畠 二郎

Jiro HATA

川崎医科大学検査診断学

Division of Endoscopy and Ultrasound, Depertment of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School

キーワード : gastrointestinal tract, transabdominal ultrasound

体外式超音波を用いた消化管疾患の診断上, Identification (発見) →Imaging (適切な画像の描出) →Interpretation (画像解析) というステップのいずれもが重要である. 発見には消化管の立体解剖を熟知した系統的走査, 適切な画像の描出には粘膜下層の明瞭な分離が可能な設定, 画像の拡大, 高周波プローブの使用などが必要とされる. また漠然と見た目の印象で診断するのではなく, できるだけ得られた画像を細かく分析する習慣も診断率の向上には重要であり, 適切な画像解析に役立つ10 のポイントとして, 1) 壁肥厚の程度, 2) 病変の部位と分布, 3) 層構造, 4) エコーレベル, 5) 壁外の変化, 6) 蠕動の状態, 7) 壁の硬さ, 8) 内腔の状態, 9) 壁の変形, 10) 血流, をあげそれらの持つ意味に関して概説した. これまで超音波検査の対象外とされてきた消化管であるが, 適切なアプローチにより数多くの疾患が診断可能であり,その臨床的有用性は大きい.

This presentation represents an attempt to provide an overview of an approach to the ultrasonographic diagnosis of gastrointestinal diseases in three essential steps: identification, imaging, and interpretation. Positive identification of a lesion requires systemic scanning of the entire gastrointestinal tract and must be based on thorough knowledge of anatomy. Adequate use of the ultrasound equipment must include proper magnification of ultrasound images, application of harmonic imaging, and active utilization of high-frequency probes if it is to be effective in obtaining clear images with well-defined stratification of the gastrointestinal wall. A reliable sonographic diagnosis must be based on careful analysis of the image, not a cursory glance. I propose that this analysis include the following ten factors: (1) wall thickness, (2) site and distribution of the lesion, (3) wall stratification, (4) echogenicity of the lesion, (5) extramural changes, (6) peristalsis, (7) compliance and compressibility, (8) luminal stenosis or dilatation, (9) deformity, and (10) blood flow. Identification, Imaging, and Interpretation are three keys　that open the way to detecting and accurately diagnosing an array of gastrointestinal disorders.