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Michael Smith
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Title Professor
Institution College of Medicine
Department Radiology
Address 500 University Drive Hershey PA 17033
 Mailbox: H066
Telephone 7175316069
Email
Background
PREFERRED TITLE/ROLE:

Professor Radiology, and Cellular and Molecular Physiology

SECONDARY APPOINTMENT(S)/ INSTITUTE(S)/ CENTER(S):

Cellular and Molecular Physiology

GRADUATE PROGRAM AFFILIATIONS:

Physiology, Bioengineering

EDUCATION:

Ph.D., University of Arkansas, 1978
Postdoctoral Training, University of Wisconsin, 1979-1981
Postdoctoral Training, Oxford University, 1982-1984

NARRATIVE:

The efforts of our laboratory are divided into a number of projects all concerning the use of in vivo NMR spectroscopy and imaging. The research can be classified into three areas: human studies, animal/biochemical studies, and technological development.

We are currently involved in a study to use NMR to monitor the effects of birth asphyxia or neonatal hypoxia. 31P NMR spectroscopy provides an excellent monitor of the biochemical energetics of the neonatal rat brain. This allows the examination of the effects of selected drugs and their possible protective actions against hypoxia. T2-weighted magnetic resonance imaging is used to evaluate infarct size and/or edema. The model will eventually be used to evaluate the cerebral damage and subsequent treatment of infants.

A project has recently been initiated in which the behavior of the radiofrequency magnetic field is modeled under the conditions of frequency, dielectric constant, and conductivity that would be expected for an NMR experiment in human tissue. Computer modeling of this type allows for the prediction of artifacts in spectroscopy and imaging due to perturbations caused by induced eddy currents and inductive losses of the radiofrequency coil. These models also allow the generation of specific coil geometries to solve many problems accompanying in vivo NMR applications.

The Center for Nuclear Magnetic Resonance Imaging (NMR) Research at the Hershey Medical Center has a new 3.0 Tesla instrument (MEDSPEC S300) that was built by Bruker Medizintechnik, a German company and a leader in the magnetiresonance field. It has many hardware and software capabilities unavailable to previous whole body systems. The system is equipped with a new design of actively shielded gradient coils whose high speed switching allows ultrafast imaging.

Ultrafast imaging using the echo planar technique allows images of the head or body to be obtained in only 32 msec. The higher magnetic field strength of this new 3.0 Tesla instrument provides greater signal sensitivity and sensitivity to paramagnetic materials, such as iron in blood. Ogawa et al. observed changes in the image intensity with a decrease in blood oxygen. This technique referred to as functional imaging was extended using the rapid speed of echo planar imaging to monitor brain oxygenation in real time. At 3.0 Tesla, contrast changes due to deoxygenation from brain activity should produce intensity changes of up to 20%. Functional imaging produces results very similar to PET (Positron Emission Tomography) without the need of injecting radioactive materials. The work of the laboratory is further supported by computer simulations of magnetic fields in high resolution models of the human body. In the theoretical description of an RF field (B1) in the human body, the dimension of the resonator and human sample are assumed to be small compared to the resonant wavelength. The wavelengths inside the human sample are shorter than in free space. Dielectric resonance inside the human sample further complicates the analysis of the loaded coil and B1 field in the load. A thorough description of these problems requires the use of microwave theory. Using finite element analysis, we have calculated the full wave numerical solution of Maxwell equations for MRI Birdcage resonators with and without load. The threedimensional (3D) electromagnetic field and current distributions corresponding to the various microwave modes can be presented, and the effects of dielectric resonance in the human body can be detailed. This results in both better coil design and analysis of regional radiofrequency field depositions in the tissue.
Publications
1. Yang QX, Wang J, Wang J, Collins CM, Wang C, Smith MB. Reducing SAR and enhancing cerebral signal-to-noise ratio with high permittivity padding at 3 T. Magn Reson Med. 2011 Feb; 65(2):358-62.
  View in: PubMed
 
2. Meadowcroft MD, Connor JR, Smith MB, Yang QX. MRI and histological analysis of beta-amyloid plaques in both human Alzheimer's disease and APP/PS1 transgenic mice. J Magn Reson Imaging. 2009 May; 29(5):997-1007.
  View in: PubMed
 
3. Wang Z, Lin JC, Mao W, Liu W, Smith MB, Collins CM. SAR and temperature: simulations and comparison to regulatory limits for MRI. J Magn Reson Imaging. 2007 Aug; 26(2):437-41.
  View in: PubMed
 
