METHOD FOR COMPENSATING PHASE ERROR BY USING PHASE ENCODING GRADIENT PULSE IN FAST SPIN ECHO METHOD OF IMAGE

摘要

PURPOSE: A method for compensating a phase error by using a phase encoding gradient pulse in an FSE(fast spin echo) method of image is provided to deteriorate the phenomenon of ringing artifact or blurring of images, and to improve the contrast of the images and the SNR(signal-to-noise ratio). CONSTITUTION: The FSE method of image is comprised of a 90degree RF pulse, several 180degree RF pulses, selected gradient pulses corresponding to the RF pulses, and several echo trains for applying frequency encoding gradient pulses and phase encoding gradient pulses. In a first step, a tuning bi-polar pulse having an amplitude same with a first phase encoding gradient pulse corresponding to a first 180degree RF pulse is applied between the 90degree RF pulse and the first 180degree RF pulse to find a tuning value. The amplitude of the tuning bi-polar pulse is adjusted so that a former point and a latter point of the tuning bi-polar pulse applied point becomes same. By using the adjusted gradient pulse, the pulse error of the first phase encoding gradient pulse is compensated. In this way, all phase encoding gradient pulses corresponding to the several 180degree RF pulses are compensated. Also, the tuning bi-polar pulse is removed when the image is achieved.