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Videoflow: Uroflowmetry in Children Exploiting Standard Care Video Urodynamic Imaging
Wouter van Dort1, Peter F W M Rosier1, Ruud C Wortel1
1Department of Urology, University Medical Center Utrecht, Utrecht, The Netherlands.
Insights
A new method called videoflow uses X-ray images to accurately measure urine flow rate in children. This allows for complete bladder and urethral function evaluation in young children unable to use standard uroflowmetry devices.
Area of Science:
- Pediatric Urology
- Medical Imaging
- Urodynamics
Background:
- Pressure-flow studies are standard for evaluating bladder function but challenging in young children.
- Current methods cannot measure flow rate in children unable to sit on uroflowmetry devices.
- This limits the complete assessment of bladder and urethral functions in pediatric patients.
Purpose of the Study:
- To develop and validate a method for deriving urine flow rate from video-urodynamic X-ray images.
- To enable accurate bladder and urethral function evaluation in very young children.
- To facilitate pressure-flow-based urethral resistance measurements in pediatric populations.
Main Methods:
- Retrospective analysis of 50 video urodynamic studies in children.
- Manual segmentation of X-ray images during voiding.
- Algorithmic conversion of segmented images into a calculated flow rate (videoflow).
- Comparison of videoflow with standard uroflowmetry measurements.
Main Results:
- High cross-correlation (0.98) between videoflow and standard uroflowmetry.
- Accurate videoflow maximum flow rate (Qmax) with minimal bias (+0.1 mL/s).
- Videoflow demonstrated feasibility and accuracy in children capable of voiding on a uroflowmetry toilet.
Conclusions:
- Videoflow is a feasible and accurate method for measuring urine flow rate in children.
- This technique extends urodynamic assessment to very young children who cannot sit upright.
- Enables, for the first time, pressure-flow-based urethral resistance validation in this age group.
Introduction:
Pressure-flow study, consisting of flow rate combined with detrusor pressure, is the gold standard to determine bladder outflow obstruction and evaluate the detrusor voiding contraction. In very young children, not able to sit on a uroflowmetry device, the flow rate cannot be measured. This results in an incomplete evaluation of bladder and urethral functions. The aim of this study is to derive the flow rate using standard care video-urodynamic study X-ray images.
Methods:
We retrospectively included 50 video urodynamic studies in children able to void on a uroflowmetry toilet, to correlate the outcome with standard uroflowmetry. The X-ray images taken during voiding were manually segmented and algorithmically converted into a flow rate, called "videoflow". This videoflow was compared with the measured (standard) uroflowmetry.
Results:
An excellent cross-correlation of 0.98 was found between the videoflow and normal uroflowmetry outcomes. The videoflow maximum flow rate (Qmax) was accurate with a not significant bias of +0.1 mL/s difference with standard uroflowmetry.
Conclusions:
In conclusion, the proposed videoflow is found feasible and accurate in children who are able to void in a uroflowmetry toilet. This method paves the way to measure urine flow rate in very young children who cannot yet sit upright. For the first time, this new technique will enable the validation of a pressure-flow-based urethral resistance measurement in this very young age group.
Trial Registration:
Clinical Registration Number: 23U-0621.
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01:28Imaging Studies I: Kidney, Ureter, and Bladder Studies
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