Lei Tang MD, Presenter: Nothing to Disclose

Zi-Yu Li, Abstract Co-Author: Nothing to Disclose

Ying-Shi Sun MD, PhD, Abstract Co-Author: Nothing to Disclose

Fei Shan, Abstract Co-Author: Nothing to Disclose

Xiaoting Li, Abstract Co-Author: Nothing to Disclose

Jia-Fu Ji, Abstract Co-Author: Nothing to Disclose

To explore the characteristics of the CT missed peritoneal metastasis (PM) of gastric cancer through the region-by-region comparison with diagnostic laparoscopy findings.

Total of 251 consecutive patients with advanced gastric cancer and diagnosed as free of PM by spectral CT enrolled in the study. All of the patients were performed diagnostic laparoscopy to verify the findings on CT. If PM detected during laparoscopic exploration, the exact metastasis location would be recorded and compared with CT findings. The target observation regions included the omentum, diaphragm, transverse mesocolon, parietal peritoneum and hepatogastric ligament. The concerning signs included smudge sign, uncertain small nodules and thickening of the parietal peritoneum. The smudge sign was further divided into (1) mild type: slightly and evenly increased fat density appeared as ground glass opacity (GGO), (2) moderate type: unevenly increased fat density, with patchy-like or intensive GGO, (3) severe type: unevenly and obviously increased fat density, with multiple strands, curls sign or blurred small nodules. The demonstration rates of the above signs on spectral CT would be compared and analyzed between PM positive and negative patients.

Forty-six patients were confirmed as PM positive through laparoscopic exploration. Through the region-by-region comparison, there was still no any suspected CT sign in 16 patients. Total of 43 abnormal regions in 30 patients with PM positive signs on retrospective spectral CT were detected. There were 30 PM regions in 24 patients displayed as smudge sign (mild type, 7 regions; moderate type, 11 regions; severe type, 12 regions), ten regions as thickening of the parietal peritoneum, and three regions of undetermined small nodules. The detection rate of the smudge sign on spectral CT in PM positive patients was significantly higher than that of the PM negative ones (24/46, 52.2% vs. 31/205, 15.1%, p<0.01).

Smudge sign is the most common finding in CT missed PM patients with gastric cancer, paying attention to this sign will contribute to the early detection of peritoneal metastasis.

The study retrospectively analyzed the suspect sign of CT missed peritoneal metastasis in gastric cancer, which may contribute to the early detection of peritoneal metastasis.

Tang, L, Li, Z, Sun, Y, Shan, F, Li, X, Ji, J, The Analysis of CT Missed Peritoneal Metastasis in Gastric Cancer: A Region-by-Region Comparison with Diagnostic Laparoscopy.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010358.html