background: polymer gel dosimetry is still the only dosimetry method for direct measuring of threedimensional dose distributions. mri polymer gel dosimeters are tissue equivalent and can act as a phantom material. in this study the obtained isodose maps with pagat polymer gel dosimeter were compared to those calculated with egsnrs for singleshot irradiations of 8 and 18 mm collimators of gamma ...

BACKGROUND A prototype anthropomorphic head and neck phantom has been designed to simulate the adult head and neck anatomy including some internal organs and tissues of interest, such as thyroid gland and sentinel lymph nodes (SLNs). The design of the head and neck phantom includes an inner jig holding the simulated SLNs and thyroid gland. The thyroid gland structure was manufactured using thre...

Background: Polymer gel dosimetry is still the only dosimetry method for direct measuring of threedimensional dose distributions. MRI Polymer gel dosimeters are tissue equivalent and can act as a phantom material. In this study the obtained isodose maps with PAGAT polymer gel dosimeter were compared to those calculated with EGSnrs for singleshot irradiations of 8 and 18 mm collimators of...

OBJECTIVES To assess the feasibility of an objective approach for the evaluation of low-contrast detectability in multidetector computed-tomography (MDCT) by combining a virtual phantom containing simulated lesions with an image quality metric. MATERIALS AND METHODS A low-contrast phantom containing hypodense spheric lesions (-20 HU) was scanned on a 64-slice MDCT scanner at 4 different dose ...

A method of generating images through highly scattering media is presented that involves comparing measurements of the time-dependent intensity of transmitted light with an analytical model describing the sensitivity of that intensity on localized changes in optical properties. A least-squares fitting procedure is employed to derive the amplitudes of the measurement perturbations caused by embe...

Introduction: One of scientific concern is increasing of unwanted neutron dose to the patient, in head and neck radiation therapy due to the presence of some isotopes in dental restorations and head of medical linac. The aim of this study is to measure the equivalent dose of thermal and fast neutron due to head of Siemens Primus Linac and a healthy tooth, Amalgam, Ni-Cr alloy a...

Background: Radioiodine therapy has proven to be an effective method in the treatment of patients with differentiated thyroid carcinoma after thyroidectomy. The scope of this study is to describe a method to obtain the dose of organs using medical internal radiation dosimetry (MIRD) method. At the end, the results of MIRD calculations were compared with thermoluminescent dosimeter (TLD...

introduction the gamma knife system is designed solely for non-invasive treatment of brain disorders, and it benefits from stereotactic surgical techniques. dose calculations required in the system are performed by gammaplan code; in this code, brain tissue is considered uniform. in the present study, we evaluated the effect of gamma knife system on the obtained dose through simulating a real h...

We have segmented CT torso+head and MRI head slices of two living human males. The manually segmented 129 x-ray CT transverse slices were used to create a computerized 3dimensional volume array modeling all major internal structures of the body. The original xray CT images were reconstructed in a 512x512 matrix with a resolution of 1 millimeter in the x,y plane. The z-axis resolution is 1 centi...