Reliability assessment for blood oxygen saturation levels measured with optoacoustic imaging.
- Ulrich L University of Bern, Institute of Applied Physics, Biomedical Photonics, Bern, Switzerland.
- Held KG University of Bern, Institute of Applied Physics, Biomedical Photonics, Bern, Switzerland.
- Jaeger M University of Bern, Institute of Applied Physics, Biomedical Photonics, Bern, Switzerland.
- Frenz M University of Bern, Institute of Applied Physics, Biomedical Photonics, Bern, Switzerland.
- Akarçay HG University of Bern, Institute of Applied Physics, Biomedical Photonics, Bern, Switzerland.
- 2020-04-24
Published in:
- Journal of biomedical optics. - 2020
English
SIGNIFICANCE
Quantitative optoacoustic (OA) imaging has the potential to provide blood oxygen saturation (SO2) estimates due to the proportionality between the measured signal and the blood's absorption coefficient. However, due to the wavelength-dependent attenuation of light in tissue, a spectral correction of the OA signals is required, and a prime challenge is the validation of both the optical characterization of the tissue and the SO2.
AIM
We propose to assess the reliability of SO2 levels retrieved from spectral fitting by measuring the similarity of OA spectra to the fitted blood absorption spectra.
APPROACH
We introduce a metric that quantifies the trends of blood spectra by assigning a pair of spectral slopes to each spectrum. The applicability of the metric is illustrated with in vivo measurements on a human forearm.
RESULTS
We show that physiologically sound SO2 values do not necessarily imply a successful spectral correction and demonstrate how the metric can be used to distinguish SO2 values that are trustworthy from unreliable ones.
CONCLUSIONS
The metric is independent of the methods used for the OA data acquisition, image reconstruction, and spectral correction, thus it can be readily combined with existing approaches, in order to monitor the accuracy of quantitative OA imaging.
Quantitative optoacoustic (OA) imaging has the potential to provide blood oxygen saturation (SO2) estimates due to the proportionality between the measured signal and the blood's absorption coefficient. However, due to the wavelength-dependent attenuation of light in tissue, a spectral correction of the OA signals is required, and a prime challenge is the validation of both the optical characterization of the tissue and the SO2.
AIM
We propose to assess the reliability of SO2 levels retrieved from spectral fitting by measuring the similarity of OA spectra to the fitted blood absorption spectra.
APPROACH
We introduce a metric that quantifies the trends of blood spectra by assigning a pair of spectral slopes to each spectrum. The applicability of the metric is illustrated with in vivo measurements on a human forearm.
RESULTS
We show that physiologically sound SO2 values do not necessarily imply a successful spectral correction and demonstrate how the metric can be used to distinguish SO2 values that are trustworthy from unreliable ones.
CONCLUSIONS
The metric is independent of the methods used for the OA data acquisition, image reconstruction, and spectral correction, thus it can be readily combined with existing approaches, in order to monitor the accuracy of quantitative OA imaging.
- Language
-
- English
- Open access status
- gold
- Identifiers
-
- DOI 10.1117/1.JBO.25.4.046005
- PMID 32323509
- Persistent URL
- https://sonar.ch/global/documents/284765
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