Full-body Computed Tomography Research Articles

Abstract 360: Clinical Characteristics and Outcome in Out-of-Cardiac Arrest Patients With Type A Aortic Dissection Diagnosed by Non-Contrast Computed Tomography

Background: Although type A aortic dissection (AAD) remains a life-threatening disease, the exact epidemiology of out-of-hospital cardiac arrest (OHCA) with AAD is unclear. It has been reported that the non-contrast computed tomography (CT) is useful for diagnosing AAD in patients whose hemodynamic status was unstable. Aim: We evaluated the clinical features and outcome of OHCA patients with AAD diagnosed by non-contrast CT. Methods: Between 2017 and 2022, we retrospectively collected Utstein-style data on non-traumatic adult OHCA patients transferred to our hospital and performed non-contrast full-body CT scan. We divided OHCA patients into 3 groups: patients with AAD diagnosed by CT (Group-AAD), patients with non-cardiac cause without AAD (Group-NC), and patients with cardiac cause (Group-C). The diagnostic criteria of AAD by CT were as follows: visible intimal flap; crescentic high attenuation hematoma; and inward shift of calcified intima. The clinical outcome was defined as return of spontaneous circulation (ROSC). Results: Of the 1018 non-traumatic adult OHCA patients were registered during the study period, 1015 patients underwent non-contrast CT (Group-AAD, n=79; Group-NC, n=159; Group-C, n=779). The patients who achieved return of spontaneous circulation (ROSC) was 271 (26.8%). The proportion of patients who achieved ROSC in Group-AAD was significantly smaller than the other groups (Group-AAD 10.1%, Group-NC 27.7%, Group-C 28.3%, P=0.002). Multivariable logistic regression analysis revealed that patients with AAD diagnosed by CT independently predicted failure to achieve ROSC. The presence of witnessed arrest and initial shockable rhythm were significant indenpent predictors of achieving ROSC ( Table ). Conclusion: OHCA patients with AAD diagnosed with CT were more difficult to obtain ROSC than patients with other cause.

Cerebrovascular Events in Suspected Sepsis: Retrospective Prevalence Study in Critically Ill Patients Undergoing Full-Body Computed Tomography.

PurposeThis study aimed at retrospectively evaluating full-body computed tomography (CT) examinations for the prevalence of cerebrovascular events in patients with suspected sepsis treated in the intensive care unit (ICU).MethodsAll full-body CT examinations, i.e., both cranial CT (cCT) and body CT including chest, abdomen and pelvis, for focus search in septic patients over a 12-months period were identified from three ICUs, using full-text search. From this retrospective cohort, we fully analyzed 278 cCT examinations for the occurrence of acute cerebral findings. All acute cerebrovascular events were independently reviewed by two blinded readers. Clinical and laboratory findings were extracted. The data were statistically analyzed using contingency tests.ResultsIn our population of patients with suspected sepsis, 10.8% (n = 30/278) were identified to have major cerebral events, including 7.2% (n = 20/278) major cerebrovascular events and 4.3% (n = 12/278) generalized parenchymal damage. 13.4% (n = 22/163) of patients with a severe coma as compared with non-severe coma, 4.4% (n = 3/68), showed a major cerebral event (p = 0.04). Patients referred from the cardiology/nephrology ICU ward showed major cerebral events in 16.3% (n = 22/135), as compared with 4.9% (n = 3/61) in patients from pulmonary ICU and 6.1% (n = 5/82) major cerebral events with surgical referral (p = 0.02).ConclusionOur study provides further evidence that septic patients may suffer from cerebral events with relevance to their prognosis. Severe coma and the referring ward were associated with acute cerebral conditions. Full-body CT has the advantage of both detecting of septic foci and possibly identifying ischemic or hemorrhagic stroke in this vulnerable patient population.

