Is post-mortem ultrasonography a useful tool for forensic purposes?

The Current Status of Virtual Autopsy Using Combined Imaging Modalities: A Scoping Review

Background/Objectives: Virtual autopsy (virtopsy) is a new domain of research for interdisciplinary teams of radiologists and forensic specialists. This scoping review aims to underline the current state-of-the-art research using combined imaging modalities. Methods: We searched the PubMed database using the term virtopsy for articles that are available in free full text, indexed in the Medline Database, and published in English. The query returned 49 articles on this subject that have been published since 2002. Results: The main imaging modalities used for postmortem imaging were computed tomography (PMCT), angiography (PMCTA), magnetic resonance imaging (PMMRI), and ultrasonography (PMUS). PMCT is highly effective for detecting complex osseous injuries, tracing bullet trajectories, or identifying characteristic findings in drowning cases. PMCTA is valuable for evaluating vascular lesions, particularly in natural death cases. PMMRI is superior in analyzing soft tissues, including brain and spinal structures, cerebrospinal fluid, microbleeds, and laryngohyoid lesions, and identifying cardiomyopathies in young individuals. PMUS serves as an alternative, and its portability also allows for use in forensic settings. One specific situation observed was the increased number of studies published about virtopsy during the COVID-19 pandemic. Another aspect is the increased focus on this alternative to conventional autopsy in the regions where maneuvering of the deceased is limited according to cultural and social customs. Conclusions: We underline the advantages and limitations of each imaging modality used for virtopsy. Further studies need to be developed in order to gather supplementary data regarding the use of these imaging modalities in the new era of artificial intelligence in medicine.

Post-mortem Tissue Degassing Using Positive Pressure Is Superior to Negative Pressure

OBJECTIVE

To compare the effectiveness of positive pressure (PP) and negative pressure (NP) for reducing gas inclusions in biological tissues in preparation for acoustic imaging.

METHODS

Eighteen pieces of porcine liver in degassed saline were included in this study. For the PP group (n = 9 samples), a wristwatch waterproof tester was used to pressurize samples to 0.41 MPa (59 psi) for 10 min. For the NP group (n = 9 samples), a desiccator at -0.08 MPa (-12 psi) was used for 30 min. Backscatter coefficients (BSCs) were calculated over the central frequency range of the backscattered spectra and paired-samples t-tests were performed.

RESULTS

Utilization of PP resulted in a decrease in BSC for all samples, indicating less gas post-PP (pre-PP -13.0 ± 4.3 dB [mean ± SD], post-PP -18.9 ± 5.0 dB, p = .001). Utilization of NP resulted in an increase in BSC for the majority of samples (pre-NP -14.6 ± 6.0 dB, post-NP -13.1 ± 5.3 dB, p = .177).

CONCLUSION

Utilization of a simple PP chamber consistently resulted in a decrease in tissue gas, at lower pressures than previously reported. The vacuum method is ineffective, may result in a paradoxical increase in tissue gas, and may not be recommended for tissue degassing.

Minimally Invasive Tissue Sampling via Post Mortem Ultrasound: A Feasible Tool (Not Only) in Infectious Diseases-A Case Report

In the past years the number of hospital autopsies have declined steadily, becoming almost excluded from medical training. Medicolegal (forensic) autopsies account for almost all autopsies, whereas hospital autopsies are becoming increasingly rare. Minimally invasive tissue sampling (MITS) using post mortem ultrasound offers the opportunity to increase the number of post mortem examinations in a clinical and even forensic context. MITS is a needle-based post mortem procedure that uses (radiological) imaging techniques to examine major organs of the body, acquire tissue samples and aspirate fluid from the body cavities or hollow organs. In this study, MITS was used to determine the presence of other co-existing diseases in a deceased infected 97-year-old woman with severe acute respiratory syndrome coronavirus 2. The examination of her body was carried out using ultrasound as an imaging tool and to gather ultrasound-guided biopsies as conventional autopsy was rejected by the next of kin. Ultrasound and histology identified an intravesical mass leading to an obstruction of the urinary outlet resulting in bilateral hydronephrosis and purulent pyelonephritis, which was unknown during her lifetime. Histopathological examination revealed the tumor mass to be a squamous cell carcinoma. This study has shown that MITS can be used to determine the cause of death and the presence of concomitant diseases in the infectious deceased.

