Numerical evaluation of heating of the human head due to magnetic resonance imaging

In this paper, we present a numerical model for evaluating tissue heating during magnetic resonance imaging (MRI). Our method, which included a detailed anatomical model of a human head, calculated both the electromagnetic power deposition and the associated temperature elevations during an MRI head examination. Numerical studies were conducted using a realistic birdcage coil excited at frequencies ranging from 63 to 500 MHz. The model was validated both experimentally and analytically. The experimental validation was performed at the MR test facility located at the Food and Drug Administration's Center for Devices and Radiological Health.

[1]  R. Stollberger,et al.  Spatial distribution of high-frequency electromagnetic energy in human head during MRI: numerical results and measurements , 1996, IEEE Transactions on Biomedical Engineering.

[2]  Francis A. Duck,et al.  Physical properties of tissue : a comprehensive reference book , 1990 .

[3]  E Atalar,et al.  A Green's function approach to local rf heating in interventional MRI. , 2001, Medical physics.

[4]  Jonathan P. Rothstein,et al.  Advanced Heat Transfer , 2005 .

[5]  F. Shellock,et al.  8.0‐Tesla human MR system: Temperature changes associated with radiofrequency‐induced heating of a head phantom , 2003, Journal of magnetic resonance imaging : JMRI.

[6]  Jianming Jin,et al.  On the SAR and field inhomogeneity of birdcage coils loaded with the human head , 1997, Magnetic resonance in medicine.

[7]  C. Gabriel.  Compilation of the Dielectric Properties of Body Tissues at RF and Microwave Frequencies. , 1996 .

[8]  Sampling and evaluation of specific absorption rates during patient examinations performed on 1.5-Tesla MR systems. , 2001, Magnetic resonance imaging.

[9]  Piersol Gm,et al.  The absorption of electromagnetic energy in body tissues. , 1954 .

[10]  G. M. Piersol,et al.  The absorption of electromagnetic energy in body tissues. , 1954, American journal of physical medicine.

[11]  O. Gandhi,et al.  Specific absorption rates and induced current densities for an anatomy‐based model of the human for exposure to time‐varying magnetic fields of MRI , 1999, Magnetic resonance in medicine.

[12]  Robert B. Roemer,et al.  A Mathematical Model of the Human Temperature Regulatory System - Transient Cold Exposure Response , 1976, IEEE Transactions on Biomedical Engineering.

[13]  T. Ibrahim,et al.  Analysis of B1 field profiles and SAR values for multi-strut transverse electromagnetic RF coils in high field MRI applications. , 2001, Physics in medicine and biology.

[14]  Z. Lou,et al.  Numerical analysis of electromagnetic hyperthermia of the human thorax , 2006, Medical and Biological Engineering and Computing.

[15]  SAR and Temperature Changes in the Leg Due to an RF Decoupling Coil at Frequencies Between 64 and 213 MHz , 2000, Journal of magnetic resonance imaging : JMRI.

[16]  S. Pisa,et al.  Specific absorption rate and temperature increases in the head of a cellular-phone user , 2000 .

[17]  H. H. Pennes.  Analysis of tissue and arterial blood temperatures in the resting human forearm. 1948. , 1948, Journal of applied physiology.

[18]  K. Yee.  Numerical solution of initial boundary value problems involving maxwell's equations in isotropic media , 1966 .

[19]  R. W. Lau,et al.  Electromagnetic and thermal modeling of SAR and temperature fields in tissue due to an RF decoupling coil , 1999, Magnetic resonance in medicine.

[20]  Z. Lou,et al.  Whole body heat balance during the human thoracic hyperthermia , 1990, Medical and Biological Engineering and Computing.

[21]  O. Gandhi,et al.  Magnetic resonance imaging: calculation of rates of energy absorption by a human-torso model. , 1990, Bioelectromagnetics.

[22]  Gesine Hellwig,et al.  Estimation of heat transfer and temperature rise in partial-body regions during MR procedures: an analytical approach with respect to safety considerations. , 2002, Magnetic resonance imaging.

[23]  Edl Schamiloglu,et al.  Integration of a Microstrip Patch Antenna with a Two-Dimensional Photonic Crystal Substrate , 1999 .

[24]  Michael B. Smith,et al.  SAR and B1 field distributions in a heterogeneous human head model within a birdcage coil , 1998, Magnetic resonance in medicine.

[25]  T. Duong,et al.  Evaluation of extra‐ and intracellular apparent diffusion in normal and globally ischemic rat brain via 19F NMR , 1998, Magnetic resonance in medicine.

[26]  Kam Li,et al.  The Mechanism of Absorption of Ultrahigh Frequency Electromagnetic Energy in Tissues, as Related to the Problem of Tolerance Dosage , 1956 .

[27]  Christopher M. Collins,et al.  A Method for Accurate Calculation ofB1Fields in Three Dimensions. Effects of Shield Geometry on Field Strength and Homogeneity in the Birdcage Coil , 1997 .

[28]  H. H. Pennes.  Analysis of tissue and arterial blood temperatures in the resting human forearm. , 1948, Journal of applied physiology.