Summary:Choosing proper perfusates as contrast agents is an important aspect for postmortem magnetic resonance angiography(PMMRA).However,in this emerging field,the number of suitable kinds of liquid is still very lim...Summary:Choosing proper perfusates as contrast agents is an important aspect for postmortem magnetic resonance angiography(PMMRA).However,in this emerging field,the number of suitable kinds of liquid is still very limited.The objective of this research is to compare MR images of oleic acid(OA)with paraffin oil(PO)in vitro and in ex situ animal hearts,in order to evaluate the feasibility to use OA as a novel contrast agent for PMMRA.In vitro,OA,PO and water(control)were introduced into three tubes separately and T,weighted-spin echo(Tw SE)and T2w-SE images were acquired on a 1.5T MR scanner.In the second experiment,0A and PO were injected into left coronary artery(LCA)and left ventricle(LV)of ex situ bovine hearts and their Tw-SE,Tzw-SE,Tw-multipoint Dixon(Tjw-mDixon)and 3DT2w-mDixon images were acquired.The overall results indicate that OA may have a potential to be used as a dual(T and T2 based)contrast agent for PMMRA when proper sequence parameters are utilized.However,as the pilot study was based on limited number of animal hearts,more researches using OA in cadavers are needed to validate our findings.展开更多
Modern post-mortem investigations use an increasing number of digital imaging methods,which can be collected under the term“post-mortem imaging”.Most methods of forensic imaging are from the radiology field and are ...Modern post-mortem investigations use an increasing number of digital imaging methods,which can be collected under the term“post-mortem imaging”.Most methods of forensic imaging are from the radiology field and are therefore techniques that show the interior of the body with technologies such as X-ray or magnetic resonance imaging.To digitally image the surface of the body,other techniques are regularly applied,e.g.three-dimensional(3D)surface scanning(3DSS)or photogrammetry.Today’s most frequently used techniques include post-mortem computed tomography(PMCT),post-mortem magnetic resonance imaging(PMMR),post-mortem computed tomographic angiography(PMCTA)and 3DSS or photogrammetry.Each of these methods has specific advantages and limitations.Therefore,the indications for using each method are different.While PMCT gives a rapid overview of the interior of the body and depicts the skeletal system and radiopaque foreign bodies,PMMR allows investigation of soft tissues and parenchymal organs.PMCTA is the method of choice for viewing the vascular system and detecting sources of bleeding.However,none of those radiological methods allow a detailed digital view of the body’s surface,which makes 3DSS the best choice for such a purpose.If 3D surface scanners are not available,photogrammetry is an alternative.This review article gives an overview of different imaging techniques and explains their applications,advantages and limitations.We hope it will improve understanding of the methods.展开更多
In the past 2 decades,modern radiological methods,such as multiple detector computed tomography (MDCT),MDCT-angiography,and cardiac magnetic resonance imaging (MRI)were introduced into postmortem practice for investig...In the past 2 decades,modern radiological methods,such as multiple detector computed tomography (MDCT),MDCT-angiography,and cardiac magnetic resonance imaging (MRI)were introduced into postmortem practice for investigation of sudden death (SD),including cases of sudden cardiac death (SCD).In forensic cases,the underlying cause of SD is most frequently cardiovascular with coronary atherosclerotic disease as the leading cause.There are many controversies about the role of postmortem imaging in establishing the cause of death and especially the value of minimally invasive autopsy techniques.This paper discusses the state of the art for postmortem radiological evaluation of the heart compared to classical postmortem examination,especially in cases of SCD.In SCD cases,postmortem CT is helpful to estimate the heart size and to visualize haemopericardium and calcified plaques and valves,as well as to identify and locate cardiovascular devices.Angiographic methods are useful to provide a detailed view of the coronary arteries and to analyse them,especially regarding the extent and location of stenosis and obstruction.In postsurgical cases,it allows verification and documentation of the patency of stents and bypass grafts before opening the body.Postmortem MRI is used to investigate soft tissues such as the myocardium,but images are susceptible to postmortem changes and further work is necessary to increase the understanding of these radiological aspects,especially of the ischemic myocardium.In postsurgery cases,the value of postmortem imaging of the heart is reportedly for the diagnostic and documentation purposes.The implementation of new imaging methods into routine postmortem practice is challenging,as it requires not only an investment in equipment but,more importantly,investment in the expertise of interpreting the images.Once those requirements are implemented,however,they bring great advantages in investigating cases of SCD,as they allow documentation of the body,orientation of sampling for further analyses and gathering of other information that cannot be obtained by conventional autopsy such as a complete visualization of the vascular system using postmortem angiography.展开更多
