Death due to Hypothermia: Postmortem Forensic Computed Tomography.

Transcription

1 Death due to Hypothermia: Postmortem Forensic Computed Tomography. Poster No.: C-1128 Congress: ECR 2012 Type: Educational Exhibit Authors: Y. Kawasumi, A. Usui, Y. Hosokai, M. Sato, H. Saito, T. Ishibashi, Y. Hayashizaki, M. Funayama; Sendai/JP Keywords: Forensic / Necropsy studies, CT, Diagnostic procedure, Forensics DOI: /ecr2012/C-1128 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 23

2 Learning objectives To illustrate the correlation between postmortem forensic computed tomography (CT) findings and autopsy results of hypothermia. To outline the CT findings often found in cases of death due to hypothermia. Background The use of postmortem CT in forensic medicine is becoming increasingly common [1-3]. Many differences exist between post-mortem CT findings and those of clinical CT. Therefore, direct comparisons of the CT findings and autopsy results are necessary to establish the usefulness of post-mortem CT in forensic medicine. We have carried out postmortem CT before forensic autopsy since May 2009, and have encountered several cases of death due to hypothermia. Typical findings of hypothermia in autopsy are frost erythema, haemorrhagic gastric erosions and lipid accumulation in epithelial cells [4]. However, these findings are almost impossible to detect on CT. Therefore, we describe the postmortem CT findings that are found relatively often in cases of death due to hypothermia. Imaging findings OR Procedure details CT Technique CT: Aquilion 8 MDCT, Toshiba, Japan Scanning protocol: # HEAD -Tube Voltage: 120 kvp -Tube Current: arbitrary -Rotation Time: 1.5 sec -Collimation: 4.0 mm, 8.0 mm (4-stacks) -Beam Pitch: Non-helical -Table Speed: Non-helical Page 2 of 23

3 # BODY -Tube Voltage: 120 kvp -Tube Current: arbitrary -Rotation Time: 0.75 sec -Collimation: 2.0 mm -Beam Pitch: Table Speed: 14 mm/rot All cases underwent a conventional autopsy soon after CT. Radiologists immediately interpreted the CT images, and reported the findings to the forensic pathologists in time for the autopsy. After receiving the autopsy reports from forensic pathologists, the CT images were reviewed and the correlations between CT findings and autopsy results were discussed. Findings At our institution, the cases of hypothermic death that were judged by autopsy (24 cases) have often presented the following three characteristic findings: (1) lack of increase in concentration of lung fields; (2) urine retention in the bladder; (3) clotting of blood in the heart, thoracic aorta and pulmonary artery. These findings are discussed in more detail below. (1) Lack of increase in concentration of lung fields In many cases, a varying degree of increase in concentration is found in the lung fields on post-mortem CT. This is assumed to be due to congestion, pulmonary oedema and aspiration of fluid, among others. Typical cases are presented in Figures 1 and 2. Figure 1 shows a concentration increase similar to pulmonary oedema in the whole lung field (death due to cardiovascular failure). Figure 2 shows the concentration increase localised to the dorsal portion of the lungs (death due to cervical trauma). Page 3 of 23

4 Fig. 1: Fig. 1: A typical case of post-mortem CT. Concentration increase similar to pulmonary oedema was found in the whole lung field (death was due to cardiovascular failure). References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN Page 4 of 23

5 Fig. 2: Fig. 2: Another typical case of post-mortem CT. Concentration increase was localised to the dorsal portion of the lungs (death was due to cervical trauma). References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN However, many cases of death due to hypothermia lack increases in concentration of lung fields (Figs. 3, 4). Even in those cases showing an increase, it is found as only a subpleural linear shadow (Fig. 5). These lungs seem to be dry on CT. In fact, the autopsy demonstrated that the lungs and airway of these cases were dry (Fig. 6). Page 5 of 23

6 Fig. 3: Fig. 3: A case of death due to hypothermia. No increase in concentration of lung fields was found. References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN Page 6 of 23

7 Fig. 4: Fig. 4: Another case of death due to hypothermia. No increase in concentration of lung fields was found. References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN Page 7 of 23

8 Fig. 5: Fig. 5: A case of death due to hypothermia with slight increase in concentration of lung fields. Some linear shadows were found under the pleura (arrows). References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN Page 8 of 23

9 Fig. 6: Fig. 6: Autopsy findings of a case of death due to hypothermia. The lung (a) and airway (b) were dry. References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN (2) Clotting of blood in the heart, thoracic aorta and pulmonary artery On postmortem CT, the blood in the heart, thoracic aorta and pulmonary artery may sometimes forms a fluid-fluid level and on occasion, clots. The former is the result of the deposition blood cells (Fig. 7: death due to drowning), while the latter is presumed to be the result of death taking some time, and clotting ability remaining functional until death. Almost all cases of death due to hypothermia at our institution showed clotting blood (Figs. 8, 9). Page 9 of 23

