Investigation of medical intervention with fatal outcome: the impact of post-mortem CT and CT angiography

Post-mortem Imaging of Brain/Spine Injuries: The Importance of a Comprehensive Forensic Approach

In forensic investigations, the limitations of the traditional purely autoptic approach can be overcome through post-mortem imaging (virtopsy). Virtospy has several applications to the investigation of brain and spinal injuries, whose analysis can be of forensic interest, especially in cases of suspected malpractice. In this scoping review, we briefly describe the main applications of the two most common post-mortem radiological techniques (computed tomography (CT) and magnetic resonance imaging (MRI)) to the forensic investigation of brain and spinal injuries in cases of medical malpractice or traumatic (accidental/homicidal/suicidal) deaths. Although CT represents the traditional approach to post-mortem imaging, MRI is proving to be a valuable tool to investigate brain and spinal injuries and lesions. These post-mortem radiological techniques can also be used to guide the surgeons in simulated surgical procedures on corpses in the context of training programs, thus helping operators to improve technical and non-technical skills and to reduce the risk of avoidable errors.

A qualitative exploration of the experiences of post-mortem forensic imaging in Malta: A psychological perspective

INTRODUCTION

This study aimed to qualitatively explore the experiences of post-mortem forensic imaging on theatre and trauma radiographers from a psychological perspective at a general hospital in Malta.

METHODOLOGY

The study utilised purposive sampling to recruit five radiographers undertaking forensic post-mortem imaging in a general hospital in Malta. Individual face-to-face semi-structured interviews were held. Interpretative phenomenological principles and reflexivity were applied throughout the transcription and analysis phases.

RESULTS

Four themes were developed from the interpretive phenomenological analysis of semi-structured interviews: 'The impact of the imaging process,' 'Psychological distancing,' 'Finding meaning in work,' and 'Resource needs,' the latter comprising three subordinate themes: 'Protocols,' 'Physical resources,' and 'Psychological training.'

CONCLUSION

Forensic radiography is a rewarding area of practice yet one that can be complex and have a lasting psychological impact. Many factors including working close to the cadaver, a lack of appropriate training and staffing levels and a lack of evidence-based protocols were identified by participants as contributing to potential psychological stress and emotional distress.

IMPLICATIONS FOR PRACTICE

Exploration and evaluation of the psychological experiences of radiographers undertaking post-mortem imaging will inform the development of appropriate psychological services and reinforce the need for the appropriate application of best practice guidelines and protocols to support radiographers working on traumatic cases within forensic and general radiographic practice.

Lethal hemorrhage from iliac vein rupture complicating inferior vena cava thrombosis demonstrated by post-mortem CT angiography

Spontaneous iliac vein rupture is a rare cause of retroperitoneal hemorrhage that may present to the forensic pathologist. It has been reported in association with venous thrombosis, anatomical variants such as May-Thurner syndrome, and as a complication of a long-term indwelling IVC filter. It has a female predominance and most often occurs due to rupture of the left iliac vein. This is the first report of the use of post-mortem computed tomography (PMCT) and post-mortem computed tomography angiography (PMCTA) as an adjunct to a conventional autopsy to diagnose rupture of the left iliac vein causing retroperitoneal hemorrhage arising as a complication of an inferior vena cava (IVC) thrombus. We discuss the use of PMCTA as a useful tool in the diagnosis of vascular injury and how it can be used to assist the forensic pathologist. The use of PMCT with PMCTA is an invaluable adjunct to conventional autopsy to diagnose the site of vascular rupture.

A comparison on the detection accuracy of ante mortem computed tomography vs. autopsy for the diagnosis of pelvic ring injury in legal medicine

A detailed knowledge on the exact morphology of pelvic injuries provided crucial information in understanding the mechanisms of injury and has influence on the natural course and subsequent mortality. However, forensic medical literature investigating pelvic fractures in detail is scarce to date. This case series aims to compare the accuracy in detecting pelvic injuries using autopsy and ante mortem computed tomography (CT). Nineteen deceased patients with CT scans of pelvic fractures were included retrospectively. Pelvic injuries were independently assessed by a board-certified radiologist (R) and a board-certified trauma surgeon (T), both using the ante mortem CT scans, and by a board-certified forensic pathologist using autopsy (A) results without knowledge of the CT scan findings. No patient had died causatively from a pelvic fracture. Most injuries of the pelvis were present in the pubic rami (16/18) and sacral bone (13/18), followed by the sacroiliac joint (9/18) and iliac bone fractures (8/18). Ilium fractures (A:100%;R:67%;T:67%) and injuries of the sacroiliac joint (A:83%;R:50%;T:42%) were best detected via autopsy. The diagnosis of sacral fractures (A:19%;R:94%;T:88%) and fractures of the pubic rami (A:67%;R:96%;T:96%) were most often missed in autopsy. The results show deficits in the assessment of the pelvic injury for both CT and autopsy. Autopsy was superior in detecting injuries of the sacroiliac joint, but inferior in detecting sacral and pubic bone fractures. For an encompassing evaluation of ligamento-skeletal pelvic injuries, the complementary use of both CT and autopsy is recommended.