Three-dimensional surface scanning(3DSS)and multi-detector computed tomography(MDCT)are two techniques that are used in legal medicine for digitalizing objects,a body or body parts such as bones.While these techniques...Three-dimensional surface scanning(3DSS)and multi-detector computed tomography(MDCT)are two techniques that are used in legal medicine for digitalizing objects,a body or body parts such as bones.While these techniques are more and more commonly employed,surprisingly little information is known about the quality rendering of digitalized three-dimensional(3D)models provided by each of them.This paper presents findings related to the measurement precision of 3D models obtained through observation of a study case,where a fractured skull reconstructed by an anthropologist was digitalized using both post-mortem imaging methods.Computed tomography(CT)scans were performed using an 8-row MDCT unit with two different slice thicknesses.The variability of 3D CT models superimposition allowed to assess the reproducibility and robustness of this digitalization technique.Furthermore,two 3D surface scans were done using a professional high resolution 3D digitizer.The comparison of 3D CT-scans with 3D surface scans by superimposition demonstrated several regions with significant differences in topology(average difference between+1.45 and-1.22 mm).When comparing the reproducibility between these two digitalizing techniques,it appeared that MDCT 3D models led in general to greater variability for measurement precision between scanned surfaces.Also,the reproducibility was better achieved with the 3D surface digitizer,showing 3D models with fewer and less pronounced differences(from+0.32 to-0.31 mm).These experiments suggest that MDCT provides less reproducible body models than 3D surface scanning.But further studies must be undertaken in order to corroborate this first impression,and possibly explain the reason for these findings.展开更多
Virtual anthropology(VA)is based on applying anthropological methods currently used to analyse bones to 3D models of human remains.While great advances have been made in this endeavour in the past decade,several inter...Virtual anthropology(VA)is based on applying anthropological methods currently used to analyse bones to 3D models of human remains.While great advances have been made in this endeavour in the past decade,several interrogations concerning how reliable these models are and what their proper use should be remain unanswered.In this research,a fundamental assumption of VA has been investigated:if the way we perceive and apply an anthropological method is truly similar when looking at bones macroscopically and through various 3D media.In order to answer,10 skulls of known age and sex were scanned using a computed tomography(CT)scanner and a 3D surface scanner.Two observers separately applied a defined staging method to eight suture sites on these skulls,first looking at the bone macroscopically,then at the 3D surface scan,and finally on the CT scan.Two rounds of observation were carried out by each observer.Intra-and inter-observer error were evaluated,and two sample t-tests used to evaluate if the different types of medium used yielded significantly different observations.The results show a high degree of inter-observer error,and that data obtained from 3D surface scans differ from macroscopic observation(confidence level 95%,P≤0.05).CT scans,in these settings,yielded results comparable to those obtained through macroscopic observations.These results offer many possibilities for future research,including indications on the kind of anthropological methods and anatomical landmarks that might be reliably transferable to the virtual environment.All current methods used in traditional anthropology should be tested,and if they prove unreliable,new techniques to analyse bones from virtual models should be developed.展开更多
For the medicolegal evaluation of victims of survived strangulation,a neck-magnetic resonance imaging(MRI)can be performed for assessing lesions in the inner soft tissues(fat,muscles or lymph nodes,for example).In our...For the medicolegal evaluation of victims of survived strangulation,a neck-magnetic resonance imaging(MRI)can be performed for assessing lesions in the inner soft tissues(fat,muscles or lymph nodes,for example).In our institute,such MRI examinations have been performed for a test period of 4 years with the aim of evaluating the use of this tool by forensic pathologists and identifying medicolegal indicators for the performance of neck-MRI in surviving victims of strangulation.We retrospectively reviewed medicolegal reports from all victims examined during the test period.We extracted objective lesions(e.g.petechiae,bruising and abrasions)and reported clinical symptoms(e.g.vision