The introduction and demise of full-body computed tomography (CT) scanning in Australia: implications for preventing overdiagnosis

ABSTRACT Full-body computed tomography (CT) screening came to Australia in 2002. Within a year, public access to self-referred full-body CT screening was withdrawn as a consequence of sustained professional and political pressure and legislative changes. We examine how self-referred full-body CT scans were made available to Australian consumers, and evaluate the social, cultural and system factors that contributed to their de-implementation. Using historical methodologies, insider accounts and an ethnographic content analysis of policy documents, statutory reports, grey and scholarly literatures, we show how the rapid de-implementation of full-body CT scans in Australia arose from interconnected social, cultural and system factors, and an unusual harm profile for the technology. In the Australian context, this case suggests that neither single actors nor robust health technology assessments are likely to be sufficient to protect people from the unwanted consequences of too much medicine. The coordinated interaction of multiple stakeholders achieved this unusual example of successful, early de-implementation. Each stakeholder exercised their authority within their respective remits to shape public perceptions of and access to the new CT screening service: it is possible that without the actions of each, the final de-implementation outcome may not have been achieved. These findings are timely, given growing concerns about overdiagnosis and the emergence of new forms of testing technologies. Against a background of technological optimism and commercial opportunism, a commitment to vigilance and cross-sectoral coordination across a range of decision-making roles and institutions will be key to efforts to prevent the harms of overdiagnosis.

Deep learning method for localization and segmentation of abdominal CT

Computed Tomography (CT) imaging is widely used for studying body composition, i.e., the proportion of muscle and fat tissues with applications in areas such as nutrition or chemotherapy dose design. In particular, axial CT slices from the 3rd lumbar (L3) vertebral location are commonly used for body composition analysis. However, selection of the third lumbar vertebral slice and the segmentation of muscle/fat in the slice is a tedious operation if performed manually. The objective of this study is to automatically find the middle axial slice at L3 level from a full or partial body CT scan volume and segment the skeletal muscle (SM), subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT) and intermuscular adipose tissue (IMAT) on that slice. The proposed algorithm includes an L3 axial slice localization network followed by a muscle-fat segmentation network. The localization network is a fully convolutional classifier trained on more than 12,000 images. The segmentation network is a convolutional neural network with an encoder–decoder architecture. Three datasets with CT images taken for patients with different types of cancers are used for training and validation of the networks. The mean slice error of 0.87±2.54 was achieved for L3 slice localization on 1748 CT scan volumes. The performance of five class tissue segmentation network evaluated on two datasets with 1327 and 1202 test samples. The mean Jaccard score of 97% was achieved for SM and VAT tissue segmentation on 1327 images. The mean Jaccard scores of 98% and 83% are corresponding to SAT and IMAT tissue segmentation on the same dataset. The localization and segmentation network performance indicates the potential for fully automated body composition analysis with high accuracy.

The effect of computed tomography on oxidative stress level and some antioxidant parameters.

X-rays are defined as ionizing radiation and hydrolyze the water, causing free radical formation. Oxidative stress is the damage that occurs in cells due to the lack of antioxidants, which detoxifies them, with the increased production of free radicals that occur during normal cellular metabolism. To examine the acute effects of computed tomography (CT), i.e. ionizing radiation, on oxidative stress and antioxidant defense mechanisms. The study included a total of 53 patients that were selected among the patients that underwent non-contrast full-body CT. Malondialdehyde (MDA) and reduced glutathione (GSH) levels and superoxide dismutase (SOD) and catalase (CAT) activities were investigated in blood samples taken from patients. The post-scan levels of MDA increased significantly while the post-scan levels of GSH, SOD, and CAT decreased significantly compared to their pre-scan levels. CT, which is a widely used X-ray imaging technique and has numerous known side effects, was found to increase the levels of MDA, which is an indicator of oxidative stress, and to decrease the levels of some antioxidants including GSH, SOD, and CAT.

