American Society of Radiologic Technologist (ASRT) Practice Exam

Defecography is used primarily to study what anatomical angle?

1. Length of the transverse colon

2. Angles of the right and left colic flexures

3. Anorectal angle

4. Length of the sigmoid colon

The correct answer is: Anorectal angle

Defecography is a specialized imaging study designed to evaluate the rectum, anal, and pelvic floor during the process of defecation. The primary focus of this procedure is to assess the anorectal angle, which is the angle formed between the rectum and the anal canal. Understanding the anorectal angle is crucial for diagnosing conditions such as fecal incontinence, constipation, and other disorders related to the pelvic floor and anal function. In a healthy individual, the anorectal angle typically changes during defecation, allowing for effective passage of stool. However, abnormalities in this angle can indicate dysfunctions or structural issues that may contribute to gastrointestinal problems. As such, the evaluation of the anorectal angle during defecography provides valuable insights into the patient's condition. Other options mentioned do not pertain specifically to the focus of defecography. For instance, studying the length of the transverse or sigmoid colon does not directly relate to the functionality of the anorectal region, nor does it provide the same clinical insights into defecation mechanics. The angles of the right and left colic flexures are also anatomical considerations that are not the primary focus of defecography, as this imaging modality aims to elucidate issues relevant to bowel evacuation rather than colonic