Multicenter reproducibility study of diffusion MRI and fiber tractography of the lumbosacral nerves.

BACKGROUND: Diffusion tensor imaging (DTI) has been applied in the lumbar and sacral nerves in vivo, but information about the reproducibility of this method is needed before DTI can be used reliably in clinical practice across centers. PURPOSE: In this multicenter study the reproducibility of DTI of the lumbosacral nerves in healthy volunteers was investigated. STUDY TYPE: Prospective control series. SUBJECTS: Twenty healthy subjects. FIELD STRENGTH/SEQUENCE: 3T MRI. 3D turbo spin echo, and 3.0 mm isotropic DTI scan. ASSESSMENT: The DTI scan was performed three times (twice in the same session, intrascan reproducibility, and once after an hour, interscan reproducibility). At site 2, 1 week later, the protocol was repeated (interweek reproducibility). Fiber tractography (FT) of the lumbar and sacral nerves (L3-S2) was performed to obtain values for fractional anisotropy, mean, axial, and radial diffusivity. STATISTICAL TESTS: Reproducibility was determined using the intraclass correlation coefficient (ICC), and power calculations were performed. RESULTS: FT was successful and reproducible in all datasets. ICCs for all diffusion parameters were high for intrascan (ranging from 0.70-0.85), intermediate for interscan (ranging from 0.61-0.73), and interweek reliability (ranging from 0.58-0.62). There were small but significant differences between the interweek diffusivity values (P < 0.0005). Depending on the effect size, nerve location, and parameter of interest, power calculations showed that sample sizes between 10 and 232 subjects are needed for cross-sectional studies. DATA CONCLUSION: We found that DTI and FT of the lumbosacral nerves have intermediate to high reproducibility within and between scans. Based on these results, 10-58 subjects are needed to find a 10% change in parameters in cross-sectional studies of the lumbar and sacral nerves. The small significant differences of the interweek comparison suggest that results from longitudinal studies need to be interpreted carefully, since small differences may also be caused by factors other than disease progression or therapeutic effects. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:951-963.

Fatal subarachnoid hemorrhage associated with internal carotid artery dissection resulting from whiplash trauma.

Spinal injury following inertial loading of the head and neck (whiplash) is a common sequel of low speed traffic crashes. A variety of non-musculoskeletal injuries have been described in association with injury to the spine following whiplash trauma, including traumatic brain injury, vestibular derangement, and cranial nerve injury, among others. Vascular injuries in the head and neck have, however, only rarely been described. We present the case of a middle-aged male who sustained an ultimately fatal injury that resulted from injury to the internal carotid artery (ICA) and intracerebral vascular structures following a hard braking maneuver, with no direct head- or neck contact with the vehicular interior. Based on this unusual mechanism of injury we reviewed hospital data from the United States nationwide inpatient database (NIS) to assess the frequency of similar injuries reportedly resulting from traffic crashes. The post-mortem examination revealed a left internal carotid artery dissection associated with subarachnoid hemorrhage (SAH). Based on the close temporal association, the absent prior history, and the plausibility of the injury mechanism, the injury was attributed to the braking maneuver. An analysis of NIS data demonstrated that the prevalence of subarachnoid hemorrhage is significantly higher when there is a traumatic etiology, and higher yet when the trauma is a traffic crash (odds ratio 3.3 and 4.3, respectively). The presented case, together with the hospital inpatient data analysis, indicate that although SAH in combination with ICA dissection is relatively rare, it is substantially more probable following a traffic crash. In a clinical or forensic setting the inference that magnitude of a trauma was low should not serve as a basis for either excluding a cervical artery dissection from a differential diagnosis, or for excluding the trauma as a cause of a diagnosed dissection. This case report illustrates a rare fatal outcome of inertial load to the head and neck induced by a sudden braking event in a commonly experienced non-collision traffic incident. The likely mechanism of injury resulted from interaction between the occupant and the 3-point seat belt. These findings indicate that ICA dissections are substantially more likely to be associated with SAH following head and neck trauma, regardless of the magnitude of the traumatic event or whether an impact was involved.

Towards the diagnosis of osteoporosis - contributions from coincidental diagnostic imaging findings in chiropractors' practice.

