Quantitative Mechanics of the Bladder During Voiding Using MRI.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Urology

Background:

• Understanding bladder biomechanics is crucial for diagnosing and managing urinary conditions.
• Current methods for assessing bladder function are often invasive or provide limited anatomical detail.

Purpose of the Study:

• To non-invasively quantify bladder biomechanics using Uro-Dynamic MRI.
• To characterize the relationship between bladder wall surface area and bladder volume during voiding.

Main Methods:

• Uro-Dynamic MRI with a Differential Subsampling with Cartesian Ordering sequence was employed.
• Volumetric bladder images were acquired during voiding in five healthy male subjects.
• Image segmentation and 3D rendering were used to measure bladder volume and wall surface area, alongside linear measurements for comparison.

Main Results:

• Uro-Dynamic MRI accurately assessed bladder volume, though flow rate estimations differed between methods.
• Bladder deformation varied during voiding, approaching spherical geometry post-maximum flow.
• Bladder dimensions changed asymmetrically and non-constantly with volume, showing concentric contraction after maximum flow.

Conclusions:

• Uro-Dynamic MRI enables time-resolved analysis of bladder volume and surface area changes.
• This technique provides a powerful, non-invasive tool for extracting anatomical information.
• It facilitates the development of novel, patient-specific biomechanical metrics for bladder evaluation.