4. Meadowcroft MD, Zhang S, Liu W, Park BS, Connor JR, Collins CM, Smith MB, Yang QX. Direct magnetic resonance imaging of histological tissue samples at 3.0T. Magn Reson Med. 2007 May; 57(5):835-41.
  View in: PubMed
 
5. Collins CM, Wang Z, Mao W, Fang J, Liu W, Smith MB. Array-optimized composite pulse for excellent whole-brain homogeneity in high-field MRI. Magn Reson Med. 2007 Mar; 57(3):470-4.
  View in: PubMed
 
6. Yang QX, Mao W, Wang J, Smith MB, Lei H, Zhang X, Ugurbil K, Chen W. Manipulation of image intensity distribution at 7.0 T: passive RF shimming and focusing with dielectric materials. J Magn Reson Imaging. 2006 Jul; 24(1):197-202.
  View in: PubMed
 
7. Zinnanti WJ, Lazovic J, Wolpert EB, Antonetti DA, Smith MB, Connor JR, Woontner M, Goodman SI, Cheng KC. A diet-induced mouse model for glutaric aciduria type I. Brain. 2006 Apr; 129(Pt 4):899-910.
  View in: PubMed
 
8. Collins CM, Liu W, Swift BJ, Smith MB. Combination of optimized transmit arrays and some receive array reconstruction methods can yield homogeneous images at very high frequencies. Magn Reson Med. 2005 Dec; 54(6):1327-32.
  View in: PubMed
 
9. Collins CM, Liu W, Schreiber W, Yang QX, Smith MB. Central brightening due to constructive interference with, without, and despite dielectric resonance. J Magn Reson Imaging. 2005 Feb; 21(2):192-6.
  View in: PubMed
 
10. Yang QX, Wang J, Smith MB, Meadowcroft M, Sun X, Eslinger PJ, Golay X. Reduction of magnetic field inhomogeneity artifacts in echo planar imaging with SENSE and GESEPI at high field. Magn Reson Med. 2004 Dec; 52(6):1418-23.
  View in: PubMed
 
11. Mosher TJ, Smith HE, Collins C, Liu Y, Hancy J, Dardzinski BJ, Smith MB. Change in knee cartilage T2 at MR imaging after running: a feasibility study. Radiology. 2005 Jan; 234(1):245-9.
  View in: PubMed
 
12. Yang QX, Wang J, Collins CM, Smith MB, Zhang X, Ugurbil K, Chen W. Phantom design method for high-field MRI human systems. Magn Reson Med. 2004 Nov; 52(5):1016-20.
  View in: PubMed
 
13. Mosher TJ, Liu Y, Yang QX, Yao J, Smith R, Dardzinski BJ, Smith MB. Age dependency of cartilage magnetic resonance imaging T2 relaxation times in asymptomatic women. Arthritis Rheum. 2004 Sep; 50(9):2820-8.
  View in: PubMed
 
14. Collins CM, Smith MB, Turner R. Model of local temperature changes in brain upon functional activation. J Appl Physiol. 2004 Dec; 97(6):2051-5.
  View in: PubMed
 
15. Lazovic-Stojkovic J, Mosher TJ, Smith HE, Yang QX, Dardzinski BJ, Smith MB. Interphalangeal joint cartilage: high-spatial-resolution in vivo MR T2 mapping--a feasibility study. Radiology. 2004 Oct; 233(1):292-6.
  View in: PubMed
 
16. Collins CM, Liu W, Wang J, Gruetter R, Vaughan JT, Ugurbil K, Smith MB. Temperature and SAR calculations for a human head within volume and surface coils at 64 and 300 MHz. J Magn Reson Imaging. 2004 May; 19(5):650-6.
  View in: PubMed
 
17. Mosher TJ, Collins CM, Smith HE, Moser LE, Sivarajah RT, Dardzinski BJ, Smith MB. Effect of gender on in vivo cartilage magnetic resonance imaging T2 mapping. J Magn Reson Imaging. 2004 Mar; 19(3):323-8.
  View in: PubMed
 
18. Mosher TJ, Chen Q, Smith MB. 1H magnetic resonance spectroscopy of nanomelic chicken cartilage: effect of aggrecan depletion on cartilage T2. Osteoarthritis Cartilage. 2003 Oct; 11(10):709-15.
  View in: PubMed
 
19. Collins CM, Smith MB. 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. J Magn Reson Imaging. 2003 Sep; 18(3):383-8.
  View in: PubMed
 
20. Yang QX, Lindquist MA, Shepp L, Zhang CH, Wang J, Smith MB. Two dimensional prolate spheroidal wave functions for MRI. J Magn Reson. 2002 Sep-Oct; 158(1-2):43-51.
  View in: PubMed
 
