Computer Tomography
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2021 ◽  
Vol 1 (2) ◽  
pp. 189-200
Author(s):  
Julia Gerasimova ◽  
Bernhard Ruthensteiner ◽  
Andreas Beck

High-resolution X-ray computer tomography (microCT) is a well-established technique to analyse three-dimensional microstructures in 3D non-destructive imaging. The non-destructive three-dimensional analysis of lichens is interesting for many reasons. The examination of hidden structural characteristics can, e.g., provide information on internal structural features (form and distribution of fungal-supporting tissue/hypha), gas-filled spaces within the thallus (important for gas exchange and, thus, physiological processes), or yield information on the symbiont composition within the lichen, e.g., the localisation and amount of additional cyanobacteria in cephalodia. Here, we present the possibilities and current limitations for applying conventional laboratory-based high-resolution X-ray computer tomography to analyse lichens. MicroCT allows the virtual 3D reconstruction of a sample from 2D X-ray projections and is helpful for the non-destructive analysis of structural characters or the symbiont composition of lichens. By means of a quantitative 3D image analysis, the volume of internal cephalodia is determined for Lobaria pulmonaria and the external cephalodia of Peltigera leucophlebia. Nevertheless, the need for higher-resolution tomography for more detailed studies is emphasised. Particular challenges are the large sizes of datasets to be analysed and the high variability of the lichen microstructures.


2021 ◽  
Vol 8 (2) ◽  
pp. 72-74
Author(s):  
Mukul Sharma ◽  
Biplab Rath ◽  
Kimi Soumya Padhi ◽  
Maharshi Ranjan Sahoo ◽  
Manas Ranjan Sahu

Since their origin from China, firearms have gained popularity because of easy techniques and effectiveness. This has made them a popular choice of homicide and suicide. Here we present a case where the death is by shooting from a pistol from a point blank range. Bullet takes a crazy course once entered inside the body due to the variation in fluid flow, densities of various organs and air filled cavities. It becomes all the more difficult if there is surgical manipulation. Radiographs were done to have an idea about the place of lodgment of bullet in body. The advent of various radiographic methods like computer tomography and radiography have made the job of autopsy surgeon a little bit easier.


Folia Medica ◽  
2021 ◽  
Vol 63 (3) ◽  
pp. 443-447
Author(s):  
Alexey V. Shabunin ◽  
Dmitry N. Grekov ◽  
Ivan N. Lebedinsky ◽  
Andrey I. Evsikov ◽  
Serghei Covantev ◽  
...  

Adrenal gland incidentaloma (incidental – sudden, accidental) is a mass of the adrenal gland(s), accidentally detected by an instru-mental examination conducted for other reasons. The frequency of detection of this pathology based on computer tomography of the abdominal organs is 0.5%–2%. In most cases, the mass is represented by adrenocortical adenomas without hormonal secretion. It is an extremely rare case (less than 1% of all cases) when the adrenal incidentaloma is a primary adrenal lymphoma, which accounts for 1% of all non-Hodgkin lymphomas and 3% of all extranodal lymphomas with a few cases reported in the literature. In our article, we present a case of left adrenal incidentaloma of the adrenal gland, which, during further observation and examination, increased in size, which was the reason for performing laparoscopic adrenalectomy. According to the results of the histological examination, the mass turned out to be diffuse large B-cell lymphoma.


2021 ◽  
pp. 50-57
Author(s):  
Sara Assadi ◽  
Latif Rahman ◽  
Mark Kong ◽  
Sukaina Asad

A 38-year-old woman presented to the emergency department with recurrent severe headaches. Although initial computer tomography (CT) brain imaging was unremarkable, a later CT venogram demonstrated a small subarachnoid haemorrhage. Magnetic resonance angiogram (MRA) brain imaging subsequently confirmed reversible cerebral vasoconstriction syndrome (RCVS). In the acute setting, RCVS rarely falls into a differential diagnosis for headache presentations, as in this case. The radiological variability can make diagnosis of RCVS challenging. However, there are clinical consistencies that can aid physicians into accurately diagnosing RCVS. A thorough history, including a medication history, can help identify potential triggers of RCVS. As in this case, the combination of commonly used drugs, including antihistamines, provides a plausible trigger for RCVS. The direct vasoactive role of antihistamines is unclear, yet there is suggestion for its ability to potentiate the vasoactive action of other drugs. In this case we propose a causal relationship between the use of antihistamine and the development of RCVS.


Biophysica ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 269-278
Author(s):  
Diana V. Prikule ◽  
Vladimir I. Kukushkin ◽  
Aleksandr V. Mitronin ◽  
Vladislav F. Prikuls

In vitro and in vivo methods of Raman spectroscopy have been developed to assess the degree of mineralization of the enamel of different functional groups. This article presents comparative studies that were carried out using scanning Raman microspectroscopy with various sources of laser excitation with wavelengths of 532, 785, and 1064 nm. It is shown that the intensity of Raman scattering of enamel can be a measure of its thickness. The obtained dependence of the Raman scattering intensity on the distance from the incisal edge is in good agreement with the literature data, where two independent methods (computer tomography and electron microscopy) are used to determine the enamel thickness values. The proposed methods can be considered as potential quantitative methods for express diagnostics of the state of tooth enamel in vivo.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252599
Author(s):  
Milena Adina Man ◽  
Ruxandra-Mioara Rajnoveanu ◽  
Nicoleta Stefania Motoc ◽  
Cosmina Ioana Bondor ◽  
Ana Florica Chis ◽  
...  

