Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 246
Filtrar
1.
NMR Biomed ; : e5171, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38757603

RESUMO

Magnetic resonance spectroscopy (MRS) thermometry offers a noninvasive, localized method for estimating temperature by leveraging the temperature-dependent chemical shift of water relative to a temperature-stable reference metabolite under suitable calibration. Consequentially, this technique has significant potential as a tool for postmortem MR examinations in forensic medicine and pathology. In these examinations, the deceased are examined at a wide range of body temperatures, and MRS thermometry may be used for the temperature adjustment of magnetic resonance imaging (MRI) protocols or for corrections in the analysis of MRI or MRS data. However, it is not yet clear to what extent postmortem changes may influence temperature estimation with MRS thermometry. In addition, N-acetylaspartate, which is commonly used as an in vivo reference metabolite, is known to decrease with increasing postmortem interval (PMI). This study shows that lactate, which is not only present in significant amounts postmortem but also has a temperature-stable chemical shift, can serve as a suitable reference metabolite for postmortem MRS thermometry. Using lactate, temperature estimation in postmortem brain tissue of severed sheep heads was accurate up to 60 h after death, with a mean absolute error of less than 0.5°C. For this purpose, published calibrations intended for in vivo measurements were used. Although postmortem decomposition resulted in severe metabolic changes, no consistent deviations were observed between measurements with an MR-compatible temperature probe and MRS thermometry with lactate as a reference metabolite. In addition, MRS thermometry was applied to 84 deceased who underwent a MR examination as part of the legal examination. MRS thermometry provided plausible results of brain temperature in comparison with rectal temperature. Even for deceased with a PMI well above 60 h, MRS thermometry still provided reliable readings. The results show a good suitability of MRS thermometry for postmortem examinations in forensic medicine.

2.
Forensic Sci Med Pathol ; 20(1): 14-22, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36862287

RESUMO

The aims of this study are to retrospectively evaluate the diagnostic value of T1- and T2-weighted 3-T magnetic resonance imaging (MRI) for postmortem detection of myocardial infarction (MI) in terms of sensitivity and specificity and to compare the MRI appearance of the infarct area with age stages. Postmortem MRI examinations (n = 88) were retrospectively reviewed for the presence or absence of MI by two raters blinded to the autopsy results. The sensitivity and specificity were calculated using the autopsy results as the gold standard. A third rater, who was not blinded to the autopsy findings, reviewed all cases in which MI was detected at autopsy for MRI appearance (hypointensity, isointensity, hyperintensity) of the infarct area and the surrounding zone. Age stages (peracute, acute, subacute, chronic) were assigned based on the literature and compared with the age stages reported in the autopsy reports. The interrater reliability between the two raters was substantial (κ = 0.78). Sensitivity was 52.94% (both raters). Specificity was 85.19% and 92.59%. In 34 decedents, autopsy identified an MI (peracute: n = 7, acute: n = 25, chronic: n = 2). Of 25 MI classified as acute at autopsy, MRI classified peracute in four cases and subacute in nine cases. In two cases, MRI suggested peracute MI, which was not detected at autopsy. MRI could help to classify the age stage and may indicate the area for sampling for further microscopic examination. However, the low sensitivity requires further additional MRI techniques to increase the diagnostic value.


Assuntos
Infarto do Miocárdio , Humanos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Infarto do Miocárdio/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Autopsia/métodos
3.
Acta Radiol ; 64(6): 2126-2131, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36991329

RESUMO

BACKGROUND: Projection radiography and, more recently, computed tomography (CT) play an important role in forensic age estimation. Both in terms of general criminal responsibility and government regulations concerning refugee care, it is important to differentiate correctly between youths and adults. A disadvantage of age estimation in CT is the ionizing radiation exposure. PURPOSE: To investigate how far the CT dose can be reduced without losing diagnostic confidence in assessing the different stages of ossification of the medial clavicle. MATERIAL AND METHODS: We prospectively scanned 25 postmortem cases with a fixed parameters protocol (FPP) and a care dose modulation protocol (CDMP) for different scan parameters. Two radiologists assessed the diagnostic image quality using a 5-point Likert scale. Inter-reader agreement was evaluated with Cohen's kappa. Differences in doses between FPP and CDMP were assessed with the one-tailed t-test. RESULTS: The best combination of diagnostic image quality and lowest radiation dose was obtained using a CDMP with 100 kV and 40 mAs and an FPP with 100 kV and 30 mAs. Doses for 120 kV were significantly higher (one-tailed P < 0.001). The diagnostic image quality for 80 kV was insufficient overall. DISCUSSION: Our results confirm that CT imaging at 100 kV allows a sufficient image quality that is diagnostic for age estimation in the ossification of the medial clavicle.


