Accuracy of Bladder Ultrasound Study (BUS) trial

BUS trial summary

The BUS study is a diagnostic trial which looks at how effective the use of ultrasound scanning is in diagnosing overactive bladder in women. The study is designed to evaluate if an ultrasound scan of the bladder can reduce the need for a more invasive diagnostic test called urodynamics.


The current technique for diagnosing bladder problems in women is called a urodynamics test. This is considered the 'gold standard' to which any other method of diagnosing overactive bladder should meet with in terms of accuracy.

Whilst urodynamics is universally used and is a relatively straightforward test, it involves filling the bladder and subsequently monitoring the effect on the patient. On the other hand ultrasound scanning is considered less invasive for the patient, as it uses a probe to measure the bladder wall thickness. This can tell the clinician if the bladder is 'overactive'. 

Little research has been done to date on the accuracy of the ultrasound technique, compared to urodynamics, in diagnosing women with an overactive bladder. This is why the BUS is so important.

In those centres taking part women, who are suspected as having this bladder complaint, will go through the standard urodynamics test and also asked to consent to having a bladder ultrasound. The results of the tests will be kept 'blinded' to each other, but will be analysed independently to see how accurately the ultrasound is as a diagnostic tool.

Our recruitment target is 600 women over two years and, alongside the diagnostic information obtained, we will be asking women to rate the two tests in terms of their own experiences.

It is hoped that, if ultrasound is proved an effective and acceptable alternative, it can replace urodynamics testing.

For further details on the study please see our BUS news page or contact us.