OBJECTIVES The objective of this study was to develop and test computer algorithms to export micro computed tomography (microCT) images and to generate tumour geometry and specific absorption rate (SAR) distribution for heat transfer simulation in magnetic nanoparticle hyperthermia. METHODS Computer algorithms were written to analyse and export microCT images of 3D tumours containing magnetic...

Many types of invisible electromagnetic waves are produced in our atmosphere. When these radiations penetrate our body, electric fields are induced inside the body, resulting in the absorption of power, which is different for different body parts and also depends on the frequency of radiations. Higher power absorption may result into health problems. In this communication, effects of electromag...

OBJECTIVE The purpose of this study was to measure specific absorption rate (SAR) during MRI scanning using a human torso phantom through quantification of diffusion coefficients independently of those reported by the scanner software for five 1.5 and 3 T clinical MRI systems from different vendors. METHODS A quadrature body coil transmitted the RF power and a body array coil received the sig...

The dosimetry of exposure to radiofrequency (RF) electromagnetic (EM) fields of mobile phones is generally based on the specific absorption rate (SAR, W kg(-1)), which is the electromagnetic energy absorbed in the tissues per unit mass and time. In this study, numerical methods and modelling were used to estimate the effect of a passive, metallic (conducting) superficial implant on a mobile pho...

BACKGROUND Thermal effects of radiofrequency electromagnetic fields (REMF) exposure of humans may be assessed by calculations of the parameter recognized as SAR (specific energy absorption rate) in virtual human body models, which actually do not represent anthropometric properties of the entire population. Therefore, it is important to determine the relations between SAR values and anthropomet...

The performance of perfectly matched layer (PML) absorbing boundary conditions is studied for finite-difference time-domain (FDTD) specific absorption rate (SAR) assessment, using convolutional PML (CPML) implementation of PML. This is done by investigating the variation of SAR values when the amount of free-space layers between the studied object and PML boundary is varied. Plane-wave exposure...

MRI is finding increased clinical use in neonatal populations; the extent to which electromagnetic models used for quantification of specific absorption rate (SAR) by commercial MRI scanners accurately reflect this alternative scenario is unclear. This study investigates how SAR predictions relating to adults can be related to neonates under differing conditions when imaged using 1.5 T and 3 T ...

The main purpose of this article is a complex hyperthermia applicator system design for treatment of head and neck region. The applicator system is composed of four waveguides with a stripline horn aperture and circular water bolus. The specific absorption rate (SAR) and temperature distribution from this applicator in various numerical phantom models was investigated. For used targets, the tre...

PURPOSE To gain radiofrequency (RF) pulse performance by directly addressing the temperature constraints, as opposed to the specific absorption rate (SAR) constraints, in parallel transmission at ultra-high field. METHODS The magnitude least-squares RF pulse design problem under hard SAR constraints was solved repeatedly by using the virtual observation points and an active-set algorithm. The...

This paper presents an implantable miniaturized planar inverted-F antenna (PIFA) for biomedical applications. We propose small sized PIFA that can operate over 2.45 GHz Industrial, Scientific, and Medical (ISM) band. We have investigated the effect of antenna parameters on resonant frequencies using empirical parametric studies and achieved highly compact PIFA antenna occupies a volume of 92 mm...