Summary— Two hundred and fifty patients have been studied by synchronous cine/pressure/ flow cystometry to assess the relationship between radiological trabeculation and the urodynamic findings. There is a strong association between detrusor instability and trabeculation. Trabeculation, however, may also occur in the presence of high pressure outflow obstruction, usually at prostate level, in the absence of instability.

It is suggested that frequent uninitiated detrusor contraction against a voluntarily closed sphincter is a likely cause of the more prominent varieties of trabeculation. However, the presence of minor degrees of trabeculation noted at cystoscopic examination in the absence of detrusor instability is not disputed.