Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Curr Med Imaging ; 19(5): 486-493, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35927895

RESUMO

BACKGROUND: Chest High-Resolution Computed Tomography (HRCT) is mandatory for patients with confirmed Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and a high Respiratory Rate (RR) because sublobar consolidation is the likely pathological pattern in addition to Ground Glass Opacities (GGOs). OBJECTIVE: The present study determined the correlation between the percentage extent of typical pulmonary lesions on HRCT, as a representation of severity, and the RR and peripheral oxygen saturation level (SpO2), as measured through pulse oximetry, in patients with Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)-confirmed primary (noncomplicated) SARS-CoV-2 pneumonia. METHODS: The present retrospective study was conducted in 332 adult patients who presented with dyspnea and hypoxemia and were admitted to Prince Mohammed bin Abdulaziz Hospital, Riyadh, Saudi Arabia between May 15, 2020 and December 15, 2020. All the patients underwent chest HRCT. Of the total, 198 patients with primary noncomplicated SARS-CoV-2 pneumonia were finally selected based on the typical chest HRCT patterns. The main CT patterns, GGO and sublobar consolidation, were individually quantified as a percentage of the total pulmonary involvement through algebraic summation of the percentage of the 19 pulmonary segments affected. Additionally, the statistical correlation strength between the total percentage pulmonary involvement and the age, initial RR, and percentage SpO2 of the patients was determined. RESULTS: The mean ± Standard Deviation (SD) age of the 198 patients was 48.9 ± 11.4 years. GGO magnitude alone exhibited a significant weak positive correlation with patients' age (r = 0.2; p = 0.04). Sublobar consolidation extent exhibited a relatively stronger positive correlation with RR than GGO magnitude (r = 0.23; p = 0.002). A relatively stronger negative correlation was observed between the GGO extent and SpO2 (r = - 0.38; p = 0.002) than that between sublobar consolidation and SpO2 (r = - 0.2; p = 0.04). An increase in the correlation strength was demonstrated with increased case segregation with GGO extent (r = - 0.34; p = 0.01). CONCLUSION: The correlation between the magnitudes of typical pulmonary lesion patterns, particularly GGO, which exhibited an incremental correlation pattern on chest HRCT, and the SpO2 percentage, may allow the establishment of an artificial intelligence program to differentiate primary SARS-CoV-2 pneumonia from other complications and associated pathology influencing SpO2.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Adulto , Pessoa de Meia-Idade , COVID-19/diagnóstico por imagem , Estudos Retrospectivos , Inteligência Artificial , Saturação de Oxigênio , Tomografia Computadorizada por Raios X/métodos
2.
Nanomaterials (Basel) ; 12(3)2022 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-35159769

RESUMO

The melting duration in the photovoltaic/phase-change material (PV/PCM) system is a crucial parameter for thermal energy management such that its improvement can realize better energy management in respect to thermal storage capabilities, thermal conditions, and the lifespan of PV modules. An innovative and efficient technique for improving the melting duration is the inclusion of an exterior metal foam layer in the PV/PCM system. For detailed investigations of utilizing different metal foam configurations in terms of their convective heat transfer coefficients, the present paper proposes a newly developed mathematical model for the PV/PCM-metal foam assembly that can readily be implemented with a wide range of operating conditions. Both computational fluid dynamic (CFD) and experimental validations proved the good accuracy of the proposed model for further applications. The present research found that the average PV cell temperature can be reduced by about 12 °C with a corresponding improvement in PCM melting duration of 127%. The addition of the metal foam is more effective at low solar radiation, ambient temperatures far below the PCM solidus temperature, and high wind speeds in nonlinear extension. With increasing of tilt angle, the PCM melting duration is linearly decreased by an average value of (13.4-25.0)% when the metal foam convective heat transfer coefficient is changed in the range of (0.5-20) W/m2.K. The present research also shows that the PCM thickness has a positive linear effect on the PCM melting duration, however, modifying the metal foam configuration from 0.5 to 20 W/m2.K has an effect on the PCM melting duration in such a way that the average PCM melting duration is doubled. This confirms the effectiveness of the inclusion of metal foam in the PV/PCM system.

