Christopher Collins

Summary

Affiliation: Pennsylvania State University
Country: USA

Publications

  1. pmc MR thermometry characterization of a hyperthermia ultrasound array designed using the k-space computational method
    Osama M Al-Bataineh
    Department of Bioengineering, The Pennsylvania State University, University Park, PA 16802, USA
    Biomed Eng Online 5:56. 2006
  2. ncbi request reprint Combination of optimized transmit arrays and some receive array reconstruction methods can yield homogeneous images at very high frequencies
    Christopher M Collins
    Center for NMR Research, Penn State College of Medicine, Hershey, PA 17033, USA
    Magn Reson Med 54:1327-32. 2005
  3. ncbi request reprint Central brightening due to constructive interference with, without, and despite dielectric resonance
    Christopher M Collins
    Center for NMR Research, Department of Radiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 21:192-6. 2005
  4. ncbi request reprint Model of local temperature changes in brain upon functional activation
    Christopher M Collins
    Center for NMR Research, Dept of Radiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
    J Appl Physiol (1985) 97:2051-5. 2004
  5. ncbi request reprint Temperature and SAR calculations for a human head within volume and surface coils at 64 and 300 MHz
    Christopher M Collins
    Center for NMR Research, Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 19:650-6. 2004
  6. pmc Array-optimized composite pulse for excellent whole-brain homogeneity in high-field MRI
    Christopher M Collins
    Center for NMR Research, Penn State College of Medicine, Hershey, Pennsylvania, USA
    Magn Reson Med 57:470-4. 2007
  7. ncbi request reprint Spatial resolution of numerical models of man and calculated specific absorption rate using the FDTD method: a study at 64 MHz in a magnetic resonance imaging coil
    Christopher M Collins
    Center for NMR Research, Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 18:383-8. 2003
  8. pmc Numerical field calculations considering the human subject for engineering and safety assurance in MRI
    Christopher M Collins
    Department of Radiology, The Pennsylvania State University, Hershey, PA 17033 0850, USA
    NMR Biomed 22:919-26. 2009
  9. ncbi request reprint Numerical calculations of the static magnetic field in three-dimensional multi-tissue models of the human head
    Christopher M Collins
    Department of Radiology, The Pennsylvania State University College of Medicine, Hershey 17033, USA
    Magn Reson Imaging 20:413-24. 2002
  10. pmc SAR and temperature: simulations and comparison to regulatory limits for MRI
    Zhangwei Wang
    Center for NMR Research, Penn State College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 26:437-41. 2007

