in the threshold of detectability of peritoneal implants. The direct demonstration of intraperitoneal adhesions is an important secondary finding. Disadvantages of CT-PP are (1) it is a time-consuming method and (2) it does not evaluate all the peritoneal recesses potentially involved in peritoneal carcinomatosis.