Ultrasound in legal medicine-a missed opportunity or simply too late? A narrative review of ultrasonic applications in forensic contexts

Objectives

Conventional autopsies remain the gold standard of postmortem healthcare quality assurance and help gathering extended knowledge on diseases. In answer to constantly declining autopsy rates non- or minimally invasive autopsy methods were introduced. Ultrasound is a well-established tool for imaging commonly used in clinical practice. This narrative review aims to summarize the current literature regarding the feasibility and validity of ultrasound in a forensic context.

Material and methods

A PubMed database search was carried out. Abstracts were scanned for pre-defined ex- and inclusion criteria, followed by a snowball search procedure applied to the primarily included articles.

Results

Forty-five publications met our inclusion criteria. The selected articles concern the feasibility of ultrasound in pre- or postmortem settings, forensic age estimation, and minimally invasive approaches. For imaging, ultrasound was deemed a reliable tool for the examination of epiphyses und superficial wounds, with limitations regarding internal organs and image quality due to postmortem changes. Ultrasound-guided minimally invasive approaches yielded higher success rates for adequate tissue sampling. Many investigations were carried out in low- and middle-income countries focusing on infectious diseases.

Conclusion

Ultrasound seems a promising but underutilized imaging tool in legal medicine to date. Promising approaches on its feasibility have been conducted. Especially for minimally invasive methods, ultrasound offered significant improvements on qualified biopsy sampling and thus appropriate diagnostics. Moreover, ultrasonic evaluation of epiphyses for age estimation offered valuable results. Nevertheless, further assessment of ultrasonic feasibility in forensic contexts is needed.

COVID-19 in the autopsy room-requirements, safety, recommendations and pathological findings

Modern technologies enable the exchange of information about the expansion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the continually increasing number of the coronavirus disease 2019 (COVID-19) cases almost in real time. The gravity of a current epidemiological situation is represented by the mortality rates, which are scrupulously updated daily. Performing autopsies on patients with either suspected or confirmed COVID-19 is of high importance since these might not only improve clinical management but also reduce the risk of SARS-CoV-2 infection expansion. The following paper aimed to present the most crucial aspects of SARS-CoV-2 infection from the point of view of forensic experts and pathologists, recommendations and safety precautions regarding autopsies, autopsy room requirements, possible techniques, examinations used for effective viral detection, recommendations regarding burials, and gross and microscopic pathological findings of the deceased who died due to SARS-CoV-2 infection. Autopsies remain the gold standard for determining the cause of death. Therefore, it would be beneficial to perform autopsies on patients with both suspected and confirmed COVID-19, especially those with coexisting comorbidities.

Ultrasound Elastographic Measurement of Rigor Mortis in an Animal Model: A Feasibility Study for Improved Time-of-Death Estimates in Forensic Investigations

OBJECTIVE. The purpose of our study was to assess the feasibility of 2D shear wave ultrasound elastography to quantitatively measure changes of rigor mortis. SUBJECTS AND METHODS. Muscle stiffness of two live pigs and nine sacrificed pigs was measured in kilopascals using ultrasound elastography. The nine sacrificed pigs were divided into three groups of three pigs each and placed in one of three environments at 90°F (32°C), 70°F (21°C), or 34°F (1°C). Ultrasound elastography of five muscles was performed at 1- to 2-hour intervals for up to 50 hours postmortem. For each pig and muscle location, the time to start, peak intensity, duration of peak, and time to decline of rigor mortis were identified from the graphs of muscle stiffness values over time. These outcome variables were then compared across ambient temperature, body weight, and age groups using the Wilcoxon rank sum test. RESULTS. Postmortem measurements show a rise, peak, and decline of muscle stiffness after death. Rigor mortis was highly significantly affected by ambient temperature (p < .001), was significantly affected by body weight (p = .04), and was not significantly affected by animal age or muscle location (facial vs truncal vs limb) (p > .50). Peak intensity of rigor mortis developed more quickly but attained lower levels of muscle stiffness at 90°F (80-100 kPa) compared with 70°F and 34°F (280-300 kPa) (p < .001). The duration of peak rigor mortis and the time to decline of rigor mortis were significantly longer for the lower temperatures (p < .001). CONCLUSION. Two-dimensional shear wave ultrasound elastography can quantifi-ably measure the trajectory of rigor mortis in an animal model. This new approach may have direct implications for human forensic investigations.