Research Grants

Collaborators

Detail Information

Publications28

  1. pmc MR thermometry characterization of a hyperthermia ultrasound array designed using the k-space computational method
    Osama M Al-Bataineh
    Department of Bioengineering, The Pennsylvania State University, University Park, PA 16802, USA
    Biomed Eng Online 5:56. 2006
    ..Evaluation of the probe includes ex vivo and in vivo controlled hyperthermia experiments using the noninvasive magnetic resonance imaging (MRI) thermometry...
  2. ncbi request reprint Combination of optimized transmit arrays and some receive array reconstruction methods can yield homogeneous images at very high frequencies
    Christopher M Collins
    Center for NMR Research, Penn State College of Medicine, Hershey, PA 17033, USA
    Magn Reson Med 54:1327-32. 2005
    ....
  3. ncbi request reprint Central brightening due to constructive interference with, without, and despite dielectric resonance
    Christopher M Collins
    Center for NMR Research, Department of Radiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 21:192-6. 2005
    ....
  4. ncbi request reprint Model of local temperature changes in brain upon functional activation
    Christopher M Collins
    Center for NMR Research, Dept of Radiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
    J Appl Physiol (1985) 97:2051-5. 2004
    ..All calculated changes in temperature for reasonable physiological parameters have magnitudes <0.12 degrees C and are well within the range reported in recent experimental studies involving human subjects...
  5. ncbi request reprint Temperature and SAR calculations for a human head within volume and surface coils at 64 and 300 MHz
    Christopher M Collins
    Center for NMR Research, Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 19:650-6. 2004
    ..To examine relationships between specific energy absorption rate (SAR) and temperature distributions in the human head during radio frequency energy deposition in MRI...
  6. pmc Array-optimized composite pulse for excellent whole-brain homogeneity in high-field MRI
    Christopher M Collins
    Center for NMR Research, Penn State College of Medicine, Hershey, Pennsylvania, USA
    Magn Reson Med 57:470-4. 2007
    ..Simulations indicate that with a very simple array-optimized composite pulse, excellent whole-brain excitation homogeneity can be achieved at up to 600 MHz...
  7. ncbi request reprint Spatial resolution of numerical models of man and calculated specific absorption rate using the FDTD method: a study at 64 MHz in a magnetic resonance imaging coil
    Christopher M Collins
    Center for NMR Research, Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 18:383-8. 2003
    ..To examine how fine a model resolution is necessary for calculation of specific energy absorption rate (SAR) for the human head in regions as small as 1 g...
  8. pmc Numerical field calculations considering the human subject for engineering and safety assurance in MRI
    Christopher M Collins
    Department of Radiology, The Pennsylvania State University, Hershey, PA 17033 0850, USA
    NMR Biomed 22:919-26. 2009
    ....
  9. ncbi request reprint Numerical calculations of the static magnetic field in three-dimensional multi-tissue models of the human head
    Christopher M Collins
    Department of Radiology, The Pennsylvania State University College of Medicine, Hershey 17033, USA
    Magn Reson Imaging 20:413-24. 2002
    ..Results are presented in parts per million (ppm) deviation from the applied field strength and are valid for any imaging or spectroscopy system...
  10. pmc SAR and temperature: simulations and comparison to regulatory limits for MRI
    Zhangwei Wang
    Center for NMR Research, Penn State College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 26:437-41. 2007
    ..While methods of calculation for SAR and temperature are constantly being refined, methods for interpreting results of these calculations in light of regulatory limits also warrant discussion...
  11. ncbi request reprint Consideration of magnetically-induced and conservative electric fields within a loaded gradient coil
    Weihua Mao
    Department of Radiology, Pennsylvania State University College of Medicine, Hershey, 17033, USA
    Magn Reson Med 55:1424-32. 2006
    ....
  12. pmc Exploring the limits of RF shimming for high-field MRI of the human head
    Weihua Mao
    Center for NMR Research, Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
    Magn Reson Med 56:918-22. 2006
    ..We found that a 16-element array can effectively shim a single slice at frequencies up to 600 MHz and the whole brain at up to 300 MHz, while an 80-element array can shim the whole brain at up to 600 MHz...
  13. ncbi request reprint B(1) destructive interferences and spatial phase patterns at 7 T with a head transceiver array coil
    Pierre Francois van de Moortele
    Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
    Magn Reson Med 54:1503-18. 2005
    ..Our results suggest that measuring spatial B(1) phase could help, within an MR session, to perform RF shimming in order to obtain more homogeneous B(1) in user-defined areas of the brain...
  14. pmc Faraday shields within a solenoidal coil to reduce sample heating: numerical comparison of designs and experimental verification
    BuSik Park
    Department of Bioengineering, The Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA
    J Magn Reson 202:72-7. 2010
    ..Simulations indicate that some designs should be capable of reducing temperature increase by more than 85%...
  15. ncbi request reprint Analysis of wave behavior in lossy dielectric samples at high field
    Qing X Yang
    Center for NMR Research, Department of Radiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
    Magn Reson Med 47:982-9. 2002
    ..The numerical calculation method is validated with experimental results. The general behavior of the RF field with respect to the average brain electrical properties in a frequency range of 42-350 MHz is also analyzed...
