Post-mortem tissue sampling using computed tomography guidance

PURPOSE: Currently, in forensic medicine cross-sectional imaging gains recognition and a wide use as a non-invasive examination approach. Today, computed tomography (CT) or magnetic resonance imaging that are available for patients are unable to provide tissue information on the cellular level in a non-invasive manner and also diatom detection, DNA, bacteriological, chemical toxicological and other specific tissue analyses are impossible using radiology. We hypothesised that post-mortem minimally invasive tissue sampling using needle biopsies under CT guidance might significantly enhance the potential of virtual autopsy. The purpose of this study was to test the use of a clinically approved biopsy needle for minimally invasive post-mortem sampling of tissue specimens under CT guidance. MATERIAL AND METHODS: ACN III biopsy core needles 14 gauge x 160 mm with automatic pistol device were used on three bodies dedicated to research from the local anatomical institute. Tissue probes from the brain, heart, lung, liver, spleen, kidney and muscle tissue were obtained under CT fluoroscopy. RESULTS: CT fluoroscopy enabled accurate placement of the needle within the organs and tissues. The needles allowed for sampling of tissue probes with a mean width of 1.7 mm (range 1.2-2 mm) and the maximal length of 20 mm at all locations. The obtained tissue specimens were of sufficient size and adequate quality for histological analysis. CONCLUSION: Our results indicate that, similar to the clinical experience but in many more organs, the tissue specimens obtained using the clinically approved biopsy needle are of a sufficient size and adequate quality for a histological examination. We suggest that post-mortem biopsy using the ACN III needle under CT guidance may become a reliable method for targeted sampling of tissue probes of the body.

How reliable and safe is full-body low-dose radiography (LODOX Statscan) in detecting foreign bodies ingested by adults?

OBJECTIVE: Foreign body ingestion is common and potentially lethal. This study evaluates the use of low-dose Statscans (LODOX) in emergency departments. DESIGN: This comparative cross-sectional study retrospectively assessed 28 289 digital chest x-rays and 2301 LODOX scans performed between 2006 and 2010 at a tertiary emergency centre. The radiographic appearance, image quality and location of ingested foreign bodies were evaluated in standard digital chest and LODOX radiography. The mean irradiation (μSv) and cumulative mean radiation dose per patient with the ingested foreign body were calculated according to literature-based data, together with the sensitivity and specificity for each modality. RESULTS: A total of 62 foreign bodies were detected in 39 patients, of whom 19 were investigated with LODOX and 20 with conventional digital chest radiography. Thirty-three foreign bodies were located in the two upper abdominal quadrants, 21 in the lower quadrants-which are not visible on conventional digital chest radiography-seven in the oesophagus and one in the bronchial system. The sensitivity and specificity of digital chest radiography were 44.4% and 94.1%, respectively, and for the LODOX Statscan 90% and 100%, respectively. The calculated mean radiation dose for LODOX investigations was 184 μS, compared with 524 μS for digital chest radiography. CONCLUSIONS: LODOX Statscan is superior to digital chest radiography in the diagnostic work-up of ingested foreign bodies because it makes it possible to enlarge the field of view to the entire body, has higher sensitivity and specificity, and reduces the radiation dose by 65%.

Virtopsy: postmortem imaging of laryngeal foreign bodies

CONTEXT: Death from corpora aliena in the larynx is a well-known entity in forensic pathology. The correct diagnosis of this cause of death is difficult without an autopsy, and misdiagnoses by external examination alone are common. OBJECTIVE: To determine the postmortem usefulness of modern imaging techniques in the diagnosis of foreign bodies in the larynx, multislice computed tomography, magnetic resonance imaging, and postmortem full-body computed tomography-angiography were performed. DESIGN: Three decedents with a suspected foreign body in the larynx underwent the 3 different imaging techniques before medicolegal autopsy. RESULTS: Multislice computed tomography has a high diagnostic value in the noninvasive localization of a foreign body and abnormalities in the larynx. The differentiation between neoplasm or soft foreign bodies (eg, food) is possible, but difficult, by unenhanced multislice computed tomography. By magnetic resonance imaging, the discrimination of the soft tissue structures and soft foreign bodies is much easier. In addition to the postmortem multislice computed tomography, the combination with postmortem angiography will increase the diagnostic value. CONCLUSIONS: Postmortem, cross-sectional imaging methods are highly valuable procedures for the noninvasive detection of corpora aliena in the larynx.

