Patent ID: 7610077

Claim:
A method of determining a physical or chemical parameter in physiological tissues, in vivo, by employing MRI or NMR spectroscopy, said method comprising: administering a CEST contrast agent to a subject; determining an exchange rate of the CEST agent at a specified location in vivo; and comparing said exchange rate to a standard curve to determine a physical or chemical parameter at said specified location, wherein determining the exchange rate of the CEST agent at a specified location in vivo comprises: irradiating of said subject, while in a magnetic field, at a first CEST resonant RF strength for a time period equal to or greater than T 1 ; measuring magnetization of said subject upon irradiating said subject at a first CEST resonant RF strength to obtain a first magnetization value; irradiating said subject, while in the magnetic field, at a second CEST resonant RF strength for a time period equal to or greater than T 1 , wherein said second CEST resonant RF strength is greater than said first CEST resonant RF strength; measuring magnetization of said subject upon irradiating said subject at a second CEST resonant RF strength to obtain second magnetization value; and ascertaining exchange rate of said CEST agent by employing said first CEST resonant RF strength, said second CEST resonant RF strength, said first magnetization value and said second magnetization value.