What are the CT signs of gastric cancer

Imaging examinations are often used in the diagnosis of gastric cancer, among which CT examination is relatively common. Common signs of gastric cancer patients include the following:

1. Thickening of the gastric wall: The thickening of the gastric wall is caused by the infiltration of the cancer along the gastric wall. It is mainly caused by the deep infiltration of the cancer along the gastric wall. The thickened gastric wall can be localized or diffuse. Depending on the depth of cancer infiltration, the serosal surface can be smooth or not smooth, but the mucosal surface shows different degrees of unevenness, which is one of the characteristics of gastric cancer. The density of gastric cancer lesions on plain scan is similar to that of normal gastric wall. Occasionally, in mucinous adenocarcinoma, the lesions contain a large amount of mucinous substances and show diffuse low density. In signet ring cell carcinoma, diffuse punctate calcification can sometimes be seen inside the tumor.

2. Intracavitary mass: The cancer grows into the gastric cavity, forming a mass that protrudes into the gastric cavity. The mass may be an isolated bulge or a part of the thickened gastric wall that protrudes significantly into the gastric cavity. The surface of the mass is not smooth and may be lobed, nodular or cauliflower-shaped, and may be accompanied by ulcers on the surface.

3. Ulcers: Gastric cancer forms intracavitary ulcers, which are well known in traditional radiology. CT images can better show this feature of gastric ulcers. The edges of the depressions formed by the ulcers are irregular, the bottoms are often not smooth, the surrounding stomach walls are obviously thickened, and they protrude into the stomach cavity.

4. Annular dyke: The dyke appears as a dyke-like protrusion surrounding the cancerous ulcer. Depending on the growth pattern of the tumor, the outer edge of the dyke may be sharp or unclear. Depending on the shape of the stomach, the appearance of the dyke on the CT cross-sectional image is also different.

5. Gastric cavity stenosis: CT shows gastric cavity stenosis based on gastric wall thickening. The edge of the narrow gastric cavity is relatively rigid and irregular, mostly showing asymmetric centripetal stenosis, accompanied by circumferential asymmetric gastric wall thickening. Three-dimensional reconstruction can better show the degree of gastric cavity stenosis.

6. Changes in mucosal folds: Mucosal folds appear as ridge-like protrusions on the mucosal surface in CT cross-sectional images. Continuous layers show changes in the spacing and morphology of the ridge-like protrusions. The gradual narrowing, fusion, and disappearance of the spacing indicate changes such as concentration, interruption, and destruction of the mucosal folds. These subtle changes can be better reproduced in three-dimensional images. The mucosal folds of gastric cancer are thickened and enlarged, and there is often obvious enhancement after enhancement, often accompanied by local thickening of the gastric wall.

7. Abnormal enhancement of the gastric wall: Abnormal enhancement of the gastric wall is a very significant manifestation of gastric cancer. The timing of enhancement has a great influence on the display of lesions. Mucosal lesions can be significantly enhanced 35 to 45 seconds after the injection of contrast agent, while the peak time of lesions invading the muscular layer is after the mucosal enhancement, usually after 50 to 60 seconds, and the enhancement is more obvious and lasts longer than that of normal gastric wall.