The utility of postmortem computed tomography selective coronary angiography in parallel with autopsy

[Between clinical and forensic imaging : Differences, similarities and legal framework]

Clinical imaging uses a variety of medical imaging techniques to diagnose and monitor diseases, injuries and other health conditions. These include X‑ray images, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound. These procedures are used to make accurate diagnoses and plan the best possible treatment for patients. Forensic imaging, in contrast, is used in both living and deceased persons in the context of criminal investigations. Postmortem forensic imaging techniques, such as postmortem CT (PMCT) and postmortem CT angiography (PMCTA), include some of the same procedures used in clinical imaging. An important difference between clinical and forensic imaging is the purpose and context in which the imaging studies are used. In addition, radiological procedures, such as angiography, need to be adapted and modified in the post-mortem setting. From a legal perspective clinical and forensic imaging must strictly adhere to privacy and procedural guidelines. Forensic images often need to be admissible as evidence in court, which places specific requirements on the quality, authenticity and documentation of images. In the case of living individuals, there must be a valid indication and consent from the patient. Consent must also fundamentally be obtained for post-mortem examinations, e.g. from the public prosecutor's office.

Assessment of Myocardial Ischemia Using Coronary Postmortem Computed Tomography Angiography Based on the Voronoi Algorithm: A Case Report

Postmortem computed tomography angiography (PMCTA) is a valuable tool for diagnosing vascular conditions, such as hemorrhages, in trauma cases. This case report demonstrates the use of the Voronoi algorithm to assess myocardial ischemia using coronary PMCTA. A male in his 70s was found unconscious in a car after colliding with a traffic light pole. Despite medical interventions, including pericardial drainage and cardiopulmonary resuscitation, the patient died two hours later. PMCTA revealed significant filling defects in the left anterior descending artery (LAD), consistent with plaque rupture and narrowing observed during autopsy. The cause of death in this case was likely cardiac tamponade due to cardiac rupture secondary to myocardial infarction resulting from LAD stenosis. Cardiac perfusion areas were analyzed using the Voronoi algorithm, demonstrating a total myocardial volume of 151.9 mL in the left ventricle. Perfusion volumes were calculated as 92.9 mL (61.2%) for the LAD, 34.2 mL (22.5%) for the left circumflex artery, and 24.9 mL (16.4%) for the right coronary artery. The predicted ischemic volume distal to the LAD stenosis was estimated to be 49.8 mL (32.8%). Furthermore, the ischemic areas observed during autopsy macroscopically corresponded well with the predicted ischemic regions. This case highlights that combining PMCTA with the Voronoi algorithm provides an accurate method for assessing myocardial ischemic areas, offering a non-invasive approach to visualize and quantify perfusion and ischemic regions.

The value of PMCTA in the diagnosis of coronary atherosclerosis in isolated human hearts

Postmortem computed tomography (PMCT) has a limited value in investigating coronary artery disease, despite several obvious advantages over the conventional autopsy. To address this issue, postmortem computed tomography angiography (PMCTA) has been introduced into various studies, where it has been used to investigate natural and unnatural deaths involving vascular damage, occlusion, or other pathologies of the vascular system. To investigate the application value of PMCTA in the diagnosis of coronary artery stenosis in ex situ hearts, the water-based contrast media were injected into isolated hearts, scaned, and finally compared with gold standards (autopsy and histology findings of the coronary artery). This study involved 16 subjects from the Academy of Forensic Science who were suspected to have died of sudden death without traumatic injuries. Unenhanced PMCT was performed first, followed by PMCTA using a water-based contrast agent, injected into the coronary arteries of isolated hearts using a self-designed angiography device. The image data were reconstructed into three-dimensional (3D) angiography images using software in the angiography facility. The 3D images were recorded and evaluated by two radiologists and then statistically analysed. The results of PMCTA were consistent with the gold standards for the diagnosis of coronary artery stenosis (P > 0.05). However, water-based contrast media can only be used to examine the pathological changes of blood vessels, which may have limitations in the diagnosis of causes of death such as myocardial oedema. PMCTA can be used as a new method to evaluate the degree of coronary atherosclerosis in addition to traditional autopsy. The 3D reconstruction technique reveals the coronary artery lesions more objectively and vividly and provides the opportunity to re-read the data at any time.

