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1.
Radiol Case Rep ; 19(7): 2895-2897, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38706814

RESUMO

Posterior Reversible Encephalopathy Syndrome (PRES) is a radio-clinical entity associating reversible damage of the central nervous system and typical brain imaging. The clinical context is often suggestive with, in half of cases, the use of vasoactive substances (cannabis, antidepressants, nasal decongestants) and/or postpartum. The etiologies are dominated by hypertensive encephalopathy, preeclampsia, eclampsia, immunosuppressive therapies, and systemic diseases. We report a case of posterior encephalopathy syndrome occurring in a young female without hypertension. It was about a 40-year-old female without hypertension underlying condition, received at the emergency department for headaches and generalized tonic-clonic seizures. The physical examination was unremarkable, and her blood pressure was 130/70 mm Hg. CT scan revealed bilateral white matter hypodensity in the posterior occipital regions and a right frontal subarachnoid hemorrhage. There was no aneurysmal malformation of the polygon of Willis and no cerebral thrombophlebitis. Brain MRI showed T2 and FLAIR hypersignal areas in the occipital and frontal cortico-subcortical regions, with no diffusion signal abnormalities or contrast enhancement, and a right frontal subarachnoid hemorrhagic lesion with no other impairment. The diagnosis of reversible posterior encephalopathy syndrome was made up, and the outcome was favorable under treatment. Posterior reversible encephalopathy syndrome is an uncommon but probably underdiagnosed condition. Hypertensive encephalopathy is the most common etiology. However, there would be cases of PRES without hypertension as shown in this observation.

2.
Urol Case Rep ; 53: 102674, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38414816

RESUMO

Cystic dysplasia of the testis is characterized by the presence of multiple cysts within the testicular parenchyma. It is a rare benign tumor. It is often accompanied by kidney malformations. There is no consensus on treatment. We report here the case of testicular dysplasia revealed by a torsion of the spermatic cord in an adult. The diagnosis of cystic dysplasia of the testis was made intraoperatively and confirmed by pathology. An orchiectomy was performed. Serum testicular cancer markers were normal postoperatively.

3.
Ann Med Surg (Lond) ; 86(1): 477-480, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38222728

RESUMO

Background: Anterior dislocation of the shoulder associated with a diaphyseal fracture of the ipsilateral humerus is a rare and controversial occurrence, with very few cases reported in the literature. Case presentation: We present a case of a 39-year-old right-handed driver who presented with an anterior dislocation of the shoulder associated with a diaphyseal fracture of the ipsilateral humerus following a road traffic accident. The lateral approach to the fracture allowed us to use two forceps to gain a good grip on the proximal fragment and perform the maneuver to reduce the dislocation. The fracture was reduced and fixed with a molded Lecestre-type plate. Conclusion: In this case, we employed the approach of initially reducing the shoulder dislocation with forceps, followed by osteosynthesis of the humeral fracture. The functional results were excellent after 6 months.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38194390

RESUMO

Automatic identification of visual learning style in real time using raw electroencephalogram (EEG) is challenging. In this work, inspired by the powerful abilities of deep learning techniques, deep learning-based models are proposed to learn high-level feature representation for EEG visual learning identification. Existing computer-aided systems that use electroencephalograms and machine learning can reasonably assess learning styles. Despite their potential, offline processing is often necessary to eliminate artifacts and extract features, making these methods unsuitable for real-time applications. The dataset was chosen with 34 healthy subjects to measure their EEG signals during resting states (eyes open and eyes closed) and while performing learning tasks. The subjects displayed no prior knowledge of the animated educational content presented in video format. The paper presents an analysis of EEG signals measured during a resting state with closed eyes using three deep learning techniques: Long-term, short-term memory (LSTM), Long-term, short-term memory-convolutional neural network (LSTM-CNN), and Long-term, short-term memory-Fully convolutional neural network (LSTM-FCNN). The chosen techniques were based on their suitability for real-time applications with varying data lengths and the need for less computational time. The optimization of hypertuning parameters has enabled the identification of visual learners through the implementation of three techniques. LSTM-CNN technique has the highest average accuracy of 94%, a sensitivity of 80%, a specificity of 92%, and an F1 score of 94% when identifying the visual learning style of the student out of all three techniques. This research has shown that the most effective method is the deep learning-based LSTM-CNN technique, which accurately identifies a student's visual learning style.


