A research group at Tohoku University and Graduate School, Dokkyo Medical University, and the University of Waterloo in Canada has developed an ultra-high-frame rate system that visualizes the flow vector (direction and velocity) distribution within the urethra during urination at a high frame rate of more than 1 frames per second. Developed sonic imaging technology.For the first time, we have achieved detailed visualization of the flow inside the urethra, which has degenerated due to conditions such as benign prostatic hyperplasia.
Degeneration of the urethra, such as prostatic hyperplasia, is one of the main causes of urinary symptoms, and when it becomes chronic, patients' QOL deteriorates, so effective diagnostic and treatment techniques are needed.Although treatment methods have diversified, there has been no means to evaluate in detail the influence of the urethral lumen condition on urine output.
This time, the research group used a technology called high frame rate ultrasound imaging to produce B-mode videos (tomographic images of organs) and flow vector videos (images of the spatial distribution of flow direction and speed) at a rate of 1,250 images/second. We have developed a new transrectal ultrasound imaging system that can simultaneously acquire high frame rates.
Using this system, we performed urinary flow imaging on a male subject with urinary symptoms. During the beginning and end of urination, the flow path expanded and contracted, the flow path angle changed, and the flow developed in about 1 second. We succeeded in visualizing the dynamics such as cycling and stopping.
The results revealed that at the end of micturition, the movement of the external urethral sphincter causes contraction of the urethra to propagate from the outlet side to the cystometer, and that this movement causes urine to flow back into the bladder, as if swallowed. .It has been found that whirlpools and jet flows occur within the urethra, especially when there is a stricture within the urethra.
The results of this research will enable detailed observation of the flow during drainage, and are expected to contribute to the development of treatments such as optimal medication for each patient and minimally invasive surgery.
Paper information:[Medical Physics] Transrectal Ultrasound Vector Projectile Imaging for Time-Resolved Visualization of Flow Dynamics in the Male Urethra: A Clinical Pilot Study
