1997 Volume 53 Issue 12 Pages 1789-1794
Image uniformity refers to the ability of the MR imaging system to produce a constant signal response throughout the scanned volume when the object being imaged has homogeneous MR characteristics. To facilitate the determination of image uniformity in diagnostic magnetic resonance images, reports such as the NEMA Standard and AAPM report have been issued. However, these methods of evaluation are impractical in cases such as the day-to-day quality control of the machine or comparisons between the different MR systems, because these methods affect the signa-to-noise ratio(SNR) and create problems by displaying nonuniformity locations. Therefore, we present a new method for evaluating uniformity, called the test segment method. The influence of SNR on the NEMA test and the segment method were examined. In addition, the results of the two methods were compared for certain nonuniformity conditions, Results showed that the segment method did not affect SNR and provided good display of nonuniformity.