Key points

The methods and parameters for coronary angiography in isolated human hearts were standardized based on the previous researcher.PMCTA in isolated human hearts is including the 3D reconstruction technique that reveals the coronary artery lesions more objectively and vividly, and provides the opportunity to re-read the data at anytime.PMCTA could only be used to examine the pathological changes of blood vessels, which might have limitations for the diagnosis of causes of death.PMCTA in isolated human hearts can be viewed as an auxiliary method for establishing the cause of death, which can provide an assessment of degree and extent of arterial stenosis and accurately help determine the abnormal location.

Coronary artery involvement in a patient with IgG4-related disease

Immunoglobulin G4-related disease (IgG4-RD) is a chronic fibro-inflammatory disorder of obscure etiology characterized by significant infiltration of IgG4-positive plasma cells toward several organs. Coronary artery involvement is rarely seen in IgG4-RD patients; thereby, we aim to outline the noninvasive imaging findings of this rare case. Cardiac magnetic resonance (CMR) and coronary computed tomography angiography (CCTA) from a 15-year-old female diagnosed with IgG4-RD via histopathological assessment of orbital biopsy, were analyzed. CMR showed a severely reduced left ventricular ejection fraction and akinesia of the basal to mid-lateral, anterior, and septal walls. Inflammation of the basal to apical lateral wall and subendocardial infarction of the basal to apical lateral and mid inferoseptal walls were also evident. CCTA findings showed stenosis in branches of the left main artery (LM), left anterior descending artery (LAD), and right coronary artery (RCA), aortitis, and aortic wall thickening. After courses of proper treatment with prednisolone, Cellcept, and adalimumab, follow-up CMR showed significant improvement in LV systolic function and resolution of inflammation. Although IgG4-RD is an uncommon cause of coronary artery disease, it can cause lethal complications such as myocardial infarction. Hence, clinicians should be aware of cardiac complications in these patients.

Technical note: Semiautomated targeted postmortem computed tomography angiography of the pulmonary arteries using a robotic system

INTRODUCTION

To better depict vascular lesions on postmortem computed tomography (PMCT), whole-body postmortem computed tomography angiography (PMCTA) can be used in forensic diagnostics. Targeted angiography, in which only a specific vessel is filled with contrast agent, might help in cases of traumatic changes that render whole-body PMCTA impossible. Moreover, in targeted PMCTA, the contrast agent does not affect the haptics of any other organs. In this article, we describe automated, CT-guided targeted angiography of the pulmonary artery (PA) using the Virtobot system.

MATERIAL AND METHODS

Our study group consisted of 8 deceased persons (3 males, 5 females). We first performed an unenhanced CT scan and used the data obtained to plan the needle trajectories with the Virtobot planning software. Then, the needle was fully automatically placed by the Virtobot system. Subsequently, 50 ml of contrast agent was injected manually, and the CT scan was repeated (targeted PMCTA).

RESULTS AND DISCUSSION

We tested a new method for performing semiautomated targeted postmortem angiography of the PAs using a robotic needle placement system (Virtobot). In 6 out of our 8 cases, the injection of contrast agent in the PA was successful. In five of the six successful cases, there was reflux of contrast agent to some extent, but the reflux did not affect the readout. In general, the procedure was easy to plan based on a PMCT data set, and the pulmonary trunk was easy to reach with a robotic needle placement system.