disorder,dysphasia)from the reports.These findings were compared to those reported from the neck-MRI.In total,112 victims were clinically examined after suspected strangulation.Eleven of these victims underwent an MRI examination of the neck.Eighty-four of the victims presented objective lesions during the clinical examination,with eight showing signs of both petechiae and bruising.Neck-MRI was performed in four of these eight victims and three of them showed lesions visible in MRI.Of 76 victims with bruising as the only objective finding,66 victims described clinical symptoms.Of those 66 victims,seven were examined by MRI and two demonstrated lesions in MRI.When MRI was performed,relevant findings were detected in 45%of the cases.This leads to the suspicion that many more findings could have been detected in the other victims,if an MRI had been performed in those cases.Our results lead us to the conclusion that an MRI examination of victims of suspected strangulation is useful,and strict indications for its application should be established.展开更多
Sex estimation is considered one of the first steps in the forensic identification process.Morphological and morphometrical differences between males and females have been used as means for morphoscopic and metric met...Sex estimation is considered one of the first steps in the forensic identification process.Morphological and morphometrical differences between males and females have been used as means for morphoscopic and metric methods on both cranial and postcranial skeletal elements.When dry skeletal elements are not available,virtual data can be used as a substitute.The present research explores 3-dimensional(3D)scans from a Turkish population to test a sex estimation method developed by Purkait(2005).Overall,296 individuals were used in this study(158 males and 138 females).Purkait’s triangle parameters were measured on computed tomography(CT)scans obtained from both right and left femora of each patient at the Bakirkoy Dr.Sadi Konuk Training Research Hospital(Istanbul,Turkey).Intra-and inter-observer errors were assessed for all variables through technical error of measurements analysis.Bilateral asymmetry and sex differences were evaluated using parametric and non-parametric statistical approaches.Univariate and multivariate discriminant function analyses were then conducted.Observer errors demonstrated an overall agreement within and between experts,as indicated by technical error of measurement(TEM)results.No bilateral asymmetries were reported,and all parameters demonstrated a statistically significant difference between males and females.Fourteen discriminant models were generated by applying single and combined parameters,producing a total correct sex classification ranging from 78.4%to 92.6%.In addition,over 67%of the total sample was accurately classified,with 95%or greater posterior probabilities.Our study demonstrates the feasibility of 3D sex estimation using Purkait’s triangle on a Turkish population,with accuracy rates comparable to those reported in other populations.This is the first attempt to apply this method on virtual data and although further validation and standardisation are recommended for its application on dry bone,this research constitutes a significant contribution to the development of population-specific standards when only virtual data are available.展开更多
This case reports on a 68-year-old man who was found dead in hospital next to his bed.Before this,he had been treated with intravenous antibiotics for pneumonia.The body was found with a peripheral venous catheter con...This case reports on a 68-year-old man who was found dead in hospital next to his bed.Before this,he had been treated with intravenous antibiotics for pneumonia.The body was found with a peripheral venous catheter connected to a nasal cannula delivering oxygen(O_(2))from the wall.Extensive medico-legal examinations were performed,including post-mortem computed tomography(CT),complete conventional autopsy,histological and immunohistochemistry analysis,toxicological analysis and post-mortem chemistry.Additionally,CT-guided gas sampling was performed at multiple sites to collect samples for gas analysis.During the external examination,massive subcutaneous emphysema was visible over the entire surface of the body.The CT scan revealed the presence of gas throughout the vascular system,and in the subcutaneous and muscular tissues.The autopsy confirmed the presence of lobar pneumonia and multiple gas bubbles in the vascular system.The gas analysis results showed a subnormal concentration of oxygen,confirming the suspected pure O_(2) embolism.Moreover,the carbon dioxide(CO_(2))concentration in the gas sample from the heart was elevated to a level similar to those found in scuba diving fatalities.This could come from degassing of dissolved CO_(2) that accumulated and was trapped in the cardiac cavity.Based on the results of the different exams performed,and especially the gas analysis results,it was concluded that the cause of death was O_(2) embolism.展开更多
基金This project was supported by a grant from China Scholarship Council(No.CSC 201707070113).