Assuntos
Aprendizado Profundo , Humanos , Redes Neurais de Computação , Eletroencefalografia/métodos , Aprendizado de Máquina , Artefatos
5.
Artigo em Inglês | MEDLINE | ID: mdl-38082937

RESUMO

It has been more than three decades since researchers began investigating functional near-infrared spectroscopy (fNIRs) and its applications with near-infrared light for use in both clinical and pre-clinical settings. In order to increase the accuracy of fNIRs of complex tissue structures, it is necessary to create more advanced image reconstruction methods. Real fNIRs data have been used to develop an implementation of the L1-Norm approach for tackling the inverse problem in this work. The Monte Carlo (MC) simulation is used to construct the sensitivity matrix for this research. Finally, a numerical algorithm for the L1-Norm approach of image reconstruction is developed and implemented in MATLAB to aid in the process. The results showed good agreement with the actual fNIRs data.


Assuntos
Algoritmos , Espectroscopia de Luz Próxima ao Infravermelho , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Simulação por Computador , Processamento de Imagem Assistida por Computador/métodos
6.
Radiol Case Rep ; 18(12): 4458-4460, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37860781

RESUMO

Cerebral amyloid angiopathy (CAA) is an age-related cerebral microangiopathy characterized by the accumulation of amyloid-beta peptide in the wall of leptomeningeal arteries and cortical vessels. Diagnosis of sporadic amyloid angiopathy is most often made in elderly patient with lobar hematoma. We report a case of a 68-year-old female who had minimal head injury. Cerebral CT showed a right cerebellar hematoma. Follow-up MRI after 4 months showed signs of cerebral amyloid angiopathy. Through this observation, we describe the MRI semiology that helps make the diagnosis of cerebral amyloid angiopathy.

7.
Radiol Case Rep ; 18(8): 2545-2548, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37255699

RESUMO

Atypical fibromuscular dysplasia of the bulb or carotid web is a nonatheromatous pathology more common in African and African-American populations. It is implicated in the occurrence of cerebral infarcts of unknown causes. Its diagnosis is made by angio-CT of the supra-aortic trunks and is characterized by a defect in the posterior wall of the bulb. Treatment with antiplatelet agents prevents the occurrence of stroke, but radical treatment remains surgical and endovascular. We report 2 observations of carotid web diagnosed and medically managed at the regional hospital of Saint Louis.

8.
Clin Case Rep ; 11(4): e7268, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37102094

RESUMO

Key Clinical Message: Weber's syndrome revealing a Percheron artery infarction is a rare clinical occurrence. Its diagnosis requires careful clinical examination and brain MRI, which is the gold standard for diagnosis. If this is not available, combined cerebral CT scan with a CT angiography of supra-aortic arteries may be useful for the diagnosis. Abstract: Percheron's artery (PA) occlusion is an uncommon type of stroke involving paramedian thalamus and/or midbrain infarction. It accounts for 4%-18% of all thalamic infarcts and 0.1%-2% of all strokes. Its clinical manifestations are variable and its mode of presentation as Weber's syndrome is exceptional due to the unusual clinical presentation.

9.
Radiol Case Rep ; 18(5): 1772-1774, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36926538

RESUMO

Pylephlebitis is a complication of intra-abdominal infections. Its occurrence during cholecystitis is a rare situation. We report the case of a 43-year-old female patient who presented with septic thrombosis of the right portal branch following acute calculous cholecystitis diagnosed on abdominal CT. The clinical evolution was favorable under antibiotic therapy and a cholecystectomy was scheduled.