BACKGROUND: Osteoporosis is significantly associated with fractures and burdens the health of especially older people. Osteoporotic fractures cause pain, disability, and increased mortality. Early diagnosis of osteoporosis allows earlier initiation of treatment, thereby reducing the risk of osteoporotic fractures. Chiropractors encounter potential osteoporotic patients daily, and perform radiological evaluation of these and other patients, including evaluation of X-rays done for other purposes than osteoporosis. Therefore, chiropractors may identify vertebral fractures, vertebral deformity or osteopenia not otherwise suspected or recorded. METHODS: This study examines procedures available to the chiropractor to describe conventional X-rays with the focus of osteoporosis related findings. We review the indications for radiological examination in chiropractic practice, and in the realm of osteoporosis we describe radiological methods available for examination of conventional radiographs, and the necessity of inter-disciplinary communication. RESULTS: National guidelines are available regarding referral for X-rays in chiropractic practice. Standardized protocols ensure image acquisition of the highest quality in the chiropractors' radiological department. Conventional X-ray examination is not indicated on clinical suspicion of osteoporosis alone, as bone mineral density testing is the diagnostic test. Radiological assessment of all available X-rays of patients above the age of 50 years should include evaluation of the bone quality, and hip and vertebral fracture assessment. The Singh index, Genant Semi-Quantitative tool (GSQ), and Algorithm-Based Qualitative method (ABQ) should be used consistently during interpretation. Referral for additional imaging and evaluation should be prompt and systematic when needed. CONCLUSIONS: This article presents an overview of evidence-based radiological procedures for the purpose of promoting early diagnosis of osteoporosis. We present recommendations to the clinicians where we propose an opportunistic evaluation of X-rays, done for any reason, which include systematic evaluation of bone quality, presence of hip and vertebral fractures, and vertebral deformation of all patients above the age of 50 years. Detailed referral to healthcare professionals for further diagnostic evaluation is performed when needed. Consistent, high-quality radiological procedures in chiropractic practices could feasibly contribute to the timely diagnosis of osteoporosis, ultimately minimizing the impact of osteoporosis-related complications on patients' health.

Systematic diagnostics and documentation for whiplash.

Whiplash injuries are common in Denmark affecting around 16,000 new patients annually. Approximately 50% of the casualties develop chronic symptoms and 10% become disabled. Many of these patients will have contact to the healthcare system, and there is a need for structured and knowledge-based examination, diagnosis and recording of findings in all clinical settings. This review discusses which variables should be recorded in clinical practice, in order to establish the best possible foundation for a structured individualized treatment protocol of the whiplash patient.

Investigation of a fatal airplane crash: autopsy, computed tomography, and injury pattern analysis used to determine who was steering the plane at the time of the accident. A case report.

A fatal accident is reported in which a small single-engine light airplane crashed. The airplane carried two persons in the front seats, both of whom possessed valid pilot certificates. Both victims were subject to autopsy, including post-mortem computed tomography scanning (PMCT) prior to the autopsy. The autopsies showed massive destruction to the bodies of the two victims but did not identify any signs of acute or chronic medical conditions that could explain loss of control of the airplane. PMCT, histological examination, and forensic chemical analysis also failed to identify an explanation for the crash. A detailed review of an airplane identical to the crashed airplane was performed in collaboration with the Danish Accident Investigation Board and the Danish National Police, National Centre of Forensic Services. The injuries were described using the abbreviated injury scale, the injury severity score, 3-dimensional reconstructions of the PMCT, and an injury pattern analysis. We describe how, on basis of these data, we reached a conclusion about which of the two victims was the most likely to have been in control of the airplane at the time of accident. Furthermore, we argue that all victims of fatal airplane crashes should be subject to forensic autopsy, including PMCT and forensic chemical analysis. The continuous accumulation of knowledge about injury patterns from "simple" accidents is the foundation for the correct analysis of "difficult" accidents.

Advanced magnetic resonance imaging of chronic whiplash patients: a clinical practice-based feasibility study.