文摘Summary:Choosing proper perfusates as contrast agents is an important aspect for postmortem magnetic resonance angiography(PMMRA).However,in this emerging field,the number of suitable kinds of liquid is still very limited.The objective of this research is to compare MR images of oleic acid(OA)with paraffin oil(PO)in vitro and in ex situ animal hearts,in order to evaluate the feasibility to use OA as a novel contrast agent for PMMRA.In vitro,OA,PO and water(control)were introduced into three tubes separately and T,weighted-spin echo(Tw SE)and T2w-SE images were acquired on a 1.5T MR scanner.In the second experiment,0A and PO were injected into left coronary artery(LCA)and left ventricle(LV)of ex situ bovine hearts and their Tw-SE,Tzw-SE,Tw-multipoint Dixon(Tjw-mDixon)and 3DT2w-mDixon images were acquired.The overall results indicate that OA may have a potential to be used as a dual(T and T2 based)contrast agent for PMMRA when proper sequence parameters are utilized.However,as the pilot study was based on limited number of animal hearts,more researches using OA in cadavers are needed to validate our findings.
文摘Modern post-mortem investigations use an increasing number of digital imaging methods,which can be collected under the term“post-mortem imaging”.Most methods of forensic imaging are from the radiology field and are therefore techniques that show the interior of the body with technologies such as X-ray or magnetic resonance imaging.To digitally image the surface of the body,other techniques are regularly applied,e.g.three-dimensional(3D)surface scanning(3DSS)or photogrammetry.Today’s most frequently used techniques include post-mortem computed tomography(PMCT),post-mortem magnetic resonance imaging(PMMR),post-mortem computed tomographic angiography(PMCTA)and 3DSS or photogrammetry.Each of these methods has specific advantages and limitations.Therefore,the indications for using each method are different.While PMCT gives a rapid overview of the interior of the body and depicts the skeletal system and radiopaque foreign bodies,PMMR allows investigation of soft tissues and parenchymal organs.PMCTA is the method of choice for viewing the vascular system and detecting sources of bleeding.However,none of those radiological methods allow a detailed digital view of the body’s surface,which makes 3DSS the best choice for such a purpose.If 3D surface scanners are not available,photogrammetry is an alternative.This review article gives an overview of different imaging techniques and explains their applications,advantages and limitations.We hope it will improve understanding of the methods.