Visual perception in Parkinson disease dementia and dementia with Lewy bodies

OBJECTIVE To quantify visual discrimination, space-motion, and object-form perception in patients with Parkinson disease dementia (PDD), dementia with Lewy bodies (DLB), and Alzheimer disease (AD). METHODS The authors used a cross-sectional study to compare three demented groups matched for overall dementia severity (PDD: n = 24; DLB: n = 20; AD: n = 23) and two age-, sex-, and education-matched control groups (PD: n = 24, normal controls [NC]: n = 25). RESULTS Visual perception was globally more impaired in PDD than in nondemented controls (NC, PD), but was not different from DLB. Compared to AD, PDD patients tended to perform worse in all perceptual scores. Visual perception of patients with PDD/DLB and visual hallucinations was significantly worse than in patients without hallucinations. CONCLUSIONS Parkinson disease dementia (PDD) is associated with profound visuoperceptual impairments similar to dementia with Lewy bodies (DLB) but different from Alzheimer disease. These findings are consistent with previous neuroimaging studies reporting hypoactivity in cortical areas involved in visual processing in PDD and DLB.

Finite element analysis predicts experimental failure patterns in vertebral bodies loaded via intervertebral discs up to large deformation

Vertebral compression fracture is a common medical problem in osteoporotic individuals. The quantitative computed tomography (QCT)-based finite element (FE) method may be used to predict vertebral strength in vivo, but needs to be validated with experimental tests. The aim of this study was to validate a nonlinear anatomy specific QCT-based FE model by using a novel testing setup. Thirty-seven human thoracolumbar vertebral bone slices were prepared by removing cortical endplates and posterior elements. The slices were scanned with QCT and the volumetric bone mineral density (vBMD) was computed with the standard clinical approach. A novel experimental setup was designed to induce a realistic failure in the vertebral slices in vitro. Rotation of the loading plate was allowed by means of a ball joint. To minimize device compliance, the specimen deformation was measured directly on the loading plate with three sensors. A nonlinear FE model was generated from the calibrated QCT images and computed vertebral stiffness and strength were compared to those measured during the experiments. In agreement with clinical observations, most of the vertebrae underwent an anterior wedge-shape fracture. As expected, the FE method predicted both stiffness and strength better than vBMD (R2 improved from 0.27 to 0.49 and from 0.34 to 0.79, respectively). Despite the lack of fitting parameters, the linear regression of the FE prediction for strength was close to the 1:1 relation (slope and intercept close to one (0.86 kN) and to zero (0.72 kN), respectively). In conclusion, a nonlinear FE model was successfully validated through a novel experimental technique for generating wedge-shape fractures in human thoracolumbar vertebrae.

All-sky Meteor Orbit System AMOS and preliminary analysis of three unusual meteor showers

All-sky Meteor Orbit System (AMOS) is a semi-autonomous video observatory for detection of transient events on the sky, mostly the meteors. Its hardware and software development and permanent placement on several locations in Slovakia allowed the establishment of Slovak Video Meteor Network (SVMN) monitoring meteor activity above the Central Europe. The data reduction, orbital determination and additional results from AMOS cameras–the SVMN database– as well as from observational expeditions on Canary Islands and in Canada provided dynamical and physical data for better understanding of mutual connections between parent bodies of asteroids and comets and their meteoroid streams. We present preliminary results on exceptional and rare meteor streams such as September ε Perseids (SPE) originated from unknown long periodic comet on a retrograde orbit, suspected asteroidal meteor stream of April α Comae Berenicids (ACO) in the orbit of meteorites Příbram and Neuschwanstein and newly observed meteor stream Camelopardalids (CAM) originated from Jupiter family comet 209P/Linear.