Lint: post-void-residual

"The post-void residual refers to the volume of urine that remains in the urinary bladder after micturating. It may be estimated by visualisation using ultrasound or directly measured with urethral catheterisation."

"compression of the efferent sacral nerve roots (S2-4) may decrease one's ability to voluntarily contract the detrusor, resulting in an elevated post-void residual"

"The post-void residual may be formally measured using one of several proposed formulae or (more commonly at the point of care) semi-quantified into abnormally elevated and normal."

"Using a suprapubic transducer, the urinary bladder is located and centred on the screen; the width and anteroposterior dimensions are traditionally measured with the probe in a transverse orientation. After rotation of the probe marker cephalad to a sagittal plane, the infero-superior height is obtained. An estimation of volume (and, if performed immediately after micturition, a post-void residual) in millilitres may be calculated either using the volume of an ellipsoid π/6 x width x height x length, although using a correction of 0.7 (rather than π/6 = ~0.524) has been shown to be closer to voided/catherised volumes ⁵."

"Several considerations in the differential diagnosis for an abnormally elevated (exceeding 100-200 mL in an adult or >10% of bladder capacity in a paediatric patient) post-void residual include:"

"Calculator: urinary bladder volume"