BACKGROUND Three-dimensional ultrasound (3D-US) is used in planning and treatment during external beam radiotherapy. The accuracy of the technique depends not only on the achievable image quality in clinical routine, but also on technical limitations of achievable precision during calibration. Refraction of ultrasound waves is a known source for geometric distortion, but such an effect was not ...

background: most of the current brachytherapy treatment planning systems (tps) use the tg-43u1 recommendations for dosimetry in water phantom, not considering the heterogeneity effects. objective: the purpose of this study is developing a method for obtaining correction factors for heterogeneity for cs-137 brachytherapy sources based on pre-calculated mc simulations and interpolation. method: t...

Introduction: Proton magnetic resonance spectroscopy (MRS) is a well-known device for analyzing the biological fluids metabolically. Obtaining accurate and reliable information via MRS needs a homogeneous magnetic field in order to provide well-defined peaks and uniform water suppression. There are lots of reasons which can disturb the magnetic field homogeneity which can be corrected by a proc...

Dose distributions of (192)Ir HDR brachytherapy in phantoms simulating water, bone, lung tissue, water-lung and bone-lung interfaces using the Monte Carlo codes EGS4, FLUKA and MCNP4C are reported. Experiments were designed to gather point dose measurements to verify the Monte Carlo results using Gafchromic film, radiophotoluminescent glass dosimeter, solid water, bone, and lung phantom. The re...

It is possible to obtain a quality assurance (QA) of the dosimetry within a short time by using the new mathematical tools for a water phantom where dose measurements were made at two points only for a few square field sizes of the linear accelerator beam. The human body is not homogeneous. Water phantom makes it possible to create inhomogeneous phantoms by introducing blocks within it at suita...

This study was carried out to investigate the suitability of using the optically stimulated luminescence dosimeter (OSLD) in measuring surface dose during radiotherapy. The water equivalent depth (WED) of the OSLD was first determined by comparing the surface dose measured using the OSLD with the percentage depth dose at the buildup region measured using a Markus ionization chamber. Surface dos...

BACKGROUND AND PURPOSE Time-of-flight MR angiography (TOF MRA), with its advantage of high spatial resolution, is widely used for visualization of intracranial arteries. Fat signal intensity from bone marrow can interfere with vessel signal intensity, especially in maximum intensity projection reconstructions. Use of a technique such as fat saturation or water excitation can reduce this signal ...

The aim of the present Monte Carlo study is to evaluate the variation of energy deposition in healthy tissues in the human eye which is irradiated by brachytherapy sources in comparison with the resultant dose increase in the gold nanoparticle (GNP)-loaded choroidal melanoma. The effects of these nanoparticles on normal tissues are compared between 103Pd and 125I as two ophthalmic brachytherapy...

The aim of this document is to define the quality assurance (QA) methods for scanners using the ice-water phantom and the corresponding software developed within the IMI QuIC-ConCePT project, for the upcoming ‘BOS2’ trials. The outlined methods are what we consider to constitute the best use of currently available data following our recent papers [1] [2] in which we studied ADC (apparent diffus...

BACKGROUND The purpose of this article is to describe a steady-state free precession (SSFP) sequence for fat suppressed cine cardiovascular magnetic resonance (CMR). A rapid phase-modulated binomial water excitation (WE) pulse is utilized to minimize repetition time and acquisition time. METHODS Three different water-excitation pulses were combined with cine-SSFP for evaluation. The frequency...