Integration of spectroscopy and imaging to optimize evaluation of voiding dysfunction

Abstract

Voiding dysfunction occurs due to the interplay of anatomic, physiologic and functional elements. Hence, integration of new imaging and spectroscopy modalities offers the potential for improving patient assessment by enabling the causal structural defects, formal staging of pelvic floor dysfunction and underlying physiologic mechanisms to be better defined. The purpose of this review is to outline the limitations of current imaging, and highlight the advantages of newer technologies in the evaluation of patients with voiding dysfunction due to loss of structural integrity of the pelvic floor. The everyday action of voiding belies the complex interplay of neural control of the voiding cycle, precise function of healthy organ systems and hemodynamic changes in the microcirculation required for the bladder to fill and empty normally. Brain mediated control initiates voluntary voiding, and integrity of the spinal cord is required to transmit neural signaling to the bladder. A spino-bulbo-spinal reflex is integral to voluntary voiding while urine storage is dependent on lumbosacral spinal reflexes (27). The bladder microcirculation is uniquely adapted to maintain perfusion as the organ's size and wall thickness alter as it fills and empties, and to preferentially perfuse the detrusor muscle prior to bladder contraction. The structure of the pelvic floor is integral to continence; with incontinence in various forms a consequence of the effects of damage, structural weakness or organ prolapse. Urinary incontinence due to loss of pelvic floor integrity is a complex condition. With aging and the effects of illness and injury the normal supportive function of the pelvic floor muscles, ligaments and fascia becomes compromised. Progressive reduction or traumatic loss of soft tissue support results in pelvic organ prolapse (POP), which is a prevalent and debilitating disorder (25). POP is part of the spectrum of abnormalities occurring with pelvic floor dysfunction (35). POP is defined as abnormal symptomatic displacement of the pelvic organs from their normal anatomic position; herniation of some or all of the pelvic viscera occurs, including the urethra, bladder, vaginal vault, cervix, small bowel,