International consultation on incontinence‐research society (ICI‐RS) report on non‐invasive urodynamics: The need of standardization of ultrasound bladder and detrusor wall thickness measurements to quantify bladder wall hypertrophy

Abstract

Ultrasonic measurements of urinary bladders are suitable to quantify bladder wall hypertrophy due to bladder outlet obstruction, detrusor overactivity, or neurogenic bladder dysfunction in adult men or women and in children. Quantification of bladder wall hypertrophy seems to be useful for the assessment of diseases, prediction of treatment outcomes, and longitudinal studies investigating disease development and progression. Four distinct measurement techniques have been published using bladder wall thickness (BWT), detrusor wall thickness (DWT), or ultrasound-estimated bladder weight (UEBW) assessed by suprapubic or transvaginal positioning of ultrasound probes and different bladder filling volumes. As a result, different threshold and reference values were established causing confusion. This ICI-RS report summarizes the agreements of different research groups in terms of ultrasonic BWT or DWT measurements, critically discusses the four ultrasonic measurement techniques, suggests criteria for quality control, and proposes future research activities to unify measurement strategies. For quality control, all future reports should provide information about frequency of the ultrasound probe, bladder filling volume at measurement, if BWT, DWT, or UEBW was measured, enlargement factor of the ultrasound image, and one ultrasound image with marker positioning. The ICI-RS intends to found a standardization committee that will initiate and judge studies on ultrasonic bladder wall measurements to clarify the most suitable, most accurate, and least invasive measurement technique.