Energy imparted is a measure of the total ionizing energy deposited in the patient during a radiologic examination and may be used to quantify the patient dose in diagnostic radiology. Values of the energy imparted per unit exposure-area product, omega (z), absorbed by a semi-infinite water phantom with a thickness z, were computed for x-ray spectra with peak x-ray tube voltages ranging from 50...

BACKGROUND Evaluation of changes in tumor size from images acquired by ultrasound (US), computed tomography (CT) or magnetic resonance imaging (MRI) is a common measure of cancer chemotherapy efficacy. Tumor size measurement based on either the World Health Organization (WHO) criteria or the Response Evaluation Criteria in Solid Tumors (RECIST) is the only imaging biomarker for anti-cancer drug...

acute lymphoblastic leukemia (all) is the most common form of childhood cancer representing 80-85% of all leukemia. we describe a 3 years old girl with pain, swelling and tenderness in extremities since 8 months prior to her present admission. x-ray of extremities revealed callus formation, osteopenia and site of healed fractures. bone marrow aspiration revealed all-l2 with normal peripheral sm...

This study presents the application of the Presage/optical-CT 3D dosimetry system for relative dosimetry in the Radiologic Physics Center (RPC) Head and Neck (H&N) IMRT phantom. Performance of the system was evaluated by comparison with the "gold-standard" RPC credentialing test. A modified Presage cylindrical insert was created that extended the capability of the RPC H&N phantom to 3D dosimetr...

An urgent requirement for 3D dosimetry has been recognized because of high failure rate (~25%) in RPC credentialing, which relies on point and 2D dose measurements. Comprehensive 3D dosimetry is likely to resolve more errors and improve IMRT quality assurance. This work presents an investigation of the feasibility of PRESAGE/optical-CT 3D dosimetry in the Radiologic Physics Center (RPC) IMRT H&...

a young known case of multiple sclerosis was evaluated with chief complaint of gradually progressed left lower limb weakness over 3 weeks. pathologic examination of a mass in brain magnetic resonance imaging confirmed the diagnosis of glioblastoma multiforme (gbm). given the importance of the definite diagnosis of malignant glioma and its effect on patient’s management, gbm should be considered...

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...

The head and neck is a challenging anatomic site for intensity-modulated radiation therapy (IMRT), requiring thorough testing of planning and treatment delivery systems. Ideally, the phantoms used should be anatomically realistic, have radiologic properties identical to those of the tissues concerned, and allow for the use of a variety of devices to verify dose and dose distribution in any targ...

background: the heterogeneous composition of the human body presents numerous tissue types and cavities with widely differing radiologic properties. the aim of the present work was to develop a low cost homogeneous and heterogeneous phantom and the absorbed dose were measured by ionization chamber for different radiotherapy treatment techniques and compared with treatment planning system absorb...

Introduction: Phantom studies facilitate the implementation of radiation dose surveillance as a function of radiographic technical parameters for minimizing patient radiation dose. The evidence of such investigations can then be used to evaluate technical parameters used in the radiographic procedures to reduce radiation dose without compromising the image quality. Material and Methods: This ex...