V3-12: Real-time MRI assessment of age-related voiding function and urethral form
Boys and elder males often present with lower urinary tract symptoms (LUTS). LUTS is usually caused by neurological disorders or smooth muscle dysfunction but can result from abnormal urethral anatomy. In males, voiding may be altered by the morphological characteristics of the urethra, and boys and elder men with LUTS sometimes have imaging findings showing urethral obstruction and high-pressure bladder. The present study used real-time magnetic resonance imaging (rtMRI) to investigate the morphological characteristics and dynamic motion of the bladder and urethra. Using intergenerational imaging data, we evaluated the relationship between voiding function and urethral anatomy throughout life in males._x000D_
This study enrolled 15 males: 4 school-aged boys and 4 pubescent males with nocturnal enuresis or daytime incontinence, 3 healthy young men (control), and 4 elder men. All patients underwent rtMRI during micturition while in a lateral position on an MRI table. Dynamic images were used to measure and evaluate urethral anatomy, length of the prostatic urethra, and the angles of the urethra and posterior bladder base._x000D_ _x000D_
Prepubescent males with LUTS had kinking and defects of the urethra; the young men (control) had no kinking. At puberty, the urethra was straight or exhibited mild kinking. There was less movement of the bladder neck and urethra in the elder men than in the younger men (Fig. 1). Movement of the lower urinary tract was inversely associated with age. _x000D_
In children with an undeveloped prostate, the structure of the urethra is more fragile than in adults. This is likely a characteristic of urethral morphology in children. During development of secondary sex characteristics, urethral maturation in the prostate increases urethral resistance, and kinking of the posterior urethra may resolve spontaneously. Limitations in bladder neck and urethra movement in males appear to be strongly associated with age and voiding function.