小腸疾患診断におけるカプセル内視鏡の有用性と限界

Utilities and Limitations of Small Bowel Capsule Endoscopy in Diagnosing Small Bowel Pathologies

要旨●小腸内視鏡機器の進歩・普及に伴い，小腸疾患診断において内視鏡検査は必要不可欠な検査モダリティとなった．低侵襲かつ高い全小腸観察率を特徴とするカプセル内視鏡は，上部・下部内視鏡検査で出血源を認めない原因不明の消化管出血例に対して高い有用性を発揮するが，腸管蠕動により受動的に管腔内を移動する本検査法は小腸病変の精査には不向きであった．しかし，視野角拡大，画像解像度の向上，フレームレート調整機能追加などにより病変性状評価能も改善されてきた．また，本検査法の問題点の一つである画像読影についても，人工知能の応用による見落とし率低下や読影時間短縮の可能性が報告され，有用性・利便性の向上が期待される．

　Enteroscopy has become a mandatory modality for diagnosing small bowel diseases with the application of advance enteroscopy instruments to daily clinical practice. Small bowel capsule endoscopy, characterized by minimal invasiveness and a high rate of whole small bowel observation, has been the first choice of modality for patients with obscure gastrointestinal bleeding. However, it is inappropriate for diagnosing small bowel pathologies considering the device's passive movement through the gastrointestinal tract. Various instrumental improvements have recently been introduced, including viewing angle, image resolution, and adaptive frame rate. Furthermore, artificial intelligence has been applied to decrease oversight and shorten the reading time, thereby expecting a more reliable and convenient examination.