Table 1.

Definitions of histopathological staging and tomographic criteria.

Category T (6th ed.)	Category T (7th ed.)	Histological criteria	Tomographic criteria
T1	T1	Invasion of the lamina propria (T1a) or submucosa (T1b)	Lesion non detectable at CT Focal thickening or abnormal enhancement of the gastric mucosa, with a preserved hypodense strip deep to the lesion, corresponding to the submucosal layer (Figure 1)
T2	T2 or T3	Muscularis propria (T2) or subserosal layer (T3) invasion	Thickening and abnormal enhancement involving the whole thickness of the gastric wall, with smooth external contour of the stomach (Figure 2)
T3	T4A	Extraserosal extension (invasion of the visceral peritoneum)	Thickening and abnormal enhancement involving the whole thickness of the gastric wall, associated with linear or reticular striations extending towards the perigastric fat (Figure 3)
T4	T4B	Invasion of adjacent organs/structures	The above described alterations extend to adjacent organs/structures (Figure 4)