Assuntos
Clavícula , Redução da Medicação , Adulto , Adolescente , Humanos , Clavícula/diagnóstico por imagem , Estudos Prospectivos , Determinação da Idade pelo Esqueleto/métodos , Tomografia Computadorizada por Raios X/métodos , Epífises/diagnóstico por imagem , Doses de Radiação
4.
Radiol Med ; 128(2): 234-241, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36637741

RESUMO

PURPOSE: To evaluate the added value of ultra-short echo time (UTE) and fast field echo resembling a CT using restricted echo-spacing (FRACTURE) MR sequences in the assessment of the osseous cervical spine using CT as reference. MATERIALS AND METHODS: Twenty-seven subjects underwent postmortem CT and MRI within 48 h. Datasets were anonymized and analyzed retrospectively by two radiologists. Morphological cervical spine alterations were rated on CT, UTE and FRACTURE images. Afterward, neural foraminal stenosis was graded on standard MR and again after viewing additional UTE/FRACTURE sequences. To evaluate interreader and intermodality reliability, intra-class correlation coefficients (ICC) and for stenosis grading Wilcoxon-matched-pairs testing with multiple comparison correction were calculated. RESULTS: Moderate interreader reliability (ICC = 0.48-0.71) was observed concerning morphological findings on all modalities. Intermodality reliability was good between modalities regarding degenerative vertebral and joint alterations (ICC = 0.69-0.91). Compared to CT neural stenosis grades were more often considered as nonsignificant on all analyzed MR sequences. Neural stenosis grading scores differed also significantly between specific bone imaging sequences, UTE and FRACTURE, to standard MR sequences. However, no significant difference was observed between UTE and FRACTURE sequences. CONCLUSION: Compared to CT as reference, UTE or FRACTURE sequence added to standard MR sequences can deliver comparable information on osseous cervical spine status. Both led to changes in clinically significant stenosis gradings when added to standard MR, mainly reducing the severity of neural foramina stenosis.


Assuntos
Vértebras Cervicais , Imageamento por Ressonância Magnética , Humanos , Constrição Patológica , Reprodutibilidade dos Testes , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos
5.
Forensic Sci Int ; 334: 111240, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35276540

RESUMO

Sudden cardiac death (SCD) is an important public health issue. In young persons aged between 1 and 40 years, most SCDs are caused by potentially inherited cardiac diseases, often not detectable during conventional medico-legal investigations and therefore termed as sudden unexplained deaths (SUD). In this study, we describe the implementation, feasibility and importance of a standardized procedure to investigate SUD cases within the forensic framework at the Zurich Institute of Forensic Medicine in Switzerland. This new approach involves a multidisciplinary collaboration including forensic autopsy, second pathology expert opinion, post-mortem molecular genetic testing, cardiac counselling of relatives, and a tentative financing. This procedure is in line with the published Swiss and European recommendations on the management of SCDs. During a two-year pilot project, 39 sudden and unexpected death cases were collected, whereof 10 deceased remained without any identifiable cause of death after medico-legal investigation and second expert evaluation. Molecular autopsy, including 393 genes involved in cardio-vascular and metabolic diseases, identified eight pathogenic or likely pathogenic genetic variants in five out of the 10 deceased (50%). Cardio-genetic follow-up investigations in the families of the 10 deceased revealed phenotype-positive relatives in four families and required specific therapies, including an implantable cardioverter defibrillator (ICD) for primary prevention. Multidisciplinary collaboration is crucial for an optimal management of sudden unexplained death cases, to identify additional relatives at risk, and to prevent other tragic deaths within a family.


