(Sunday, 7/12/2020) [Eastern Time (GMT-4)]
Room: AAPM ePoster Library
Purpose: To quantify the impact of a z resolution enhancement reconstruction technique in axial CT image reconstruction on standard reconstruction metrics.
Methods: The Fine Z image reconstruction option (GE Healthcare, Waukesha WI) enables enhancement of the Z resolution through a combination of adaptive z detail enhancement in the projection and the image space. It takes advantage of the rich data available when there is overlap in the image space, i.e. 0.625mm thickness with a 0.3125mm interval. In the same manner that reconstruction kernels have been used for years to improve in-plane spatial resolution, the Fine Z option enables enhanced z resolution with the associated trade-off of increased image noise.
The z resolution was assessed on the Revolution CT with the standard sloped wire methodology where in-plane measurements of the length of a sloped wire (slope 4:1) are used to assess z axis spatial resolution. Data was acquired for 4 z locations to cover the complete 160mm z extent, reconstructed with the bone plus kernel with 14mm DFOV. Noise was assessed with measurements from a 20cm water phantom, reconstructed with bone plus kernel 25cm DFOV.
Results: The average improvement in ratio [FineZ/Orig] for the zMTF was: 1.35 (50% MTF) and 1.30 (10% MTF). The std dev of the image noise increased by a ratio of 1.22 [FineZ/Orig].
Conclusion: This work indicates the potential for image kernel like behavior in the z direction. This may be beneficial for high resolution tasks where there is a desire to increase the image sharpness in the z direction.
Funding Support, Disclosures, and Conflict of Interest: The authors are employees of GE Healthcare.
Keywords
Not Applicable / None Entered.
Taxonomy
Not Applicable / None Entered.
Contact Email