10.
Comput Biol Med ; 153: 106429, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36587570

RESUMO

A brain tumor is a dynamic system in which cells develop rapidly and abnormally, as is the case with most cancers. Cancer develops in the brain or inside the skull when aberrant and odd cells proliferate in the brain. By depriving the healthy cells of leisure, nutrition, and oxygen, these aberrant cells eventually cause the healthy cells to perish. This article investigated the development of glioma cells in treating brain tumors. Mathematically, reaction-diffusion models have been developed for brain glioma growth to quantify the diffusion and proliferation of the tumor cells within brain tissues. This study presents the formulation the two-stage successive over-relaxation (TSSOR) algorithm based on the finite difference approximation for solving the treated brain glioma model to predict glioma cells in treating the brain tumor. Also, the performance of TSSOR method is compared to the Gauss-Seidel (GS) and two-stage Gauss-Seidel (TSGS) methods in terms of the number of iterations, the amount of time it takes to process the data, and the rate at which glioma cells grow the fastest. The implementation of the TSSOR, TSGS, and GS methods predicts the growth of tumor cells under the treatment protocol. The results show that the number of glioma cells decreased initially and then increased gradually by the next day. The computational complexity analysis is also used and concludes that the TSSOR method is faster compared to the TSGS and GS methods. According to the results of the treated glioma development model, the TSSOR approach reduced the number of iterations by between 8.0 and 71.95%. In terms of computational time, the TSSOR approach is around 1.18-76.34% faster than the TSGS and GS methods.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Neoplasias Encefálicas/diagnóstico por imagem , Algoritmos , Encéfalo/patologia
11.
Comput Methods Programs Biomed ; 228: 107242, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36423484

RESUMO

BACKGROUND AND OBJECTIVE: Brain connectivity plays a pivotal role in understanding the brain's information processing functions by providing various details including magnitude, direction, and temporal dynamics of inter-neuron connections. While the connectivity may be classified as structural, functional and causal, a complete in-vivo directional analysis is guaranteed by the latter and is referred to as Effective Connectivity (EC). Two most widely used EC techniques are Directed Transfer Function (DTF) and Partial Directed Coherence (PDC) which are based on multivariate autoregressive models. The drawbacks of these techniques include poor frequency resolution and the requirement for experimental approach to determine signal normalization and thresholding techniques in identifying significant connectivities between multivariate sources. METHODS: In this study, the drawbacks of DTF and PDC are addressed by proposing a novel technique, termed as Efficient Effective Connectivity (EEC), for the estimation of EC between multivariate sources using AR spectral estimation and Granger causality principle. In EEC, a linear predictive filter with AR coefficients obtained via multivariate EEG is used for signal prediction. This leads to the estimation of full-length signals which are then transformed into frequency domain by using Burg spectral estimation method. Furthermore, the newly proposed normalization method addressed the effect on each source in EEC using the sum of maximum connectivity values over the entire frequency range. Lastly, the proposed dynamic thresholding works by subtracting the first moment of causal effects of all the sources on one source from individual connections present for that source. RESULTS: The proposed method is evaluated using synthetic and real resting-state EEG of 46 healthy controls. A 3D-Convolutional Neural Network is trained and tested using the PDC and EEC samples. The result indicates that compared to PDC, EEC improves the EEG eye-state classification accuracy, sensitivity and specificity by 5.57%, 3.15% and 8.74%, respectively. CONCLUSION: Correct identification of all connections in synthetic data and improved resting-state classification performance using EEC proved that EEC gives better estimation of directed causality and indicates that it can be used for reliable understanding of brain mechanisms. Conclusively, the proposed technique may open up new research dimensions for clinical diagnosis of mental disorders.