文摘In the past 2 decades,modern radiological methods,such as multiple detector computed tomography (MDCT),MDCT-angiography,and cardiac magnetic resonance imaging (MRI)were introduced into postmortem practice for investigation of sudden death (SD),including cases of sudden cardiac death (SCD).In forensic cases,the underlying cause of SD is most frequently cardiovascular with coronary atherosclerotic disease as the leading cause.There are many controversies about the role of postmortem imaging in establishing the cause of death and especially the value of minimally invasive autopsy techniques.This paper discusses the state of the art for postmortem radiological evaluation of the heart compared to classical postmortem examination,especially in cases of SCD.In SCD cases,postmortem CT is helpful to estimate the heart size and to visualize haemopericardium and calcified plaques and valves,as well as to identify and locate cardiovascular devices.Angiographic methods are useful to provide a detailed view of the coronary arteries and to analyse them,especially regarding the extent and location of stenosis and obstruction.In postsurgical cases,it allows verification and documentation of the patency of stents and bypass grafts before opening the body.Postmortem MRI is used to investigate soft tissues such as the myocardium,but images are susceptible to postmortem changes and further work is necessary to increase the understanding of these radiological aspects,especially of the ischemic myocardium.In postsurgery cases,the value of postmortem imaging of the heart is reportedly for the diagnostic and documentation purposes.The implementation of new imaging methods into routine postmortem practice is challenging,as it requires not only an investment in equipment but,more importantly,investment in the expertise of interpreting the images.Once those requirements are implemented,however,they bring great advantages in investigating cases of SCD,as they allow documentation of the body,orientation of sampling for further analyses and gathering of other information that cannot be obtained by conventional autopsy such as a complete visualization of the vascular system using postmortem angiography.
文摘Three-dimensional surface scanning(3DSS)and multi-detector computed tomography(MDCT)are two techniques that are used in legal medicine for digitalizing objects,a body or body parts such as bones.While these techniques are more and more commonly employed,surprisingly little information is known about the quality rendering of digitalized three-dimensional(3D)models provided by each of them.This paper presents findings related to the measurement precision of 3D models obtained through observation of a study case,where a fractured skull reconstructed by an anthropologist was digitalized using both post-mortem imaging methods.Computed tomography(CT)scans were performed using an 8-row MDCT unit with two different slice thicknesses.The variability of 3D CT models superimposition allowed to assess the reproducibility and robustness of this digitalization technique.Furthermore,two 3D surface scans were done using a professional high resolution 3D digitizer.The comparison of 3D CT-scans with 3D surface scans by superimposition demonstrated several regions with significant differences in topology(average difference between+1.45 and-1.22 mm).When comparing the reproducibility between these two digitalizing techniques,it appeared that MDCT 3D models led in general to greater variability for measurement precision between scanned surfaces.Also,the reproducibility was better achieved with the 3D surface digitizer,showing 3D models with fewer and less pronounced differences(from+0.32 to-0.31 mm).These experiments suggest that MDCT provides less reproducible body models than 3D surface scanning.But further studies must be undertaken in order to corroborate this first impression,and possibly explain the reason for these findings.
文摘Virtual anthropology(VA)is based on applying anthropological methods currently used to analyse bones to 3D models of human remains.While great advances have been made in this endeavour in the past decade,several interrogations concerning how reliable these models are and what their proper use should be remain unanswered.In this research,a fundamental assumption of VA has been investigated:if the way we perceive and apply an anthropological method is truly similar when looking at bones macroscopically and through various 3D media.In order to answer,10 skulls of known age and sex were scanned using a computed tomography(CT)scanner and a 3D surface scanner.Two observers separately applied a defined staging method to eight suture sites on these skulls,first looking at the bone macroscopically,then at the 3D surface scan,and finally on the CT scan.Two rounds of observation were carried out by each observer.Intra-and inter-observer error were evaluated,and two sample t-tests used to evaluate if the different types of medium used yielded significantly different observations.The results show a high degree of inter-observer error,and that data obtained from 3D surface scans differ from macroscopic observation(confidence level 95%,P≤0.05).CT scans,in these settings,yielded results comparable to those obtained through macroscopic observations.These results offer many possibilities for future research,including indications on the kind of anthropological methods and anatomical landmarks that might be reliably transferable to the virtual environment.All current methods used in traditional anthropology should be tested,and if they prove unreliable,new techniques to analyse bones from virtual models should be developed.
