Scaling law for noise variance and spatial resolution in differential phase contrast computed tomography
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)
Purpose: The noise variance versus spatial resolution relationship in differential phase contrast (DPC) projection imaging and computed tomography (CT) are derived and compared to conventional absorption-based x-ray projection imaging and CT. Methods: The scaling law for DPC-CT is theoretically derived and subsequently validated with phantom results from an experimental Talbot-Lau interferometer system. Results: For the DPC imaging method, the noise variance in the differential projection images follows the same inverse-square law with spatial resolution as in conventional absorption-based x-ray imaging projections. However, both in theory and experimental results, in DPC-CT the noise variance scales with spatial resolution following an inverse linear relationship with fixed slice thickness. Conclusions: The scaling law in DPC-CT implies a lesser noise, and therefore dose, penalty for moving to higher spatial resolutions when compared to conventional absorption-based CT in order to maintain the same contrast-to-noise ratio.
- OSTI ID:
- 22096898
- Journal Information:
- Medical Physics, Journal Name: Medical Physics Journal Issue: 2 Vol. 38; ISSN 0094-2405; ISSN MPHYA6
- Country of Publication:
- United States
- Language:
- English
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