Assuntos
Encéfalo , Humanos , Encéfalo/diagnóstico por imagem
12.
Radiol Case Rep ; 18(1): 243-245, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36340222

RESUMO

Pylephlebitis is a thrombotic occlusion of the portal vein or its branches secondary to infection in regions that drain to the portal venous system. Clinical presentation is often atypical, and patients may initially present with non-specific abdominal symptoms. We report a case of pylephlebitis secondary to inflammatory colitis depicted by CT scan in a 35-year-old female admitted for acute abdominal pain associated with vomiting and fever.

13.
Bioengineering (Basel) ; 9(12)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36550932

RESUMO

Communication, neuro-prosthetics, and environmental control are just a few applications for disabled persons who use robots and manipulators that use brain-computer interface (BCI) systems. The brain's motor imagery (MI) signal is an essential input for a brain-related task in BCI applications. Due to their noninvasive, portability, and cost-effectiveness, electroencephalography (EEG) signals are the most widely used input in BCI systems. The EEG data are often collected from more than 100 different locations in the brain; channel selection techniques are critical for selecting the optimum channels for a given application. However, when analyzing EEG data, the principal purpose of channel selection is to reduce computational complexity, improve classification accuracy by avoiding overfitting, and reduce setup time. Several channel selection assessment algorithms, both with and without classification-based methods, extracted appropriate channel subsets using defined criteria. Therefore, based on the exhaustive analysis of the EEG channel selection, this manuscript analyses several existing studies to reduce the number of noisy channels and improve system performance. We review several existing works to find the most promising MI-based EEG channel selection algorithms and associated classification methodologies on various datasets. Moreover, we focus on channel selection methods that choose fewer channels with great precision. Finally, our main finding is that a smaller channel set, typically 10-30% of total channels, provided excellent performance compared to other existing studies.

14.
Ann Med Surg (Lond) ; 82: 104716, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36268386

RESUMO

Introduction and importance: Parry-Romberg syndrome (PRS) is a rare clinical entity characterized by progressive atrophy of the hemifacial region, occasionally associated with systemic manifestations. The presence of facial muscles spasms is exceptional. Case presentation: We report the case of a young woman who presented with progressive atrophy of the right hemiface associated with vitiligo and facial muscles spasms. The diagnosis of Parry Romberg syndrome was retained. Electromyogram showed an intermittent motor unit potential. Cerebral MRI showed atrophy of the muscle and subcutaneous fat of the right hemiface. She received corticosteroid in combination with botulinum toxin injection, which stopped the spasms. Clinical discussion: It is a rare condition with a poorly understood etiology, which is responsible for the delay in diagnosis often noted. The association of this syndrome with neurological signs is exceptional and rarely described in the literature. Injection of botulinum toxin associated with corticosteroids can stop the spasms but only surgery can reduce the facial deformities. Conclusion: Parry-Romberg syndrome is a rare disease, more frequent in women. It poses a real diagnostic problem and its treatment is poorly codified.

15.
Radiol Case Rep ; 17(11): 4120-4122, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36072962

RESUMO

Intracranial aneurysms are focal dilations of an intracranial artery. They can be discovered incidentally, during a hemorrhagic stroke or subarachnoid hemorrhage, but it is rare for it to be detected after an ischemic stroke. The prevalence of the association between symptomatic carotid occlusion or stenosis and intracranial aneurysms is estimated to be 6.3%. We report the case of a patient hospitalized for the management of a stroke in whom investigations had revealed the coexistence of right carotid occlusion and multiple aneurysms in the right middle cerebral artery. The diagnosis was made by CT angiography of supra-aortic trunks.

