Chan Lauren, Shin Lewis K, Pai Reetesh K, Jeffrey R Brooke
Stanford University School of Medicine, Stanford University Medical Center; Stanford, CA, USA.
Ultrasound Q. 2011 Jun;27(2):71-9. doi: 10.1097/RUQ.0b013e31821b6eea.
Appendicitis is one of the most common causes of the acute abdomen often requiring emergent surgery. Delayed diagnosis leads to the progression of uncomplicated appendicitis to complicated (gangrenous, perforated) appendicitis, often changing clinical management. Computed tomography and ultrasound are imaging modalities of choice to preoperatively diagnose appendicitis. Recent concerns of radiation exposure and cost have renewed interest in using ultrasound as an initial, diagnostic study. A sonographic pictorial and histopathologic review of the continuum of appendicitis is presented. A comprehensive sonographic examination of the appendix should investigate the size (maximal diameter), the echogenic submucosal layer integrity, the mural color Doppler signature, the presence of a fecalith, and the periappendiceal changes. Features of an uncomplicated appendicitis include size greater than 6 to 7 mm, hyperemia on color Doppler, mural thickening, and an intact echogenic submucosal layer. Gangrenous appendicitis is characterized by loss of the echogenic submucosal layer with absent color Doppler flow. Loculated pericecal fluid, prominent pericecal fat, and circumferential loss of the submucosal layer are suggestive of perforation. Sonographic staging can triage management of appendicitis by directing urgent laparoscopic appendectomy for uncomplicated appendicitis, open appendectomy for complicated appendicitis, and conservative management (antibiotics with percutaneous drainage) for perforated appendicitis with abscess formation.
阑尾炎是急腹症最常见的病因之一，常需急诊手术。诊断延误可导致单纯性阑尾炎进展为复杂性（坏疽性、穿孔性）阑尾炎，这常常会改变临床治疗方案。计算机断层扫描和超声是术前诊断阑尾炎的常用影像学检查方法。近期对辐射暴露和成本的关注重新激发了人们对将超声作为初始诊断检查手段的兴趣。本文呈现了阑尾炎连续过程的超声图像及组织病理学回顾。对阑尾进行全面的超声检查应包括观察其大小（最大直径）、黏膜下层回声的完整性、壁层彩色多普勒血流信号特征、粪石的存在情况以及阑尾周围的变化。单纯性阑尾炎的特征包括直径大于6至7毫米、彩色多普勒显示充血、壁层增厚以及黏膜下层回声完整。坏疽性阑尾炎的特征是黏膜下层回声消失且彩色多普勒血流信号缺失。局限性盲肠周围积液、明显的盲肠周围脂肪以及黏膜下层的环形缺失提示穿孔。超声分期可指导阑尾炎的治疗决策，对于单纯性阑尾炎行急诊腹腔镜阑尾切除术，对于复杂性阑尾炎行开腹阑尾切除术，对于伴有脓肿形成的穿孔性阑尾炎则采取保守治疗（抗生素联合经皮引流）。
