To investigate the optimum pelvis X-ray acquisition factors for a 10-year-old child. Secondly, to evaluate the impact of each acquisition factor on image quality (IQ) and radiation dose. Images were acquired using a pelvis phantom and a range of acquisition parameters; e.g. tube potential, additional filtration and source-to-image distance (SID). Automatic exposure control (AEC) was used with two orientations (head towards/away from two outer chambers) and three different chamber selections. Visual IQ was evaluated using relative and absolute-VGA methods. Radiation doses were measured by placing a dosimeter on the anterior surface of the phantom. Regression analysis was used to determine optimum parameters. The optimised technique (178.8 µGy), with diagnostic IQ, was with 89kVp, 130 cm SID and with 1 mm Al + 0.1 mm Cu filtration. This technique was with the head towards the two outer AEC chambers. Regression analysis showed that SID had the lowest impact on IQ (β = 0.002 95% CI -0.001 to 0.005) and dose (β = -0.96 95% CI -0.40 to -1.53). The impact of filtration on dose (β = -76.24 95% CI -86.76 to -85.72) was higher than tube potential (β = -13.44 95% CI -14.34 to -12.53). The following impact ratios were higher on IQ than radiation dose: filtration/kVp; 11.28 times, filtration/SID; 7.01 times and kVp/SID; 0.62 times. Optimised parameters were identified as 89 kVp, 130 cm SID and with 1 mm Al + 0.1 mm Cu additional filtration. Regression analysis demonstrated that filtration and tube potential had the greatest effect on radiation dose and IQ, respectively.

Introduction: To reduce the risks involved with ionising radiation exposure, typical values (TVs) and diagnostic reference levels (DRLs) have been established to help keep radiation doses 'as low as reasonably practicable. TVs/DRLs provide standardised radiation dose metrics that can be used for comparative purposes. However, for paediatrics, such values should consider the size of the child instead of their age. This study aimed to establish and compare paediatric TVs for chest, abdomen and pelvis radiography. Methods: Study methods followed processes for establishing paediatric DRLs as outlined by the Health Information and Quality Authority (HIQA). Kerma-area product (KAP) values, excluding rejected images, were retrospectively acquired from the study institution's Picture Archiving and Communications System (PACS). Paediatric patients were categorised into the following weight-based groupings (5 to <15 kg, 15 to <30 kg, 30 to <50 kg, 50 to 80 kg) and stratified based on the examination that was performed (chest, abdomen, and pelvis), and where it was performed (the different X-ray rooms). Anonymised data were inputted into Microsoft Excel for analysis. Median and 3rd quartile KAP values were reported together with graphical illustrations. Results: Data from 407 X-ray examinations were analysed. For the previously identified weight categories (5 to <15 kg, 15 to <30 kg, 30 to <50 kg, 50 to 80 kg), TVs for the chest were 0.10, 0.19, 0.37 and 0.53 dGy.cm(2), respectively. For the abdomen 0.39, 1.04, 3.51 and 4.05 dGy.cm(2) and for the pelvis 0.43, 0.87, 3.50 and 7.58 dGy.cm(2). Between X-ray rooms TVs varied against the institutional TVs by -60 to 119 % (chest), -50 to 103 % (abdomen) and -14 and 24 %% (pelvis). Conclusion: TVs in this study follow established trends with patient weight and examination type and are comparable with published literature. Variations do exist between individual examination rooms and reasons are multifactorial. Given that age and size do not perfectly correlate further work should be undertaken around weight-based TVs/DRLs in the paediatric setting.

Developing and researching antenna designs are analogous to excavating in an undiscovered mine. This paper proposes a multi-band antenna with a new hexagonal ring shape, theoretically designed, developed, and analyzed using a CST before being manufactured. The antenna has undergone six changes to provide the best performance. The results of the surface current distribution and the electric field distribution on the surface of the hexagonal patch were theoretically analyzed and studied. The sequential approach taken to determine the most effective design is logical, and prevents deviation from the work direction. After comparing the six theoretical results, the fifth model proved to be the best for making a prototype. Measured results represent that the proposed antenna can operate well in three bands with a return loss of -11.24 dB at 2.9 GHz, -25.99 dB at 4.9 GHz, and -21.26 dB at 5.4 GH. This type of antenna belongs to various wireless communication systems, including 2G, 3G, 4G, and 5G.

Hepatotropic virus HCV, which can infect hepatocytes, is also lymphotropic and can infect lymphocytes as well. Epidemiological, clinical, and biological evidence suggests that the pathogenesis of at least a portion of B-cell non-Hodgkin lymphomas (NHLs) are related to HCV infection. In the last six years, the approval of the new IFN-free antiviral treatment (AVT) with DAAs revolutionized the treatment of chronic HCV infection and many studies show improvement of lymphoid malignancies associated with HCV infection upon the use of direct-acting antivirals (DAAs). DAAs alone can improve indolent lymphomas and DAAs combined with chemotherapy improve the outcome of more aggressive lymphomas as many studies show that patients with HCV infection and lymphoid malignancies usually presented with a higher stage, have a higher frequency of extranodal presentation and a lower response rate (RR), disease free survival (DFS), and overall survival (OS) compared with other patients with lymphoid malignancies without HCV infection. Moreover, a number of lymphoid malignancies had reported soon after DAAs treatment for HCV infection. This is a systematic review of DAAs and their effect on lymphoid malignancies when given either combined or without chemotherapy. In addition, the review contains all cases reported before for the development of lymphoid malignancies after DAAs treatment for HCV infection.