BACKGROUND: Whiplash injury is common following road traffic crashes affecting millions worldwide, with up to 50% of the injured developing chronic symptoms and 15% having a reduced working capability due to ongoing disability. Many of these patients receive treatment in primary care settings based upon clinical and diagnostic imaging findings. Despite the identification of different types of injuries in the whiplash patients, clinically significant relationships between injuries and chronic symptoms remains to be fully established. This study investigated the feasibility of magnetic resonance imaging (MRI) techniques including quantitative diffusion weighted imaging and measurements of cerebrospinal fluid (CSF) flow as novel non-invasive biomarkers in a population of healthy volunteers and chronic whiplash patients recruited from a chiropractic clinic for the purpose of improving our understanding of whiplash injury. METHODS: Twenty chronic whiplash patients and 18 healthy age- and gender matched control subjects were included [mean age ± SD (sex ratio; females/males), case group: 37.8 years ± 9.1 (1.22), control group: 35.1 years ± 9.2 (1.25)]. Data was collected from May 2019 to July 2020. Data from questionnaires pertaining to the car crash, acute and current symptoms were retrieved and findings from clinical examination and MRI including morphologic, diffusion weighted and phase-contrast images were recorded. The apparent diffusion coefficient and fractional anisotropy were calculated, and measurement and analysis of CSF flow was conducted. Statistical analyses included Fisher's exact test, Mann Whitney U test and analysis of variance between groups. RESULTS: The studied population was described in detail using readily available clinical tools. No statistically significant differences were found between the groups on MRI. CONCLUSIONS: This study did not show that MRI-based measures of morphology, spinal cord and nerve root diffusion or cerebrospinal fluid flow are sensitive biomarkers to distinguish between chronic whiplash patients and healthy controls. The detailed description of the chronic whiplash patients using readily available clinical tools may be of great relevance to the clinician. In the context of feasibility, clinical practice-based advanced imaging studies with a technical setup similar to the presented can be expected to have a high likelihood of successful completion.

High-resolution ex vivo magnetic resonance angiography: a feasibility study on biological and medical tissues.

BACKGROUND: In biomedical sciences, ex vivo angiography is a practical mean to elucidate vascular structures three-dimensionally with simultaneous estimation of intravascular volume. The objectives of this study were to develop a magnetic resonance (MR) method for ex vivo angiography and to compare the findings with computed tomography (CT). To demonstrate the usefulness of this method, examples are provided from four different tissues and species: the human placenta, a rice field eel, a porcine heart and a turtle. RESULTS: The optimal solution for ex vivo MR angiography (MRA) was a compound containing gelatine (0.05 g/mL), the CT contrast agent barium sulphate (0.43 mol/L) and the MR contrast agent gadoteric acid (2.5 mmol/L). It was possible to perform angiography on all specimens. We found that ex vivo MRA could only be performed on fresh tissue because formalin fixation makes the blood vessels permeable to the MR contrast agent. CONCLUSIONS: Ex vivo MRA provides high-resolution images of fresh tissue and delineates fine structures that we were unable to visualise by CT. We found that MRA provided detailed information similar to or better than conventional CTA in its ability to visualize vessel configuration while avoiding interfering signals from adjacent bones. Interestingly, we found that vascular tissue becomes leaky when formalin-fixed, leading to increased permeability and extravascular leakage of MR contrast agent.

Imaging occult lesions in the cervical spine facet joints.

Discrete injuries in the lower cervical spine facet joints have been reported in studies of motor vehicle crash victims. We conducted a detailed investigation of these joints from 20 motor vehicle crash fatalities and 22 decedents due to nontraumatic causes, using conventional radiology, computed tomography, and magnetic resonance imaging to examine whether the diagnostic imaging procedures could identify injuries in the facet joints. The diagnostic imaging procedures identified facet joint fractures in 4 of the 19 trauma cases with computed tomography having the highest sensitivity and obtaining good correlation with findings from the microscopical evaluation. No diagnostic imaging procedure could reliably evaluate the integrity of the synovial folds or the joint spaces for bleeding despite microscopical evidence of such findings in these structures in a large proportion of the motor vehicle crash fatalities. This study emphasizes the need for scientific evidence of validity and reliability of advanced diagnostic imaging procedures in forensic settings, in particular, with regard to occult soft tissue lesions, and cautions uncritical use of negative results from these procedures until such evidence has been produced.

Non-fatal injuries to the cervical spine facet joints after a fatal motor vehicle crash: a case report.

