Random Acquisition of Spectral Projections in Four-Dimensional Spectral-Spatial EPR Imaging: A Feasibility Study...

Area of Science:

• Medical imaging
• Biophysics
• Tumor microenvironment analysis

Background:

• Continuous-wave electron paramagnetic resonance (CW-EPR) imaging requires numerous spectral projections for accurate 4D spectral-spatial data reconstruction, crucial for tumor oxygen mapping.
• Acquiring many projections prolongs imaging time, hindering clinical applicability.

Purpose of the Study:

• To enhance CW-EPR imaging acquisition speed by reducing the number of spectral projections needed.
• To investigate a novel strategy of random spectral projection acquisition combined with data synthesis to maintain image quality.

Main Methods:

• Implemented a strategy of randomly collecting spectral projections and synthesizing the unrecorded ones.
• Applied the developed method to a numerical phantom and a mouse Hs766T xenograft model for validation.
• Utilized the Algebraic Reconstruction Technique (ART) for image reconstruction, which can handle incomplete data sets.

Main Results:

• Demonstrated the feasibility of the random acquisition and synthesis strategy in both phantom and in vivo studies.
• Confirmed that random acquisition prevents image degradation, particularly in linewidth mapping, essential for oxygen mapping.
• Showcased potential for accelerated 4D spectral-spatial imaging in CW-EPR.

Conclusions:

• The proposed method significantly enhances CW-EPR imaging speed without compromising image quality for oxygen mapping.
• Random spectral projection acquisition and data synthesis offer a viable approach to overcome current time limitations in EPR imaging.
• This technique holds promise for more efficient tumor microenvironment characterization using CW-EPR.