Correlation and assessment of coronary artery luminal stenosis: Post-mortem computed tomography angiogram versus histopathology

BACKGROUND

Post-mortem Computed Tomography (PMCT) allows non-invasive or minimally invasive detection of findings that may or may not be visible during conventional autopsy, however, it does not allow the investigator to draw any conclusions regarding patency of the vessel's lumen. To address this deficiency, Post-mortem Computed Tomography Angiography (PMCTA) utilizing different contrast media and techniques have been introduced with various studies looking at the correlation between PMCTA, autopsy (gross) findings and coronary artery histology in diagnosing coronary artery disease.

OBJECTIVES

The aim of this study is to investigate the sensitivity and specificity of PMCTA in diagnosing coronary artery stenosis using water-based contrast media introduced though the vessels of the neck, compared to the gold standard of diagnosis i.e. gross and histological evaluation of the coronary artery.

METHOD

This was a cross sectional study of 158 arterial sections involving 37 subjects recruited from the National Institute of Forensic Medicine (IPFN), Hospital Kuala Lumpur (HKL). An unenhanced PMCT was performed followed by PMCTA using water-based contrast media introduced though the vessels of the neck. Coronary artery stenosis was determined using multiplanar reconstructionD while the degree of stenosis was determined by calculating the percentage of luminal diameter divided by the diameter of the vessel internal elastic.

RESULTS

The analysis of PMCTA and histopathology examinations revealed a sensitivity of 61.5%, specificity of 91.7%; positive predictive value (PPV) of 40.0% and negative predictive value (NPV) of 96.4%.

CONCLUSION

PMCTA utilizing water-based contrast introduced though the vessels of the neck yielded similar results as other methods and techniques of PMCTA. We would therefore conclude that PMCTA utilizing this technique could be used to assess the degree of calcification and the presence of significant stenosis.

Postmortem computed tomography angiography (PMCTA) and traditional autopsy in cases of sudden cardiac death due to coronary artery disease: a systematic review and meta-analysis

INTRODUCTION

Several studies have been performed to assess the efficacy of postmortem computed tomography angiography (PMCTA) in solving cases of sudden cardiac death, even in comparison with the traditional autopsy. However, the results were often inconsistent and inconclusive. Therefore, a global discussion on the subject through a systematic review of the literature and a meta-analysis is necessary.

METHODS

A systematic search of PubMed was performed up to April 23, 2018. Studies exploring the role of PMCTA in cases of sudden cardiac death and the accuracy of this method in diagnosing the cause of death compared to traditional autopsy were included.

RESULTS

The overall sensitivity and specificity of the seven included studies, using conventional autopsy as a reference standard, were 92% and 95%, respectively. The positive and negative likelihood ratios were, respectively, 20.76 (95% CI 1.16-370.2) and 0.08 (95% CI 0.03-0.17), showing that PMCTA represents a strong indicator of the posttest probability of disease. The diagnostic odds ratio and the area under the curve were, respectively, 261.54 (95% CI 1.87-5760.53) and 0.93 (95% CI 0.90-0.95), indicating a high diagnostic power of the test.

CONCLUSION

PMCTA demonstrated a high accuracy in the diagnosis of parietal and luminal coronary changes but was less effective in detecting myocardial ischemia and necrosis. Therefore, the only radiological investigation is often insufficient to determine the cause of sudden death and the conventional autopsy remains the gold standard. However, PMCTA can improve the performance of the autopsy, serving as an aid and guide in the sampling phase for histopathological investigations.

Modern post-mortem imaging: an update on recent developments

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.

Diagnosis of coronary artery disease using targeted post-mortem computed tomography coronary angiography: a case report