Injuries to the lower cervical spine facet joints may be identified in people killed in road traffic crashes. However, many of these injuries are not identified on diagnostic imaging procedures despite histological evidence of injury. This case report illustrates possible non-lethal pathological conditions in the facet joints following fatal road traffic trauma. The cervical spine segments C4 to C7 were removed en bloc and examined with magnetic resonance imaging, computed tomography and conventional radiology. The specimen was fixated in alcohol, embedded in methylmethacrylate, and divided into 3 mm thick parasaggital slices from where 10 microm thick sections were produced and evaluated with light microscopy. Injuries identified on microscopy included haemarthrosis, capsular avulsion, synovial fold contusions and subchondral fractures. None of the injuries were detected on diagnostic imaging or at routine autopsy. Discrete injuries to the cervical spine facet joints were identified using supplemental histological procedures in this case report. Post-mortem diagnostic imaging did not reveal these injuries and future studies should investigate the nature, prevalence and clinical relevance of such lesions.

Histological Osteoarthritic Changes in the Human Cervical Spine Facet Joints Related to Age and Sex.

STUDY DESIGN: Cross-sectional autopsy study. OBJECTIVE: Quantify histological changes in the lower cervical spine facet joints with regard to age and sex using systematic random sampling of entire joints. SUMMARY OF BACKGROUND DATA: Neck pain is a common debilitating musculoskeletal condition and one of the highest ranked causes of years lived with disability. The cause of neck pain is multifactorial and osteoarthritis is one potential cause. The cervical spine facet joints have been implicated in the etiology of chronic neck pain. Hence, a detailed description of their anatomy and age- and sex-related changes is needed. METHODS: The lower four cervical spine segments (C4-C7 included) were obtained from 72 subjects during autopsy; 29 women (median age 53 years [22-77]) and 43 men (median age 38 years [20-78]). A total of 1132 articular facets were embedded in toto in hard plastic and sliced into 3-mm thick sections from where 10 µm thick histological sections were produced. Morphological variables were evaluated microscopically and histomorphometric variables were retrieved using random sampling methods. Data were analyzed with a linear regression model. RESULTS: Significant associations were found between increasing age and in particular splitting, fissures, osteophytes, thickness of the calcified cartilage, and subchondral bone plate. The thickness of the calcified cartilage and subchondral bone plate increased with increasing age, whereas the hyaline cartilage thickness decreased. Males had more extensive degenerative changes in the cartilage. CONCLUSION: Using semiquantitative histological methods, degenerative findings were observed at all spinal levels involving the articular cartilage and the osseous structures of the cervical spine facet joints similar to those observed in larger weight-bearing joints. In particular, the thickening of the calcified cartilage and the subchondral bone identified the osteocartilaginous junction as an important area in osteoarthritis. These findings may be relevant for the pathogenesis of osteoarthritis. LEVEL OF EVIDENCE: 3.

An unusual case of sudden unexpected death: postmortem investigation and biomechanical analysis of the cervical spine.

A naked man died under peculiar circumstances and the postmortem examination revealed unexpected lesions in the cervical spine. Investigations of the cervical spine (computed tomography, magnetic resonance imaging, and histological examination) showed that a piece of bone was torn of the anterior part of vertebra C6 and that there was fresh bleeding in the surrounding tissue. The cause of death remained unclear but was most likely cardiac arrhythmia initiated by beta-2 agonist inhalation due to an acute asthmatic attack. Data from biomechanical investigation using finite element analysis supported the conclusion that the cervical spine injury was secondary to impact during falling as a consequence of the cardiac arrhythmia.

Serious bicycle crash injury in chiropractic practice - a case report of delayed diagnosis.

