×

Temperature measurement near an ice ball using a proton resonance frequency method and recalculation of susceptibility artifacts

  • US 8,706,190 B2
  • Filed: 11/10/2010
  • Issued: 04/22/2014
  • Est. Priority Date: 11/10/2010
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method for magnetic resonance imaging based temperature monitoring for real-time feedback to a physician for a cryoablation therapy of a lesion which creates an ice ball of the lesion to induce cell death, a border of the ice ball having a water physical state, comprising the steps of:

  • with a magnetic resonance imaging system, performing proton resonance frequency (PRF) imaging and obtaining a real-time gradient echo sequence (GRE) phase temperature image of the ice ball of the lesion undergoing the cryoablation therapy and surrounding tissue adjacent the lesion;

    applying an algorithm to said real-time gradient echo sequence phase temperature image that corrects temperature errors at said border of the ice ball, said temperature error correction correcting susceptibility contrast errors caused by a distortion of a local magnetic field resulting from differences in susceptibility between frozen tissue and non-frozen tissue, said algorithm accounting for the susceptibility differences by simulating susceptibility artifacts, wherein said susceptibility differences are determined by searching for a minimum of a cost function defined as a standard deviation at a corrected temperature series, the border of the ice ball being assumed to have a water physical state transition temperature so that the algorithm corrects phase data for the gradient echo sequence phase temperature image for said susceptibility artifacts; and

    said algorithm comprising the following

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×