Correct visualization of the anal ring.
Thornton
S C
SC
Hirshorn
S A
SA
Bradway
M
M
Levien
D
D
D001003:Anal Canal / Q000473:pathology*; D001005:Anus Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003113:Colonoscopy / Q000379:methods*; D006801:Humans; D012680:Sensitivity and Specificity