Vibrational Photoacoustic Tomography: Chemical Imaging beyond the Ballistic Regime.
Proof-of-concept of vibrational photoacoustic tomography is demonstrated with a homebuilt Raman laser generating greater than 100 mJ of energy per pulse at 1197 nm wavelength. We employed this system for excitation of second overtone transition of C-H bonds. Vibrational photoacoustic signal from C-H rich polyethylene tube phantom placed under 3 cm thick chicken breast tissue was obtained with a signal to noise ratio of 2.5. Further, we recorded photoacoustic image of a polyethylene ring placed under 5 mm chicken tissue with excellent contrast. This development opens new opportunities of performing label free vibrational imaging in the deep tissue regime.
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
Justin Rajesh
JR
Rajian
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
Rui
R
Li
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
Pu
P
Wang
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA.
Ji-Xin
JX
Cheng
Photoacoustic tomography; Raman laser; lipid; molecular vibration