Pengaruh Antiscatter grid Terhadap Dosis dan Kualitas Citra pada Prosedur Radiologi Intervensional

The study discusses the threshold of thickness required for antiscatter grid use on Siemens Artis Zee at “Dharmais” National Cancer Center, Jakarta. The device has adjustable modes of low, medium, and high fluoroscopy. Patients are represented by Polymethyl Methacrylate (PMMA) phantom with a thickness variation of 7-22 cm of 1 cm interval. The dose metrics was measured as the entrance skin dose (ESD) and the transmission dose, while the image quality metric employed being signal to noise ratio (SNR), leading the result to FOM as squared SNR per dose. The FOM bridged dose and image quality to determine threshold of antiscatter grid usage on fluoroscopy based on fantom thickness. As a result, antiscatter grid are recommended to be used for objects 11 cm and thicker on the use of low fluoroscopy mode, and 16 cm and thicker objects on high fluoroscopy mode. In medium fluoroscopy mode, no threshold was yielded due to tube current being higher than other modes, hence it is recommended to remove the antiscatter grid during the use of the medium fluoroscopy mod

Pengukuran MTF (Modulation Transfer Function) berdasarkan LSF (Line Spread Function) dan PSF (Point Spread Function) pada pesawat PET/CT dan SPECT/CT

This study aims to know the value of MTF obtained by using two methods: LSF (Line Spread Function) and PSF (Point Spread Function) on PET/CT and SPECT/CT. Measurement done with LSF method performed by thin flood source 18F or 99mTc 12 mCi, while PSF using thin line source 18F atau 99mTc 2 mCi with diameter 0.5 mm. The MTF calculations are performed based on image profile, for PET/CT assisted by 3 filter types and 4 reconstruction algorithms while SPECT/CT based on collimator variation. MTF calculation method have done based on Tsujioka et al. (2014) by combining the ImageJ, MATLAB, and Origin spreadsheet. System performance is determined at 10% MTF. The measurement results on PET/CT showed MTF highest value obtained by the Butterworth filter and reconstruction algorithm Iterative, Iterative 3D, and Backprojection with identical MTF value (0.155 cycles/mm) for LSF method, while PSF method by using Butterworth filter and Backprojection reconstruction algorithm obtained value 0.15 cycles/mm. In SPECT/CT, the second detector with LEHR collimator give MTF value to the LSF method and PSF method sequently 0.104 cycles/mm and 0075 cycles/mm. Based on the advantages and disadvantages of both methods, generally the PSF method is recommended as a spatial resolution QC program for nuclear medicine modalities

Serious Asthma Events with Fluticasone plus Salmeterol versus Fluticasone Alone

BACKGROUND: The safe and appropriate use of long-acting beta-agonists (LABAs) for the treatment of asthma has been widely debated. In two large clinical trials, investigators found a potential risk of serious asthma-related events associated with LABAs. This study was designed to evaluate the risk of administering the LABA salmeterol in combination with an inhaled glucocorticoid, fluticasone propionate. METHODS: In this multicenter, randomized, double-blind trial, adolescent and adult patients (age, ≥12 years) with persistent asthma were assigned to receive either fluticasone with salmeterol or fluticasone alone for 26 weeks. All the patients had a history of a severe asthma exacerbation in the year before randomization but not during the previous month. Patients were excluded from the trial if they had a history of life-threatening or unstable asthma. The primary safety end point was the first serious asthma-related event (death, endotracheal intubation, or hospitalization). Noninferiority of fluticasone-salmeterol to fluticasone alone was defined as an upper boundary of the 95% confidence interval for the risk of the primary safety end point of less than 2.0. The efficacy end point was the first severe asthma exacerbation. RESULTS: Of 11,679 patients who were enrolled, 67 had 74 serious asthma-related events, with 36 events in 34 patients in the fluticasone-salmeterol group and 38 events in 33 patients in the fluticasone-only group. The hazard ratio for a serious asthma-related event in the fluticasone-salmeterol group was 1.03 (95% confidence interval [CI], 0.64 to 1.66), and noninferiority was achieved (P=0.003). There were no asthma-related deaths; 2 patients in the fluticasone-only group underwent asthma-related intubation. The risk of a severe asthma exacerbation was 21% lower in the fluticasone-salmeterol group than in the fluticasone-only group (hazard ratio, 0.79; 95% CI, 0.70 to 0.89), with at least one severe asthma exacerbation occurring in 480 of 5834 patients (8%) in the fluticasone-salmeterol group, as compared with 597 of 5845 patients (10%) in the fluticasone-only group (P<0.001). CONCLUSIONS: Patients who received salmeterol in a fixed-dose combination with fluticasone did not have a significantly higher risk of serious asthma-related events than did those who received fluticasone alone. Patients receiving fluticasone-salmeterol had fewer severe asthma exacerbations than did those in the fluticasone-only group

Characteristics and outcomes of an international cohort of 600 000 hospitalized patients with COVID-19

Background: We describe demographic features, treatments and clinical outcomes in the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) COVID-19 cohort, one of the world's largest international, standardized data sets concerning hospitalized patients. Methods: The data set analysed includes COVID-19 patients hospitalized between January 2020 and January 2022 in 52 countries. We investigated how symptoms on admission, co-morbidities, risk factors and treatments varied by age, sex and other characteristics. We used Cox regression models to investigate associations between demographics, symptoms, co-morbidities and other factors with risk of death, admission to an intensive care unit (ICU) and invasive mechanical ventilation (IMV). Results: Data were available for 689 572 patients with laboratory-confirmed (91.1%) or clinically diagnosed (8.9%) SARS-CoV-2 infection from 52 countries. Age [adjusted hazard ratio per 10 years 1.49 (95% CI 1.48, 1.49)] and male sex [1.23 (1.21, 1.24)] were associated with a higher risk of death. Rates of admission to an ICU and use of IMV increased with age up to age 60&nbsp;years then dropped. Symptoms, co-morbidities and treatments varied by age and had varied associations with clinical outcomes. The case-fatality ratio varied by country partly due to differences in the clinical characteristics of recruited patients and was on average 21.5%. Conclusions: Age was the strongest determinant of risk of death, with a ∼30-fold difference between the oldest and youngest groups; each of the co-morbidities included was associated with up to an almost 2-fold increase in risk. Smoking and obesity were also associated with a higher risk of death.&nbsp;The size of our international database and the standardized data collection method make this study a comprehensive international description of COVID-19 clinical features. Our findings may inform strategies that involve prioritization of patients hospitalized with COVID-19 who have a higher risk of death

ISARIC-COVID-19 dataset: A Prospective, Standardized, Global Dataset of Patients Hospitalized with COVID-19

The International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) COVID-19 dataset is one of the largest international databases of prospectively collected clinical data on people hospitalized with COVID-19. This dataset was compiled during the COVID-19 pandemic by a network of hospitals that collect data using the ISARIC-World Health Organization Clinical Characterization Protocol and data tools. The database includes data from more than 705,000 patients, collected in more than 60 countries and 1,500 centres worldwide. Patient data are available from acute hospital admissions with COVID-19 and outpatient follow-ups. The data include signs and symptoms, pre-existing comorbidities, vital signs, chronic and acute treatments, complications, dates of hospitalization and discharge, mortality, viral strains, vaccination status, and other data. Here, we present the dataset characteristics, explain its architecture and how to gain access, and provide tools to facilitate its use