Patent ID: 6518757
Filing Date: 2003-02-11
Classification: G01N

Abstract:
A method for performing phase encoded inside-out magnetic resonance imaging, comprising steps of:(a) applying a static magnetic field in a volume of an earth formation surrounding a borehole which polarizes the nuclear spin within the volume of earth formation; (b) applying an excitation pulse into the formation that rotates the nuclear spin from a longitudinal axis of the static magnetic field to a plane transverse thereto; (c) applying a sequence of refocusing pulses a period of time after termination of the excitation pulse to generate a plurality of echoes; (d) detecting the echoes from the formation induced by each pulse in the sequence of refocusing pulses; (e) advancing the phase of the nuclear spin in the volume of earth formation by altering the magnetic field such that for a period of time, the strength of the magnetic field in the volume is spatially dependent; (f) repeating steps (c) through (e) until a desired number of echoes are obtained; (g) adding the echoes of each refocusing sequence to generate an average echo for each refocusing sequence; and (h) generating an image from the averaged echoes.