BACKGROUND: Bicyclists are vulnerable road users and are at risk of serious spinal injury if involved in traffic crashes. In Denmark approximately 25 bicyclists are killed each year and some 20.000 bicycle related casualties are registered in the National Patient Registry each year. In addition to these figures, a large number of casualties remain unregistered despite injury. Many of the casualties will consult chiropractors in primary practice with or without preceding evaluation in the established emergency care facilities. Therefore, chiropractors are expected to be able to proficiently evaluate these patients clinically and radiologically in order to ensure the best possible patient care. CASE PRESENTATION: This report involves a middle-aged female who consulted several physicians following a collision with a motor vehicle while riding a bike. Despite clinical symptoms and consequent examinations she suffered from inadequate diagnostic evaluation until a radiological examination was performed 18 days following the injurious crash identifying unstable cervical spine fractures. CONCLUSIONS: The presented case is an example of the serious spinal injuries bicyclists may suffer when involved in high-energy traffic crashes despite wearing a bicycle helmet. The case report highlights the need for relevant clinical (including radiological) decision strategies when dealing with trauma patients in chiropractic practice. This involves the direct access to radiological procedures with no unnecessary delay when indicated as in most trauma cases. Furthermore, clearly defined and easy accessible referral schemes from primary care settings to emergency departments must be available to the chiropractic physician. Chiropractors are clinically competent to examine and diagnose, including radiologically evaluate, patients who have been injured in traffic crashes. Hence, chiropractors may contribute to the diagnosis, management and rehabilitation of spinal injured patients following many types of crashes and accident, including bicycle crashes.

Diffusion tensor imaging of peripheral nerves in non-fixed post-mortem subjects.

PURPOSE: While standard magnetic resonance imaging (MRI) sequences are increasingly employed in post-mortem (PM) examinations, more advanced techniques such as diffusion tensor imaging (DTI) remain unexplored in forensic sciences. Therefore, we studied the temporal stability and reproducibility of DTI and fiber tractography (FT) in non-fixed PM subjects. In addition, we investigated the lumbosacral nerves with PMDTI and compared their tissue characteristics to in vivo findings. METHODS: MRI data were acquired on a 1.5T MRI scanner in seven PM subjects, consisting of six non-trauma deaths and one chronic trauma death, and in six living subjects. Inter-scan (within one session) and inter-session (between days) reproducibility of diffusion parameters, fractional anisotropy (FA), and mean diffusivity (MD), were evaluated for the lumbosacral nerves using Bland-Altman and Jones plots. Diffusion parameters in nerves L3-S2 were compared to living subjects using the non-parametric Mann-Whitney U test. RESULTS: Reproducibility of diffusion values of inter-scan 95% limits of agreement ranged from -0.058 to 0.062 for FA, and (-0.037 to 0.052)×10(-3)mm(2)/s for MD. For the inter-session this was -0.0423 to 0.0423, and (-0.0442 to 0.0442)×10(-3)mm(2)/s for FA, and MD, respectively. Although PM subjects showed approximately four-fold lower diffusivity values compared to living subjects, FT results were comparable. The chronic trauma case showed disorganization and asymmetry of the nerves. CONCLUSION: We demonstrated that DTI was reproducible in characterizing nervous tissue properties and FT in reconstructing the architecture of lumbosacral nerves in PM subjects. We showed differences in diffusion values between PM and in vivo and showed the ability of PMDTI and FT to reconstruct nerve lesions in a chronic trauma case. We expect that PMDTI and FT may become valuable in identification and documentation of PM nerve trauma or pathologies in forensic sciences.

Inside out: modern imaging techniques to reveal animal anatomy.

Animal anatomy has traditionally relied on detailed dissections to produce anatomical illustrations, but modern imaging modalities, such as MRI and CT, now represent an enormous resource that allows for fast non-invasive visualizations of animal anatomy in living animals. These modalities also allow for creation of three-dimensional representations that can be of considerable value in the dissemination of anatomical studies. In this methodological review, we present our experiences using MRI, CT and µCT to create advanced representation of animal anatomy, including bones, inner organs and blood vessels in a variety of animals, including fish, amphibians, reptiles, mammals, and spiders. The images have a similar quality to most traditional anatomical drawings and are presented together with interactive movies of the anatomical structures, where the object can be viewed from different angles. Given that clinical scanners found in the majority of larger hospitals are fully suitable for these purposes, we encourage biologists to take advantage of these imaging techniques in creation of three-dimensional graphical representations of internal structures.

Esophageal injury in fatal rear-impact collisions.

