Transrectal scanning: an alternative when transvaginal scanning is not feasible

Abstract

In scanning the female pelvis the clear images of transvaginal sonography (TVS) result from placing the transducer close to the region of interest. The advantages of TVS over transabdominal sonography (TAS) and transperineal sonography are well documented. Transrectal scanning is proposed mostly for ultrasound guidance in draining a pelvic abscess. Our aim was to investigate the applicability of transrectal scanning (TRS) for cases in which TVS is impossible. Forty-two patients with an absolute or a relative contraindication to TVS were scanned transabdominally and transrectally. The TRS was performed using a transvaginal probe, which was lubricated and slowly advanced into the rectum. The technique used was similar to that of TVS. Images were compared for resolution and quality. All scans were completed without significant patient discomfort or complaints. TRS was clearly superior to TAS in 31 cases. In nine cases TAS furnished some clinical information but TRS yielded better images. Only in one such case was TAS similar in quality to TRS. In four obese patients TAS did not reveal sufficient pelvic anatomy to generate a clinical diagnosis, whereas TRS revealed two sets of normal ovaries and two patients with ovarian cysts. In the two cases with vaginal agenesis TRS revealed the diagnosis of Rokitansky-Küster syndrome. In three of the four patients with ruptured membranes the cervix could be measured precisely. Transrectal scanning should be used liberally after proper patient selection and counseling. The images obtained are superior to TAS and comparable to those obtained by TVS.