Dr. Lina Hacker Profile

Dr. Lina Hacker

at Univ of Oxford

SPIE Involvement:

Author

Publications (25)

SPIE Journal Paper | 14 August 2024 Open Access

Tutorial on phantoms for photoacoustic imaging applications

Lina Hacker, James Joseph, Ledia Lilaj, Srirang Manohar, Aoife Ivory, Ran Tao, Sarah Bohndiek, Members of IPASC

JBO, Vol. 29, Issue 08, 080801, (August 2024) https://doi.org/10.1117/12.10.1117/1.JBO.29.8.080801

KEYWORDS: Acoustics, Materials properties, Tissues, Standards development, Imaging systems, Photoacoustic imaging, Optical properties, Biomedical applications, Design, Calibration

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SPIE Journal Paper | 11 June 2024 Open Access

Tutorial on methods for estimation of optical absorption and scattering properties of tissue

Ran Tao, Janek Gröhl, Lina Hacker, Antonio Pifferi, Darren Roblyer, Sarah E. Bohndiek

JBO, Vol. 29, Issue 06, 060801, (June 2024) https://doi.org/10.1117/12.10.1117/1.JBO.29.6.060801

KEYWORDS: Tissues, Scattering, Optical properties, Absorption, Tissue optics, Signal detection, Diffusion, Light scattering, Light sources and illumination, Light absorption

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SPIE Journal Paper | 5 June 2024 Open Access

Distribution-informed and wavelength-flexible data-driven photoacoustic oximetry

Janek Gröhl, Kylie Yeung, Kevin Gu, Thomas R. Else, Monika Golinska, Ellie V. Bunce, Lina Hacker, Sarah E. Bohndiek

JBO, Vol. 29, Issue S3, S33303, (June 2024) https://doi.org/10.1117/12.10.1117/1.JBO.29.S3.S33303

KEYWORDS: Education and training, Computer simulations, In vivo imaging, Blood, Tissues, Error analysis, Oximetry, Network architectures, Acoustics, Photoacoustic spectroscopy

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Proceedings Article | 13 March 2024 Presentation

Early radiotherapy response assessment using multi-scale photoacoustic imaging in breast cancer models

Thierry Lefebvre, Mariam-Eleni Oraiopoulou, Ellie Bunce, Monika Golinska, Thomas Else, Paul Sweeney, Lina Hacker, Steven Kupczak, Yi Cheng, Lisa Young, Sarah Bohndiek

Proceedings Volume PC12842, PC128420M (2024) https://doi.org/10.1117/12.3002821

KEYWORDS: Radiotherapy, Photoacoustic imaging, Tumor growth modeling, Breast cancer, Oxygenation, Multispectral imaging, Tomography, Visualization, Photoacoustic spectroscopy, Oxygen

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Proceedings Article | 13 March 2024 Poster

The international photoacoustic standardization consortium: on the path towards a standardized phantom for photoacoustic imaging

Lina Hacker, James Joseph, Ledia Lilaj, Srirang Manohar, Aoife Ivory, Ran Tao, Tom Else, Sarah Bohndiek

Proceedings Volume PC12842, PC128421Y (2024) https://doi.org/10.1117/12.3003056

KEYWORDS: Photoacoustic spectroscopy, Fabrication, Reproducibility, Copolymers, Optical properties, Imaging systems, Acoustics, Titanium dioxide, Polymers, Photoacoustic imaging

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Proceedings Article | 13 March 2024 Presentation

The International Photoacoustic Standardization Consortium: consensus on properties of tissue-mimicking phantom materials in photoacoustic imaging

Lina Hacker, James Joseph, Ledia Lilaj, Srirang Manohar, Sarah Bohndiek

Proceedings Volume PC12842, PC1284213 (2024) https://doi.org/10.1117/12.3000533

KEYWORDS: Materials properties, Photoacoustic spectroscopy, Photoacoustic imaging, Acoustics, Optical properties, Tissue optics, Scattering, Reproducibility, Optics manufacturing, Manufacturing

