STAGE (depth of invasion) | New MDCT criteria |
T1a (mucosa) | Tumor shows enhancement and/or thickening of the inner mucosal layer, as compared to the adjacent normal mucosal layer, with an intact low-density-stripe layer. |
T1b (submucosa) | Disruption of the low-density-stripe layer (less than 50% of the thickness) is visualized. |
T2 (muscolaris propria) | Disruption of the low-density-stripe layer (greater than 50% of the thickness) is visualized without abutting on the outer, slightly high-attenuating layer. |
T3 (subserosa) | Discrimination between the enhancing gastric lesion and the outer layer is visually impossible, and a smooth outer margin of the outer layer or a few small linear strandings in the perigastric fat plane are visualized. |
T4a (serosa) | An irregular or nodular outer margin of the outer layer and/or a dense band-like perigastric fat infiltration is visualized. |
T4b (adjacent organs) | Obliteration of the fat plane between the gastric lesion and the adjacent organs or direct invasion of the adjacent organs. |