In this paper, we present a novel implementation of a dose calculation application, based on the GEANT4 Monte Carlo toolkit. Validation studies were performed with an homogeneous water phantom and an Alderson-Rando anthropomorphic phantom both irradiated with high-energy photon beams produced by a clinical linear accelerator. As input, this tool requires computer tomography images for automatic...

Components of an Ultrasound Quality Assurance Program 257 Quality Assurance and Preventive Maintenance 257 Tissue-Mimicking Phantoms 257 Tissue Properties Represented in Phantoms 257 Typical Quality Assurance Phantom Design 257 Cautions About Phantom Desiccation 258 Basic Quality Control Tests 259 Visual Inspection 259 Transducer Choice 259 System Sensitivity 260 Photography and Gray-Scale Hard...

Routine constancy checks of electron energy are often time consuming because of the necessity to measure a dose at two depths. A technique is described that uses a double-wedge shaped phantom positioned on a Profiler diode array for measuring an electron energy constancy metric similar to R(50). The double-wedge electron profiles are invariant to phantom alignment in the wedge direction, unlike...

A method of reconstructing three-dimensional, in vivo dose distributions delivered by intensity-modulated radiotherapy (IMRT) is presented. A proof-of-principle experiment is described where an inverse-planned IMRT treatment is delivered to an anthropomorphic phantom. The exact position of the phantom at the time of treatment is measured by acquiring megavoltage CT data with the treatment beam ...

A proposed method to obtain the dose for Computed Tomography was evaluated on long a phantom, made of polyethylene. This phantom is 600 mm large. Adopting an empirical characterized function , tendency asymptotical grow by increase scanning length can estimate in infinite single axial rotation x-ray tube. The curve estimated different clinical protocols: tension, pitch, head/body, and center/pe...

The purpose of this study is to validate numerical simulations of flow and pressure in an abdominal aortic aneurysm (AAA) using phase-contrast magnetic resonance imaging (PCMRI) and an in vitro phantom under physiological flow and pressure conditions. We constructed a two-outlet physical flow phantom based on patient imaging data of an AAA and developed a physical Windkessel model to use as out...

PURPOSE This study aimed to provide comparative measurements of the effective dose from direct and indirect digital panoramic units according to phantoms and exposure parameters. MATERIALS AND METHODS Dose measurements were carried out using a head phantom representing an average man (175 cm tall, 73.5 kg male) and a limbless whole body phantom representing an average woman (155 cm tall, 50 k...

Background Quantitative MR relaxometry techniques are increasingly used in cardiac MR applications, e.g. MOLLI for high resolution T1 mapping. To use these techniques in the clinic, we must understand how to make comparable measurements across vendor systems and software versions and compare results across sites. A standardized phantom used for regular quality control is one approach. The Bioma...

Background: Small photon fields are increasingly used in modern radiotherapy especially in intensity modulated radiation therapy (IMRT) and stereotactic radiosurgery (SRS) treatments. Accurate beam profile and central axis depth doses measurements of such beams are complicated due to the electron disequilibrium. Hence the EBT2 (external beam therapy) Gafchromic film was used for dosimetry of sm...

We report the magneto-optic Kerr effect (MOKE) angle of Au magnetically excited by spin accumulation. perform time-resolved polar MOKE measurements on Au/Co heterostructures. In our experiment, ultrafast optical excitation Co drives accumulation into an adjacent layer. The accumulation, together with spin-orbit coupling, leads to nonzero terms in off-diagonal conductivity tensor Au, which we me...