SU-E-I-35: Investigation of Commercially Available Image Uniformity Filters in MRI Imaging

Authors


Abstract

Purpose:

To investigate and compare the performance of two types of imaging filters that are used in commercial MRI scanners to improve the image uniformity for phased array coil imaging.

Methods:

ACR QC phantom and manufacturer supplied sphere phantom were used and the axial images were acquired using the ACR standard T1 protocol and a standard clinical axial T1 protocol. The scanner platform used in the measurement is an open-bore 3T system (GE MRI 750w). An 8 Channel HD phased array head coil was used. The image acquisition was done with no imaging filter, a calibration based filter (PURE), and an image based filter (SCIC). The Percentage Image Uniformity (PIU) was calculated according to the ACR guideline. Profile plot of the images were obtained to assess detailed performance of the filters. The ROI at the center of the sphere phantom across different slices were also recorded.

Results:

The PIU values are 74.5% (no filter), 81.6% (PURE), and 92.1 (SCIC). Only the result from the SCIC filter would pass the ACR accreditation criteria. The profile plot also shows that the PURE leaves a valley like shape towards the center of the phantom. However, due to the factor that PURE filter utilizes the information from a volumetric calibration; it yields more uniform intensity across slices.

Conclusion:

This work indicates that the SCIC filter yields the highest in-plane uniformity value, but the PURE filter yields better cross slice uniformity. The choice of filter for clinical imaging may depend on specific applications. The result needs to be verified for consistency on multiple systems using both phantoms and patients to fully understand the impact on image quality.

Ancillary