title: Distinction between saltwater drowning and freshwater drowning by assessment of sinus fluid on post-mortem computed tomography.
abstract: OBJECTIVE
  To evaluate the difference in sinus fluid volume and density between saltwater and freshwater drowning and diagnose saltwater drowning in distinction from freshwater drowning.
  
  
  METHODS
  Ninety-three drowning cases (22 saltwater and 71 freshwater) were retrospectively investigated; all had undergone post-mortem CT and forensic autopsy. Sinus fluid volume and density were calculated using a 3D-DICOM workstation, and differences were evaluated. Diagnostic performance of these indicators for saltwater drowning was evaluated using a cut-off value calculated by receiver operating characteristic (ROC) analysis.
  
  
  RESULTS
  The median sinus fluid volume was 5.68 mL in cases of saltwater drowning (range 0.08 to 37.55) and 5.46 mL in cases of freshwater drowning (0.02 to 27.68), and the average densities were 47.28 (14.26 to 75.98) HU and 32.56 (-14.38 to 77.43) HU, respectively. While sinus volume did not differ significantly (p = 0.6000), sinus density was significantly higher in saltwater than freshwater drowning cases (p = 0.0002). ROC analysis for diagnosis of saltwater drowning determined the cut-off value as 37.77 HU, with a sensitivity of 77 %, specificity of 72 %, PPV of 46 % and NPV of 91 %.
  
  
  CONCLUSIONS
  The average density of sinus fluid in cases of saltwater drowning was significantly higher than in freshwater drowning cases; there was no significant difference in the sinus fluid volume.
  
  
  CONCLUSIONS
  • Sinus fluid density of saltwater drowning is significantly higher than freshwater drowning. • Cut-off value was 37.77 HU based on the ROC analysis. • The cut-off value translated to 91 % NPV for diagnosis of saltwater drowning.
authors.affiliation: Department of Clinical Imaging, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan. ssu@rad.med.tohoku.ac.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kawasumi
authors.affiliation: Department of Diagnostic Image Analysis, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Usui
authors.affiliation: Department of Clinical Imaging, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Clinical Imaging, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Diagnostic Image Analysis, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Nami
authors.initials: N
authors.lastname: Daigaku
authors.affiliation: Department of Diagnostic Image Analysis, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hosokai
authors.affiliation: Department of Forensic Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Hayashizaki
authors.affiliation: Department of Forensic Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Funayama
authors.affiliation: Department of Clinical Imaging, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ishibashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy / Q000379:methods; D001826:Body Fluids; D004332:Drowning / Q000000981:diagnostic imaging*; D005260:Female; D005618:Fresh Water; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D010256:Paranasal Sinuses / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012189:Retrospective Studies; D000068357:Saline Waters; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: Computed tomography; Drowning; Freshwater; Paranasal sinuses; Saltwater