Browsing by Subject "Photoacoustic imaging"

Now showing 1 - 4 of 4
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    Assessing breast tumor margin by multispectral photoacoustic tomography
    (Optical Society of America, 2015-03-12) Li, Rui; Wang, Pu; Lan, Lu; Lloyd Jr., Frank P.; Goergen, Craig J.; Chen, Shaoxiong; Cheng, Ji-Xin; Department of Pathology and Laboratory Medicine, IU School of Medicine
    An unmet need exists in high-speed and highly-sensitive intraoperative assessment of breast cancer margin during conservation surgical procedures. Here, we demonstrate a multispectral photoacoustic tomography system for breast tumor margin assessment using fat and hemoglobin as contrasts. This system provides ~3 mm tissue depth and ~125 μm axial resolution. The results agreed with the histological findings. A high sensitivity in margin assessment was accomplished, which opens a compelling way to intraoperative margin assessment.
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    Comparative Quantification of Arterial Lipid by Intravascular Photoacoustic-Ultrasound Imaging and Near-Infrared Spectroscopy-Intravascular Ultrasound
    (Springer, 2018-11-28) Kole, Ayeeshik; Cao, Yingchun; Hui, Jie; Bolad, Islam A.; Alloosh, Mouhamad; Cheng, Ji-Xin; Sturek, Michael; Cellular and Integrative Physiology, School of Medicine
    Intravascular photoacoustic-ultrasound (IVPA-US) imaging and near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) are two hybrid modalities that detect arterial lipid, with comparison necessary to understand the relative advantages of each. We performed in vivo and ex vivo IVPA-US imaging of the iliac arteries of Ossabaw swine with metabolic syndrome (MetS) and lean swine to investigate sensitivity for early-stage atherosclerosis. We repeated imaging ex vivo with NIRS-IVUS for comparison to IVPA-US and histology. Both modalities showed significantly greater lipid in MetS vs. lean swine, but only IVPA-US localized the lipid as perivascular. To investigate late-stage atherosclerosis, we performed ex vivo IVPA-US imaging of a human coronary artery with comparison to NIRS-IVUS and histology. Two advanced fibroatheromas were identified, with agreement between IVPA-measured lipid area and NIRS-derived lipid content. As confirmed histologically, IVPA-US has sensitivity to detect lipid content similar to NIRS-IVUS and provides additional depth resolution, enabling quantification and localization of lipid cores within plaques.
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    Photoacoustic tomography of intact human prostates and vascular texture analysis identify prostate cancer biopsy targets
    (Elsevier, 2018-08-03) Bungart, Brittani L.; Lan, Lu; Wang, Pu; Li, Rui; Koch, Michael O.; Cheng, Liang; Masterson, Timothy A.; Dundar, Murat; Cheng, Jin-Xin; Urology, School of Medicine
    Prostate cancer is poorly visualized on ultrasonography (US) so that current biopsy requires either a templated technique or guidance after fusion of US with magnetic resonance imaging. Here we determined the ability for photoacoustic tomography (PAT) and US followed by texture-based image processing to identify prostate biopsy targets. K-means clustering feature learning and testing was performed on separate datasets comprised of 1064 and 1197 nm PAT and US images of intact, ex vivo human prostates. 1197 nm PAT was found to not contribute to the feature learning, and thus, only 1064 nm PAT and US images were used for final feature testing. Biopsy targets, determined by the tumor-assigned pixels' center of mass, located 100% of the primary lesions and 67% of the secondary lesions. In conclusion, 1064 nm PAT and US texture-based feature analysis provided successful prostate biopsy targets.
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    Spectral analysis assisted photoacoustic imaging for lipid composition differentiation
    (Elsevier, 2017-06-06) Cao, Yingchun; Kole, Ayeeshik; Lan, Lu; Wang, Pu; Hui, Jie; Sturek, Michael; Cheng, Ji-Xin; Cellular and Integrative Physiology, School of Medicine
    Recent advances in atherosclerotic plaque detection have shown that not only does lipid core size and depth play important roles in plaque rupture and thrombi formation, but lipid composition, especially cholesterol deposition, is equally important in determining lesion vulnerability. Here, we demonstrate a spectral analysis assisted photoacoustic imaging approach to differentiate and map lipid compositions within an artery wall. The approach is based on the classification of spectral curves obtained from the sliding windows along time-of-flight photoacoustic signals via a numerical k-means clustering method. The evaluation result on a vessel-mimicking phantom containing cholesterol and olive oil shows accuracy and efficiency of this method, suggesting the potential to apply this approach in assessment of atherosclerotic plaques.