Targeted post-mortem computed tomography (PMCT) combined with coronary angiography has the potential to play a significant role in the investigation of sudden cardiac death. The authors utilized a targeted PMCT coronary angiography in a case involving a 53-year-old man who died from acute myocardial ischemia and cardiac decompensation which may result from coronary artery disease (CAD). The victim collapsed suddenly at work and died soon after arrival to hospital. The body was examined using PMCT and targeted PMCT coronary angiography. The left anterior descending coronary artery exhibited 75%–100% stenosis in the middle segment; however, the distal segment could not be clearly visualized. In addition, the left circumflex and right coronary artery exhibited calcification, atherosclerosis and an area of 50% stenosis. Signs of cardiogenic pulmonary oedema were also identified. The imaging results suggested that this individual had coronary atherosclerosis and probably died from CAD. The autopsy and histological examination revealed acute myocardial ischemia and myocardial scarring, confirming the cause of death while excluding other probabilities. In summary, targeted post-mortem computed tomography angiography (PMCTA) can visualize the arteries and estimate the degree of principal pathological changes. This method is a simple, reliable and sensitive technique for identifying the presence of coronary atherosclerosis. It is a valuable post-mortem forensic imaging method and should be recommended in the investigation of suspicious cardiac deaths.

Freezing preparation for macroscopic forensic investigation in putrefied brain

PURPOSE

To evaluate the usefulness of the applied freezing technique in putrefied brain for macroscopic investigation.

MATERIALS AND METHODS

From October 2015 to September 2016, first the brains of 10 cadavers (control group: male 6, female 4, age 20-80 (mean 61.5), postmortem intervals (PMI) 14-75 (mean 29.7)days) were inspected following the standard practice (without freezing preparation), and then with 10 cadavers (freezing group: male 7, female 3, age 41-88 (mean 60.4), PMI 7-75 (mean 29.2)days) the freezing technique was used before the autopsy. The cut brain was investigated, and the gray-white matter difference was evaluated macroscopically.

RESULTS

In the control group, the brain parenchyma leaked out like sludge in 5, and there was difficulty maintaining its structure in 7. The gray-white matter difference was well visible in 3, but hard to distinguish in 3, and the total scores ranged from 0 to 9 (mean 4.4) points. In the freezing group, the entire putrefied brain was extracted as a solid organ, the gray-white matter differences were well visible, and the total scores were 6.7-9 (8.3) points. The gray-white matter difference was preserved in the freezing group (p<0.05).

CONCLUSION

The freezing procedures to evaluate the putrefied brain have been successfully applied, and it could be statistically more useful in putrefied brain investigation than the ordinary procedure. Postmortem CT can be useful to evaluate not only the degree of brain putrefaction, but also the degree of brain parenchyma freezing.

The effect of post-mortem computed tomography angiography (PMCTA) using water-soluble, iodine-based radiographic contrast on histological analysis of the liver, kidneys and left ventricle of the heart

The purpose of this study was to investigate the impact of post-mortem computed-tomography angiography (PMCTA) on the histology of the liver, kidneys and heart. Multiple tissue cores were collected from the liver, left and right kidneys and left ventricle utilizing CT-guided biopsy. Subsequent whole body PMCTA was performed using a solution of polyethylene glycol and iodinated radiographic contrast, and an embalming pump. Corresponding biopsy cores were collected at autopsy, and blinded histology analysis assessing for PMCTA-induced histology artefact was performed. The blinded analysis of pre-PMCTA and post-PMCTA biopsy samples demonstrated that whole body PMCTA had no effect on the histological analyses of the liver (0%, CI = 0-13.7%), left ventricle of the heart (0%, CI = 0-36.9%) and right kidney (0%, CI = 13.2%), however likely caused increased Bowman's capsule spaces in the left kidney of one case (4%, CI = 0.01-20.4%). Other artefactual histological changes identified included eosinophilic material in the liver, whiter interstitium and dilated tubules in kidney samples, and autolysis-related changes, however these could not be categorically attributed to the PMCTA procedure. PMCTA causes zero or minimal effect to the histological examination of the liver, left kidney, right kidney and left ventricle, and as such performing PMCTA prior to autopsy is unlikely to impact autopsy histological results in these organs.

Assessing age-related change in Japanese mental foramen opening direction using multidetector computed tomography

OBJECTIVE

The purpose of this study was to investigate how the opening direction of the mental foramen (MF) changes with age in a Japanese population using multi-detector computed tomography (MDCT).

