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Browsing by Author "Lan, Lu"
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Item 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 MedicineAn 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.Item Cylindrical illumination with angular coupling for whole-prostate photoacoustic tomography(Optical Society of America, 2019-02-22) Bungart, Brittani; Cao, Yingchun; Yang-Tran, Tiffany; Gorsky, Sean; Lan, Lu; Roblyer, Darren; Koch, Michael O.; Cheng, Liang; Masterson, Timothy; Cheng, Ji-Xin; Department of Medicine, IU School of MedicineCurrent diagnosis of prostate cancer relies on histological analysis of tissue samples acquired by biopsy, which could benefit from real-time identification of suspicious lesions. Photoacoustic tomography has the potential to provide real-time targets for prostate biopsy guidance with chemical selectivity, but light delivered from the rectal cavity has been unable to penetrate to the anterior prostate. To overcome this barrier, a urethral device with cylindrical illumination is developed for whole-prostate imaging, and its performance as a function of angular light coupling is evaluated with a prostate-mimicking phantom.Item A fiber optoacoustic guide with augmented reality for precision breast-conserving surgery(Springer Nature, 2018-05-18) Lan, Lu; Xia, Yan; Li, Rui; Liu, Kaiming; Mai, Jieying; Medley, Jennifer Anne; Obeng-Gyasi, Samilia; Han, Linda K.; Wang, Pu; Cheng, Ji-Xin; Radiology and Imaging Sciences, School of MedicineLumpectomy, also called breast-conserving surgery, has become the standard surgical treatment for early-stage breast cancer. However, accurately locating the tumor during a lumpectomy, especially when the lesion is small and nonpalpable, is a challenge. Such difficulty can lead to either incomplete tumor removal or prolonged surgical time, which result in high re-operation rates (~25%) and increased surgical costs. Here, we report a fiber optoacoustic guide (FOG) with augmented reality (AR) for sub-millimeter tumor localization and intuitive surgical guidance with minimal interference. The FOG is preoperatively implanted in the tumor. Under external pulsed light excitation, the FOG omnidirectionally broadcasts acoustic waves through the optoacoustic effect by a specially designed nano-composite layer at its tip. By capturing the acoustic wave, three ultrasound sensors on the breast skin triangulate the FOG tip's position with 0.25-mm accuracy. An AR system with a tablet measures the coordinates of the ultrasound sensors and transforms the FOG tip's position into visual feedback with <1-mm accuracy, thus aiding surgeons in directly visualizing the tumor location and performing fast and accurate tumor removal. We further show the use of a head-mounted display to visualize the same information in the surgeons' first-person view and achieve hands-free guidance. Towards clinical application, a surgeon successfully deployed the FOG to excise a "pseudo tumor" in a female human cadaver. With the high-accuracy tumor localization by FOG and the intuitive surgical guidance by AR, the surgeon performed accurate and fast tumor removal, which will significantly reduce re-operation rates and shorten the surgery time.Item High‐speed Intraoperative Assessment of Breast Tumor Margins by Multimodal Ultrasound and Photoacoustic Tomography(Wiley, 2018) Lu, Rui; Lan, Lu; Xia, Yan; Wang, Pu; Han, Linda K.; Dunnington, Gary L.; Obeng-Gyasi, Samilia; Sandusky, George E.; Medley, Jennifer A.; Crook, Susan T.; Cheng, Ji-Xin; Medicine, School of MedicineConventional methods for breast tumor margins assessment need a long turnaround time, which may lead to re‐operation for patients undergoing lumpectomy surgeries. Photoacoustic tomography (PAT) has been shown to visualize adipose tissue in small animals and human breast. Here, we demonstrate a customized multimodal ultrasound and PAT system for intraoperative breast tumor margins assessment using fresh lumpectomy specimens from 66 patients. The system provides the margin status of the entire excised tissue within 10 minutes. By subjective reading of three researchers, the results show 85.7% [95% confidence interval (CI), 42.0% ‐ 99.2%] sensitivity and 84.6% (95% CI, 53.7% ‐ 97.3%) specificity, 71.4% (95% CI, 30.3% ‐ 94.9%) sensitivity and 92.3% (95% CI, 62.1% ‐ 99.6%) specificity, and 100% (95% CI, 56.1% ‐ 100%) sensitivity and 53.9% (95% CI, 26.1% ‐ 79.6%) specificity respectively when cross‐correlated with post‐operational histology. Furthermore, a machine learning‐based algorithm is deployed for margin assessment in the challenging ductal carcinoma in situ tissues, and achieved 85.5% (95% CI, 75.2% ‐ 92.2%) sensitivity and 90% (95% CI, 79.9% ‐ 95.5%) specificity. Such results present the potential of using mutlimodal ultrasound and PAT as a high‐speed and accurate method for intraoperative breast tumor margins evaluation.Item 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 MedicineProstate 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.Item 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 MedicineRecent 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.