The use of imaging in the diagnosis of lower urinary tract disorders and pelvic organ prolapse in women

The wide range of pelvic floor disorders is often difficult to assess thoroughly based on clinical examination alone. The assessment of patients with pelvic floor dysfunction necessitates a combination of clinical skills and adjunct investigations, including detailed imaging. A variety of static and dynamic imaging modalities are currently available in the field of urogynaecology, however their role in identifying the structural and functional causes of pelvic floor disorders remains equivocal. This thesis poses the null hypothesis that imaging techniques, namely three- and four-dimensional (3D/4D) ultrasound and spiral computed tomography (CT) have no role in clinical urogynaecology. The hypothesis would be false if such imaging techniques yield measurable differences in anatomical and functional indices of the lower urinary tract and pelvic floor. The interaction between the vagina and its supportive structures, as well as their behaviour under the mechanical load of increased abdominal pressure can be modelled as a biomechanical system; In the present thesis the changes in dimensions of the levator ani muscle (LAM) in women with pelvic floor dysfunction (PFD) were measured in vivo, under progressively increased abdominal pressure, with the use of translabial ultrasound imaging demonstrating that real-time in vivo study of the deformation of the pelvic floor with 3D/4D translabial ultrasound is feasible and reliable. The reliability of translabial 3D ultrasound imaging of the urethral sphincter in non-pregnant, nulliparous and asymptomatic women was also assessed. Very good to excellent inter- and intra-observer agreement was demonstrated proving the reproducibility of a method which doesn’t carry the inherent limitations of the endovaginal and transanal approach. The potential structural differences in urethral sphincter and pelvic floor between white and black women attributing to the different prevalence of stress urinary incontinence in the two racial groups were assessed with 3D ultrasound imaging. Young nulliparous black women were found to have significantly larger urethral rhabdosphincter muscle (RS) and wider levator hiatus than their white counterparts. The prevalence of pubovisceral muscle avulsion, as one of the proposed types of pelvic floor trauma during childbirth, was calculated in a general gynaecological cohort with the use of spiral CT of the pelvis. A significantly lower prevalence of pubovisceral muscle avulsion was found in the studied group in comparison to previous reports, which underlines the great variability in depiction of LAM morphometry between different imaging modalities. In chapter 8, the additive value of 3D/4D pelvic floor ultrasound in evaluating the postoperative outcome of surgical prolapse repair is studied through a randomised control trial in which two different surgical techniques for repairing posterior wall prolapse are compared. At the end of this thesis, suggestions for further research into the value of new imaging modalities in enhancing clinical assessment of women with pelvic floor dysfunction are made.Open Acces