狭窄を来す大腸疾患─診断のプロセスを含めた総合画像診断の立場から：上皮性腫瘍，非上皮性腫瘍，炎症性疾患，それぞれに適した検査法の組み合わせ

Processes of the Diagnosis for Stenotic Lesions in the Large Intestine Using Integrated Imaging Modalities

要旨●今日では大腸疾患のほとんどが内視鏡を用いて診断されているが，狭窄性病変の診断は例外で，他の画像診断法を活用して診断する必要がある．特に，腸管外に主座を有する病変の評価にはCT検査やMRI検査が，腸管自体の変化を捉えるには注腸X線造影検査が有用である．狭窄部にみられる所見は，（1）隆起を伴う狭窄，（2）潰瘍を伴う狭窄，（3）びらんを伴う狭窄，（4）これらがみられない狭窄に大別されるが，（4）の診断が最も難しい．本稿ではそれぞれの所見に対応する疾患の特徴とともに，鑑別の要点について述べた．

　At present, most colorectal diseases are diagnosed by colonoscopy ; however, the diagnosis of diseases causing stenosis often becomes possible only by employment of other imaging modalities such as barium enema, CT, MRI, and ultrasonography. Of these, CT is useful for evaluation of extramural changes and barium enema for evaluation of mural ones. The findings related to stenotic lesions are classified into four categories : 1）stenoses with elevated lesions, 2）stenoses with ulcers, 3）stenoses with erosions, and 4）stenoses without such changes. Of them, the last category is the most difficult to diagnose. In this article, the features of disorders corresponding to each finding and the points of differential diagnosis are described.