Study on CT findings of gastric stromal tumors

Objective: To investigate CT findings in gastric stromal tumors(GST). Methods: Both plain and enhanced spiral CT findings in 46 cases with gastric stromal tumor were retrospectively analyzed. In all patients, diagnosis was confirmed with immunohistochemical markers. CT features were retrospectively studied and summarized. Statistical analysis of the shape, growth pattern, necrosis and enhancement patterns was performed with χ2 test in 43 cases with single gastric stromal tumor. Results: Of the 46 GST patients, 43 patients had single GST and multiple CST was detected in 3 cases. In the 43 cases with single GST, tumors were found in the gastric body in 24 cases, gastric fundus in 16 cases, and in the gastric antrum in 3 cases. GST mostly grow along the vertical plane of gastric wall, with a large size but local attachment. The tumor size was less than 5 cm in diameter in 14 cases. Of them, ten cases had a regular shape, 10 cases showed homogeneous enhancement, and 4 cases exhibited central necrosis, 7 tumors showed intra-luminal growth and 5 tumors showed extra-luminal growth, while the other 2 cases involved both intra and extra lumina. Twenty-nine cases had tumors larger than 5 cm in diameter. Of them, 24 cases had irregular shape, 27 cases showed inhomogeneous enhancement, 24 cases had central necrosis, 5 tumor's showed intra-luminal growth and 9 tumor's showed extra-luminal growth, while 15 cases involved both intra and extra lumina. The tumor size of GST closely was related to the shape, growth pattern, necrosis and the inhomogeneous enhancement patterns of the GST (P<0.05). The enhancement of the tumor was more intense in venous phase and delayed phase. Five cases showed septal enhancement, 4 tumors exhibited marked enhancement in arterial phase with up to 60 HU. Conclusions: CT can precisely display the location, shape and size of gastric stromal tumors. It is very helpful to provide useful information for early diagnosis and evaluation. (authors)