The presacral space is located between the rectum and the sacrococcygeal part of the spine.
The levator ani and coccygeus muscles form the inferior boundary, peritoneal reflections define the superior boundary, and the ureters and iliac vessels define the lateral borders of this space1. The presacral space contains a variety of tissues, including fat, mesenchymal tissue, lymph nodes, nerve plexuses and vessels.
An increase in the width of the presacral space measurement is considered indicative of pathology in the rectum and/or other structures in the pelvis. This alteration is usually seen in lower GI barium enema studies and on plain film.
The upper limits of normal for the presacral space width is 15 mm in patients younger than 45 years 2. However, some patients have measurements over 15 mm with no apparent reason (fewer still have measurements above 20 mm). This possibility increases with increased age. Factors such as age, sex and the weight of the patient should be taken into consideration 2.