Using Virtual Reality to Study Real Patient Anatomy

Utilizing virtual reality (VR) is an excellent way to learn anatomy. The user can visualize different anatomical structures from all angles (360 degrees) allowing for understanding the relative 3D distances between various structures, and overall interacts with the anatomies within an immersive environment. Other benefits of VR include reduced uses of cadaver donors and animal models, as well as a more engaging learning experience than a textbook. Today, some medical schools have already incorporated VR into their curriculum. However, the bodies for study are often idealized models of “perfected” anatomy. Bones, organs, and vessels are typically depicted as smooth, straight anatomies that only represent a healthy human patient population. In the Visible Heart® Laboratories, we have developed several VR tutorials based on real patient anatomies via whole body scans from donated individuals to the Anatomy Bequest Program at the University of Minnesota. This allows the user to “fly” around the bodies of these patients with varying demographics and disease states. This allows for better understanding the patient comorbidities, conditions, and potentially techniques on how to treat patients as a whole.The 3D renderings in the VR scenes were specifically modeled from full body computed tomography (CT) scans of these fresh human cadavers. To highlight the vessels in the imaging, the bilateral carotid arteries, jugular veins, and femoral arteries and veins were cannulated and ~8 liters of radiopaque contrast was manually injected to the body. Each full body CT scan was performed allowing for <600μm resolution. A similar protocol was repeated with a 3T MRI of the thoracic cavity for better visualizations of the thoracic and abdominal cavities. These DICOM datasets were then uploaded into Materialise Mimics software where bones, arteries, veins, lungs, and organs, were individually segmented and rendered into 3D models. These were next imported into Unity, a free video game development platform.When any user wears the HTC Vive VR headset and holds the controller, they are able to “fly” through these real patients’ anatomies (Figure 1). These bodies have been digitally preserved through these DICOM datasets and computational models. Relevant medical history, including disease states and device implants, can also be studied. So far, two full body specimens have been reconstructed in VR – a 60 y/o white male with history of congestive heart failure and a brain tumor and a 76 y/o white male with history of chronic obstructive pulmonary disease. Additionally, we have used VR to study cadaver vasculatures (arteries and veins) to gain an understanding of how the insertion of transcatheter devices affects the vessels and surrounding tissues. Future anatomical educational tools in development include a multi‐user VR environments with 3D glasses (Figure 2), as well as a portable VR system which can be run on a phone or tablet.VR scene created from real human patient anatomies. Cadaver specimens were both CT and MRI scanned to create 3D models. These were imported into VR scenes and color coded to represent different anatomical structures, including the lungs, arteries, veins, bones, and other organs. The left is the view of the body from above and the right is the view from within the liver. Note again, the hepatic vasculature can be visualized in any desired orientation.Figure 1Students in a large lecture setting demonstrating the multi‐user VR capability with 3D glasses.Figure 2

Full-body CT scan in Polytrauma Diagnosis. Analysis of Ten Years’ Experience

Introduction. A computed tomography (CT) scan of the entire body has become a standard practice for the diagnosis of patients with polytrauma in many trauma centres. Purpose: evaluation of diagnostic potential of full-body CT for patients with polytrauma.Materials and methods. In the period from January 2008 to December 2018, all hemodynamically stable patients (scoring 3 and above in the Abbreviated Injury Scale (AIS) and 15 and above in the Injury Severity Score (ISS)) admitted to the Main Republican Head Injury Centre CCH №21 in Ufa with injuries in two or more anatomical areas have undergone CT scanning of head, neck (including cervical spine), chest (including thoracic spine), abdominal cavity/pelvis (including lumbar spine).Results and discussion. In the period from January 2008 to December 2018, 1498 CT examinations were conducted. Out of these examinations, 1368 and 143 cases were polytrauma — (on average 2 cases per week) and monotrauma (10 % of the study group) patients. Only 17 patients failed to complete the examination for polytrauma due to deteriorating status. All of these 17 had been returned to the intensive care unit without delay.Conclusion. In a decade 1368 patients met the established criteria for an immediate CT scan for the diagnosis of polytrauma at a large hospital providing emergency healthcare. A broad range of significant injuries was diagnosed quickly, accurately and safely. These injuries included 31 cervical spine fractures and 56 pneumothoraxes not evidenced by conventional X-ray images.

