Assessment of T staging and mesorectal fascia status using high-resolution MRI in rectal cancer with rectal distention

Table 1 Definitions used for staging rectal cancer

Histopathologic examination	MRI
pT1: Tumor invades the submucosa	MRT1: Tumor signal intensity is confined to the submucosal layer
pT2: Tumor invades the muscularis propria	MRT2: Tumor signal intensity extends into the muscle layer, with loss of the interface between the submucosa and circular muscle layer
pT3: Tumor invades through the muscularis propria into the subserosa or into the nonperitonealized pericolic or perirectal tissues	MRT3: Tumor signal intensity extends through the muscle layer into the perirectal fat, with obliteration of the interface between muscle and perirectal fat
pT4: Tumor directly invades other organs or structures or perforates the visceral peritoneum	MRT4: Tumor signal intensity extends into an adjacent structure or viscus