文摘For the medicolegal evaluation of victims of survived strangulation,a neck-magnetic resonance imaging(MRI)can be performed for assessing lesions in the inner soft tissues(fat,muscles or lymph nodes,for example).In our institute,such MRI examinations have been performed for a test period of 4 years with the aim of evaluating the use of this tool by forensic pathologists and identifying medicolegal indicators for the performance of neck-MRI in surviving victims of strangulation.We retrospectively reviewed medicolegal reports from all victims examined during the test period.We extracted objective lesions(e.g.petechiae,bruising and abrasions)and reported clinical symptoms(e.g.vision disorder,dysphasia)from the reports.These findings were compared to those reported from the neck-MRI.In total,112 victims were clinically examined after suspected strangulation.Eleven of these victims underwent an MRI examination of the neck.Eighty-four of the victims presented objective lesions during the clinical examination,with eight showing signs of both petechiae and bruising.Neck-MRI was performed in four of these eight victims and three of them showed lesions visible in MRI.Of 76 victims with bruising as the only objective finding,66 victims described clinical symptoms.Of those 66 victims,seven were examined by MRI and two demonstrated lesions in MRI.When MRI was performed,relevant findings were detected in 45%of the cases.This leads to the suspicion that many more findings could have been detected in the other victims,if an MRI had been performed in those cases.Our results lead us to the conclusion that an MRI examination of victims of suspected strangulation is useful,and strict indications for its application should be established.
文摘Sex estimation is considered one of the first steps in the forensic identification process.Morphological and morphometrical differences between males and females have been used as means for morphoscopic and metric methods on both cranial and postcranial skeletal elements.When dry skeletal elements are not available,virtual data can be used as a substitute.The present research explores 3-dimensional(3D)scans from a Turkish population to test a sex estimation method developed by Purkait(2005).Overall,296 individuals were used in this study(158 males and 138 females).Purkait’s triangle parameters were measured on computed tomography(CT)scans obtained from both right and left femora of each patient at the Bakirkoy Dr.Sadi Konuk Training Research Hospital(Istanbul,Turkey).Intra-and inter-observer errors were assessed for all variables through technical error of measurements analysis.Bilateral asymmetry and sex differences were evaluated using parametric and non-parametric statistical approaches.Univariate and multivariate discriminant function analyses were then conducted.Observer errors demonstrated an overall agreement within and between experts,as indicated by technical error of measurement(TEM)results.No bilateral asymmetries were reported,and all parameters demonstrated a statistically significant difference between males and females.Fourteen discriminant models were generated by applying single and combined parameters,producing a total correct sex classification ranging from 78.4%to 92.6%.In addition,over 67%of the total sample was accurately classified,with 95%or greater posterior probabilities.Our study demonstrates the feasibility of 3D sex estimation using Purkait’s triangle on a Turkish population,with accuracy rates comparable to those reported in other populations.This is the first attempt to apply this method on virtual data and although further validation and standardisation are recommended for its application on dry bone,this research constitutes a significant contribution to the development of population-specific standards when only virtual data are available.
文摘This case reports on a 68-year-old man who was found dead in hospital next to his bed.Before this,he had been treated with intravenous antibiotics for pneumonia.The body was found with a peripheral venous catheter connected to a nasal cannula delivering oxygen(O_(2))from the wall.Extensive medico-legal examinations were performed,including post-mortem computed tomography(CT),complete conventional autopsy,histological and immunohistochemistry analysis,toxicological analysis and post-mortem chemistry.Additionally,CT-guided gas sampling was performed at multiple sites to collect samples for gas analysis.During the external examination,massive subcutaneous emphysema was visible over the entire surface of the body.The CT scan revealed the presence of gas throughout the vascular system,and in the subcutaneous and muscular tissues.The autopsy confirmed the presence of lobar pneumonia and multiple gas bubbles in the vascular system.The gas analysis results showed a subnormal concentration of oxygen,confirming the suspected pure O_(2) embolism.Moreover,the carbon dioxide(CO_(2))concentration in the gas sample from the heart was elevated to a level similar to those found in scuba diving fatalities.This could come from degassing of dissolved CO_(2) that accumulated and was trapped in the cardiac cavity.Based on the results of the different exams performed,and especially the gas analysis results,it was concluded that the cause of death was O_(2) embolism.
