The role of 3D spiral CT in early gastric carcinoma

The purpose of this study is to assess the role of 3D imaging using spiral CT for the detection and evaluation of early gastric carcinoma (EGC).

Thirty-one patients with EGC underwent 3D and axial imaging using spiral CT, and all cases were confirmed at surgery. According to the pathologic specimens, one patient (3.2%) had type I, five (16.1%) had type IIb, 13 (42.0%) had type IIc, three (9.6%) had types IIc + IIb, three (9.6%) had types IIc + III, two (6.5%) had types IIa + IIc, two (6.5%) had types IIb + IIc, and two (6.5%) had types IIb + III. Spiral CT was first performed with 3 mm collimation, 4.5 mm/s table feed, and a 1 mm reconstruction interval in the supine position after intravenous injection of Buscopan and ingestion of gas. The 3D shaded surface display renderings were performed, analyzed, and graded as excellent, good, or poor. Axial CT scanning was performed with 5 mm collimation, 7 mm/s table feed, and a 5 mm reconstruction interval in the prone position after ingestion of water.

With use of axial CT images, 20 of 31 tumors (64.5%) were detected. Tumors were suspected in two cases, but nine were not detected. With use of 3D images, 29 of 31 tumors (93.5%) were detected (p < 0.05). Of the 31 cases of EGC, excellent 3D images were obtained in 6 patients (19.3%), good 3D images in 21 (67.7%), and poor 3D images in 2 (6.5%). In the two cases with poor images, the tumor was confined to the mucosal layer and the types were EGC IIc + IIb. In the remaining two cases (6.5%), the tumors were not detected by 3D images. In one case, the tumor was confined to the mucosal layer, and in the other it was located in the pyloric antrum. Both tumors were EGC type IIc. The two cases not detected by 3D imaging were also not detected by axial CT scanning.

The detection rate of EGC is higher using 3D imaging than axial CT scan alone.