16.
Comput Methods Programs Biomed ; 221: 106853, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35561439

RESUMO

BACKGROUND AND OBJECTIVE: Medical imaging techniques are widely employed in disease diagnosis and treatment. A readily available medical report can be a useful tool in assisting an expert for investigating the patient's health. A radiologist can benefit from an automatic medical image to radiological report translation system while preparing a final report. Previous attempts on automatic medical report generation task includes image captioning algorithms without taking domain-specific visual and textual contents into account, thus arises the question about credibility of generated report. METHODS: In this work, a novel Adaptive Multilevel Multi-Attention (AMLMA) approach is proposed by offering domain-specific visual-textual knowledge to generate a thorough and believable radiological report for any view of a human chest X-ray image. The proposed approach leverages the encoder-decoder framework incorporated with multiple adaptive attention mechanisms. The potential of a convolutional neural network (CNN) with residual attention module (RAM) is demonstrated as a strong visual encoder for multi-label abnormality detection. The multilevel visual features (local and global) are extracted from proposed visual encoder to retrieve regional-level and abstract-level radiology-based semantic information. The Word2Vec and FastText word embeddings are trained on medical reports to acquire radiological knowledge and further used as textual encoders, feeding as input to Bi-directional Long Short Term Memory (Bi-LSTM) network to learn the co-relationship between medical terminologies in radiological reports. The AMLMA employs a weighted multilevel association of adaptive visual-semantic attention and visual-based linguistic attention mechanisms. This association of adaptive attention is exploited as a decoder and produces significant improvements in the report generation task. RESULTS: The proposed approach is evaluated on a publicly available Indiana University chest X-ray (IU-CXR) dataset. The CNN with RAM shows the significant improvement in recall (0.4423), precision (0.1803) and F1-score (0.2551) for prediction of multiple abnormalities in X-ray image. The results of language generation metrics for proposed variants were acquired using the COCO-caption evaluation Application Program Interface (API). The trained embeddings with AMLMA model generates the convincing radiology report and outperform state-of-the-art (SOTA) approaches with high evaluation metrics scores for Bleu-4 (0.172), Meteor (0.247), Rouge_L (0.376) and CIDEr (0.381). In addition, a new "Unique Index" (UI) statistic is introduced to highlight the model's ability for generating unique reports. CONCLUSION: The overall architecture aids to the understanding of various X-ray image views and generating the relevant normal and abnormal radiography statements. The proposed model is emphasized on multi-level visual-textual knowledge with adaptive attention mechanism to balance visual and linguistic information for the generation of admissible radiology report.


Assuntos
Algoritmos , Redes Neurais de Computação , Humanos , Radiografia , Semântica , Software
17.
Radiol Case Rep ; 17(4): 1225-1227, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35169433

RESUMO

Pyonephrosis is a suppurative infection of the kidney caused by ureteral obstruction. It can lead to kidney failure, septic shock, and death. Thus, it requires prompt assessment and appropriate management. We report a case of a 63-year-old male with giant pyonephrosis contained 10 liters of pus and spontaneously ruptured in the adjacent muscles. This clinical case illustrates the value of computed tomography scan in the diagnosis and management of an uncommon upper urinary tract infection and its complications.

