Σφακιανάκης Αλέξανδρος
ΩτοΡινοΛαρυγγολόγος
Αναπαύσεως 5 Άγιος Νικόλαος
Κρήτη 72100
00302841026182
00306932607174
alsfakia@gmail.com

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Τρίτη 9 Αυγούστου 2022

Assessing the Sensitivity of Dual-Energy Computed Tomography 3-Material Decomposition for the Detection of Gout

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imageObjectives The aim of this study was to assess the accuracy and precision of a novel application of 3-material decomposition (3MD) with virtual monochromatic images (VMIs) in the dual-energy computed tomography (DECT) assessment of monosodium urate (MSU) and hydroxyapatite (HA) phantoms compared with a commercial 2-material decomposition (2MD) and dual-thresholding (DT) material decomposition methods. Materials and Methods Monosodium urate (0.0, 3.4, 13.3, 28.3, and 65.2 mg/dL tubes) and HA (100, 400, and 800 mg/cm3 tubes) phantoms were DECT scanned individually and together in the presence of the foot and ankle of 15 subjects. The raw data were decomposed with 3MD-VMI, 2MD, and DT to produce MSU-only and HA-only images. Mean values of 10 × 10 × 10–voxel volumes of interest (244 μm3) placed in each MSU and HA phantom well were obtained and compared with their known concentrations and across measurements with subjects' extremities to obtain accuracy and precision measures. A statistical difference was considered significant if P
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Evaluation of Virtual Grid Processed Clinical Chest Radiographs

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imageObjectives We evaluated the different Virtual Grid software ratios (Fujifilm, Tokyo, Japan) on gridless clinical chest radiographs with visual grading analysis (VGA). In addition, we investigated the 2 image quality assessment algorithms (IQAAs). Materials and Methods Gridless chest radiographs of 50 different intensive care unit patients were collected and afterward processed with Virtual Grid software. Different software (SW) grid ratios—6:1, 10:1, 13:1, 17:1, and 20:1—were applied to investigate the image quality (IQ) improvement. Image quality improvement was assessed by 4 radiologists in a relative VGA study where the reference image was processed with SW grid ratio of 10:1. One of the IQAAs used to analyze the radiographs was implemented in our department but was originally developed by the research group of the Duke University Medical Center. A general IQ score (IQS) was calculated based on contrast, detail, and noise. Another IQAA—NIQE (naturalness image quality evaluator)—available in Matlab (MATLAB Research R2019b; the MathWorks, Inc) was evaluated. Both methods were compared with VGA. Results Visual grading analysis scores of gridless radiographs are significantly lower (P
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Effective Spatial Resolution of Photon Counting CT for Imaging of Trabecular Structures is Superior to Conventional Clinical CT and Similar to High Resolution Peripheral CT