METHODS

Post-mortem MDCT scans of 121 Japanese subjects (66 males and 55 females) were carried out where all subjects possessed at least twenty teeth, including molar teeth, in the upper and lower jaws. Two angles of the mental foramen opening were measured, namely the superior-inferior angle in the coronal plane and anterior-posterior angle in the transverse plane, on the CT reconstructed images. The associations between age and these two angles were evaluated using a multiple regression analysis.

RESULTS

For male subjects, the relationship between the superior-inferior angle and age was a quadratic curve (p < 0.001). This angle increased until the subject reached their early 50s and then the angle decreased with age. In the transverse plane, there was a linear relation between the anterior-posterior angle and age (p=0.002).It was noted also that the angle decreased with age. By contrast, however, no significant associations between the two angles and age for either measurement were noted for female subjects. This study demonstrated that the opening direction of the mental foramen changes with age in Japanese male subjects. By contrast this change in the opening direction of the mental foramen was not demonstrated in Japanese female subjects. In male subjects, the opening direction moves superiorly until the individual reaches their early 50s, and then moves inferiorly with advancing age. It also shifts from a posterior to an anterior position with age.

CONCLUSION

These observed change differ from the results of previous studies. The findings could be useful for forensic science as they demonstrate a change in the position of mental foramen in a sample of contemporaneous male Japanese subjects.

Temperature dependence of viscosity, relaxation times (T1, T2) and simulated contrast for potential perfusates in post-mortem MR angiography (PMMRA)

Developments in post-mortem imaging increasingly focus on addressing recognised diagnostic weaknesses, especially with regard to suspected natural deaths. Post-mortem MR angiography (PMMRA) may offer additional diagnostic information to help address such weaknesses, specifically in the context of sudden cardiac death. Complete filling of the coronary arteries and acceptable contrast with surrounding tissue are essential for a successful approach to PMMRA. In this work, the suitability of different liquids for inclusion in a targeted PMMRA protocol was evaluated. Factors influencing cooling of paraffinum liquidum + Angiofil® (6 %) in cadavers during routine multiphase post-mortem CT angiography were investigated. The temperature dependence of dynamic viscosity (8–20 °C), longitudinal (T₁) and transverse (T₂) relaxation (1–23 °C) of the proposed liquids was quadratically modelled. The relaxation behaviour of these liquids and MR scan parameters were further investigated by simulation of a radiofrequency (RF)-spoiled gradient echo (GRE) sequence to estimate potentially achievable contrast between liquids and post-mortem tissue at different temperatures across a forensically relevant temperature range. Analysis of the established models and simulations indicated that based on dynamic viscosity (27–33 mPa · s), short T₁ relaxation times (155–207 ms) and a minimal temperature dependence over the investigated range of these parameters, paraffin oil and a solution of paraffin oil + Angiofil® (6 %) would be most suitable for post-mortem reperfusion and examination in MRI.

Use of postmortem computed tomography angiography to detect vascular injuries accompanying skull base fracture

A 58-year-old woman who had presented for upper gastrointestinal barium examination accidently slipped from the movable bed, and her head became compressed between the end of the bed and the side wall. She suffered massive bleeding from her nose and ear followed by cardiac arrest, and subsequent attempts at cardiopulmonary resuscitation failed. A medicolegal autopsy was performed to reveal the cause of death, as part of the investigation of the accident. During the autopsy, postmortem cerebral CT angiography was carried out by injection of 5% gelatin-barium emulsion as a radiopaque contrast medium into the bilateral common carotid arteries, demonstrating transudation of the contrast medium into the right acoustic meatus and the sphenoidal sinus cavity. Considering that the body appeared anemic and that PMCTA suggested vascular injuries, the cause of death was definitively determined to be hemorrhagic shock due to injuries to the right internal carotid artery, accompanied by skull base fracture. Postmortem CT angiography played an important role in confirming that the vascular injuries had been responsible for the bleeding, as the lesions could not be fully confirmed by native CT or macroscopic examination.

