直腸肛門部疾患のEUS診断

Diagnosis of Anorectal Diseases by Endoscopic Ultrasonography

要旨　直腸肛門部疾患の中で，特に直腸には種々の腫瘍性疾患や炎症性疾患を認める．直腸疾患の診断には内視鏡検査を主として用いるが，超音波内視鏡（EUS）は病変の垂直断層像が描出可能であることから，腫瘍性疾患に対しては，直腸癌の深達度診断や粘膜下腫瘍の質的診断などに有用である．また炎症性疾患に対しては，潰瘍性大腸炎の重症度の評価や，Crohn病に合併する肛門病変の診断などに有用である．EUSは直腸肛門部疾患の補助的診断法として活用できると考える．

　Among anorectal diseases, the rectum is particularly prone to various types of tumors, as well as inflammatory bowel disease. Although rectal diseases are diagnosed mainly by colonoscopy, EUS can depict vertical cross-sectional images of lesions and is therefore useful for assessing the depth of invasion of rectal cancer and the qualitative diagnosis of submucosal tumors. In patients with inflammatory bowel disease, EUS can be used to evaluate the severity of UC and to diagnose anal lesions associated with Crohn's disease. Therefore, we believe that EUS is a useful technique for the diagnosis of anorectal diseases.