21. Bus SA, Yang QX, Wang JH, Smith MB, Wunderlich R, Cavanagh PR. Intrinsic muscle atrophy and toe deformity in the diabetic neuropathic foot: a magnetic resonance imaging study. Diabetes Care. 2002 Aug; 25(8):1444-50.
  View in: PubMed
 
22. Collins CM, Yang B, Yang QX, Smith MB. Numerical calculations of the static magnetic field in three-dimensional multi-tissue models of the human head. Magn Reson Imaging. 2002 Jun; 20(5):413-24.
  View in: PubMed
 
23. Yang QX, Wang J, Zhang X, Collins CM, Smith MB, Liu H, Zhu XH, Vaughan JT, Ugurbil K, Chen W. Analysis of wave behavior in lossy dielectric samples at high field. Magn Reson Med. 2002 May; 47(5):982-9.
  View in: PubMed
 
24. Smith HE, Mosher TJ, Dardzinski BJ, Collins BG, Collins CM, Yang QX, Schmithorst VJ, Smith MB. Spatial variation in cartilage T2 of the knee. J Magn Reson Imaging. 2001 Jul; 14(1):50-5.
  View in: PubMed
 
25. Cornett JA, Herr MD, Gray KS, Smith MB, Yang QX, Sinoway LI. Ischemic exercise and the muscle metaboreflex. J Appl Physiol. 2000 Oct; 89(4):1432-6.
  View in: PubMed
 
26. Lee F, Shoemaker JK, McQuillan PM, Kunselman AR, Smith MB, Yang QX, Smith H, Gray K, Sinoway LI. Effects of forearm bier block with bretylium on the hemodynamic and metabolic responses to handgrip. Am J Physiol Heart Circ Physiol. 2000 Aug; 279(2):H586-93.
  View in: PubMed
 
27. Mosher TJ, Dardzinski BJ, Smith MB. Human articular cartilage: influence of aging and early symptomatic degeneration on the spatial variation of T2--preliminary findings at 3 T. Radiology. 2000 Jan; 214(1):259-66.
  View in: PubMed
 
28. Yang QX, Demeure RJ, Dardzinski BJ, Arnold BW, Smith MB. Multiple echo frequency-domain image contrast: improved signal-to-noise ratio and T2 (T2*) weighting. Magn Reson Med. 1999 Feb; 41(2):423-8.
  View in: PubMed
 
29. Ettinger SM, Silber DH, Gray KS, Smith MB, Yang QX, Kunselman AR, Sinoway LI. Effects of the ovarian cycle on sympathetic neural outflow during static exercise. J Appl Physiol. 1998 Dec; 85(6):2075-81.
  View in: PubMed
 
30. Silber DH, Sutliff G, Yang QX, Smith MB, Sinoway LI, Leuenberger UA. Altered mechanisms of sympathetic activation during rhythmic forearm exercise in heart failure. J Appl Physiol. 1998 May; 84(5):1551-9.
  View in: PubMed
 
31. Dardzinski BJ, Li S, Collins CM, Williams GD, Smith MB. A birdcage coil tuned by RF shielding for application at 9.4 T. J Magn Reson. 1998 Mar; 131(1):32-8.
  View in: PubMed
 
32. Dardzinski BJ, Mosher TJ, Li S, Van Slyke MA, Smith MB. Spatial variation of T2 in human articular cartilage. Radiology. 1997 Nov; 205(2):546-50.
  View in: PubMed
 
33. Shoemaker JK, Pandey P, Herr MD, Silber DH, Yang QX, Smith MB, Gray K, Sinoway LI. Augmented sympathetic tone alters muscle metabolism with exercise: lack of evidence for functional sympatholysis. J Appl Physiol. 1997 Jun; 82(6):1932-8.
  View in: PubMed
 
34. Yang QX, Dardzinski BJ, Li S, Eslinger PJ, Smith MB. Multi-gradient echo with susceptibility inhomogeneity compensation (MGESIC): demonstration of fMRI in the olfactory cortex at 3.0 T. Magn Reson Med. 1997 Mar; 37(3):331-5.
  View in: PubMed
 
35. Yang QX, Posse S, Le Bihan D, Smith MB. Double-sampled echo-planar imaging at 3 tesla. J Magn Reson B. 1996 Nov; 113(2):145-50.
  View in: PubMed
 
