System and method for controlling apparent timing dependencies for T2-weighted MRI imaging

摘要

A system and method for imaging includes applying an RF excitation pulse to a region-of-interest (ROI) in the presence of a first slice selective gradient and applying a readout gradient to acquire a echo signal from the ROI, wherein a time between the RF excitation pulse and the echo signal define an echo time (TE). A saturation module is applied to the ROI including an RF pulse configured to provide a TE-independent steady state and enforcing a predetermined time period (TR0) selected to elapse between the RF pulse of the saturation module and a subsequent application of the RF excitation pulse during repetitions of the above-described portions of the process. An image of the ROI is reconstructed using the acquired echo signals, for example, a T2-weighted image having reduced underestimations of T2 that plague traditional T2-weighted imaging processes using a short TR with a spin-echo (SE) pulse sequence.

主权项

1. A magnetic resonance imaging (MRI) system comprising:
a magnet system configured to generate a polarizing magnetic field about at least a region of interest (ROI) of a subject arranged in the MRI system; a plurality of gradient coils configured to apply a gradient field with respect to the polarizing magnetic field; a radio frequency (RF) system configured to apply RF excitation fields to the subject and a acquire MR image data therefrom; and a computer programmed to control the plurality of gradient coils and the RF system to perform the following steps:
a) apply an RF excitation pulse to the ROI in the presence of a first slice selective gradient;b) apply a refocusing RF pulse to the ROI in the presence of a second slice selective gradient;c) apply a readout gradient to acquire a echo signal from the ROI;d) apply a saturation module to the ROI including an RF pulse configured to saturate both transverse and longitudinal magnetization in the ROI;e) enforce a predetermined time period (TR0) selected to elapse between the RF pulse of the saturation module and a subsequent application of the RF excitation pulse during a repetition of steps a) through d);f) repeat steps a) through e) a plurality of times; andg) reconstruct an image of the ROI using the acquired echo signals.