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imageObjectives Photon counting computed tomography (PCCT) might offer an effective spatial resolution that is significantly improved compared with conventional state-of-the-art computed tomography (CT) and even provide a microstructural level of detail similar to high-resolution peripheral CT (HR-pQCT). The aim of this study was to evaluate the volumetric effective spatial resolution of clinically approved PCCT as an alternative to HR-pQCT for ex vivo or preclinical high-resolution imaging of bone microstructure. Materials and Methods The experiment contained 5 human vertebrae embedded in epoxy resin, which were scanned 3 times each, and on 3 different clinical CT scanners: a PCCT (Naeotom Alpha), a dual-energy CT (Somatom Force [SF]), and a single-energy CT (Somatom Sensation 40 [S40]), all manufactured by Siemens Healthineers (Erlangen, Germany). Scans were performed with a tube voltage of 120 kVp and, to provide maximum scan performance and minimum noise deterioration, with exposures of 1500 mAs (SF), 2400 mAs (S40), and 4500 mAs (PCCT) and low slice increments of 0.1 (PCCT) and 0.3 mm (SF, S40). Images were reconstructed with sharp and very sharp bone kernels, Br68 and Br76 (PCCT), Br64 (SF), and B65s and B75h (S40). Ground truth information was obtained from an XtremeCT scanner (Scanco, Brüttisellen, Switzerland). Voxel-wise comparison was performed after registration, calibration, and resampling of the volumes to isotropic voxel size of 0.164 mm. Three-dimensional point spread- and modulation-transfer funct ions were calculated with Wiener's deconvolution in the anatomical trabecular structure, allowing optimum estimation of device- and kernel-specific smoothing properties as well as specimen-related diffraction effects on the measurement. Results At high contrast (modulation transfer function [MTF] of 10%), radial effective resolutions of PCCT were 10.5 lp/cm (minimum resolvable object size 476 μm) for kernel Br68 and 16.9 lp/cm (295 μm) for kernel Br76. At low contrast (MTF 5%), radial effective spatial resolutions were 10.8 lp/cm (464 μm) for kernel Br68 and 30.5 lp/cm (164 μm) for kernel Br76. Axial effective resolutions of PCCT for both kernels were between 27.0 (185 μm) and 29.9 lp/cm (167 μm). Spatial resolutions with kernel Br76 might possibly be still higher but were technically limited by the isotropic voxel size of 164 μm. The effective volumetric resolutions of PCCT with kernel Br76 ranged between 61.9 (MTF 10%) and 222.4 (MTF 5%) elements per cubic mm. Photon counting CT improved the effective volumetric resolution by factor 5.5 (MTF 10%) and 18 (MTF 5%) compared with SF and by a factor of 8.7 (MTF 10%) and 20 (MTF 5%) compared with S40. Photon counting CT allowed obtaining similar structural information as HR-pQCT. Conclusions The effective spatial resolution of PCCT in trabecular bone imaging was comparable with that of HR-pQCT and more than 5 times higher compared with conventional CT. For ex vivo samples and when patient radiation dose can be neglected, PCCT allows imaging bone microstructure at a preclinical level of detail.
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Could red cell distribution width be used for predicting cardiac injury in neonates with COVID‐19?

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ABSTRACT

Background

Coronavirus disease 2019 (COVID-19) can affect people of all age groups and it can occasionally cause life-threatening clinical illness in immunologically immature population, especially in newborns. High red cell distribution width (RDW) values were used as early prognostic biomarker of some neonatal diseases. We aimed to determine the prognostic value of red cell distribution width in severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infected neonates.

Methods

Newborns with positive SARS-CoV-2 polymerase chain reaction (PCR) test from a nasopharyngeal swab sample, who had refractory fever (>38°C and lasting more than 24 hours during hospitalization) screened for multisystem inflammatory syndrome in newborns (MIS-N), systemic inflammatory indexes calculated and cardiologic evaluation performed to these patients. Due to troponin levels (high: >45 ng/L and low: ≤45 ng/L) patients were grouped.

Results

Of the 68 SARS-CoV-2 PCR-positive newborns, 26 patients had refractory fever. Comparison of laboratory findings between the high and low troponin groups showed that RDW and neutrophil/lymphocyte ratio values were significantly higher in patients with high troponin levels (p = 0.022 and p = 0.030, respectively). The cut-off values with optimal sensitivity and specificity were determined as 1.00 for neutrophil/lymphocyte ratio (p = 0.205) and 16.6 for red cell distribution width (p = 0.014). None of the patients died.

Conclusions

Neonatal coronavirus disease 2019 generally has a benign prognosis, but can progress to severe disease and cases of MIS-N are rare. RDW could be prognostic in diagnosis and management of neonates with SARS-CoV-2 infection with high troponin levels.