Assuntos
Morte Súbita Cardíaca , Testes Genéticos , Autopsia/métodos , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/patologia , Morte Súbita Cardíaca/prevenção & controle , Testes Genéticos/métodos , Humanos , Fenótipo , Projetos Piloto , Suíça
6.
Forensic Sci Int ; 332: 111196, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35123259

RESUMO

OBJECTIVES: Due to taphonomic processes such as burial, fire, or animal activity, bones are often found incomplete, which can pose problematic for establishing the biological profile of the deceased using anthropological methods. The aim of this study is to test the feasibility of using statistical shape modeling (SSM) to reconstruct full femora from simulated partial femora and determine the accuracy of the reconstruction. Moreover, we assess the accuracy of sex estimation and the degree of stature error added based on the reconstructed femur using different anthropological methods. METHODS: A total of 42 (28 female, 14 female) 3D models of left femora extracted from computed tomography (CT) scans were used. We performed a leave-one-out cross-validation (LOOCV) where 41 bones were used to build the SSM and one bone was used for testing. This bone was cut in 1 cm steps proximally, distally and from both ends up to 10 cm, reconstructed using SSM, and tested using the methods established by Stewart and Purkait (2005), Trotter and Gleser (1952), as well as a method based on SSM. with landmarks being automatically identified. RESULTS: The error induced by reconstructing the femur to the length measurements was low, which translated into useful stature estimations (single sided cuts up to 10 cm: 0.4-1.1%, double sided<2% for cuts shorter than 6 cm). Using Purkaits method for sex estimation on reconstructed bones looked promising as well (single sided: 90.5% when compared to applying Purkaits method on the original bone, double sided 78.6% (10 cm cut) to 97.6% (1-3 cm cuts)) Using SSM for sex classification looked promising as well (single sided cut: 81-85.7%, double sided cut: 59.5-85.3%) CONCLUSION: SSM can be used to reconstruct fragmented femora. These reconstructions can be used for sex and stature estimations, at the cost of lower accuracy. Using SSM might give investigators an additional tool to gain information about the biological profile of a deceased in cases where the fragmentation of a femur does not allow for using other anthropological methods.

7.
Int J Legal Med ; 136(2): 649-656, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34817651

RESUMO

BACKGROUND: Cases of external hemorrhage are difficult to recognize on postmortem computed tomography (PMCT). PURPOSE: To investigate the effects of blood loss on CT attenuation of the spleen, liver, kidneys, and lungs on PMCT and to assess the relationship between blood loss and organ weight. METHODS: A total of 125 cases with blood loss were sex- and age-matched to 125 control cases without blood loss. Individual organ attenuation was measured on transverse CT images. Organ weights of the liver, spleen, kidneys, and lung were extracted from the autopsy protocols. RESULTS: Organ weight was significantly lower in cases with blood loss (lung 30%, spleen 28%, kidneys 14%, liver 18%) than in controls. CT attenuation of the lungs was significantly lower (30%) in cases with blood loss than in controls. CT attenuation of the spleen and kidneys did not significantly differ between cases and controls. CT attenuation of the liver was significantly higher (25%) in cases with blood loss than in controls. CONCLUSION: Blood loss decreases organ weight and CT attenuation of the lungs but appears to have no significant effect on CT attenuation of the spleen and kidneys. The increased liver attenuation in cases with blood loss compared to controls was an unexpected finding and remains challenging to explain. One probable interpretation refers to different levels of hepatic glycogen; however, further work is warranted to substantiate this hypothesis.


Assuntos
Baço , Tomografia Computadorizada por Raios X , Autopsia , Hemorragia/diagnóstico por imagem , Humanos , Tamanho do Órgão , Baço/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
9.
In Vivo ; 35(6): 3147-3155, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34697145

RESUMO

BACKGROUND/AIM: The quantitative evaluation of fat tissue, mainly for the determination of liver steatosis, is possible by using dual-energy computed tomography. Different photon energy acquisitions allow for estimation of attenuation coefficients. The effect of variation in radiation doses and reconstruction kernels on fat fraction estimation was investigated. MATERIALS AND METHODS: A six-probe-phantom with fat concentrations of 0%, 20%, 40%, 60%, 80%, and 100% were scanned in Sn140/100 kV with radiation doses ranging between 20 and 200 mAs before and after calibration. Images were reconstructed using iterative kernels (I26,Q30,I70). RESULTS: Fat fractions measured in dual-energy computed tomography (DECT) were consistent with the 20%-stepwise varying actual concentrations. Variation in radiation dose resulted in 3.1% variation of fat fraction. Softer reconstruction kernel (I26) underestimated the fat fraction (-9.1%), while quantitative (Q30) and sharper kernel (I70) overestimated fat fraction (10,8% and 13,1, respectively). CONCLUSION: The fat fraction in DECT approaches the actual fat concentration when calibrated to the reconstruction kerneö. Variation of radiation dose caused an acceptable 3% variation.