3.
Sci Rep ; 11(1): 20476, 2021 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-34650073

RESUMO

The increased frequency of neurological manifestations, including central nervous system (CNS) manifestations, in patients with coronavirus disease 2019 (COVID-19) pandemic is consistent with the virus's neurotropic nature. In most patients, brain magnetic resonance imaging (MRI) is a sensitive imaging modality in the diagnosis of viral encephalitides in the brain. The purpose of this study was to determine the frequency of brain lesion patterns on brain MRI in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia patients who developed focal and non-focal neurological manifestations. In addition, it will compare the impact of the Glasgow Coma Scale (GCS) as an index of deteriorating cerebral function on positive brain MRIs in both neurological manifestations. This retrospective study included an examination of SARS-CoV-2 pneumonia patients with real-time reverse transcription polymerase chain reaction (RT-PCR) confirmation, admitted with clinicoradiologic evidence of COVID-19 pneumonia, and who were candidates for brain MRI due to neurological manifestations suggesting brain involvement. Brain imaging acquired on a 3.0 T MRI system (Skyra; Siemens, Erlangen, Germany) with a 20-channel receive head coil. Brain MRI revealed lesions in 38 (82.6%) of the total 46 patients for analysis and was negative in the remaining eight (17.4%) of all finally enclosed patients with RT-PCR confirmed SARS-CoV-2 pneumonia. Twenty-nine (63%) patients had focal neurological manifestations, while the remaining 17 (37%) patients had non-focal neurological manifestations. The patients had a highly significant difference (p = 0.0006) in GCS, but no significant difference (p = 0.4) in the number of comorbidities they had. Brain MRI is a feasible and important imaging modality in patients with SARS-CoV-2 pneumonia who develop neurological manifestations suggestive of brain involvement, particularly in patients with non-focal manifestations and a decline in GCS.


Assuntos
Encefalopatias/etiologia , Encéfalo/diagnóstico por imagem , COVID-19/complicações , Adulto , Idoso , Encéfalo/patologia , Encefalopatias/diagnóstico por imagem , Encefalopatias/patologia , COVID-19/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , SARS-CoV-2/isolamento & purificação
4.
Sci Rep ; 11(1): 14958, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294777

RESUMO

Ischemic heart disease (IHD), also known as coronary artery disease (CAD), is a leading cause of morbidity and mortality in adults. The aims of this research were to study the recent advances on the prognostic and diagnostic value, drawbacks, and the future directions of cardiac magnetic resonance imaging (CMRI) in the diagnosis of IHD. One hundred patients with IHD who had been clinically diagnosed were enrolled in this study prospectively. CMRI; Siemens Magnetom Sola 1.5 T MRI scanner was used to examine the patients. To confirm the diagnosis, conventional coronary angiography was used. CMRI revealed that the left ventricular (LV) volumes and systolic function of male and female patients differed by age decile were 28.9 ± 3.5%; 32 ± 1.7%, 53.3 ± 11.2; 58 ± 6.6 ml, 100.6 ± 7.1; 98.3 ± 14.7 bpm, 5.4 ± 1.4; 5.8 ± 1.5 L/min, 189 ± 14.3; 180 ± 10.9 ml, and 136 ± 3.1; 123 ± 4.4 ml for the left ventricle ejection fraction (LVEF), stroke volume (SV), heart rate, cardiac output, end diastolic volume (EDV), and end systolic volume (ESV), respectively. CMRI has sensitivity, specificity, and accuracy of 97%, 33.33%, and 95.15%, respectively. Finally, CMRI provides a comprehensive assessment of LV function, myocardial perfusion, and viability, as well as coronary anatomy.


Assuntos
Imagem Cinética por Ressonância Magnética/instrumentação , Isquemia Miocárdica/diagnóstico por imagem , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Angiografia Coronária , Diagnóstico Precoce , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Sensibilidade e Especificidade , Volume Sistólico , Função Ventricular Esquerda , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA