Nerve imaging for surgical guidance

Sparing nerve during surgical procedure such as radical prostatectomy is crucial in minimizing post-operative complication. In this project, we aim to provide intra-operative functional nerve localization. Voltage-sensitive-dye imaging was developed by using fluorescence (FL) and photoacoustic (PA) imaging, where the optical contrast upon membrane potential variation was identified. In particular, PA imaging showed depth-profiling of…

Molecular photoacoustic imaging using spectroscopic reconstruction algorithms for prostate-specific membrane antigen (PSMA)-targeted imaging

We have developed a molecular PA imaging system capable of visualizing PSMA molecular contrast in vivo. We have designed a series of PA imaging contrast agents composed of three functional parts (Figure 1). The middle component is a linker that tethers the PSMA ligand to bulky optical dyes such as IRDye800CW, ICG, and Alexafluor750, which…

Large scale, real-time, transcranial neurophysiology imaging

The feasibility of transcranial functional PA imaging of cerebral oxygenation in the piglet brain (5-day old, 2kg) was demonstrated (Figure 1a). Multi-spectral PA data were collected (700-900 nm in 10-nm intervals) while applying various fractional inspired oxygen (FiO2) levels to induce graded hypoxia. The ground-truth sO2 was also measured by direct sampling of venous blood…

Large scale, real-time, transcranial electrophysiological recording

PA imaging has a potential to sense the electrophysiological state of biological tissue. Voltage sensitive dyes are designed to monitor membrane potential by detecting fluorescence changes in response to neuronal or muscle electrical activity. Through our collaboration with Prof. Les Loew (University of Connecticut) who pioneered VSD synthesis, we have reported the first PA VSD…

Diagnostic Ultrasound Megahertz Signal Detection with Multi-bounce Laser Microphone

For clinical diagnosis and surgical monitoring and guidance, many imaging modalities are able to non-invasively show regional anatomy and position details, but few of them are able to provide functional information. Monitoring the concentration of metabolism-related species or bio-markers could also be helpful during surgery and in interventional imaging. For example, to determine whether the…

Molecular imaging of aggressive prostate tumor, targeting prostate-specific membrane antigen

H. K. Zhang, Y. Chen, J. Kang, A. Lisok, M. G. Pomper, E. M. Boctor, “Prostate specific membrane antigen-targeted photoacoustic imaging of prostate cancer in vivo,” Journal of Biophotonics 11(9), e201800021, 1 Sep. 2018 Y. Wu, W. Lesniak, J. Kang, S. Ray, M. G. Pomper, E. M. Boctor, “Multispectral photoacoustic imaging of aggressive prostate cancer in vivo using PAMAM dendrimer conjugated agent,” IEEE International…

Transcranial sensing of cerebral physiology to prevent perinatal hypoxic-ischemic encephalopathy & stroke

J. Kang, R. C. Kohler, S. Adams, E. M. Graham, and E. M. Boctor, “Light-emitting diode-based transcranial photoacoustic measurement of sagittal sinus oxyhemoglobin saturation in hypoxic neonatal piglets,” bioRxiv 262451, 24 Aug. 2020 J. Kang, E. M. Boctor, S. Adams, E. Kulikowicz, H. K. Zhang, R. C Koehler, E. M Graham “Validation of noninvasive photoacoustic measurements of…

Listening to membrane potential

J. Kang, S. D. Kadam, J. Elmore, B. J. Sullivan, H. Valentine, A. P. Malla, M. M. Harraz, A. Rahmim, J. U. Kang, L. M. Loew, M. Baumann, A. A. Grace, A. Gjedde, E. M. Boctor, and D. F. Wong, “Transcranial photoacoustic imaging of NMDA-evoked focal circuit dynamics in rat hippocampus,” Journal of Neural Engineering 17(2), 025001, 8…

Ultrasound tomography reconstruction using deep learning methods

The current technique for prostate cancer detection is B-mode transrectal ultrasound (TRUS) guided systematic core needle biopsy. However, due to the limited sensitivity and capability of categorizing aggressiveness of prostate cancer in B-mode images, additional imaging modality such as magnetic resonance imaging (MRI) is necessary to support targeted biopsies. To reduce the imaging cost, we…