Assuntos
Fígado Gorduroso , Tomografia Computadorizada por Raios X , Humanos , Imagens de Fantasmas , Fótons , Doses de Radiação
10.
In Vivo ; 35(6): 3277-3287, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34697159

RESUMO

BACKGROUND/AIM: Multiparametric dual energy comptuted tomography (CT) imaging allows for multidimensional tissue characterization beyond the measurement of Hounsfield units. The purpose of this study was to evaluate multiple imaging parameters for different abdominal organs in dual energy CT (DECT) and analyze the effects of the contrast agent on these different parameters and provide normal values for characterization of parenchymatous organs. PATIENTS AND METHODS: This retrospective analysis included a total of 484 standardized DECT scans of the abdomen. Hounsfield Units (HU), rho (electron density relative to water), Zeff (effective atomic number) and FF (fat fraction) were evaluated for liver, spleen, kidney, muscle, fat-tissue. Independent generalized estimation equation models were fitted. RESULTS: In DECT imaging there is only little difference in mean HUmixed for parenchymatous abdominal organs. Analysis including Zeff, rho and FF allows for better discrimination while a large overlap remains for liver, spleen and muscle. Including multidimensional analysis and the effects of contrast medium further enhances tissue characterization. Small differences remain for liver and spleen. CONCLUSION: Organ characterization using multiparametric dual energy CT analysis is possible. An increased number of parameters obtained from DECT improves organ characterization. To our knowledge this is the first attempt to provide normal values for characterization of parenchymatous organs.


Assuntos
Meios de Contraste , Tomografia Computadorizada por Raios X , Abdome/diagnóstico por imagem , Fígado/diagnóstico por imagem , Estudos Retrospectivos
11.
Forensic Sci Med Pathol ; 17(4): 726-729, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34106424

RESUMO

The computed tomography (CT) scan of a 19-year-old man who died from an occipito-frontal gunshot wound presented an impressive radiating fracture line where the entire sagittal suture burst due to the high intracranial pressure that arose from a near-contact shot from a 9 mm bullet fired from a Glock 17 pistol. Photorealistic depictions of the radiating fracture lines along the cranial bones were created using three-dimensional reconstruction methods, such as the novel cinematic rendering technique that simulates the propagation and interaction of light when it passes through volumetric data. Since the brain had collapsed, depiction of soft tissue was insufficient on CT images. An additional magnetic resonance imaging (MRI) examination was performed, which enabled the diagnostic assessment of cerebral injuries.


Assuntos
Armas de Fogo , Ferimentos por Arma de Fogo , Adulto , Humanos , Imageamento Tridimensional , Masculino , Crânio , Suturas , Tomografia Computadorizada por Raios X , Ferimentos por Arma de Fogo/diagnóstico por imagem , Adulto Jovem
12.
Int J Legal Med ; 135(5): 1903-1912, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33909145

RESUMO

OBJECTIVES: The aim of this study was to measure the mediastinal-thoracic volume ratio (CTR_VOL) on PMCT as a more accurate version of traditional CTR, in order to assess the terminal positional relationship between the heart and lungs in the different causes of death with regard to age, gender, BMI, cardiomegaly, and lung expansion. MATERIALS: Two hundred fifty consecutive postmortem cases with pre-autopsy PMCT and full forensic autopsy were retrospectively evaluated. The lungs and the mediastinum were manually segmented on the PMCT data and the correspondent volumes were estimated in situ. CTR_VOL was calculated as the ratio of the mediastinal to the thoracic volume. The volume measurements were repeated by the same rater for the evaluation of the intrarater reliability. Age, gender, body weight and height, heart weight at autopsy, and cause of death were retrieved from the autopsy reports. Presence of lung expansion was radiologically evaluated in situ. RESULTS: CTR_VOL was positively associated with age and BMI but not with gender and was higher for cardiomegaly compared to normal hearts, lower for asphyxiation-related deaths compared to cardiac deaths and intoxications, and lower for cases with lung expansion. The intrarater reliability was excellent for the calculated volumes of both lungs and mediastinum. CONCLUSION: The results of the present study support CTR_VOL as a tool to assess the relationship between the heart and lungs in situ, which differs significantly between the studied cause of death categories.


