Journal of Radiation Research and Applied Sciences最新文献

This paper considers the competing risks model with two causes of death to analyze time-to-event data for a group of male mice exposed to three hundred roentgen radiation for 5–6 weeks. The analysis is based on the assumption that the parent distribution is the Xgamma distribution and the data are gathered using an adaptive Type-I progressively censored sample. Two estimation approaches are considered to complete the analysis: maximum likelihood and Bayesian methods. Besides acquiring the estimations of the model parameters, the estimations of the reliability and failure rate are also discussed. Both point and interval estimates using both estimation approaches are studied. In Bayesian estimations, the squared error loss function is used and the Markov Chain Monte Carlo technique is proposed to get samples from the joint posterior distribution. The various methods are compared using simulation studies to compare their performance. The mentioned radiation data set is investigated and the analysis showed the suitability of the competing risks model with Xgamma distribution to analyze the data and to estimate the reliability metrics.

Purpose

In study, it was aimed to evaluate the dose volume histograms (DVH) of extended SSD technique, VMAT-based, and helical tomotherapy plans dosimetrically in a multi-institutional context to achieve higher plan quality and to harmonize total body irradiation plans.

Methods

Four different clinical centers participated in the study. The CT images of ten patients were used in this study. During the first phase, ten patients enrolled for TBI were planned by multiple centers according to a common protocol. During the second phase, all centers shared their plans’ DVHs. Treatment plans were evaluated according to the critical organ dose limits. Statistical analysis was performed in the SPSS (version 22.0) program (p < 0.05).

Results

In study, the results indicated that there was a statistically significant and considerable difference in the dose coverage of PTV, beam delivery time and MU, lens doses, and kidney doses between the four techniques (p < 0.001). The mean lung doses of the four centers were below 10 Gy. No significant difference in maximum liver doses between plans was obtained.

Conclusion

In conclusion, although four treatment techniques were suitable for TBI treatment, more homogeneous dose distribution, and lower critical organ doses were obtained with the tomotherapy technique. However, treatment time, MU, and dose rate for lung were disadvantages of the tomotherapy technique. When it comes to deciding on the TBI treatment method, it need to be reviewed some important points. It is needed to sufficient data on long-term results to be able to standardize TBI techniques between centers.

Total knee arthroplasty is an effective method for treating severe knee joint diseases, but the changes in patellar height and psychological state of patients after surgery are still of great concern. Select a group of patients who have undergone total knee replacement surgery as the research subjects, use radioactive CT imaging to examine the knee joints of the patients, and input them into the computer system for analysis. Based on the position, shape, and surrounding structure of the patella in the images, process them to obtain the specific value of patellar height. Radioactive CT imaging examination showed that there was a significant change in patellar height in patients after total knee arthroplasty, and the degree of change was related to the preoperative knee joint condition. The results showed that there was a significant change in patellar height in patients after total knee arthroplasty. The results of the radioactive CT imaging examination showed a significant increase in patellar height after surgery, with a significant improvement compared to before. The psychological evaluation results of the patient showed that after surgery, the patient's psychological condition significantly improved, and the levels of anxiety and depression were significantly reduced.

Amide proton transfer (APT) magnetic resonance imaging (MR) is a new imaging technology that has shown promise in the non-invasive characterization of brain malignancies, particularly meningiomas and glioblastomas. Th works aims to evaluate the existing literature in Amide proton transfer (APT) magnetic resonance imaging (MR) to explore the efficacy of APT MR imaging in the characterization of meningiomas and glioblastomas tumors. The review gives an overview of APT MR imaging principles, examines its potential benefits and limits, and highlights the important findings from the selected research. To discover relevant research published up to the current day, a literature search was undertaken in electronic databases such as PubMed and Google Scholar. The search is based on keywords and medical terms related to APT MR imaging, meningiomas, and glioblastomas. The review gives an overview of APT MR imaging principles, examines its potential benefits and limits, and highlights the important findings from the selected research. It showed that the majority of studies found encouraging results in distinguishing meningiomas and glioblastomas from surrounding normal brain tissue using APT MR imaging. For tumor characterization, APT signal intensity assessments such as APT asymmetry analysis and APT ratio analysis were used. The work concluded that the Amide proton transfer MR imaging has the potential to be a non-invasive imaging method for the diagnosis of meningiomas and glioblastomas. It provides useful information about tumor metabolism and cellular composition, which can help with diagnosis, therapy planning, and prognosis.

