Mihmanli Ismail, Kantarci Fatih, Dogra Vikram S
Department of Radiology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey.
Ultrasound Q. 2011 Jun;27(2):87-104. doi: 10.1097/RUQ.0b013e31821c7f21.
Endoanorectal ultrasonography (EARUS) may be used for diagnosing various anorectal disorders. EARUS is easy to perform, has a short learning curve, and causes less discomfort than routine digital examination. Anal sphincters can be clearly visualized, and one can easily distinguish between the internal (hypoechoic) and external (hyperechoic) anal sphincters. Other pelvic floor structures, like the puborectalis muscle, can also be visualized. The use of contrast agents can increase the accuracy of EARUS in the assessment of perianal fistulae. In addition, EARUS is an excellent alternative to expensive magnetic resonance imaging. Besides its use in incontinence and perianal sepsis, the presence of slight or massive submucosal invasion in early rectal cancer may be imaged in greater detail. With 3-dimensional EARUS, it is possible to diagnose the anorectal diseases, in multiplane, with high spatial resolution, adding important information about the therapeutic decision. The normal sonographic anatomy of the anorectum, sonographic findings of anorectal diseases, and indications and limitations of endosonography with complementary techniques such as transvaginal and transperineal ultrasound are reviewed in this article.
直肠内超声检查（EARUS）可用于诊断各种肛肠疾病。EARUS操作简便，学习曲线短，与常规指诊相比引起的不适更少。肛门括约肌可清晰显示，能够轻松区分内部（低回声）和外部（高回声）肛门括约肌。其他盆底结构，如耻骨直肠肌，也能被显示出来。使用造影剂可提高EARUS在评估肛瘘方面的准确性。此外，EARUS是昂贵的磁共振成像的绝佳替代方法。除了用于尿失禁和肛周脓毒症外，早期直肠癌轻微或大量黏膜下侵犯的情况也能更详细地成像。借助三维EARUS，能够在多平面以高空间分辨率诊断肛肠疾病，为治疗决策增添重要信息。本文综述了直肠肛管的正常超声解剖、肛肠疾病的超声表现以及内镜超声检查与经阴道和经会阴超声等辅助技术的适应证和局限性。