Assuntos
Patologia Legal , Pulmão/diagnóstico por imagem , Pulmão/patologia , Mediastino/diagnóstico por imagem , Mediastino/patologia , Adulto , Autopsia , Causas de Morte , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
13.
Forensic Sci Med Pathol ; 17(2): 254-261, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33905073

RESUMO

Post mortem computed tomography (PMCT) can aid in localizing foreign bodies, bone fractures, and gas accumulations. The visualization of these findings play an important role in the communication of radiological findings. In this article, we present an algorithm for automated visualization of gas distributions on PMCT image data of the thorax and abdomen. The algorithm uses a combination of region growing segmentation and layering of different visualization methods to automatically generate overview images that depict radiopaque foreign bodies, bones and gas distributions in one image. The presented method was tested on 955 PMCT scans of the thorax and abdomen. The algorithm managed to generate useful images for all cases, visualizing foreign bodies as well as gas distribution. The most interesting cases are presented in this article. While this type of visualization cannot replace a real radiological analysis of the image data, it can provide a quick overview for briefings and image reports.


Assuntos
Algoritmos , Osso e Ossos , Corpos Estranhos , Patologia Legal , Fraturas Ósseas , Tomografia Computadorizada por Raios X , Autopsia , Osso e Ossos/diagnóstico por imagem , Corpos Estranhos/diagnóstico por imagem , Patologia Legal/instrumentação , Patologia Legal/métodos , Gases/análise , Humanos , Processamento de Imagem Assistida por Computador
14.
Dentomaxillofac Radiol ; 50(5): 20200615, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33591846

RESUMO

OBJECTIVES: Calcification of the epiglottis is a normal physiological degenerative process, although it can also be a consequence of infection or trauma. There are three possible forensically relevant consequences from epiglottic calcification: misinterpretation as foreign bodies, dysphagia as a major contributing factor to aspiration, and association with difficult intubation or a misplaced ventilation tube. It is the aim of this study (I) to inquire about the prevalence of epiglottic calcification in postmortem CT in general and (II) to investigate whether calcification of the epiglottis is linked to a higher incidence of failed endotracheal intubation. METHODS: We retrospectively analysed 2930 consecutive cases in postmortem CT at the Institute of Forensic Medicine. RESULTS: The prevalence of epiglottic calcification was 4.1%. Higher age and male sex are associated with an increased risk of epiglottic calcification. There was no calcification of the epiglottis in the cases with misplacement of the ventilation tube in the esophagus. CONCLUSIONS: To verify the result of our study, that is, the calcification of the epiglottis is not linked to a higher incidence of failed endotracheal intubation, it might be reasonable to repeat this study with a more representative study population. The high interindividual variations of calcified epiglottis could be used for identification.


Assuntos
Epiglote , Intubação Intratraqueal , Epiglote/diagnóstico por imagem , Humanos , Intubação Intratraqueal/efeitos adversos , Masculino , Prevalência , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
15.
Forensic Sci Med Pathol ; 17(2): 185-191, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33587253

RESUMO

Dead bodies exhibit a variable range of changes with advancing decomposition. To quantify intracorporeal gas, the radiological alteration index (RAI) has been implemented in the assessment of postmortem whole-body computed tomography. We used this RAI as a proxy for the state of decomposition. This study aimed to (I) investigate the correlation between the state of decomposition and the season in which the body was discovered; and (II) evaluate the correlations between sociodemographic factors (age, sex) and the state of decomposition, by using the RAI as a proxy for the extent of decomposition. In a retrospective study, we analyzed demographic data from all autopsy reports from the Institute of Forensic Medicine of Zurich between January 2017 to July 2019 and evaluated the radiological alteration index from postmortem whole-body computed tomography for each case. The bodies of older males showed the highest RAI. Seasonal effects had no significant influence on the RAI in our urban study population with bodies mostly being discovered indoors. Autopsy reports contain valuable data that allow interpretation for reasons beyond forensic purposes, such as sociopolitical observations.