Several immune cell populations participate in the development of radiation-induced cardiac fibrosis. However, the underlying mechanism remains to be elucidated. Male C57BL/6 mice (8–12 weeks old) were anesthetized and exposed to a single cardiac radiation dose of 20 Gy using the small-animal radiation research platform. We conducted echocardiography and histological analysis to identify cardiac fibrosis from a functional and pathological perspective. Time-of-flight mass cytometry (CyTOF) was used to describe the compositional changes of immune cells 1, 4, and 8 weeks after cardiac irradiation in mouse peripheral blood and cardiac tissue samples. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to measure CD14 and CD105 mRNA levels from peripheral blood cells in eight patients who received thoracic radiotherapy 6 months ago. We observed reduced cardiac systolic function and increased collagen deposition in cardiac tissue after irradiation. Transforming growth factor-β, tumor necrosis factor-α, and interleukin-6 expression significantly elevated in the plasma. We identified a significant increase in CD45⁺ immune cell levels four weeks after cardiac irradiation using CyTOF, and neutrophil, monocyte, and macrophage levels elevated in blood samples after cardiac irradiation (four weeks). In cardiac tissue samples, monocyte and macrophage levels increased after cardiac irradiation (four weeks) compared with control group. Macrophages and monocytes were further analyzed, and the proportion of Ly6C^hiCD103⁺ myeloid cells increased after cardiac irradiation in tissue samples (four weeks). RT-qPCR revealed that CD14 expression was higher in patients with cardiac injured group than in the control group (Previous studies reported that Ly6C^hi monocytes in mice are similar to CD14 + CD16⁻ monocytes in humans). We found that Ly6C^hiCD103⁺ myeloid cells are critical subsets in radiation-induced cardiac fibrosis and might play protective roles in the process. Ly6C^hiCD103⁺ myeloid cells may be considered an early biomarker for detecting radiation-induced cardiac fibrosis.

Knee osteoarthritis (KOA) is one of the most popular joint diseases endangering human health because of its high incidence, disability, and younger onset. However, there is no suitable method for early diagnosis, evaluation, and treatment of KOA. In recent years, some clinical studies have found that ultrasound can detect early changes in KOA in advance, and the automatic segmentation of ultrasound images can achieve rapid and effective quantitative research on KOA. However, in ultrasound images, the soft tissue boundaries of the lesion are blurred, making lesion segmentation difficult. Although the U-Net family is one of the best networks for image segmentation, they still have defects such as blurred segmentation boundaries, distorted morphology, and insufficient accuracy when segmenting ultrasound images. To address this issue, we added attention, atrous spatial pyramid pooling (ASSP), and edge loss function terms into the Unet3+ network, which improved the contour clarity and accuracy of output images (the improved Unet3+ Dice acc = 78.74%. Then, we extract the key features of the improved Unet3+ for outputting meniscus images: calculating meniscus area and distance, where the average accuracy of the area is: area_ avg_ acc = 91.12%, with an average distance accuracy of distance_ avg_ acc = 91.14%. This thesis creates a new dataset collection from West China Hospital, Sichuan University, and automated measurement of knee meniscus protrusion area has been achieved for the first time. This article is the first to apply deep learning to ultrasound image segmentation of the knee meniscus, helping doctors conduct qualitative and quantitative analysis of the diagnosis and treatment of early KOA. The results indicate that the improved Unet3+ can assist doctors in automatically diagnosing and evaluating KOA based on meniscus ultrasound images, which is beneficial for guiding early clinical intervention.

This study explores the dual functional capabilities of rare earth (REE) doped BaO–B₂O₃–Li₂O–Al₂O₃–P₂O₅ glasses, with an emphasis on the 1.50Dy-Tb-Eu composition, previously recognized for its superior luminescent properties. By employing Monte Carlo simulations and Phy-X/PSD software, we have methodically evaluated the gamma-ray and neutron shielding efficacies of these materials. Our key findings indicate that the 1.50Dy-Tb-Eu sample not only excels in luminescence but also demonstrates superior gamma-ray shielding, characterized by low exposure buildup factors, and other related properties across varying energy spectra. Furthermore, the Tb-Eu3.0 variant, enriched with the highest Europium (Eu) content among the bi-REE doped glasses, exhibited the most effective neutron attenuation. Additionally, our investigation into the mechanical properties of these glasses, through the estimation of their Elastic Moduli using a mixture rule approach, revealed a significant enhancement in stiffness with the incorporation of Dy, Eu, and Tb. The mechanical properties were evaluated using a mixture rule approach to estimate the Elastic Moduli. This highlights the crucial role of these dopants in not only improving the luminescent and radiation shielding capabilities but also in strengthening the mechanical integrity of the glasses. The study substantiates the premise that the integration of specific REE elements significantly enhances the glass materials' shielding properties without compromising their luminescent functionality. The obtained findings would be significant for implications on the development of advanced materials tailored for industries where high optical quality, effective radiation protection, and robust mechanical properties are paramount. It can be concluded that Dy-Tb-Eu incorporation into BaO–B₂O₃–Li₂O–Al₂O₃–P₂O₅ glasses can be considered as a monotonic strategy to achieve a harmonious balance between luminescence, radiation shielding, and mechanical performance.