title: Three-dimensional ultrasound device for rapid determination of bladder volume.
abstract: OBJECTIVE
  We sought to assess the accuracy, reliability, and clinical utility of the noninvasive determination of bladder volume using an automated, compact three-dimensional (3-D) ultrasound device.
  
  
  METHODS
  We prospectively tested 249 adult outpatients for accuracy (n = 182), by comparing scan versus catheter volumes, or reliability (n = 67), by comparing the scan readings of two independent observers. Two models of the bladder scan device were tested (BVI-2500, 1994 and 1995 models).
  
  
  RESULTS
  Scan and catheter volumes were correlated (y = 1.02x + 12.6, R2 = 0.90, P < 0.001) across a range of zero to 1015 cc, regardless of which machine model was used. Scan volume underestimated catheter volume by an average of 10 cc in men and 20 cc in women. If a scan-predicted volume of 100 cc or greater were used as a cutpoint for clinical importance, the device exhibited a sensitivity of 97%, a specificity of 91%, and an overall accuracy of 94%. These results were not affected by age, gender, height, weight, diagnosis, uterine presence/prostate size, or user experience. The two observers, one a graduate physician and the other a college student, achieved essentially the same volume determinations (y = 0.96x + 0.13, R2 = 0.90, P < 0.001).
  
  
  CONCLUSIONS
  Volume determinations obtained with the bladder scan device are accurate and reliable in adult outpatients. A special technician is not required. These results may be attributable to use of automated planimetry and 3-D volumetry, rather than a fixed geometric formula, to custom measure each bladder shape.
authors.affiliation: Urological Sciences Research Foundation, Culver City, CA 90232, USA.
authors.forename: L S
authors.initials: LS
authors.lastname: Marks
authors.forename: F J
authors.initials: FJ
authors.lastname: Dorey
authors.forename: M L
authors.initials: ML
authors.lastname: Macairan
authors.forename: C
authors.initials: C
authors.lastname: Park
authors.forename: J B
authors.initials: JB
authors.lastname: deKernion
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D013997:Time Factors; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D001743:Urinary Bladder / Q000000981:diagnostic imaging*