  16. ncbi request reprint Strategies for shimming the breast
    Nimrod Maril
    Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
    Magn Reson Med 54:1139-45. 2005
    ..Since many clinical scanners do not have either higher-order shim or automated higher shimming algorithms that work in the presence of fat, the suggested combination provides an effective means to correct inhomogeneities in the breast...
  17. pmc Reducing SAR and enhancing cerebral signal-to-noise ratio with high permittivity padding at 3 T
    Qing X Yang
    Departments of Radiology, The Pennsylvania State University College of Medicine, 500 University Drive, Hershey, Pennsylvania, USA
    Magn Reson Med 65:358-62. 2011
    ..Thus, dielectric pads may be used to provide a relatively simple and low-cost method for improving quality and safety of MRI in a variety of applications at 3 T...
  18. ncbi request reprint Effect of gender on in vivo cartilage magnetic resonance imaging T2 mapping
    Timothy J Mosher
    Penn State Center for NMR Research, Department of Radiology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 19:323-8. 2004
    ..To determine if gender is a significant variable for in vivo magnetic resonance imaging (MRI) T2-mapping of knee articular cartilage in young asymptomatic volunteers...
  19. ncbi request reprint Phantom design method for high-field MRI human systems
    Qing X Yang
    Center for NMR Research, Department of Radiology, Pennsylvania State University College of Medicine, Hershey 17033, USA
    Magn Reson Med 52:1016-20. 2004
    ....
  20. ncbi request reprint Hexagonal zero mode TEM coil: a single-channel coil design for imaging multiple small animals
    Jelena Lazovic
    Center for NMR Research, Department of Radiology, Pennsylvania State University College of Medicine, Hershey, 17033, USA
    Magn Reson Med 53:1150-7. 2005
    ..The hexagonal coil design utilizes a single receiver and allows for simultaneous imaging of six small animals with no significant compromise in SNR...
  21. pmc Consideration of physiological response in numerical models of temperature during MRI of the human head
    Zhangwei Wang
    Center for NMR Research, Penn State College of Medicine, Hershey, Pennsylvania 17033, USA
    J Magn Reson Imaging 28:1303-8. 2008
    ..To examine the thermal effects of the physiological response to heating during exposure to radiofrequency (RF) electromagnetic fields in magnetic resonance imaging (MRI) with a head-specific volume coil...
  22. pmc A method to separate conservative and magnetically-induced electric fields in calculations for MRI and MRS in electrically-small samples
    BuSik Park
    Department of Bioengineering, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
    J Magn Reson 199:233-7. 2009
    ....
  23. pmc Experimental and numerical assessment of MRI-induced temperature change and SAR distributions in phantoms and in vivo
    Sukhoon Oh
    Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
    Magn Reson Med 63:218-23. 2010
    ....
  24. pmc Direct magnetic resonance imaging of histological tissue samples at 3.0T
    Mark D Meadowcroft
    Center for NMR Research, Department of Radiology, Pennsylvania State University College of Medicine, Milton S Hershey Medical Center, Hershey, Pennsylvania 17033, USA
    Magn Reson Med 57:835-41. 2007
    ..This work demonstrates the feasibility of using a microimaging histological coil to image thin slices of pathologically diseased tissue to obtain a precise one-to-one comparison between stained tissue and MR images...
  25. ncbi request reprint Polarization of the RF field in a human head at high field: a study with a quadrature surface coil at 7.0 T
    Jinghua Wang
    Center for NMR Research, Department of Radiology, Pennsylvania State University College of Medicine, Hershey 17033, USA
    Magn Reson Med 48:362-9. 2002
    ..Theoretical and experimental results for a phantom and the human head at 7.0 T are presented. The results are theoretically important and practically useful for high-field quadrature coil design and application...
  26. ncbi request reprint Effects of end-ring/shield configuration on homogeneity and signal-to-noise ratio in a birdcage-type coil loaded with a human head
    Wanzhan Liu
    Department of Radiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, USA
    Magn Reson Med 51:217-21. 2004
    ..The surrounding shield configuration results in the most homogeneous B1 and highest SNR in the coil loaded with the human head at both frequencies, followed closely by the solid connection configuration...
  27. ncbi request reprint Change in knee cartilage T2 at MR imaging after running: a feasibility study
    Timothy J Mosher
    Pennsylvania State University Center for NMR Research, Department of Radiology, Milton S Hershey Medical Center, 500 University Drive, Hershey, PA 17033, USA
    Radiology 234:245-9. 2005
    ..These in vivo observations agree well with published ex vivo results and support the hypothesis that cartilage compression results in greater anisotropy of superficial collagen fibers...
  28. ncbi request reprint Theoretical and experimental evaluation of detached endcaps for 3 T birdcage coils
    Marcello Alecci
    FMRIB Centre, Department of Clinical Neurology, University of Oxford, John Radcliffe Hospital, Oxford, UK
    Magn Reson Med 49:363-70. 2003
    ..This novel endcap design is easy to implement with existing birdcage coils, and could prove useful when flexibility in access to the RF coil is required...

Research Grants2

  1. MRI Gradient Coils with Improved Stimulation Threshold
    Christopher Collins; Fiscal Year: 2005
    ..This work will lay the foundation for development of clinically useful head and body gradient coils that can outperform existing coils before inducing PNS. ..
  2. MR Physics Simulation Package for Pulse, Sequence, and Hardware Design
    Christopher Collins; Fiscal Year: 2009
    ....