Figure 4.

Oxygen saturation and tumor perfusion kinetics in a heterogeneous orthotopic pancreatic tumor. A) Representative Oxy-Hemo PA imaging of a heterogeneous orthotopic pancreatic cancer. B-mode image and oxygen saturation map (Oxy-Hemo photoacoustic imaging) are placed side-by-side showing the same imaging window. PA-derived oxygen saturation map is displayed as in figure 2. The green and yellow lines represent different tumor regions. Average O₂ saturation levels are presented above the tumor regions in green and yellow, respectively. B) Microbubble wash-in curve of different tumor regions after bolus i.v. injection of microbubbles. C) Peak enhancement quantified by Vevo CQ^TM. The heat map represents contrast signal peak enhancement, range from 30 (red) to 10 (blue) dB. A higher tumor perfusion is observed in region 1 compared to region 2.