introduction: in diagnostic and therapeutic procedures, dosimetric studies are performed on the dosimetric systems in order to comply the radiation safety standards. monte carlo methods are used due to the high complexity and cost of patient-specific phantom construction. the high complexity of the digitized phantoms greatly increases the time and computational task of the monte carlo calculati...

introduction: nasopharyngeal carcinoma is one of the most common malignancies in the head and neck region and radiotherapy is its treatment of choice. in spite of the fact that it is widely used, due to the presence of many sensitive organs or tissues in this region, patients may suffer from a wide range of side effects. one such sensitive tissue is the spinal cord. if the absorbed dose to spin...

OBJECTIVE The purpose of this study is to design an anthropomorphic heterogeneous head phantom that can be used for MRI and other electromagnetic applications. MATERIALS AND METHODS An eight compartment, physical anthropomorphic head phantom was developed from a 3T MRI dataset of a healthy male. The designed phantom was successfully built and preliminarily evaluated through an application tha...

This study evaluated the feasibility of utilizing a 3D-printed anthropomorphic patient-specific head phantom for patient-specific quality assurance (QA) in intensity-modulated radiotherapy (IMRT). Contoured left and right head phantoms were converted from DICOM to STL format. Fused deposition modeling (FDM) was used to construct an anthropomorphic patient-specific head phantom with a 3D printer...

Introduction: The use of electronic portal imaging devices (EPIDs) is a method for the dosimetric verification of radiotherapy plans both pretreatment and in-vivo. The aim of this study was to test a 2D EPID-based dosimetry algorithm for dose verification of some plans inside a homogenous and anthropomorphic phantom and in-vivo, as well. Materials and Methods: </strong...

A student volunteer was asked to stand just behind a mannequin so that the student was looking at the back of the mannequin's plastic head. The experimenter stood off to one side and used her two hands to stroke and tap the back of the student's head in perfect synchrony with the back of the mannequin's head. After 1-2 min the majority of naive subjects tested began experiencing the sensations ...

The quality of images obtained from cone-beam computed tomography (CBCT) is important in diagnosis and treatment planning for dental and maxillofacial applications. However, X-ray scattering inside a human head is one of the main factors that cause a drop in image quality, especially in the CBCT system with a wide-angle cone-beam X-ray source and a large area detector. In this study, the X-ray ...