Fatal right coronary artery rupture following blunt chest trauma: detection by postmortem selective coronary angiography

Coronary artery injury is a rare complication following blunt chest trauma (BCT), and can be fatal. Here we report findings on postmortem selective coronary angiography of right coronary artery rupture after an assault involving blunt trauma to the chest. A woman in her 60s died after her son stomped on her chest. There were no appreciable signs of injury on external examination, and cause of death could not be determined by postmortem computed tomography (PMCT). Internal findings indicated that an external force had been applied to the anterior chest, as evidenced by subcutaneous hemorrhage and pericardial and cardiac contusions. Postmortem coronary angiography revealed irregularity of the intima and of the fat tissue surrounding the proximal part of the right coronary artery associated with a local filling defect. Histopathological examination suggested coronary rupture with dissection of the tunica media and compression of the lumen cavity. The key points in the present case are that no fatal injuries could be determined on external examination, and the heart and coronary artery injuries were not evident on PMCT. Criminality might be overlooked in such cases, as external investigation at the crime scene would be inadequate and could result in a facile diagnosis of cause of death. This is the first report of coronary artery rupture with dissection that was detected by CT coronary angiography, and provides helpful findings for reaching an appropriate decision both forensically and clinically.

Sudden death due to coronary artery dissection associated with fibromuscular dysplasia revealed by postmortem selective computed tomography coronary angiography: A case report

We present an autopsy case of sudden death due to coronary artery dissection associated with fibromuscular dysplasia (FMD) in a young female patient. Postmortem selective coronary artery computed tomography (CT) angiography revealed dissections of the left anterior descending and left circumflex arteries. These findings were confirmed by subsequent autopsy. Histopathological examination revealed coronary artery FMD, which is considered a risk factor for dissection. To the best of our knowledge, this is the first postmortem radiology-pathology correlation of coronary artery dissection associated with FMD.

The utility of the combination of the corrosion cast method and post mortem MSCT scans

A careful post-mortem investigation is needed to determine the cause of death of patients bearing coronary stents and to describe complications of stent implantation. The main purpose of this study was to combine post mortem methods of CT angiography and corrosion cast preparation for the visualization of coronary stenoses, coronary stents, instent restenosis, and stent occlusion. Injection-corrosion method was combined with post-mortem MSCT angiography to characterize the pathomorphological changes after stent implantation in 6 male cadaver hearts. Multi-slice computed tomography was employed to visualize the coronary artery system. For image post processing, multiplanar reconstructions, maximal intensity projections and three dimensional reconstructions were used. This study was assessing the feasibility of post mortem MSCT for intracoronary stent evaluation. We described a method for characterization of the coronary side branch stenosis caused by stent implantation. Post mortem CT imaging proved to be a feasible and highly reproducible technique for the characterization of pathological changes in the coronary system.

Observation of vertebral artery damage using angioscopy in autopsy cases

The vertebral arteries are important blood vessels that supply the cerebral circulation in conjunction with the internal carotid arteries. In cases of subarachnoid hemorrhage, it is necessary to examine the vertebral arteries as potential sources of bleeding due to blunt trauma (head and neck) or of cerebral embolism that originated on the surface of the damaged intima as a result of hyperflexion or hyperextension. However, a considerable part of the vertebral arterial surface is surrounded by bone, resulting in challenges during examination in a routine autopsy. In this study, angioscopy was used to inspect the vertebral artery intima for damage in cases of neck injury, head injury, or neck strangulation. Intimal damage was detected in 34 out of the total 75 cases. Of the 28 cases with cervical discopathy or fracture, 61% had intimal damage. In addition, postmortem application of computed tomography angiography was performed to identify the injured vessel in a case with traumatic subarachnoid hemorrhage, and a perforated hole was detected using angioscopy, which did not introduce autopsy-related artifacts. Therefore, angioscopy may be a useful and nondestructive method to identify intimal damage in the vertebral arteries during an autopsy.