Assuntos
Patologia Legal , Mudanças Depois da Morte , Tomografia Computadorizada por Raios X , Fatores Etários , Autopsia , Feminino , Patologia Legal/métodos , Humanos , Masculino , Estudos Retrospectivos , Estações do Ano , Fatores Sexuais , Suíça
16.
Int J Legal Med ; 135(2): 593-603, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33410928

RESUMO

AIM: The aim of this retrospective study was to determine the accuracy of postmortem computed tomography and different radiological signs for the determination of the bleeding source in cases with hemoperitoneum confirmed at autopsy. METHODS: Postmortem computed tomography data of consecutive cases with hemoperitoneum confirmed at autopsy were reviewed by two raters, blinded to the autopsy findings. The determination of possible bleeding sources was based on the presence of the sentinel clot sign, blood or sedimented blood surrounding an organ, intraparenchymal abnormal gas distribution, and parenchymal disruption. The bleeding source and the cause of hemoperitoneum (traumatic, surgical, natural, or resuscitation) as reported in the autopsy report were noted. The survival intervals of the deceased were calculated when information about the time of an incident related to death was available in the autopsy reports. RESULTS: Eighty-five cases were included in the study. Postmortem computed tomography showed 79% sensitivity and 92.1% specificity for the detection of the bleeding source. The sentinel clot sign was associated with surgical or natural causes of hemoperitoneum and longer survival intervals. Sedimented blood around the bleeding source was associated with resuscitation. Abnormal gas distribution within organs and combination of multiple radiological signs provided higher sensitivity. CONCLUSION: Postmortem computed tomography provides moderate sensitivity and high specificity for determining the bleeding source in cases with hemoperitoneum. Different PMCT signs are associated with different causes of hemoperitoneum and survival intervals.


Assuntos
Patologia Legal , Hemoperitônio/diagnóstico por imagem , Hemoperitônio/etiologia , Adulto , Idoso , Autopsia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Retrospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X
17.
Eur Radiol Exp ; 5(1): 3, 2021 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-33442787

RESUMO

The detection and assessment of cerebral lesions and traumatic brain injuries are of particular interest in forensic investigations in order to differentiate between natural and traumatic deaths and to reconstruct the course of events in case of traumatic deaths. For this purpose, computed tomography (CT) and magnetic resonance imaging (MRI) are applied to supplement autopsy (traumatic death) or to supplant autopsy (natural deaths). This approach is termed "virtual autopsy." The value of this approach increases as more microlesions and traumatic brain injuries are detected and assessed. Focusing on these findings, this article describes the examination of two decedents using CT, 3-T, and 7-T MRI. The main question asked was whether there is a benefit in using 7-T over 3-T MRI. To answer this question, the 3-T and 7-T images were graded regarding the detectability and the assessability of coup/contrecoup injuries and microlesions using 3-point Likert scales. While CT missed these findings, they were detectable on 3-T and 7-T MRI. However, the 3-T images appeared blurry in direct comparison with the 7-T images; thus, the detectability and assessability of small findings were hampered on 3-T MRI. The potential benefit of 7-T over 3-T MRI is discussed.


Assuntos
Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Autopsia , Encéfalo/diagnóstico por imagem
18.
J Forensic Leg Med ; 77: 102087, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33249345

RESUMO

This case report describes medicolegal examinations of a decedent with a fatal gunshot wound. The decedent lied on the floor as a bullet was fired into his chest. Computed tomography (CT) and magnetic resonance imaging (MRI) were performed as part of the judicial investigation. The MRI examination was valuable for delineating the wound channel through the left ventricle, which was deemed the main cause for internal bleeding and fatal blood loss. The diagnostic value of CT for the detection of injuries was low in this case. However, CT allowed for the virtual investigation of bullet fragments. According to CT-based dual-energy index calculations, it could be inferred that the fragments were most likely made of lead matching .357 Magnum R-P cartridges that were found at the scene. The bullet fragments were located underneath the skin at the suspected exit wound. The exit wound was actually an exit-re-entrance wound, as it can be assumed that the fragments re-entered the body after the bullet burst from hard ground upon exiting the body of the decedent, who was lying on the floor. CT visualized an uncommon annular distribution pattern for the bullet fragments surrounding the exit-re-entrance wound. The formation of such an annular distribution pattern of bullet fragments and the relevant conclusions that may be drawn from such a distribution pattern are discussed in this article.