Early full-body computed tomography in patients after extracorporeal cardiopulmonary resuscitation (eCPR)

IntroductionInitiation of venoarterial extracorporeal membrane oxygenation (ECMO) under ongoing cardiopulmonary resuscitation (eCPR) in patients with refractory cardiac arrest may improve otherwise deleterious outcome. In general, the duration of mechanical resuscitation from collapse to ECMO ranges from 40 to 70 min. CPR-related injuries are reported frequently in non-eCPR patients. We wanted to quantify CPR-related injuries in eCPR patients. MethodsAll eCPR patients cannulated at a tertiary referral medical center between October 2010 and October 2017 were included in a retrospective registry study. A full-body CT scan was performed within the first 24 h after eCPR. ResultsA total of 103 patients (mean age 58.8 ± 16.7 years, CPR duration 61.7 ± 31.9 min, and hospital survival 13.6 %) underwent eCPR and immediate full-body computed tomography (CT). Full-body CT detected the cause for collapse in 16.5% of patients. Average number of pathologies detected per CT scan was 6.5 ± 3.3 findings per patient, of which 2.6 ± 1.5 findings were retrospectively considered of clinical relevance for subsequent treatment. Most frequent findings were multiple rib or sternal fractures (65.5%), pneumo- or hemothorax (32.3%) and pulmonary infiltrates (91.3%). Intracranial bleedings and cerebral edema were frequent (10.7% and 26.2%). A total of 20 patients (19.4%) had findings in whole-body CT that were considered to be so severe that further treatment was considered futile and therapy was subsequently discontinued. Most findings were associated with poor outcome with the exception of rib fractures, bleedings and abdominal trauma, which might have been caused by vigorous resuscitation efforts and were associated with favorable outcome. ConclusionA full-body CT scan performed after eCPR revealed substantial clinically significant findings. Therefore, it might be reasonable to routinely perform a full-body CT in all eCPR patients.

Synchrotron MicroCT Reveals the Potential of the Dual Contrast Technique for Quantitative Assessment of Human Articular Cartilage Composition.

ABSTRACTDual contrast micro computed tomography (CT) shows potential for detecting articular cartilage degeneration. However, the performance of conventional CT systems is limited by beam hardening, low image resolution (full‐body CT), and long acquisition times (conventional microCT). Therefore, to reveal the full potential of the dual contrast technique for imaging cartilage composition we employ the technique using synchrotron microCT. We hypothesize that the above‐mentioned limitations are overcome with synchrotron microCT utilizing monochromatic X‐ray beam and fast image acquisition. Human osteochondral samples (n = 41, four cadavers) were immersed in a contrast agent solution containing two agents (cationic CA4+ and non‐ionic gadoteridol) and imaged with synchrotron microCT at an early diffusion time point (2 h) and at diffusion equilibrium (72 h) using two monochromatic X‐ray energies (32 and 34 keV). The dual contrast technique enabled simultaneous determination of CA4+ (i.e., proteoglycan content) and gadoteridol (i.e., water content) partitions within cartilage. Cartilage proteoglycan content and biomechanical properties correlated significantly (0.327 < r < 0.736, p < 0.05) with CA4+ partition in superficial and middle zones at both diffusion time points. Normalization of the CA4+ partition with gadoteridol partition within the cartilage significantly (p < 0.05) improved the detection sensitivity for human osteoarthritic cartilage proteoglycan content, biomechanical properties, and overall condition (Mankin, Osteoarthritis Research Society International, and International Cartilage Repair Society grading systems). The dual energy technique combined with the dual contrast agent enables assessment of human articular cartilage proteoglycan content and biomechanical properties based on CA4+ partition determined using synchrotron microCT. Additionally, the dual contrast technique is not limited by the beam hardening artifact of conventional CT systems. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 38:563–573, 2020

Transorbital penetrating trauma caused by a fall on the antenna of a radio receiver: Case report and review

