胃・十二指腸感染症の病態と画像診断

Pathophysiology and Imaging Diagnosis of Gastric and Duodenal Infections

要旨●感染性胃炎としてサイトメガロウイルス胃炎，胃梅毒，胃結核，胃カンジダ症を，感染性十二指腸炎としてWhipple病，十二指腸非結核性抗酸菌症，ランブル鞭毛虫症，糞線虫症を取り上げ，各疾患の病態と画像診断を概説した．これらの胃・十二指腸感染症はまれであるが生命予後に影響する可能性が高い疾患が多く，拾い上げ診断が重要である．診断は主に内視鏡下生検に基づくため，各疾患の病態を理解し特徴的な内視鏡所見と至適生検部位に精通しておく必要がある．特に，感染性十二指腸炎の拾い上げ診断と他疾患との鑑別には“白色絨毛”に着目することが有用である．

　Cytomegalovirus gastritis, gastric syphilis, gastric tuberculosis, and gastric candidiasis are referred to as infectious gastritis, whereas Whipple's disease, duodenal non-tuberculosis, rumble flagellosis, and fecal nematode disease are considered infectious duodenitis. The pathogenesis and imaging diagnosis of each disease are outlined in this article. These gastrointestinal and duodenal infections are rare but have a high potential to affect a patient's life prognosis ; thus, a pick-up diagnosis is important. Given that the diagnosis is mainly based on the endoscopic biopsy findings, it is necessary to understand the pathogenesis of each disease and be familiar with the characteristic endoscopic findings and optimal biopsy sites. Particularly, focusing on the “white villi” to identify and diagnose infectious duodenitis and differentiate it from other diseases is essential.