神崎 智子¹, 畠 二郎², 今村 祐志², 眞部 紀明², 桶井 一秀³, 楠 裕明⁴, 鎌田 智有¹, 塩谷 昭子¹, 春間 賢¹

Tomoko KANZAKI¹, Jiro HATA², Hiroshi IMAMURA², Noriaki MANABE², Kazuhide OKEI³, Hiroaki KUSUNOKI⁴, Tomoari KAMADA¹, Akiko SHIOTANI¹, Ken HARUMA¹

¹川崎医科大学消化管内科学, ²川崎医科大学検査診断学（内視鏡・超音波）, ³川崎医科大学自然科学, ⁴川崎医科大学総合臨床医学

¹Division of Gastroenterology, Department of Internal Medicine, Kawasaki Medical School, ²Division of Endoscopy and Ultrasound, Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, ³Department of Natural Sciences, Kawasaki Medical School, ⁴Department of General Medicine, Kawasaki Medical School

キーワード : bowel ischemia, ultrasound, contrast-enhanced ultrasonography, intestine

目的：腸管虚血における超音波造影剤Sonazoid^®を用いた造影超音波の有用性を明らかにする．方法：対象は2007年3月から2009年2月の間に腹痛を訴え，かつ超音波Bモード上で2.5 cm 以上の腸管の拡張（n＝40）または1分間に5回以下の蠕動の低下（n＝13）を認めた53例，ならびに基礎疾患に心血管病変を有し，かつ説明困難なアシドーシスを呈することから腸管虚血が疑われた12例である（のべ65例，男性35例，女性30例，平均年齢70.4±16.1歳）．Sonazoid^®をワンショットで静注した後に，低音圧ハーモニックイメージングで再度観察し，腸管壁の染影態度を正常あるいは減弱に分類した．確定診断は手術（n＝30），剖検（n＝6），内視鏡検査（n＝3），腹部血管造影検査（n＝1），経過観察（n＝25）により総合的に行った．結果：造影超音波上で腸管壁染影態度を正常と判断した50例全例を腸管虚血無しと最終診断した．染影態度を減弱と判断した15例のうち，14例で腸管虚血有りと最終診断した．感度は100％（95％ 信頼区間（CI）80.7‐100％），特異度は98％（95％ CI 89.5‐99.9％），陽性予測値は93％（95％ CI 68.1‐99.8％），陰性予測値は100％（95％ CI 94.1‐100％）であった．結論：超音波造影剤Sonazoid^®を用いた造影超音波は，腸管虚血の診断において感度と特異度のきわめて高い画像診断法であり，臨床上有用である．

Purpose: To determine the usefulness of contrast-enhanced ultrasonography with the contrast agent Sonazoid^® for the detection of bowel ischemia. Methods: From March 2007 to February 2009, 65 patients (35 men and 30 women, mean age 70.4±16.1 years) were enrolled. Fifty-three patients complained of acute abdominal pain with small bowel dilatation (n=40) or reduced bowel peristalsis (n=13). Twelve patients were clinically suspected of having bowel ischemia. After Sonazoid^® injection, bowel segments were scanned using harmonic imaging, and the signal intensities were classified as normalor diminished. The definitive diagnosis was confirmed by surgery in 30 patients, autopsy in 6, endoscopy in 3, angiography in 1, and clinical follow-up in 25. Results: All 50 patients with normal signal intensities were confirmed not to have bowel ischemia. In the 15patients with diminished signal intensities, 14 patients were confirmed to have bowel ischemia, resulting in an overall sensitivity of 100% [95% confidence interval (CI)80.7-100%], a specificity of 98% [95% CI 89.5-99.9%], a positive predictive value of 93% (95% CI 68.1-99.8%), and a negative predictive value of 100% (95% CI 94.1-100%). Conclusion: Contrast-enhanced ultrasonography with Sonazoid^® is a highly sensitive and specific method for the diagnosis of bowel ischemia.