10 Fig. 7: Fig. 7: A case of death due to drowning. Fluid-fluid level is formed in the heart (arrows). References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN Fig. 8: Fig. 8: A case of death due to hypothermia. Clotting of blood was found in the heart (arrows). References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN Page 10 of 23

11 Fig. 9: Fig. 9: Another case of death due to hypothermia. Clotting of blood was found in the aorta and pulmonary artery (arrows). References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN (3) Urine retention in the bladder Cases of hypothermia tend to retain more urine in the bladder than non-hypothermic cases. Figure 10 shows the bladder of a typical hypothermic case, and Figure 11 shows a non-hypothermic case (death due to thoracic trauma). In many hypothermic cases, a large amount of urine is found in the bladder, and the bladder is firm. The average amount of urine retention in our previous hypothermic cases was ml, while that of nonhypothermic cases was 92.9 ml. Page 11 of 23

12 Fig. 10: Fig. 10: The bladder of a patient who died death due to hypothermia. The bladder retained a large amount of urine and was firm. References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN Page 12 of 23

13 Fig. 11: Fig. 11: The bladder in a non-hypothermic case. The amount of urine in the bladder was small (death was due to thoracic trauma). References: Y. Kawasumi; Diagnostic Radiology, Sendai, JAPAN At our institution, all cases that showed all of the above three findings were cases of death due to hypothermia. However, the findings were absent in some hypothermic cases. It is necessary to examine additional findings to increase diagnostic performance of postmortem CT. Images for this section: Page 13 of 23

14 Fig. 1: Fig. 1: A typical case of post-mortem CT. Concentration increase similar to pulmonary oedema was found in the whole lung field (death was due to cardiovascular failure). Page 14 of 23

15 Fig. 2: Fig. 2: Another typical case of post-mortem CT. Concentration increase was localised to the dorsal portion of the lungs (death was due to cervical trauma). Page 15 of 23

16 Fig. 3: Fig. 3: A case of death due to hypothermia. No increase in concentration of lung fields was found. Page 16 of 23

17 Fig. 4: Fig. 4: Another case of death due to hypothermia. No increase in concentration of lung fields was found. Page 17 of 23

18 Fig. 5: Fig. 5: A case of death due to hypothermia with slight increase in concentration of lung fields. Some linear shadows were found under the pleura (arrows). Page 18 of 23

19 Fig. 6: Fig. 6: Autopsy findings of a case of death due to hypothermia. The lung (a) and airway (b) were dry. Fig. 7: Fig. 7: A case of death due to drowning. Fluid-fluid level is formed in the heart (arrows). Page 19 of 23

20 Fig. 8: Fig. 8: A case of death due to hypothermia. Clotting of blood was found in the heart (arrows). Fig. 9: Fig. 9: Another case of death due to hypothermia. Clotting of blood was found in the aorta and pulmonary artery (arrows). Page 20 of 23

21 Fig. 10: Fig. 10: The bladder of a patient who died death due to hypothermia. The bladder retained a large amount of urine and was firm. Page 21 of 23

22 Fig. 11: Fig. 11: The bladder in a non-hypothermic case. The amount of urine in the bladder was small (death was due to thoracic trauma). Page 22 of 23

23 Conclusion Lack of increase in concentration of the lung field, clotting of blood in the heart, thoracic aorta and pulmonary artery, and urine retention in the bladder are often found in cases of death due to hypothermia on post-mortem CT. These findings may be useful in diagnosis of death due to hypothermia using postmortem CT. Personal Information Yusuke KAWASUMI M.D. Ph.D. Tohoku University Graduate School of Medicine Department of Clinical Imaging 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, , Japan References 1. R. Dirnhofer, C. Fackowski, P. Vock, et al. (2006) VIRTOPSY: Minimally invasive, imaging-guided virtual autopsy. RadioGraphics 26: S. A. Bolliger, M. J. Thali, S. Ross, et al. (2007) Virtual autopsy using imaging: bridging radiologic and forensic sciences. A review of the Virtopsy and similar projects. Eur Radiol 18: E. Aghayev, L. Sraub, R. Dirnhofer, et al. (2008) Virtopsy - The concept of a centralised database in forensic medicine for analysis and comparison of radiological and autopsy data. Journal of Forensic and Legal Medicine 15: M. Tsokos (ed.) (2008) Forensic Pathology Reviews, volume 5, Humana Press, Totowa. Page 23 of 23