Background: Electronic portal imaging devices (EPIDs) play an important role in radiation therapy portal imaging, geometric and dosimetric verifications. A successful utilization of EPIDs for imaging and dosimetric purposes requires a reliable quality control process routine to be carried out regularly. In this study, two in-house phantoms were developed and analyzed for implementation in a qua...

background: breast is one of the main radiological sensitive organs, hence it is important to evaluate absorbed dose to this organ especially to the glandular parts. it is the aim of this study to measure mean glandular dose and image contrast in terms of different mammographic parameters. materials and methods: in this study two mammography machines located at said-al shohada (giotto) and shah...

conclusions compared to iohexol and iopamidol, iodixanol use was associated with a lower patient perception of heat and lower hr while maintaining similar contrast-to-noise and signal-to-noise ratios. results baseline hr was similar across the patients assigned to iohexol, iopamidol, and iodixanol (65.3 ± 9.7, 66.9 ± 10.9, and 65.3 ± 13.3, respectively; p = ns). compared to iohexol and iopamido...

background: butterworth, gaussian, hamming, hanning, and parzen are commonly used spect filters during filtered back-projection (fbp) reconstruction, which greatly affect the quality and size accuracy of image. materials and methods: this study involved a cardiac phantom in which 1.10 cm thick cold defect was inserted into its myocardium wall and filled with 4.0 μci/ml (0.148 mbq/ml) 99mtc conc...

abstractbackground: delivering the radiation dose to the target volume and minimizing the dose to normal tissues are the main objectives in radiotherapy. the aim of our study is to enhance the contrast of the portal image to increase the accuracy of delineation of the organs in the irradiation field.   methods: the software was written based on local enhancement of the pixel values in image mat...

 ABSTRACTBackground: Delivering the radiation dose to the target volume and minimizing the dose to normal tissues are the main objectives in radiotherapy. The aim of our study is to enhance the contrast of the portal image to increase the accuracy of delineation of the organs in the irradiation field.   Methods: The software was written based on local enhancement of the pixel values in image ma...

introduction breast cancer is one of the most common types of cancer among women.  early detection of breast cancer is the key to reducing the associated mortality rate. the presence of microcalcifications clusters (mccs) is one of the earliest signs of breast cancer. due to poor imaging contrast of mammograms and noise contamination, radiologists may overlook some diagnostic signs, specially t...

background: mammography is the primary imaging technique for detection and diagnosis of breast cancer; however, the contrast of a mammogram image is often poor, especially for dense and glandular tissues. in these cases the radiologist may miss some diagnostically important microcalcifications. in order to improve diagnosis of cancer correctly, image enhancement technology is often used to enha...

Introduction Breast cancer is one of the most common types of cancer among women.  Early detection of breast cancer is the key to reducing the associated mortality rate. The presence of microcalcifications clusters (MCCs) is one of the earliest signs of breast cancer. Due to poor imaging contrast of mammograms and noise contamination, radiologists may overlook some diagnostic signs, specially t...

up to 19% of breast malignancies may be missed by conventional imaging techniques, especially when they are concurrent or co-located with other benign lesions. however, more sensitive techniques, such as magnetic resonance imaging (mri), are often too expensive for routine use in developing countries. contrast-enhanced, dual-energy digital mammography (cesm) is a recently introduced imaging mod...