In vivo Estimation of Murine Myocardial Oxygenation with Physiological Signal Gating and Motion Compensation

Photoacoustic Imaging (PAI) with high persistence (multiple frame averaging) has been utilized to quantify murine myocardial oxygenation (
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) in vivo. But these methods may not be suitable to identify subtle
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variations associated with ischemia and suffer from lower spatiotemporal resolution due to averaging. We propose a physiological signal gated PAI technique with motion compensation that addresses these issues termed OPMC (Oxygenation estimation with Physiological signal gating and Motion Compensation). Our OPMC method involved adaptive beamforming (photoacoustic sub aperture processing), spatiotemporal singular value decomposition and inter wavelength motion compensation. Results from one mouse show that OPMC enabled evaluation of the temporal progression of myocardial oxygen saturation over a cardiac cycle. For example, we observed higher
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values at end-diastole (≈ 80%) which gradually reduced during systole (≈ 72 %) and finally recovering to higher oxygenation at diastole (≈800/0) for the mouse under consideration.