18.
Mali Med ; 37(2): 44-52, 2022.
Artigo em Francês | MEDLINE | ID: mdl-38506213

RESUMO

OBJECTIVE: The objective of this work was to study the place of ultrasound in the positive diagnosis, etiology and choice of the therapeutic modality of acute intestinal intussusception. MATERIAL AND METHODS: This was a retrospective, descriptive, cross-sectional, multicenterstudy, carried out over a period of 18 months (January 1, 2016 to June 30, 2017) on 45 patient files collected in the radiologydepartments (Aristide Le Dantec and Albert Royer). Were included all patients aged less than 14 years, admitted with acute abdominal pain, whose diagnosis of IIA was retained on ultrasound. Pneumatic disinvagination was performed in patients without signs of severity. We studied the time of management, the ultrasound aspects of the invagination puddles, the therapeutic choice but also the radiosurgical concordance and the factors of failure of the pneumatic enema. Statistical analysis was done by SPSS version 21.0 software. RESULTS: Ultrasound was used to make the diagnosis of IIA in 43 cases (95.5%). The sonographic characteristics were as follows: 27.9% of the IIA were located in the right hypochondrium, 19 cases were ileo-caecal, 10 (22.2%) ileo-caeco-colic, 9 (20%) ileo-colic, 4 (8.9%) colo-colic and one (2.2%) gregelic; 44 cases were idiopathic and one case was a Meckel's diverticulum The management time was less than 48 hours in 34% of cases and 66% more than 48 hours. Pneumatic reduction was performed in 18 cases (40%), with success in 14 cases (77.8%) and one case of pneumoperitoneum complication. Surgery was performed in 31 cases (68.8%). The sensitivity and specificity of ultrasound in the diagnosis of signs of severity were 77.7% and 78.9%. Good agreement was observed between the results of the Doppler ultrasound and the intraoperative findings. Ultrasound parameters associated with failed pneumatic deinvagination were: outer cylinder thickness ≥10 mm, adenopathy at the level of the small-axis bladder ≥10 mm, effusion in the bladder, and hypovascularization of the bladder head. Hypovascularization of the boudin head was the only factor independently associated with failure of pneumatic disinvagination. CONCLUSION: Ultrasound is a powerful imaging modality in the positive diagnosis, etiology, severity and therapeutic choice of IIA.


OBJECTIF: L'objectif de ce travail était d'étudier la place de l'échographie dans le diagnostic positif, étiologique et le choix de la modalité thérapeutique des invaginations intestinales aigues. MATÉRIEL ET MÉTHODES: Il s'agissait d'une étude rétrospective, descriptive, transversale, multicentrique, réalisée sur une période de 18 mois (01 Janvier 2016 au 30 Juin 2017) portant sur 45 dossiers de patients colligés dans les services de radiologie (Aristide Le Dantec et Albert Royer). Ont été inclus tous les patients âgés de moins de 14 ans, admis dans un tableau de douleur abdominale aigue, dont le diagnostic d'IIA était retenu à l'échographie. Une désinvagination pneumatique a été réalisée chez les patients sans signe de gravité.Nous avons étudié le délai de prise en charge, les aspects échographiques des boudins d'invagination, le choix thérapeutique mais aussi la concordance radio-chirurgicale et les facteurs d'échec du Lavement pneumatique. L'analyse statistique a été faite par le logiciel SPSS version 21.0. RÉSULTATS: L'échographie a permis de faire le diagnostic d'IIA dans 43 cas (95,5%). Les caractéristiques échographiques étaient les suivantes : 27,9% des IIA siégeaient au niveau de l'hypochondre droit, 19 cas de forme iléo-caecales, 10(22,2%) cas iléo-caeco-colique, 9(20%) casiléo-colique, 4(8,9%)cascolo-colique et un cas (2,2%) grélo-grélique; 44 cas idiopathiques et un cas de diverticule de Meckel. Le delais de prise en charge était inférieur à 48heures dans 34 % des cas et 66% supérieur à 48heures. Une réduction pneumatique a été réalisée dans 18 cas (40%), avec succès dans 14 cas (77,8%) et un cas de complication à type de pneumopéritoine. Une chirurgie était réalisée dans 31 cas (68,8%). La sensibilité et la spécificité de l'échographie dans le diagnostic des signes de gravité étaient de 77,7% et 78,9%. Une bonne concordance étaitobservée entre les résultats de l'écho-Doppler et les constatations peropératoires. Les paramètreséchographiquesassociés à un échec de la désinvagination pneumatique étaient : une épaisseur du cylindre externe ≥10 mm, des adénopathies au niveau du boudin de petit axe ≥10 mm, un épanchement dans le boudin et une hypovascularisation de la tête du boudin. L'hypovascularisation de la tête du boudin était le seul facteur indépendamment associe à l'échec de la désinvagination pneumatique. CONCLUSION: L'échographie est une modalité performante d'imagerie dans le diagnostic positif, étiologique, de gravité et dans le choix thérapeutique des IIA.