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Rapid quantitative monitoring of SARS‐CoV‐2 spike protein mediated syncytia formation using split NanoLuc

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Abstract

SARS-CoV-2 infection causes syncytial pneumocyte in patients and this has been considered as a defining feature of severe COVID-19 cases. Traditional methods of syncytia quantification require the morphology characterization of fused cells either with light microscope or fluorescent microscope, which is time-consuming and not accurate. Here we developed a rapid and sensitive coculture system measuring spike-induced syncytia by using NanoLuc complementation system. We found the formation of syncytia occurred rapidly after ACE2-expressing cells exposure to spike protein. In addition, we found furin cleavage as well as the cell surface protease TMPRSS2 enhanced syncytia formation. Finally, we showed that this coculture system can be used to test the ability of different compound to inhibit syncytia formation, thus providing a useful tool to screen anti-syncytial drugs.

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Humoral responses after inactivated COVID‐19 vaccination in individuals with and without prior SARS‐CoV‐2 infection: A prospective cohort study

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Abstract

Background

We evaluated and compared humoral immune responses after inactivated COVID-19 vaccination among naïve individuals, asymptomatically infected individuals, and recovered patients with varying severity.

Methods

In this multicenter, prospective cohort study, blood samples from 666 participants were collected before and after two doses of inactivated COVID-19 vaccination.

Results

Among 392 SARS-CoV-2-naïve individuals, the seroconversion rate increased significantly from 51.8% (median anti-spike protein pan-immunoglobulins [S-Igs] titer:0.8 U/mL) after the first dose to 96% (median S-Igs titer:79.5 U/mL) after the second dose. 32% of naïve individuals had detectable neutralizing antibodies (NAbs) against the original strain, but all of them lost neutralizing activity against the Omicron variant. In 274 individuals with natural infection, humoral immunity was significantly improved after a single vaccine dose, with median S-Igs titers of 757.8U/mL, 1247.0U/mL, 1280.0U/mL, and 2367.0U/mL for asymptomatic infections, mild cases, moderate cases, and severe/critical cases, respectively. NAb titers also improved significantly. However, the second dose did not substantially increase antibody levels.

Conclusions

Although a booster dose is needed for those without infection, our findings indicate that recovered patients should receive only a single dose of the vaccine, regardless of the clinical severity, until there is sufficient evidence to confirm the benefits of a second dose.

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A case of primary neuroendocrine carcinoma of the mandibular gingiva treated using multimodal therapy

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Publication date: Available online 8 August 2022

Source: Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology

Author(s): Tomoaki Hamana, Shigeru Sakurai, Atsuko Hamada, Shinnichi Sakamoto, Hisako Furusho, Shigeaki Toratani

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False-negative and false-positive outcomes of computer aided detection on brain metastasis: secondary analysis of a multicenter, multireader study

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Abstract
Background
Errors have seldom been evaluated in computer-aided detection on brain metastases. This study aimed to analyze false negatives (FNs) and false positives (FPs) generated by a brain metastasis detection system (BMDS) and by readers.
Methods
A deep learning-based BMDS was developed and prospectively validated in a multicenter, multireader study. Ad hoc secondary analysis was restricted to the prospective participants (148 with 1,066 brain metastases and 152 normal controls). Three trainees and three experienced radiologists read the MRI images without and with the BMDS. The number of FNs and FPs per patient, jackknife alternative free-response receiver operating characteristic figure of merit (FOM), and lesion features associated with FNs were analyzed for the BMDS and readers using binary logistic regression.
Results
The FNs, FPs, and the FOM of the stand-alone BMDS were 0.49, 0.38, and 0.97, respectively. Com pared with independent reading, BMDS-assisted reading generated 79% fewer FNs (1.98 vs. 0.42, P <0.001); 41% more FPs (0.17 vs. 0.24, P <0.001) but 125% more FPs for trainees (P <0.001); and higher FOM (0.87 vs. 0.98, P <0.001). Lesions with small size, greater number, irregular shape, lower signal intensity, and located on non-brain surface were associated with FNs for readers. Small, irregular, and necrotic lesions were more frequently found in FNs for BMDS. The FPs mainly resulted from small blood vessels for the BMDS and the readers.
Conclusions
Despite the improvement detection performance, attention should be paid to FPs and small lesions with lower enhancement for radiologists, especially for less-experienced radiologists.
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Prediction models for carbapenem‐resistant Enterobacterales carriage at liver transplantation: A multicenter retrospective study