Summary We report the case of a patient who died after falling on the antenna of a radio receiver that was stood on the floor. External examination showed an orificial contuse wound, less than a centimetre in diameter, on the right upper eyelid. There was no ocular lesion. Full-body CT (computed tomography) scan imagery revealed a fracture of the roof of the right orbit and diffuse intra and pericerebral haemorrhages. Those haemorrhages had caused the death of the patient. Penetrating transorbital traumas represent a very small part of cranial traumas and orbital pathologies. They are usually linked to the high-velocity traumas associated with traffic accidents or penetration by firearm projectiles. Low-energy penetrating transorbital traumas are even less frequent; associated prognoses are rarely lethal and generally functional. These traumas cause minimal palpebral or periocular wounds that can seem insignificant upon external forensic examination, especially when the foreign body involved is fully intracranial or absent. Performing a cerebral scan, or even post-mortem angiography, thus appears to be a key-procedure, very useful to the medical examiner.

A comparative analysis of the findings of postmortem computed tomography scan and traditional autopsy in traumatic deaths: Is technology mutually complementing or exclusive?

Background: Postmortem examination is indispensable to ascertain the cause of an unnatural death and as such is mandatory by the law. From ages, traditional autopsy (TA) has proved its worth in establishing the cause of death in the deceased despite some inherent difficulties and challenges and has enjoyed an insurmountable status. The increasing use of application of the modern-day radiology for postmortem examination has however opened a new arena overcoming some of the difficulties of the TA. There are conflicting reports in the published literature regarding superiority of one modality of the postmortem over the other. Objective: The objective of this study was to compare the findings of postmortem computed tomography (CT) scan and TA in the victims of traumatic deaths and to analyze whether postmortem CT can be used to replace TA. Materials and Methods: All patients with a history of trauma that were declared brought dead on arrival in the emergency department were subjected to full-body CT scan. An experienced radiologist reported the findings of CT scan. Subsequently, a forensic expert subjected the patients to TA. The physician who performed autopsy was blinded to the findings of CT scan and vice versa. An individual who was not part of the radiology or forensic team then entered the findings of CT scan and autopsy in a predesigned Pro forma. An unbiased assessor finally compared the findings of the two modalities and analyzed the results. McNemar's test was used to ascertain the level of significance between the findings reported by these two modalities considering P = 0.05 as statistically significant. The agreement or disagreement on cause of death reported by these two modalities was also assessed. Results: About 95% of the deceased were males. The mean age of the corpses was 35 years (range 16–67 years). CT was found superior in picking up most of the bony injuries, air-containing lesions, hemothorax, and hemoperitoneum. However, autopsy was found more sensitive for soft-tissue and solid visceral injuries. Both modalities were equally helpful in identifying extremity fractures. Statistically significant agreement (>95%) on cause of death by both modalities was not achieved in any patient of trauma. Conclusion: Postmortem CT scan is promising in reporting injuries in traumatic deaths and can significantly complement the conventional autopsy. However, at present, it cannot be considered as a replacement for TA.

Virtopsy in conjoined ischiopagus twins

To propose a multidisciplinary protocol for postmortem disclosure of complex fetal malformations, comparing ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and autopsy in a case of conjoined ischiopagus twins. A screening second-trimester ultrasound diagnosed ischiopagus twins at 20 gestational weeks in a 31-year-old woman without any previous ultrasound examination. The couple decided for pregnancy termination. The formalin-fixed fetuses underwent full-body CT, MRI, and autopsy. ultrasound accurately diagnosed ischiopagus twins. CT was very accurate in the description of bone components. MRI allowed better visualization of the visceral organs than CT. Only autopsy could disclose the aspect of the two gastrointestinal tracts and the external genitalia. Prenatal ultrasound represents the standard diagnostic exam for conjoined twins. CT-MRI virtual autopsy (virtopsy) may be an option if the couple refuses to authorize necropsy or may be useful to plan a minimally invasive autopsy preserving the external phenotype.

