Noninvasive quantitative estimation of infravesical obstruction using ultrasonic measurement of bladder weight.
OBJECTIVE
Ultrasound estimated bladder weight was compared to pressure-flow studies to test the ability of ultrasound estimated bladder weight to predict infravesical obstruction.


METHODS
A total of 65 men with urinary symptoms underwent ultrasonic measurement of bladder weight and pressure-flow studies. Assuming the bladder is a sphere, ultrasound estimated bladder weight was calculated from bladder wall thickness measured ultrasonically and intravesical volume.


RESULTS
Ultrasound estimated bladder weight correlated significantly (p < 0.0001) with the Abrams-Griffiths number, urethral resistance factor and the Schäfer grade of obstruction. A cutoff value of 35 gm. for ultrasound estimated bladder weight revealed a diagnostic accuracy of 86.2% (56 of 65 cases) for infravesical obstruction with 12.1 (4 of 33) and 15.6% (5 of 32) false-positive and false-negative rates, respectively.


CONCLUSIONS
Ultrasound estimated bladder weight can be measured noninvasively at the bedside and it is promising as a reliable predictor of infravesical obstruction.
Kojima
M
M
Department of Urology, Kyoto Prefectural University of Medicine, Japan.
Inui
E
E
Ochiai
A
A
Naya
Y
Y
Ukimura
O
O
Watanabe
H
H
D000368:Aged; D000369:Aged, 80 and over; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011237:Predictive Value of Tests; D011470:Prostatic Hyperplasia / Q000150:complications; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging* / Q000473:pathology*; D001748:Urinary Bladder Neck Obstruction / Q000000981:diagnostic imaging* / Q000209:etiology