Post-mortem ultrasonography: a safer alternative to autopsies in COVID-19 deaths

Ultrasonography is known to have many applications in the diagnoses of diseases, as well as in guiding medical practitioners through precise medical procedures. However, its use as a post-mortem radiographic modality has been limited. Post-mortem ultrasonographic techniques are considered to be a safer alternative to high-risk post-mortem procedures, especially in infectious diseases. The present communication discusses the possibilities of using ultrasonography in post-mortem examinations in times of the ongoing COVID-19 pandemic to minimize the associated risk of SARS-CoV-2 infection of those working in mortuaries during full-body dissection in traditional autopsies. Post-mortem ultrasonography can be useful in reducing the extent of autopsies, thus decreasing the risk of exposure of forensic personnel.

Dutch guideline for clinical foetal-neonatal and paediatric post-mortem radiology, including a review of literature

Clinical post-mortem radiology is a relatively new field of expertise and not common practice in most hospitals yet. With the declining numbers of autopsies and increasing demand for quality control of clinical care, post-mortem radiology can offer a solution, or at least be complementary. A working group consisting of radiologists, pathologists and other clinical medical specialists reviewed and evaluated the literature on the diagnostic value of post-mortem conventional radiography (CR), ultrasonography, computed tomography (PMCT), magnetic resonance imaging (PMMRI), and minimally invasive autopsy (MIA). Evidence tables were built and subsequently a Dutch national evidence-based guideline for post-mortem radiology was developed. We present this evaluation of the radiological modalities in a clinical post-mortem setting, including MIA, as well as the recently published Dutch guidelines for post-mortem radiology in foetuses, neonates, and children. In general, for post-mortem radiology modalities, PMMRI is the modality of choice in foetuses, neonates, and infants, whereas PMCT is advised in older children. There is a limited role for post-mortem CR and ultrasonography. In most cases, conventional autopsy will remain the diagnostic method of choice.

CONCLUSION

Based on a literature review and clinical expertise, an evidence-based guideline was developed for post-mortem radiology of foetal, neonatal, and paediatric patients. What is Known: • Post-mortem investigations serve as a quality check for the provided health care and are important for reliable epidemiological registration. • Post-mortem radiology, sometimes combined with minimally invasive techniques, is considered as an adjunct or alternative to autopsy. What is New: • We present the Dutch guidelines for post-mortem radiology in foetuses, neonates and children. • Autopsy remains the reference standard, however minimal invasive autopsy with a skeletal survey, post-mortem computed tomography, or post-mortem magnetic resonance imaging can be complementary thereof.

Diagnosis of congenital abnormalities with post-mortem ultrasound in perinatal death

PURPOSE

To determine the sensitivity and specificity of post-mortem ultrasound in the diagnosis of major congenital abnormalities of fetuses using conventional autopsy as the standard of reference.

MATERIAL AND METHODS

All fetuses coming from terminations of pregnancy or intrauterine fetal deaths in a single institution were included. A total of 75 fetuses were included during the study period. The results of post-mortem ultrasound examinations were compared to those of conventional autopsy that served as standard of reference.

RESULTS

Gestational age of the fetuses ranged from 15 to 38 weeks gestation. A complete post-mortem ultrasound assessment was possible in all fetuses. Regarding detection of brain abnormalities, post-mortem ultrasound had a sensitivity of 81.5% or 4/5 (95% CI: 63.3-91.8%), and a specificity of 97.9% (95% CI: 89.1-99.6%). Specificities for the diagnosis of thoracic, cardiac, urinary tract, spinal and bone abnormalities were 100%.

CONCLUSION

Post-mortem ultrasound shows high sensitivity and specificity for the diagnosis of congenital structural abnormalities as compared to conventional autopsy, with the exception of congenital cardiac diseases.

FORENSIC RADIOLOGY AND IMAGING FOR VETERINARY RADIOLOGISTS

Imaging studies are often of evidentiary value in medicolegal investigations involving animals and the role of the veterinary radiologist is to interpret those images for courts as an expert or opinion witness. With progressing interest in prosecuting animal crimes and strengthening of penalties for crimes against animals, the participation of veterinary radiologists in medicolegal investigations is expected to increase. Veterinary radiologists who are aware of radiographic and imaging signs that result in animal suffering, abuse, or neglect; knowledgeable in ways radiology and imaging may support cause of death determinations; conversant in postmortem imaging; comfortable discussing mechanisms and timing of blunt or sharp force and projectile trauma in imaging; and prepared to identify mimics of abuse can assist court participants in understanding imaging evidence. The goal of this commentary review is to familiarize veterinary radiologists with the forensic radiology and imaging literature and with the advantages and disadvantages of various imaging modalities utilized in forensic investigations. Another goal is to provide background information for future research studies in veterinary forensic radiology and imaging.