Assuntos
Balística Forense/métodos , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Ferimentos por Arma de Fogo/diagnóstico por imagem , Lesões nas Costas/diagnóstico por imagem , Lesões nas Costas/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Suicídio Consumado , Traumatismos Torácicos/diagnóstico por imagem , Traumatismos Torácicos/patologia , Ferimentos por Arma de Fogo/patologia
19.
J Forensic Leg Med ; 77: 102093, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33316735

RESUMO

Traffic incidents are one of the most frequent causes of death in young adults worldwide. Depending on the location of the incident, the velocity of the vehicle(s), the weather condition, traffic incidents are often complicated making the investigation of the circumstances difficult. Here we report a case of an incinerated body involved in a vehicle incident. Differential diagnosis included natural cause of death during driving, fatal traumatic injuries, death due to fire and positional asphyxia. The body was submitted to PMCT prior to autopsy as part of a research protocol (N. 1388/2016) at the Department of Medical Imaging of the University Hospital of Heraklion in Crete, Greece. Unenhanced PMCT revealed craniofacial fractures, a thin film of subdural haemorrhage and an epidural fluid collection. The findings were interpreted as consistent with an impact to the face, causing craniofacial fractures mainly on the right side, and an acute subdural hematoma. Autopsy findings corroborated the diagnosis. The epidural hematoma was deemed to be post-mortem heat-induced. This case is an excellent example of the diagnostic value of PMCT in the medicolegal investigation of death.


Assuntos
Incêndios , Hematoma Subdural Agudo/diagnóstico por imagem , Hematoma Subdural/diagnóstico por imagem , Fraturas Cranianas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Acidentes de Trânsito , Autopsia/métodos , Queimaduras , Ossos Faciais/diagnóstico por imagem , Ossos Faciais/lesões , Humanos , Masculino , Adulto Jovem
20.
J Magn Reson Imaging ; 53(4): 1029-1039, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33368790

RESUMO

BACKGROUND: To assess changes of the craniocervical junction (CCJ), computed tomography (CT) is considered the reference standard. Recent advances in bone depiction on magnetic resonance imaging (MRI) enable high-quality visualization of osseous structures. Consequently, MRI may serve as an alternative to CT, without the use of ionizing radiation. PURPOSE: To compare two MRI sequences optimized for bone visualization to the CT reference standard in the assessment of the osseous CCJ. STUDY TYPE: Prospective. POPULATION/SUBJECTS: Twenty-seven decedents and five healthy volunteers. FIELD STRENGTH/SEQUENCE: 3T/ultrashort-echo time gradient echo (UTE) and optimized 3D-multiecho in-phase gradient echo sequences (FRACTURE). ASSESSMENT: All decedents were scanned with both MRI sequences and CT. Three observers rated degeneration to obtain a score for the upper (atlanto-dental and left/right atlanto-occipital joint) and for the lower part of the CCJ (left and right atlanto-axial joint). Two reader rated the following quantitative parameters: basion-axial-interval, atlanto-dental-interval, atlanto-occipital-interval, Powers-ratio, and signal/contrast-to-noise-ratio. As a proof of concept, five healthy volunteers were scanned with both MRI sequences. STATISTICAL TESTS: Degeneration was assessed on a Likert scale by three independent observers. Interrater and intermodality reliability were calculated using an intraclass correlation coefficient. To compare distance measurements between examination methods, a Friedman test, between-degenerative ratings, and a Kruskal-Wallis test were performed. RESULTS: Degenerative ratings of the CCJ between MRI sequences and CT showed a good interrater and intermodality agreement. MRI sequences tended to underestimate the degree of degeneration compared to CT, and this became more marked with increasing degeneration severity. There were no significant relationships between distance measurements and the degree of degeneration (PCT = 0.62, PUTE = 0.64, PFRACTURE = 0.67). The in vivo examination proved the feasibility of both MRI methods in a clinical setting. DATA CONCLUSION: Quantitative and qualitative ratings on MR images were comparable to CT images; thus, MRI may be a valid alternative to CT assessing the CCJ. LEVEL OF EVIDENCE: 1. TECHNICAL EFFICACY STAGE: 3.


Assuntos
Imageamento Tridimensional , Imageamento por Ressonância Magnética , Humanos , Estudos Prospectivos , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...