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Methods for imaging pulmonary and cardiac vasculature and evaluating blood flow using dissolved polarized 129Xe

  • US 6,346,229 B1
  • Filed: 03/17/1999
  • Issued: 02/12/2002
  • Est. Priority Date: 03/18/1998
  • Status: Expired due to Term
First Claim
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1. A method for MRI imaging the pulmonary and/or cardiac vasculature using dissolved-phase polarized 129Xe, comprising the steps of:

  • delivering polarized 129Xe gas to a predetermined region of the patient'"'"'s body, the polarized gas having a dissolved imaging phase associated therewith;

    exciting a predetermined region of the patient'"'"'s body having a portion of the dissolved phase polarized gas therein with at least one large flip angle RF excitation pulse;

    acquiring at least one MR image associated with the dissolved phase polarized gas after said exciting step, wherein said delivering step includes having the patient inhale the polarized 129Xe gas into the lungs, the polarized 129Xe having a gas phase resonance which is higher than the dissolved-phase resonance, and wherein at least a portion of the polarized 129Xe gas enters into the pulmonary vasculature in a dissolved-phase, and wherein at least a portion of the dissolved-phase polarized 129Xe then enters the blood stream with an associated perfusion rate wherein a differential MRI image is obtained which comprising data associated with the physiology of the lungs of the patient, the physiology of the vasculature of the patient, blood flow in the patient, and perfusion in the patient, the data corresponding to both the 129Xe gas and dissolved-gas phase, and wherein said differential image is obtained by exciting the 129Xe gas phase with an RF pulse having an excitation pulse frequency which corresponds to the resonance of the gas phase and exciting the dissolved phase with an RF pulse having an excitation frequency which corresponds to the resonance of the dissolved phase, and wherein the gas phase RF excitation pulse is a small flip angle pulse and the dissolved phase RF excitation pulse is a large flip angle pulse.

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