Postmortem imaging as a complementary tool for the investigation of cardiac death

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.Key pointsThere are no established guidelines for the interpretation of postmortem imaging examination of the heartAt present, postmortem imaging methods are considered as less accurate than the autopsy for cardiac deathsPostmortem imaging is useful as a complementary tool for cardiac deathsThere is still a need to validate postmortem imaging in cardiac deaths by comparing with autopsy findings.

State of the art in post-mortem computed tomography: a review of current literature

Computed tomography (CT) and other advanced diagnostic imaging techniques are gaining popularity in forensic pathology. This paper aims to define and offer complete and easily accessible "state of the art" for post-mortem computed tomography (PMCT), by reviewing the latest international literature. The proposed format answers the "five Ws" that follows: (1) What: We report the different kinds of CT scan and settings generally used in post-mortem imaging. The machine most employed is a 8/16-slice spiral CT, usually without contrast enhancement. The introduction of some variables, such as CT-guided biopsies, post-mortem ventilation, and PMCT angiography is becoming increasingly useful. (2) Why: Literature highlights the many advantages of PMCT. Limitations can be partly overcome by modern imaging techniques and combined evaluation with traditional autopsy. (3) Who: Most authors agree that collaboration between different specialists, i.e., radiologists and pathologists, is the best scenario, since radiologic, anatomic, and forensic skills are needed simultaneously. The most important human factor is "teamwork". (4) When: Literature provides no absolute limits for performing PMCT. Some authors have tested PMCT as a replacement for conventional autopsy but found some limitations. Others evaluated PMCT as a guide or screening tool for traditional autopsy. (5) Where: Many research groups around the world have performed studies on the use of PMCT. Although few countries adopt PMCT in routine practice, its use is rapidly spreading.

Ocular Venous Air Embolism (OVAE): A Review

Purpose:

The purpose of this article is to review and analyze reported cases of ocular venous air embolism (OVAE) to develop a reliable clinical definition of OVAE and effective prevention strategies.

Methods:

We reviewed all reports of suspected air embolism during vitrectomy published in PubMed since the introduction of pars plana vitrectomy, and 5 cases found elsewhere and separately reported concurrent with this review.

Results:

OVAE is a precipitous drop in end-tidal CO2, a choroidal detachment, or a choroidal wound, followed by signs of impending or actual cardiovascular collapse, during vitrectomy air infusion. In each case meeting the above clinical definition, entrained air was found whenever it was sought (8/8, 100%), either by antemortem imaging or postmortem forensic investigations. Most OVAE cases were fatal (9/13, 69%), with 8 of 9 deaths (89%) occurring the day of surgery.

Conclusions:

OVEA is a rare but usually fatal complication of air infusion into the eye during vitrectomy. Although received with skepticism when first reported (2005), OVAE may be the most lethal type of surgical air embolization because of its high entrainment pressure and proximity to the heart. Because the effective response time to avoid a fatal OVAE outcome can be less than 1 minute, use of preventive measures is critical—most notably a “time out” before air infusion to confirm infusion cannula positioning, and immediate cessation of air infusion if choroidal detachment is detected.

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.

Fatal Road Traffic Vehicle Collisions With Pedestrian Victims: Forensic Postmortem Computed Tomography and Autopsy Correlation

Fatal car-to-pedestrian collisions regularly appear in the forensic pathologist's routine, particularly in places of extended urbanization. Postmortem computed tomography has gained an exceptional role to supplement autopsy worldwide, giving information that is supplementary or complimentary to conventional autopsy. In this retrospective study, a total number of 320 findings in a series of 21 pedestrians fatally hit by cars and trucks of both postmortem computed tomography and autopsy were correlated. According to our results, it is best to combine both methods to give well-founded answers to questions pertaining to both collision reconstruction and cause of death.

Towards multi-phase postmortem CT angiography in children: a study on a porcine model

PURPOSE

Multi-phase postmortem computed tomography angiography (MPMCTA) is a growing technique, which is standardized for adults. Application of this protocol for a children population is not so well defined. Our study aims to adapt the adult's protocol to children, using a porcine model.

MATERIAL AND METHODS

Three groups of 18 pigs were studied, with a weight distribution between 4 and 48 kg. Different pump devices were used. Pigs of group I were studied using the Virtangio® machine, whereas pigs of groups II and III were studied using used the Medrad® machine. Study of vascular opacification was possible using a semi-quantitative method based on 26 arterial and 26 venous segments that were distributed over the entire body from the cephalic extremity to the posterior pawns.

RESULTS

While thoracic, abdominal, and pelvic vascular opacification were complete for each individual pig in a group, group III showed better vascular opacification for the cephalic extremity. This was also true for anterior and posterior pawns vascular opacification. Spearman correlation tests showed a significant relationship between anthropometric characteristics of pigs, injection parameters, and percentage of opacified segments. A higher percentage of opacification was obtained for individuals of lower weights, with comparatively lower quantities of contrast agent injected.

