In assessing patients who present as the final common pathway with the symptom complex of evacuatory dysfunction, there is general recognition that the vast majority of them have a multiplicity of pelvic-floor and perineal soft-tissue abnormalities across compartments. A dynamic imaging modality is required to define the real-time integration of these anomalies and to highlight their significance in each case, particularly when there is clinical or radiographic evidence of a dominant pathology and where corrective surgery is contemplated. Dynamic transperineal ultrasound (DTP-US) is a simple, radiation-free, inexpensive, and learnable technique that highlights pathology in each pelvic compartment and the interplay between compartments during straining and simulated bolus defecation. Another significant advantage of the technique is its ability to demonstrate tissues that lie well beyond the focal distance of an endoanal probe. Studies on selected patient subgroups with complex evacuatory difficulty are awaited that compare DTP-US with its counterpart, dynamic magnetic resonance (MR) imaging. We suggest that using DTP-US for realtime assessment of pelvic-floor function is best performed by the clinician managing the case or in close collaboration with the radiologist for the best potential clinical outcome. Consideration should be given to its formal accreditation by coloproctologists, gastroenterologists, radiologists, gynecologists, and biofeedback therapists.
Imaging Atlas of the Pelvic Floor and Anorectal Diseases p. 189-196