ESPR postmortem imaging task force: where we begin

A new task force on postmortem imaging was established at the annual meeting of the European Society of Paediatric Radiology (ESPR) in Graz, Austria, in 2015. The postmortem task force is separate from the child abuse task force as it covers all aspects of fetal, neonatal and non-forensic postmortem imaging. The main focus of the task force is the guidance and standardization of non-radiographic postmortem imaging, particularly postmortem CT and postmortem MRI. This manuscript outlines the starting point of the task force, with a mission statement, outline of current experience, and short- and long-term goals.

Topographical distribution of blubber in finless porpoises (Neophocaena asiaeorientalis sunameri): a result from adapting to living in coastal waters

BACKGROUND

Blubber has many functions, among which energy storage, thermoregulation, buoyancy, and hydrodynamic streamlining are the most frequently cited. Within and between taxa, variations in its structure and distribution likely reflect different adaptations of a species to its life history requirements, environment, health, and function. Here, we use ultrasound to describe the distribution of blubber in the finless porpoise (Neophocaena asiaeorientalis sunameri) based on examinations of 34 fresh cadavers recovered as accidental fisheries bycatch.

RESULTS

Measurements of blubber depth determined by ultrasound positively correlated with conventional measurements using a scalpel and calipers. Whereas conventional surgical incision and visual examination revealed two layers of blubber, ultrasound revealed up to three layers; thus, ultrasound reveals additional structural detail in blubber while crude necropsy techniques do not. Across life history categories, ultrasound revealed the distribution of inner blubber to be topographically consistent with that of full-depth blubber. Blubber in the dorsal region was stratified into three layers and was significantly thicker than that in the lateral and ventral regions, in which a middle layer was normally absent.

CONCLUSIONS

Ultrasoundprovides a fast, effective, and accurate means to determine blubber thickness and structure, and thus, assessment of the health of fresh finless porpoise carcasses. Blubber depth is determined largely by the thickness of the inner and middle layers, wherein lipids are concentrated. The thickening of blubber in the dorsal thoracic-abdominal region suggests multiple roles of thermal insulation, lipid storage, and, we speculate, to facilitate vertical stability in the complex shallow and estuarine waters in which this animal absent of a dorsal fin occurs.

Indications, advantages and limitations of perinatal postmortem imaging in clinical practice

Just as there is a range of paediatric imaging techniques available during life, a similar repertoire is available as part of the foetal and perinatal postmortem examination. In this article, we review the literature regarding the diagnostic utility of postmortem radiography, US, CT and MRI in this clinical setting. There is limited direct evidence on the diagnostic utility of any of these techniques, apart from postmortem MRI, which when combined with other noninvasive investigations, has been shown to be highly sensitive and specific for many foetal postmortem diagnoses. The main disadvantages of postmortem MRI include the longer duration of imaging, the need for appropriate training in the interpretation of normal postmortem changes, and possible non-diagnostic imaging examinations in early gestation foetuses. As less-invasive autopsy becomes increasingly available, the true utility of these techniques will evolve, and clinical guidelines for maximal diagnostic yield can be developed.

CT-guided percutaneous needle placement in forensic medicine

We have developed a technique of CT-guided needle placement in the destructed human body in forensic practice. A sixty-year-old male was found in a burned car and he was also destructed severely. Although blood was needed for the external examination, it was difficult to approach the vessels because of the severely burned condition of the cadaver. Thus, we attempted to obtain a blood sample from a vessel using a CT-guided technique. Postmortem CT demonstrated the presence of blood-containing vessels in the pelvis. Indeed, CT-guided needle placement had no difficulty with surface markers, table location, or depth measurement from the surface. CT-guide needle placement is a feasible and reliable technique, so that when the tissue/blood sample is at risk of being spoiled, CT-guided needle placement could be a substitute for conventional sampling techniques.