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Proceedings Article | 13 March 2024 Presentation

Enabling longitudinal quantitative photoacoustic mesoscopy of vascular networks through image co-registration

Thierry Lefebvre, Paul Sweeney, Janek Gröhl, Lina Hacker, Emma Brown, Thomas Else, Mariam-Eleni Oraiopoulou, Algernon Bloom, David Lewis, Sarah Bohndiek

Proceedings Volume PC12842, PC128421G (2024) https://doi.org/10.1117/12.3002744

KEYWORDS: Image segmentation, Photoacoustic spectroscopy, Photoacoustic imaging, Mathematical optimization, Image processing algorithms and systems, Deformation, Image resolution, Education and training, Ear, Deep learning

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Proceedings Article | 13 March 2024 Presentation

On the path towards standardized phantoms in photoacoustic imaging: prospects, challenges, and future directions

Lina Hacker

Proceedings Volume PC12862, PC128620Y (2024) https://doi.org/10.1117/12.3026088

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SPIE Journal Paper | 20 December 2023 Open Access

Effects of skin tone on photoacoustic imaging and oximetry

Thomas R. Else, Lina Hacker, Janek Gröhl, Ellie V. Bunce, Ran Tao, Sarah E. Bohndiek

JBO, Vol. 29, Issue S1, S11506, (December 2023) https://doi.org/10.1117/12.10.1117/1.JBO.29.S1.S11506

KEYWORDS: Skin, Blood, Photoacoustic spectroscopy, Oxygenation, Monte Carlo methods, Tissue optics, Photoacoustic imaging, Oximetry, Image restoration, Reflectivity

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SignificancePhotoacoustic imaging (PAI) provides contrast based on the concentration of optical absorbers in tissue, enabling the assessment of functional physiological parameters such as blood oxygen saturation (sO2). Recent evidence suggests that variation in melanin levels in the epidermis leads to measurement biases in optical technologies, which could potentially limit the application of these biomarkers in diverse populations.AimTo examine the effects of skin melanin pigmentation on PAI and oximetry.ApproachWe evaluated the effects of skin tone in PAI using a computational skin model, two-layer melanin-containing tissue-mimicking phantoms, and mice of a consistent genetic background with varying pigmentations. The computational skin model was validated by simulating the diffuse reflectance spectrum using the adding-doubling method, allowing us to assign our simulation parameters to approximate Fitzpatrick skin types. Monte Carlo simulations and acoustic simulations were run to obtain idealized photoacoustic images of our skin model. Photoacoustic images of the phantoms and mice were acquired using a commercial instrument. Reconstructed images were processed with linear spectral unmixing to estimate blood oxygenation. Linear unmixing results were compared with a learned unmixing approach based on gradient-boosted regression.ResultsOur computational skin model was consistent with representative literature for in vivo skin reflectance measurements. We observed consistent spectral coloring effects across all model systems, with an overestimation of sO2 and more image artifacts observed with increasing melanin concentration. The learned unmixing approach reduced the measurement bias, but predictions made at lower blood sO2 still suffered from a skin tone-dependent effect.ConclusionPAI demonstrates measurement bias, including an overestimation of blood sO2, in higher Fitzpatrick skin types. Future research should aim to characterize this effect in humans to ensure equitable application of the technology.

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Proceedings Article | 17 March 2023 Presentation

Multispectral filter arrays for early cancer detection in endoscopy

Katie-Lou White, Calum Williams, Lina Hacker, Sarah Bohndiek

Proceedings Volume PC12361, PC1236105 (2023) https://doi.org/10.1117/12.2648855

KEYWORDS: Multispectral imaging, Endoscopy, Cameras, Cancer, Optical filters, Near infrared, Diagnostics, RGB color model, Luminescence, Imaging systems

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