Neck injuries resulting from motor vehicle collisions (MVC), often referred to as whiplash trauma and injury, often demonstrate little or no evidence of significant tissue damage. In rare instances, however, serious injury to the anterior neck organ injuries can result from such trauma. The present study describes esophageal injury associated with rear-impact collisions, based on a unique case report, review of the scientific literature and a query in the National Automotive Sampling System (NASS) database of the US National Highway Traffic Safety Administration. The Medline search and present case study totaled five cases of rear-impact collision-related serious esophageal injury (laceration or rupture). In the four published cases all patients survived, whereas in the presented case study, the patient died due to mediastinitis and sepsis. The NASS query revealed an additional three cases out of a total of 55,926 investigated crashes. All three cases were associated with fatalities. Although no anatomical or bioengineering studies have presented data on the behavior of the esophagus during rear-impact whiplash loading, sudden tensile and/or compressive forces is the likely explanation of injury, often in combination with a local fracture of a vertebral body. In these 8 cases significant esophageal injury carried a substantial (50%) risk of mortality. Clinicians should be aware of the potential for significant complications in the whiplash trauma-exposed patient who complains of chest pain, mid-thoracic pain, discomfort in the neck and throat, respiratory distress, or hoarseness. For those forensic specialists involved in whiplash cases these study results highlight the need to consider esophageal injuries as a rare but potential consequence of whiplash trauma.

[Autopsy and blood testing for alcohol and drugs/medicine after traffic fatalities is not routinely conducted]. / Obduktion og blodprøvetagning udføres sjaeldent ved trafikdrab.

INTRODUCTION: In some road traffic crashes with fatal outcome, the police investigations lead to charges against and prosecution of a person. The police can request a medico-legal autopsy as well as a toxicological examination, but the extent to which this is done, and the role here of in the legal setting is unknown. MATERIAL AND METHODS: Information concerning traffic crashes with fatal outcome in the period 2000-2004 in Aarhus Police District was retrieved and compared. The information included comprised crash specific and legal information, as well as medical data concerning autopsy, examination for alcohol, drugs and/or medicine. RESULTS: In all, 81 traffic crashes had a fatal outcome for 92 persons, of whom 17 (18%) were autopsied, 55 (60%) were tested for alcohol, and five (5%) were examined for drugs/medicine. Twenty-six were charged with negligent homicide, of which 18 were convicted. Autopsy was performed in four of these cases, 19 were tested for alcohol and one was tested for drugs/medicine. CONCLUSION: This study shows that the police requests few medico-legal autopsies following road traffic fatalities, and that testing for alcohol as well as drugs/medicine is not conducted routinely. As a consequence, important information may not come to the knowledge of the police in cases of negligent homicide. We recommend that postmortem examination be conducted routinely in traffic-related homicide cases to secure the best possible conditions for a legal evaluation.

Contributions from forensic imaging to the investigation of upper cervical fractures.

Injuries to the upper cervical spine (UCS) are common in traumatic deaths and postmortem computed tomography (PMCT) may contribute to the forensic investigation. This study presents PMCT in comparison with autopsy in the examination of UCS injury. Thirteen consecutive cases with UCS fracture and / or cranio-cervical dislocation were examined with PMCT and autopsy, and the findings were correlated. Neither of the techniques identified all UCS injuries. Fractures of atlas and axis were best visualized with PMCT whereas cranio-cervical dislocation was better identified during autopsy. Serious injuries were present after both high- and low-energy trauma. Medico-legal autopsy in combination with PMCT produced a thorough evaluation of UCS injuries. By combining these procedures detailed investigations, including accident reconstruction and injury pattern analysis, can be performed. This study supports the routine application of PMCT, as a supplement to the medico-legal autopsy of deaths with UCS injuries.

Traumatic death in ankylosing spondylitis.

Ankylosing spondylitis (AS) is a chronic rheumatic disease that causes spinal rigidity with an increased risk of spinal fractures. We present a case report where a middle-aged man, in apparent good health, died following a fall from his bike. Postmortem computed tomography (CT) showed several fractures in the cervical and thoracic spine, with displacement into the spinal canal as well as spinal changes consistent with AS. The cause of death was determined to be upper spinal cord injury caused by cervical spinal fractures that were facilitated by spinal rigidity from AS. Further investigation into the medical records revealed that the decedent had previously been treated for AS. This case report illustrates the importance of obtaining a detailed medical history when investigating deaths, including nonfatal conditions, such as AS. Furthermore, it shows the value of CT in the evaluation of the mechanism and manner of death.