Bladder volume determination using a dedicated, portable ultrasound scanner.

Urethral catheterization, the standard method for measurement of bladder volume, is associated with patient discomfort plus the risks of urethral trauma and urinary tract infection. A portable ultrasound instrument that automatically determines bladder volume was used for 164 determinations and the digital readout correlated with the catheterized volume (r2 equals 0.79). This instrument is a noninvasive alternative to urethral catheterization for the determination of bladder volume in most patients.