36. Ettinger SM, Silber DH, Collins BG, Gray KS, Sutliff G, Whisler SK, McClain JM, Smith MB, Yang QX, Sinoway LI. Influences of gender on sympathetic nerve responses to static exercise. J Appl Physiol. 1996 Jan; 80(1):245-51.
  View in: PubMed
 
37. Williams GD, Smith MB. Application of the accurate assessment of intracellular magnesium and pH from the 31P shifts of ATP to cerebral hypoxia-ischemia in neonatal rat. Magn Reson Med. 1995 Jun; 33(6):853-7.
  View in: PubMed
 
38. Sinoway LI, Smith MB, Enders B, Leuenberger U, Dzwonczyk T, Gray K, Whisler S, Moore RL. Role of diprotonated phosphate in evoking muscle reflex responses in cats and humans. Am J Physiol. 1994 Aug; 267(2 Pt 2):H770-8.
  View in: PubMed
 
39. Batman BA, Hardy JC, Leuenberger UA, Smith MB, Yang QX, Sinoway LI. Sympathetic nerve activity during prolonged rhythmic forearm exercise. J Appl Physiol. 1994 Mar; 76(3):1077-81.
  View in: PubMed
 
40. Williams GD, Mosher TJ, Smith MB. Simultaneous determination of intracellular magnesium and pH from the three 31P NMR Chemical shifts of ATP. Anal Biochem. 1993 Nov 1; 214(2):458-67.
  View in: PubMed
 
41. Sinoway LI, Rea RF, Mosher TJ, Smith MB, Mark AL. Hydrogen ion concentration is not the sole determinant of muscle metaboreceptor responses in humans. J Clin Invest. 1992 Jun; 89(6):1875-84.
  View in: PubMed
 
42. Williams GD, Palmer C, Roberts RL, Heitjan DF, Smith MB. 31P NMR spectroscopy of perinatal hypoxic-ischemic brain damage: a model to evaluate neuroprotective drugs in immature rats. NMR Biomed. 1992 May-Jun; 5(3):145-53.
  View in: PubMed
 
43. Smith MB, Tassone RF, Mosher TJ. Potential health risk due to cardiac applications of echo planar imaging. Ann N Y Acad Sci. 1992 Mar 31; 649:359-62.
  View in: PubMed
 
44. Mosher TJ, Williams GD, Doumen C, LaNoue KF, Smith MB. Error in the calibration of the MgATP chemical-shift limit: effects on the determination of free magnesium by 31P NMR spectroscopy. Magn Reson Med. 1992 Mar; 24(1):163-9.
  View in: PubMed
 
45. Williams GD, Enders B, Smith MB. Effect of pH and inorganic phosphate on creatine kinase inactivation: an in vitro 31P NMR saturation-transfer study. Biochem Int. 1992 Feb; 26(1):35-42.
  View in: PubMed
 
46. Sterns DA, Ettinger SM, Gray KS, Whisler SK, Mosher TJ, Smith MB, Sinoway LI. Skeletal muscle metaboreceptor exercise responses are attenuated in heart failure. Circulation. 1991 Nov; 84(5):2034-9.
  View in: PubMed
 
47. Masiakos PT, Williams GD, Berkich DA, Smith MB, LaNoue KF. 31P NMR saturation-transfer study of the in situ kinetics of the mitochondrial adenine nucleotide translocase. Biochemistry. 1991 Aug 27; 30(34):8351-7.
  View in: PubMed
 
48. Mosher TJ, Smith MB. Magnetic susceptibility measurement using a double-DANTE tagging (DDT) sequence. Magn Reson Med. 1991 Mar; 18(1):251-5.
  View in: PubMed
 
49. Berkich DA, Williams GD, Masiakos PT, Smith MB, Boyer PD, LaNoue KF. Rates of various reactions catalyzed by ATP synthase as related to the mechanism of ATP synthesis. J Biol Chem. 1991 Jan 5; 266(1):123-9.
  View in: PubMed
 
50. Mosher TJ, Smith MB. A DANTE tagging sequence for the evaluation of translational sample motion. Magn Reson Med. 1990 Aug; 15(2):334-9.
  View in: PubMed
 
51. Palmer C, Smith MB. Assessing the risk of kernicterus using nuclear magnetic resonance. Clin Perinatol. 1990 Jun; 17(2):307-29.
  View in: PubMed
 
 
Keyword
Last Name
Institution
    
 
 
 
Keywords   
Magnetic Resonance Imaging
Image Enhancement
Cartilage, Articular
Head
Knee Joint
See all (196) keywords
Co-Authors  
Collins, Christopher
Mosher, Timothy
Silber, David
Sinoway, Lawrence
Yang, Qing
See all (16) people
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