Introduction: One of the most valuable goals of phantoms, replacing with human goals in the field of research and quality control of diagnostic X-ray systems. There are various algorithms and methods for obtaining Homogeneity and CT number linearity for CT scan device. One of the most famous of these methods, the method is to use a uniform and homogeneous environment to comput...

Imaging complex vascular structures by X-ray microcomputed tomography (μ-CT) is becoming vital for research purposes in pathology of diseases. Acrylic-based polymerizable resins are widely adopted the contrast agent to prepare pathological specimens imaging structures. For at higher resolution, it promising develop inorganic-type agents with attenuation coefficient as well low viscosity, homoge...

Quality control testing of CT scanners in our region includes a measurement of CT numbers in the American College of Radiology (ACR) CT phantom using a standardized protocol. CT number values are clinically relevant in determining the composition of various tissues in the body. Accuracy is important in the characterization of tumors, assessment of coronary calcium, and identification of urinary...

Introduction: Recent studies of Computed Tomography (CT) conducted on patient dose reduction have recommended using an iterative reconstruction algorithm and mA (mili-Ampere) dose modulation. The current study aimed to evaluate Iterative Dose Reduction Algorithm (IDREAM) as an iterative reconstruction algorithm. Material and Methods: Two CT p...

Introduction: One of the main steps in the optimization process in diagnostic imaging is the quality control of radiology devices. The usual method of CT scan calibration is used of a phantom. The phantom created a certain weakening for the radiation through which it passes. One of the most suitable methods for quantitative analysis of the resolution and contrast in CT scan im...

normal 0 false false false en-us x-none ar-sa aim: ct number (hu) and linear attenuation coefficient contain useful information which  can be determined during usual ct scanning for the prediction of breast cancerous cells existence based on hemoglobin concentration. methods: this study used breast phantom containing major and minor vessels with diameters of 10 and 5 mm, respectively. the major...

Metallic eye shields have been widely used for near-eye treatments to protect critical regions, but have never been incorporated into treatment plans because of the unwanted appearance of the metal artifacts on CT images. The purpose of this work was to test the use of an acrylic dummy eye shield as a substitute for a metallic eye shield during CT scans. An acrylic dummy shield of the same size...

introduction: breast conserving radiotherapy is one of the most common procedures performed in any radiation oncology department. a tangential parallel-opposed pair is usually used for this purpose. this technique is performed using 2d or 3d treatment planning systems. the aim of this study was to compare 2d treatment planning with 3d treatment planning in tangential irradiation in breast conse...

The purpose of this study was to evaluate the fabrication of a complete denture using a CAD/CAM system. Cone beam CT was used to measure the complete denture and the artificial teeth. After a 3D complete denture image was structured using 3D CAD software, we factored out the artificial teeth and obtained a 3D denture base image. A machining center cut an acrylic resin block, and fabricated an a...

BACKGROUND Cognitive therapy (CT) has been studied in 78 controlled clinical trials from 1977 to 1996. METHOD The meta-analysis used Hedges and Olkin d+ and included 48 high-quality controlled trials. The 2765 patients presented non-psychotic and non-bipolar major depression, or dysthymia of mild to moderate severity. RESULTS At post-test CT appeared significantly better than waiting-list, ...