ObjectiveTo investigate the CT presenting rate and features of gastric bare area (GBA, including the area posterior to GBA and the adipose tissue in the gastrophrenic ligament) without pathologic changes.MethodsThirty cases with superior peritoneal ascites, but without pathological involvement of GBA were included into the study to show the normal condition of GBA, including the presenting rate and CT features. We selected some cases with GBA invasion by inflammation or neoplasm to observe their CT features. ResultsAll cases with superior peritoneal ascites showed the GBA against the contrast of ascites with the presenting rate of 100%. The GBA appeared at the level of gastricesophageal conjunction and completely disappeared at the level of hepatoduodenal ligament and Winslow’s foramen. The maximum scope of GBA presented at the level of the sagital part of the left portal vein with mean right to left distance of （4.39±0.08）cm (3.8~5.7 cm) (distance between the left and right layer of the gastrophrenic ligament). In acute pancreatitis, the width of GBA increased, in which local hypodensity area could be seen. In gastric leiomyosarcoma invading GBA, the mass could not separate from the crus of the diaphragm. In lymphoma and metastasis invading GBA, the thickness of GBA increased and the density was heterogeneous, in which lymph nodes presenting as small nodes or fused mass. ConclusionThe results of this study show that it is helpful to use contrast enhanced spiral CT scanning to observe the change of GBA and to diagnose retroperitoneal abnormalities that involving GBA comprehensively and accurately.
【Abstract】ObjectiveTo study the CT features of bare area involvement in gastric carcinoma and their anatomicpathological basis, and to evaluate the role of multi-detector CT in the diagnosis of bare area involvement. Methods In 196 consecutive gastric carcinoma cases, 56 were found bare area involvement and divided into proximal gastric carcinoma (PGC) group and distal gastric carcinoma (DGC) group according to anatomic position of primary tumor. CT images and incidence of gastric bare area (GBA) involvement in the PGC group were observed and compared with those of DGC group. Results The lesion appeared as nodule or mass in bare area in 46 cases and as metastatic lymphadenopathy in 10 cases. CT features of GBA involvement included: ① widening of gastric bare area and blurring or obliteration of the thin fat strip between gastric wall and diaphragm; ② irregular mass with heterogeneous enhancement or round lymph nodes in GBA; ③ irregular thickening of left diaphragmatic crus or gastrophrenic ligament with blurring border to the mass; ④ other metastatic lymph nodes in subphrenic extroperitoneal space. The incidence of GBA involvement in PGC group was 70.0%(42/60), significantly difference from those in DGC group (10.3%,14/136) ,P=0.025. Conclusion The incidence of GBA involvement in PGC group is significantly higher than those in DGC group. Multidetector CT is very useful for preoperative imaging evaluation of bare area involvement and lymphatic spread.