ABSTRACT
BACKGROUND: Some parametric models are used to diagnose problems of lung segmentation more easily and effectively. OBJECTIVE: The present study aims to detect lung diseases (nodules and tuberculosis) better using an active shape model (ASM) from chest radiographs. MATERIAL AND METHODS: In this analytical study, six grouping methods, including three primary methods such as physicians, Dice similarity, and correlation coefficients) and also three secondary methods using SVM (Support Vector Machine) were used to classify the chest radiographs regarding diaphragm congestion and heart reshaping. The most effective method, based on the evaluation of the results by a radiologist, was found and used as input data for segmenting the images by active shape model (ASM). Several segmentation parameters were evaluated to calculate the accuracy of segmentation. This work was conducted on JSRT (Japanese Society of Radiological Technology) database images and tuberculosis database images were used for validation. RESULTS: The results indicated that the ASM can detect 94.12 ± 2.34 % and 94.38 ± 3.74 % (mean± standard deviation) of pulmonary nodules in left and right lungs, respectively, from the JRST radiology datasets. Furthermore, the ASM model detected 88.33 ± 6.72 % and 90.37 ± 5.48 % of tuberculosis in left and right lungs, respectively. CONCLUSION: The ASM segmentation method combined with pre-segmentation grouping can be used as a preliminary step to identify areas with tuberculosis or pulmonary nodules. In addition, this presented approach can be used to measure the size and dimensions of the heart in future studies.
ABSTRACT
INTRODUCTION: There are various radioprotective agents with different mechanisms that help to decrease ionizing radiation side effects. The radioprotective effect of Cimetidine and IMOD was assessed individually and compared with the hybrid radioprotectors agents (HRPAs-IMOD and Cimetidine) on human lymphocyte cells. METHODS: Twenty healthy volunteers (ten men and ten women) participated in the present study. About 75 mL peripheral blood lymphocytes from each individual were collected, and they were divided into 36 groups. Briefly, the blood samples were treated with different concentrations of Cimetidine (12.6 and 25.2 µg/mL) and IMOD (0.04, 0.08, and 0.12 mg/mL), and also a combination of these agents, namely hybrid radioprotectors agents (HRPAs). Besides, the irradiated groups were exposed to 2 and 4 Gy of Co-60 gamma irradiation. The amount of cellular damage was assessed using the micronucleus assay. The repeated measurements and paired T-test statistical analysis were used to compare the micronucleus frequencies in different groups. RESULTS: The micronucleus frequencies were significantly reduced (p < 0.05) in irradiated groups when the non-toxic concentrations of Cimetidine, IMOD, and HRPAs have been used. The reduction in micronucleus frequency was obtained 5-29% for Cimetidine and 40-51% for IMOD in peripheral blood lymphocytes irradiated with 2 Gy. This reduction in 4 Gy irradiation was 8-17% for Cimetidine and 27-37% for IMOD. The HRPAs resulted in a higher radioprotective effect, in a way that they cause up to 58% and 43% micronucleus frequency reduction in 2 and 4 Gy, respectively. CONCLUSION: In conclusion, the HRPAs showed the highest level of radioprotective. In addition, IMOD was remarkably higher radioprotective than Cimetidine, which may be related to its greater non-toxic concentrations.
