New evidence for old lore--urinary bladder distension on post-mortem computed tomography is related to intoxication

Distension of the urinary bladder is reported to be a sign of intoxication at autopsy. The purpose of this study was to compare radiologically calculated urinary bladder volume (UBV) to autopsy measurements of UBV, and to investigate the relationship between intoxication and calculated UBV.

Autopsy reports, toxicology reports and post-mortem CTs of 332 adult human cadavers were retrospectively analyzed, 259 cases were included in the final population. Spearman's rho test was used to compare calculated UBV to autopsy measurements. Significance levels for UBV in relation to toxicology results were investigated with the Mann-Whitney test. Spearman's rho test was also used to correlate the widest left-right bladder diameter on axial images to calculated UBV. Both calculated UBV and axial diameters were subjected to receiver operating characteristics curve analysis. Sensitivity and specificity were calculated for individual cutoff values.

There is a strong correlation and high consistency (r=0.92, p<0.001) between the measured and calculated UBV. Positive toxicology results strongly correlate with calculated UBV (p<0.001). Additionally, there is a strong correlation between calculated UBV and axial urinary bladder diameter (p<0.001). UBV of 182 ml and >330 ml indicate positive toxicology results with a sensitivity/specificity of 40%/87% and 25%/97% respectively. Axial urinary bladder diameter of 8.5 cm and >10 cm indicate positive toxicology results with a sensitivity/specificity of 36%/85% and 16%/95% respectively.

Radiologically calculated UBV accurately represents the autoptically measured UBV. The occurrence of urinary bladder distension on post-mortem imaging should raise suspicion of intoxication.