Inflammation has an important role in the progression of various viral pneumonia, including COVID-19. Circulating biomarkers that can evaluate inflammation and immune status are potentially useful in diagnosing and prognosis of COVID-19 patients. Even more so when they are a part of the routine evaluation, chest CT could have even higher diagnostic accuracy than RT-PCT alone in a suggestive clinical context. This study aims to evaluate the correlation between inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR), platelets-to-lymphocytes ratio (PLR), and eosinophils with the severity of CT lesions in patients with COVID-19. The second objective was to seek a statically significant cut-off value for NLR and PLR that could suggest COVID-19. Correlation of both NLR and PLR with already established inflammatory markers such as CRP, ESR, and those specific for COVID-19 (ferritin, D-dimers, and eosinophils) were also evaluated. One hundred forty-nine patients with confirmed COVID-19 disease and 149 age-matched control were evaluated through blood tests, and COVID-19 patients had thorax CT performed. Both NLR and PLR correlated positive chest CT scan severity. Both NLR and PLR correlated positive chest CT scan severity. When NLR value is below 5.04, CT score is lower than 3 with a probability of 94%, while when NLR is higher than 5.04, the probability of severe CT changes is only 50%. For eosinophils, a value of 0.35% corresponds to chest CT severity of 2 (Se = 0.88, Sp = 0.43, AUC = 0.661, 95% CI (0.544; 0.779), p = 0.021. NLR and PLR had significantly higher values in COVID-19 patients. In our study a NLR = 2.90 and PLR = 186 have a good specificity (0.89, p = 0.001, respectively 0.92, p<0.001). Higher levels in NLR, PLR should prompt the clinician to prescribe a thorax CT as it could reveal important lesions that could influence the patient’s future management.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Amir Hosseini ◽  
Maryam Soleimannejad ◽  
Amir Javadi ◽  
Amirmohammad Kazemifar ◽  
Shahram Darabi ◽  
...  

2021 ◽  
Vol 11 (12) ◽  
pp. 5682
Author(s):  
Giacomo D’Angeli ◽  
Francesca Zara ◽  
Alessio Belloni ◽  
Francesco Maria D’Angeli ◽  
Michele Dello Spedale Venti ◽  
...  

The dental follicle (DF) is the tissue that surrounds the crown of the developing tooth. In X-ray, images it appears as a radiolucent area. The removal of an impacted mandibular third molar is a common procedure in oral surgery. The radiographic evidence of pathology, commonly defined as a pericoronal radiolucency measuring at least mm 2.5 mm in any dimension, is accepted for the extraction of impacted mandibular third molars. Mesioangular impactions are usually more closely placed to the inferior alveolar canal, and the use of cone beam computer tomography (CBCT) before the removal of impacted mandibular third molars has been reported to be appropriate in these cases. The aim of this study was to evaluate the microscopic features of radiographically normal DFs associated with mesioangular impacted mandibular third molars examined through CBCT. Thirteen mesioangular impacted third molars from ten patients (5 males and 5 females, mean age ± SD: 15.1 ± 1.66) with a maximum width of the DF <2.5 mm, as digitally established by CBCT, were included in this study. All the DFs associated with the removed third molars were examined histologically through the analysis of different variables. The mean (±SD) and range of the maximum width of the DFs were 1.35 (±0.47) mm and 0.71–2.21 mm, respectively. Nine (69.23%) DFs showed odontogenic remnants, five (38.46%) showed focal squamous metaplasia and eight (61.53%) mild mesenchymal myxoid degeneration. The maximum width of the DF failed to show any significant correlation with all the histological variables considered in this study. Aware of the limited number of patients included in this study, the histo-radiographic correlation in our case series confirm data in the literature, according to which normal pericoronal imaging may be associated with DF tissue changes/variations that in turn are potentially associated with the development of pathologies including odontogenic cysts and tumors. Whether these changes/variations are enough to make prophylactic germectomy of impacted third molars the standard by themselves remains to be established. However, they require accurate correlations with the radiographic data for the appropriate histologic assessment of a DF.


2021 ◽  
Author(s):  
Erik Rohkohl ◽  
Mathias Kraken ◽  
Malte Schönemann ◽  
Alexander Breuer ◽  
Christoph Herrmann

Abstract Battery cells are central components of electric vehicles. It is important for automotive OEM to utilize high quality battery cells to ensure high performance and safety of their vehicles. This results in the high demand for quality control measures and inspection methods in battery cell manufacturing. Particular relevant features of battery cells are welds for the internal electrical contact. Failures of these welds are often the cause for battery defects in the field and scrap during production. Consequently, there is a strong need to evaluate all welds during manufacturing. However, there is no established method which allows a quick, comprehensive, and cheap inline measurement of the weld quality. This paper presents a new eddy current based method for non-destructive testing of seam welds as well as a machine learning approach for its validation. A deep learning model has been trained on eddy current measurements to predict results from a reference inspection method, in this case computer tomography. The results prove that eddy current measurements can be used to replicate data acquired by computer tomography which means that eddy current measurements could be a suitable candidate for non-destructive 100% inline inspection. More general, this study demonstrates how machine learning may help to get deeper insights into measurement results and to validate new non-destructive testing techniques whose detailed features are yet unknown. The presented evaluation method enables understanding the capabilities and the limits of a new technique and to extract hidden features from the data. Furthermore, the usage of machine learning allows to perform these evaluations on artificial product samples with specific defects and features, which avoids the costly production physical samples.


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