When indicated, distal ureters can be evaluated for dilation or the presence of other anomalies (intramural (Fig. 34.2) or juxtavesical calculi).

Echo Doppler is not generally necessary for bladder scanning but can be used to assess for the presence of ureteral jets (Fig. 34.3) and in the differential diagnosis of bladder tumours [2].

It is recommended that small adjustments in gain and focus settings be made to improve both the quality of the images and the visualisation of the anterior wall (superficial to the skin) and posterior wall (deep to the skin).

Second harmonic tissue imaging can be used to further enhance images and reduce reverberation echoes.

Post-void residual urine should always be evaluated by scanning the bladder immediately after voiding [9].

In the event of a significant post-void residual volume, the patient is asked to empty the bladder again, and the scan is repeated to obtain a reliable indication of the emptying capacity.

Detrusor thickness (normally ≤3 mm) is best assessed when the bladder is partially full (250–300 cc), and it is based on the average of three measurements made on the same image. To optimise results, the measurement should be made at the anterior bladder wall, and a high-frequency (7.5 MHz) convex or linear probe should be used [1].

On ultrasound, the detrusor has a sandwich-like structure (hypoechogenic muscular wall between mucous structures that appear slightly hyperechogenic). The thickness of the bladder wall must always be measured in areas that are orthogonal to the ultrasound beam [3–10]. When measuring detrusor thickness (Fig. 34.4) or estimating bladder weight, it is necessary to calculate bladder volume capacity (reliable for values ≥250 cc) [11–12].