The significance of evaluating sphenoid sinus fluid by postmortem computed tomography in cases of drowning.

PURPOSE

In cases of drowning, the presence of sphenoid sinus fluid is a non-specific autopsy finding. However, studies have reported that fluid accumulation in the paranasal sinuses is more commonly observed in drowning victims. Furthermore, some laboratory tests, such as diatom and electrolyte analysis, can serve as supplementary diagnostic tools for diagnosing drowning. Therefore, accurate sphenoid sinus fluid sampling is an important aspect of an autopsy in suspected drowning cases. The aim of this study was to identify the significance of evaluating sphenoid sinus fluid by PMCT images in cases of drowning.

METHODS

We retrospectively reviewed 54 drowning victims who underwent PMCT and forensic autopsy. Fluid volume in the sphenoid sinus was measured using a graduated syringe during autopsy and a three-dimensional (3D) workstation based on PMCT images was used for the purpose of comparison. The Mann-Whitney U test and Spearman's rank correlation coefficient was used to evaluate statistically significant differences and correlations. Additionally, a Bland-Altman plot was employed to assess the agreement between PMCT and autopsy.

RESULTS

The median volume was 1.65 (range 0.00-12.4) ml and 1.55 (range 0.00-7.00) ml in the PMCT and autopsy, respectively, showing a statistically insignificant difference (p = 0.294) and a significant correlation (Rs = 0.896). In 35 cases, the PMCT overestimated the fluid volume more than the autopsy, whereas in 14 cases, the PMCT underestimated the fluid volume. No fluid was identified in seven cases during the autopsy, whereas in five patients, no fluid was found in both PMCT and autopsy. By analyzing the Bland-Altman plot, a bias of 0.73 ± 1.4 ml and limits of agreement ranging from -2.04 to 3.51 ml were observed for sphenoid sinus fluid volume measurements.

CONCLUSIONS

Based on the limitations of traditional fluid volume measurement in the sphenoid sinus during autopsy, we propose the utilization of PMCT volumetric analysis prior to autopsy as a means to enhance the detection of sphenoid sinus fluid in cases of drowning.