This study evaluated a new body composition phantom and its use for quality control and cross-calibration of dual-energy X-ray absorptiometry (DXA) instruments for measurements of body composition. We imaged the variable composition phantom (Lunar, Madison, WI) on eight different DXA devices. Deviations of up to 7% fat were observed when we compared the percent fat values measured by the differ...

introduction after the publication of task group number 43 dose calculation formalism by the american association of physicists in medicine (aapm), this method has been known as the most common dose calculation method in brachytherapy treatment planning. in this formalism, the water phantom is introduced as the reference dosimetry phantom, while the attenuation coefficient of the sources in the...

Introduction: Brachytherapy is one type of internal radiation therapy where radiation sources, which are usually encapsulated, are placed as close as possible to the tumor site or inside the patient's body. In this technique, it is important to determine dose distribution around the brachytherapy capsule to create optimal treatment plant. In this way, dosimetric parameters are...

Introduction After the publication of Task Group number 43 dose calculation formalism by the American Association of Physicists in Medicine (AAPM), this method has been known as the most common dose calculation method in brachytherapy treatment planning. In this formalism, the water phantom is introduced as the reference dosimetry phantom, while the attenuation coefficient of the sources in the...

Introduction: The aim of this work was to assess Dixon-based MRI techniques for fat quantification in the calf muscle at 3T. It has been reported in the literature that a strong correlation (r=0.96) exists between 3-point Dixon (3PD) and known concentrations of fat and water in a phantom study at 1.5T [1] and strong correlation (r2=0.985) between 3PD and MRS in a phantom study at 3.0T [2]. In t...

BACKGROUND: Assessment of quantitative parameters using magnetic resonance imaging (MRI) is a relevant trend. Fat fraction (FF) calculation provides new opportunities for accurate diagnosis and will replace invasive methods such as biopsy in the future. Quantification enable reliable dynamic monitoring assessment drug therapy. However, radiologists clinical specialists must be confident accurac...

PURPOSE To determine the degree of extraneous lipid contamination in defined volumes of interest studied with single-volume proton MR spectroscopy. METHODS Single-volume proton MR spectroscopy was performed on a fat/water phantom and in three volunteers using the stimulated-echo acquisition mode (STEAM) and point-resolved spectroscopy (PRESS) localization methods. Three different volumes of i...

INTRODUCTION Chemical shift-encoded techniques for quantitatively measuring the presence of fat have a number of important applications in MRI, including bone marrow, muscle, brain, liver and heart studies. However, inaccurate modeling of the acquired signal can result in significant bias in the estimates of fat amplitude or fat fraction. Specifically, modeling the T2* decay (or the decay rate ...

Introduction: In vitro dosimetric verification prior to patient treatment plays a key role in accurate and precision radiotherapy treatment delivery. Since the human body is a heterogeneous medium, the aim of this study was to design a heterogeneous pelvic phantom for radiotherapy quality assurance. Material and Methods: A pelvic phantom was ...