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Prediction models for carbapenem-resistant Enterobacterales carriage at liver transplantation: A multicenter retrospective study

Graphical abstract:


Abstract

Background

Carbapenem-resistant Enterobacterales (CRE) colonisation at liver transplantation (LT) increases the risk of CRE infection after LT, which impacts on recipients' survival. Colonization status usually becomes evident only near LT. Thus, predictive models can be useful to guide antibiotic prophylaxis in endemic centres.

Aims

This study aimed to identify risk factors for CRE colonisation at LT in order to build a predictive model.

Methods

Retrospective multicentre study including consecutive adult patients who underwent LT, from 2010 to 2019, at two large teaching hospitals. We excluded patients who had CRE infections within 90 days before LT. CRE screening was performed in all patients on the day of LT. Exposure variables were considered within 90 days before LT and included cirrhosis complications, underlying disease, time on the waiting list, MELD and CLIF-SOFA scores, antibiotic use, intensive care unit and hospital stay, and infections. A machine learning model was trained to detect the probability of a patient being colonized with CRE at LT.

Results

A total of 1544 patients were analyzed, 116 (7.5%) patients were colonized by CRE at LT. The median time from CRE isolation to LT was 5 days. Use of antibiotics, hepato-renal syndrome, worst CLIF sofa score, and use of beta-lactam/beta-lactamase inhibitor increased the probability of a patient having pre-LT CRE. The proposed algorithm had a sensitivity of 66% and a specificity of 83% with a negative predictive value of 97%.

Conclusions

We created a model able to predict CRE colonization at LT based on easy-to-obtain features that could guide antibiotic prophylaxis

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The long term vaccine‐induced anti‐SARS‐CoV‐2 immune response is impaired in quantity and quality under TNFα blockade

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Abstract

Background

The humoral immune response to SARS-CoV-2 vaccination in patients with chronic inflammatory disease (CID) declines more rapidly with TNFα inhibition. Furthermore, the efficacy of current vaccines against Omicron variants of concern (VOC) including BA.2 is limited. Alterations within immune cell populations, changes in IgG affinity and the ability to neutralise a pre-VOC strain and the BA.2 virus were investigated in these at-risk patients.

Methods

Serum levels of anti-SARS-CoV-2 IgG, IgG avidity and neutralising antibodies (NA) were determined in anti-TNFα patients (n=10) and controls (n=24 healthy individuals; n=12 patients under other disease-modifying anti-rheumatic drugs, oDMARD) before and after the second and third vaccination by ELISA, immunoblot and live virus neutralisation assay. SARS-CoV-2-specific B- and T cell subsets were analysed by multicolour flow cytometry.

Results

IgG avidity and anti-pre-VOC NA titres decreased f aster in anti-TNFα recipients than in controls 6 months after the second vaccination (healthy individuals: avidity: p≤0.0001; NA: p=0.0347; oDMARDs: avidity: p=0.0012; NA: p=0.0293). Total plasma cell counts were increased in anti-TNFα patients (Healthy individuals: p=0.0344; oDMARDs: p=0.0254), whereas absolute numbers of SARS-CoV-2-specific cells were comparable 7 days after vaccination. These patients had lower BA.2 NA titres compared to both other groups, even after the third vaccination.

Conclusions

We show a reduced SARS-CoV-2 neutralising capacity in patients under TNFα blockade. In this cohort, the plasma cell response appears to be less specific and show stronger bystander activation. While these effects were observable after the first two vaccinations and with older VOC, the differences in responses to BA.2 were enhanced.

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