Computed Tomography Scanner Productivity and Entry-Level Models in the Global Market.

Objective This study evaluated the productivity of computed tomography (CT) models and characterized their simplest (entry-level) models' supply in the world market. Methods CT exam times were measured in eight health facilities in the state of Rio de Janeiro, Brazil. Exams were divided into six stages: (1) arrival of patient records to the examination room; (2) patient arrival; (3) patient positioning; (4) data input prior to exam; (5) image acquisition; and (6) patient departure. CT exam productivity was calculated by dividing the total weekly working time by the total exam time for each model. Additionally, an internet search identified full-body CT manufacturers and their offered entry-level models. Results The time durations of 111 CT exams were obtained. Differences among average exam times were not large, and they were mainly due to stages not directly related to data acquisition or image reconstruction. The survey identified that most manufacturers offer 2- to 4-slice models for Asia, South America, and Africa, and one offers single-slice models (Asia). In the USA, two manufacturers offer models below 16-slice. Conclusion Productivity gains are not linearly related to “slice” number. It is suggested that the use of “shareable platforms” could make CTs cheaper, increasing their availability.

The importance of empiric abdominal computed tomography after urgent laparotomy for trauma: Do they reveal unexpected injuries?

Many institutions now use empiric full-body computed tomography (CT) as a standard step in the initial workup of stable trauma patients. Recent data suggest that these scans may reveal unexpected injuries and improve survival in patients with polytrauma. However, patients who are unstable on presentation are often taken to the operating room (OR) without CT. Many of these patients undergo empiric full-body CTs after being stabilized in the OR, yet few data exist regarding how often early postoperative CT reveals unexpected injuries within compartments that have been explored surgically. Thus, the objective of this study was to determine if empiric abdominal/pelvic (ABD) CT after emergent trauma laparotomies are likely to reveal missed injuries requiring urgent management and improve patient management compared with clinical judgment alone. We review retrospectively 496 trauma patients who required urgent exploratory laparotomy at UPMC Presbyterian Hospital from 2007 to 2011. Patients were included if they went to the OR for exploratory laparotomy directly from the emergency department within 2hours of arrival. Patients were excluded if they received any preoperative ABD CT imaging. Patients who expired in the OR were similarly excluded. Patients were stratified into 2 groups based on whether or not they received an empiric ABD CT in the 24hours immediately after laparotomy. Medical records were reviewed to look for differences in missed injuries, urgent reexplorations, nontherapeutic interventions, and time to urgent reexploration. There were 278 patients who met inclusion at exclusion criteria and constituted the study cohort. Of these patients, 124 underwent early empiric postoperative ABD CT imaging (45%). The remaining 154 patients did not undergo early ABD imaging (no CT group). The overall cohort had a 45% incidence of damage control procedures and a 9% rate of negative laparotomy. The 2 groups were statistically similar in age, presenting vitals, and abdominal Abbreviated Injury Scores. When the ABD CT group was compared with the no CT group, there was no difference in the overall rate of urgent reexplorations (7.3 vs 7.1%; P=.956), nontherapeutic urgent reexplorations (22 vs 18%; P=.822), or time to urgent reexploration (14±10 vs 12±10hours; P=.686). Out of the 124 ABD CT patients, only 5 (4.0%) were diagnosed with injuries that were not identified at the time of the initial operation or caused by operative technique. When controlling for demographics, mechanism of injury, and injury severity, a logistic regression analysis revealed that early postoperative ABD CT was not associated with any differential risk of the need for further intervention (odds ratio, 0.85; 95% CI, 0.37-1.9; P=.691). The use of ABD CT soon after trauma laparotomy did not provide meaningful improvements in patient care in the cohort studied. Further higher level research is needed to clarify what role empiric ABD CT should play in the early postoperative period.

Role of virtopsy in the post-mortem diagnosis of drowning

Due to admitted limits of autopsy-based studies in the diagnosis of drowning, virtopsy is considered the new imaging horizon in these post-mortem studies. The aim of our study was to evaluate the role of virtopsy performed through computed tomography (CT) in the forensic diagnosis of drowning. We retrospectively examined the CT data of four cadavers recovered from sea water and suspected to have died by drowning. Each patient underwent a full-body post-mortem CT scan, and then a traditional autopsy. All the cadavers showed fluid in the airways and patchy ground-glass opacities in the lung. Only one patient had no fluid in the digestive tract; this patient had a left parietal bone fracture with a large gap and other multiple bone fractures (nose, clavicle, first rib and patella). One of the three patients who had fluid in the digestive tract had no fluid in the paranasal sinuses. This latter patient showed cerebral oedema with subarachnoid and intraventricular haemorrhage, multiple bone fractures (orbital floor, ribs, sacrum and acetabular edge) and air in the heart, in the aorta and in bowel loops. To date, there are no autopsy findings pathognomonic of drowning. This study proves that virtopsy is a useful tool in the diagnosis of drowning in that it allows us to understand if the victim was alive or dead when he entered the water and if the cause of death was drowning.

Accuracy and reliability of measurements obtained from computed tomography 3D volume rendered images

Forensic pathologists commonly use computed tomography (CT) images to assist in determining the cause and manner of death as well as for mass disaster operations. Even though the design of the CT machine does not inherently produce distortion, most techniques within anthropology rely on metric variables, thus concern exists regarding the accuracy of CT images reflecting an object's true dimensions. Numerous researchers have attempted to validate the use of CT images, however the comparisons have only been conducted on limited elements and/or comparisons were between measurements taken from a dry element and measurements taken from the 3D-CT image of the same dry element.A full-body CT scan was performed prior to autopsy at the Office of the Chief Medical Examiner for the State of Maryland. Following autopsy, the remains were processed to remove all soft tissues and the skeletal elements were subject to an additional CT scan. Percent differences and Bland–Altman plots were used to assess the accuracy between osteometric variables obtained from the dry skeletal elements and from CT images with and without soft tissues. An additional seven crania were scanned, measured by three observers, and the reliability was evaluated by technical error of measurement (TEM) and relative technical error of measurement (%TEM).Average percent differences between the measurements obtained from the three data sources ranged from 1.4% to 2.9%. Bland–Altman plots illustrated the two sets of measurements were generally within 2mm for each comparison between data sources. Intra-observer TEM and %TEM for three observers and all craniometric variables ranged between 0.46mm and 0.77mm and 0.56% and 1.06%, respectively. The three-way inter-observer TEM and %TEM for craniometric variables was 2.6mm and 2.26%, respectively. Variables that yielded high error rates were orbital height, orbital breadth, inter-orbital breadth and parietal chord. Overall, minimal differences were found among the data sources and high accuracy was noted between the observers, which prove CT images are an acceptable source to collect osteometric variables.

Primary sarcoma of the lung: A very rare diagnosis and poor prognosis

Primary lung sarcoma is a very rare malignant tumor, accounting for less than 0.5% of all lung tumors. We describe the case of a 50-year-old man who presented with primary pulmonary sarcoma. X-ray chest and thoracic computed tomography (CT) revealed a 40 mm Χ 60 mm mass in the right upper lobe. Biopsy was reported as fusiform sarcoma. Extensive clinical examination, followed by full body CT scan was performed to exclude primary synovial sarcoma located peripherally and distant metastases. Hence, surgical excision was planned after three cycles of chemotherapy, but the patient died after the second cycle. Because a sarcoma of the lung is rare, data regarding its natural history and published cases are limited. Further investigation and data collection are required to optimize the treatment of this group of rare and aggressive tumors.

CT appearance of gas collections can predict the cause of death in scuba diving accidents

Objectives To define the computed tomography (CT) semiology of post-mortem gas collections linked to putrefaction, post-mortem off-gassing and decompression illness (DI) after fatal diving accidents and to establish CT diagnostic criteria for different causes of death in diving. Materials and methods A 4-year prospective study was conducted including cases of death diving referred to our center. For each subject a hyperbaric physician analyzed the circumstances of death and interviewed rescue crews and witnesses. A post-mortem full body CT scan was conducted followed by an autopsy. The following criteria were examined: intra-arterial gas, intravenous gas, complete pneumatization of supra-aortic trunks, complete pneumatization of the right ventricle, presence of subcutaneous emphysema limited to the thoracic area, and presence of a pneumothorax. Results Eighteen subjects were included in the study. The presence of intra-arterial gas associated with death by DI had a negative predictive value (NPV) of 100% but the positive predictive value (PPV) was only 54% because of post-mortem off-gassing. The PPV reached 70% when considering pneumatization of the supra-aortic trunks. Pneumothorax had a poor PPV (53%) for DI. Putrefaction gas is not visible in the arteries for the first 24 h after death. Conclusion Pneumothorax, subcutaneous emphysema, and/or intra-arterial gas, all of which are classical criteria for DI diagnosis, are not specific to a DI. Complete pneumatization of supra-aortic trunks and of the right ventricle are the best CT criteria to detect a fatal DI when the scanner is conducted within 24 h after death.

A 67‐Year‐Old Woman Receiving Tumor Necrosis Factor α Inhibitor Therapy Presenting With Neurologic Dysfunction

A 67‐Year‐Old Woman Receiving Tumor Necrosis Factor α Inhibitor Therapy Presenting With Neurologic Dysfunction

Eruptive pigmentation around naevi and seborrhoeic keratoses in a patient with stage III melanoma: hyperpigmented halo or ‘Nottus’ phenomenon

Funding sources: none. Conflicts of interest: none declared. Madam, The appearance of white, vitiligo‐like macules around pigmented moles (Sutton halo naevus or Sutton phenomenon) is a well‐known phenomenon, and has been described in the context of melanoma. We report the case of a man with stage III melanoma who developed a sudden and synchronous, eruptive pigmentation around most of his naevi and seborrhoeic keratoses. A 65‐year‐old man with a medical history of tobacco smoking and dyslipidaemia presented in March 2006 with an extensive subcutaneous mass of the right scapular region, which was resected. Histological examination demonstrated dermal metastasis of melanoma. Thorough skin examination revealed many melanocytic naevi without atypical features and a few seborrhoeic keratoses, but no lesion consistent with primitive cutaneous melanoma. A highly suspect, enlarged, right axillary lymph node was detected and lymph node dissection was performed in December 2006, showing melanoma metastases with extracapsular extension in two of 12 resected lymph nodes. Staging investigations, including a positron‐emission tomography scan and a full body computed tomography (CT) scan, did not detect any visceral metastasis. Adjuvant immunotherapy with interferon alfa‐2a (3 × 3 million IU weekly) was administered, but had to be discontinued 5 months later because of liver enzyme elevation. At a follow‐up visit 6 months after discontinuation of the treatment, a striking modification of his skin lesions was noted. Most of his naevi were surrounded by a light‐brown, ill‐defined, round or oval macular halo (Fig. 1), associated with brownish macules without a central lesion. He had experienced neither pruritus nor perilesional erythema, and his general condition was good. Histological examination of five lesions surrounded by brown macules demonstrated hypermelanosis of the epidermal basal layer without significant melanocytic hyperplasia in the periphery (corresponding to the pigmented halo) (Fig. 2), and a typical compound dermal naevus in the centre. In one sample, the central brown papule corresponded to a seborrhoeic keratosis (not shown). There was no pigmentary incontinence, melanophages, inflammatory cells or fibrosis in the underlying dermis. A full body CT scan at this time did not reveal any visceral metastasis, while urine analysis ruled out melanuria. Regular clinical and paraclinical follow‐up was pursued, allowing the detection in 2010 of a right axillar metastatic lymph node recurrence, treated with lymph node dissection. Since this date, he has remained recurrence free.