To characterize ultrasound bladder measures, and to determine whether these measures were associated with measures of lower urinary tract dysfunction.

Three-dimensional ultrasounds were used to assess bladder surface area (SA), bladder wall thickness (BWT), and estimated bladder weight (EBW) in a random sample of the Olmsted County, Minnesota, male population. Uroflowometry was used to determine maximum urinary flow rates, and ultrasound was used to assess postvoid residual volume. Prostate volume was assessed with transrectal ultrasound and prostate-specific antigen (PSA) levels were assessed from serum samples. Correlation and linear regression analyses assessed relationships between bladder measures and prostate volume, PSA, maximum flow rate, and postvoid residual.

Among 259 men, median bladder SA was 228 cm² (25th, 75th percentiles: 180, 279), median BWT was 2.3 mm (25th, 75th percentiles: 1.8, 2.7), and median EBW was 48.5 g (25th, 75th percentiles: 43.7, 53.0). Decreased bladder SA was correlated with increased PSA level, increased prostate volume, higher American Urological Association Symptom Index (AUASI) scores (r_s = −0.13 to −0.21; P = .03-.001), and decreased maximum flow rate (r_s = 0.21, P = .001). Increased BWT was correlated with increased PSA level (r_s = 0.22, P = .0003), increased prostate volume (r_s = 0.17, P = .01), and decreased maximum flow rate (r_s = −0.14, P = .03). Increased EBW was correlated with increased maximum flow rate (r_s = 0.14, P = .03) and decreased AUASI score (r_s = −0.13, P = .04).

Decreased SA and EBW were moderately associated with decreased maximum flow rate and increased AUASI scores, suggesting that such measures may provide insight into detrusor dysfunction.