19.
Front Genet ; 12: 657999, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34868192

RESUMO

Background: Exposure to genotoxic stress such as radiation is an important public health issue affecting a large population. The necessity of analyzing cytogenetic effects of such exposure is related to the need to estimate the associated risk. Cytogenetic biological dosimetry is based on the relationship between the absorbed dose and the frequency of scored chromosomal aberrations. The influence of confounding factors on radiation response is a topical issue. The role of ethnicity is unclear. Here, we compared the dose-response curves obtained after irradiation of circulating lymphocytes from healthy donors of African and European ancestry. Materials and Methods: Blood samples from six Africans living in Africa, five Africans living in Europe, and five Caucasians living in Europe were exposed to various doses (0-4 Gy) of X-rays at a dose-rate of 0.1 Gy/min using an X-RAD320 irradiator. A validated cohort composed of 14 healthy Africans living in three African countries was included and blood samples were irradiated using the same protocols. Blood lymphocytes were cultured for 48 h and chromosomal aberrations scored during the first mitosis by telomere and centromere staining. The distribution of dicentric chromosomes was determined and the Kruskal-Wallis test was used to compare the dose-response curves of the two populations. Results: No spontaneous dicentric chromosomes were detected in African donors, thus establishing a very low background of unstable chromosomal aberrations relative to the European population. There was a significant difference in the dose response curves between native African and European donors. At 4 Gy, African donors showed a significantly lower frequency of dicentric chromosomes (p = 8.65 10-17), centric rings (p = 4.0310-14), and resulting double-strand-breaks (DSB) (p = 1.32 10-18) than European donors. In addition, a significant difference was found between African donors living in Europe and Africans living in Africa. Conclusion: This is the first study to demonstrate the important role of ethnic and environmental factors that may epigenetically influence the response to irradiation. It will be necessary to establish country-of-origen-specific dose response curves to practice precise and adequate biological dosimetry. This work opens new perspective for the comparison of treatments based on genotoxic agents, such as irradiation.

20.
Artif Intell Med ; 122: 102213, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34823835

RESUMO

Improving longevity is one of the greatest achievements in humanity. Because of this, the population is growing older, and the ubiquity of knee osteoarthritis (OA) is on the rise. Nonetheless, the understanding and ability to investigate potential precursors of knee OA have been impeded by time-consuming and laborious manual delineation processes which are prone to poor reproducibility. A method for automatic segmentation of the tibiofemoral joint using magnetic resonance imaging (MRI) is presented in this work. The proposed method utilizes a deeply supervised 2D-3D ensemble U-Net, which consists of foreground class oversampling, deep supervision loss branches, and Gaussian weighted softmax score aggregation. It was designed, optimized, and tested on 507 3D double echo steady-state (DESS) MR volumes using a two-fold cross-validation approach. A state-of-the-art segmentation accuracy measured as Dice similarity coefficient (DSC) for the femur bone (98.6 ± 0.27%), tibia bone (98.8 ± 0.31%), femoral cartilage (90.3 ± 2.89%), and tibial cartilage (86.7 ± 4.07%) is achieved. Notably, the proposed method yields sub-voxel accuracy for an average symmetric surface distance (ASD) less than 0.36 mm. The model performance is not affected by the severity of radiographic osteoarthritis (rOA) grades or the presence of pathophysiological changes. The proposed method offers an accurate segmentation with high time efficiency (~62 s) per 3D volume, which is well suited for efficient processing and analysis of the large prospective cohorts of the Osteoarthritis Initiative (OAI).


Assuntos
Cartilagem Articular , Osteoartrite do Joelho , Humanos , Processamento de Imagem Assistida por Computador/métodos , Articulação do Joelho/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Osteoartrite do Joelho/diagnóstico por imagem , Estudos Prospectivos , Reprodutibilidade dos Testes
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