CONCLUSION

Postmortem computed tomography angiography (PMCTA) was possible for all the individuals, particularly for small weights (4 kg) using the Medrad® machine. However, further studies are needed to better understand the procedure.

Air embolism: diagnosis and management

Air embolism is an uncommon, but potentially life-threatening event for which prompt diagnosis and management can result in significantly improved patient outcomes. Most air emboli are iatrogenic. Arterial air emboli may occur as a complication from lung biopsy, arterial catheterization or cardiopulmonary bypass. Immediate management includes placing the patient on high-flow oxygen and in the right lateral decubitus position. Venous air emboli may occur during pressurized venous infusions, or catheter manipulation. Immediate management includes placement of the patient on high-flow oxygen and in the left lateral decubitus and/or Trendelenburg position. Hyperbaric oxygen therapy is the definitive treatment which may decrease the size of air emboli by facilitating gas reabsorption, while also improving tissue oxygenation and reducing ischemic reperfusion injury.

Technical note: A preliminary comparative study between classical and interventional radiological approaches for multi-phase post-mortem CT angiography

PURPOSE

Multi-phase post-mortem computed tomography angiography (MPMCTA) is a new diagnostic tool, used in forensic pathology. On the one hand, this technique allows a better and direct visualization of vascular and solid organ lesions. On the other hand, the invasiveness of the procedure-which requires surgical denudation (inguinal and/or cervical) and the insertion of surgical cannulas-leads to many relatives refusing scientific autopsies. Our hypothesis states that a minimally-invasive procedure combining interventional radiological techniques with MPMCTA (replacement of surgical cannulas by radiological catheters) will improve the approval rate of scientific autopsies by families. The aim of this study was to evaluate the feasibility of the minimally-invasive MPMCTA approach and to compare its performance to the current reference-standard (the conventional approach).

MATERIAL AND METHODS

We included consecutively 16 corpses divided in two groups according to the contrast enhancement approach: radiological catheters (n=8), and surgical cannulas (n=8). Corpses were chosen and assigned randomly from our local data. The quality of the imaging procedure was compared according to four items: global vascular opacification, cerebral venous opacification, and lower limbs opacification (arterial and venous).

RESULTS

A minimally-invasive approach for scientific autopsies is feasible through a radiological catheter. Vascular opacification was optimal in 8 out of 8 cases and was no less effective than the control reference group using surgical cannula incision associated with their non-occlusive aspects.

Diagnostic accuracy of postmortem imaging vs autopsy-A systematic review

Background Postmortem imaging has been used for more than a century as a complement to medico-legal autopsies. The technique has also emerged as a possible alternative to compensate for the continuous decline in the number of clinical autopsies. To evaluate the diagnostic accuracy of postmortem imaging for various types of findings, we performed this systematic literature review. Data sources The literature search was performed in the databases PubMed, Embase and Cochrane Library through January 7, 2015. Relevant publications were assessed for risk of bias using the QUADAS tool and were classified as low, moderate or high risk of bias according to pre-defined criteria. Autopsy and/or histopathology were used as reference standard. Findings The search generated 2600 abstracts, of which 340 were assessed as possibly relevant and read in full-text. After further evaluation 71 studies were finally included, of which 49 were assessed as having high risk of bias and 22 as moderate risk of bias. Due to considerable heterogeneity - in populations, techniques, analyses and reporting - of included studies it was impossible to combine data to get a summary estimate of the diagnostic accuracy of the various findings. Individual studies indicate, however, that imaging techniques might be useful for determining organ weights, and that the techniques seem superior to autopsy for detecting gas Conclusions and Implications In general, based on the current scientific literature, it was not possible to determine the diagnostic accuracy of postmortem imaging and its usefulness in conjunction with, or as an alternative to autopsy. To correctly determine the usefulness of postmortem imaging, future studies need improved planning, improved methodological quality and larger materials, preferentially obtained from multi-center studies.

Evaluation of post-mortem lateral cerebral ventricle changes using sequential scans during post-mortem computed tomography

In the present study, we evaluated post-mortem lateral cerebral ventricle (LCV) changes using computed tomography (CT). Subsequent periodical CT scans termed “sequential scans” were obtained for three cadavers. The first scan was performed immediately after the body was transferred from the emergency room to the institute of legal medicine. Sequential scans were obtained and evaluated for 24 h at maximum. The time of death had been determined in the emergency room. The sequential scans enabled us to observe periodical post-mortem changes in CT images. The series of continuous LCV images obtained up to 24 h (two cases)/16 h (1 case) after death was evaluated. The average Hounsfield units (HU) within the LCVs progressively increased, and LCV volume progressively decreased over time. The HU in the cerebrospinal fluid (CSF) increased at an individual rate proportional to the post-mortem interval (PMI). Thus, an early longitudinal radiodensity change in the CSF could be potential indicator of post-mortem interval (PMI). Sequential imaging scans reveal post-mortem changes in the CSF space which may reflect post-mortem brain alterations. Further studies are needed to evaluate the proposed CSF change markers in correlation with other validated PMI indicators.