Combined dynamic contrast enhanced ultrasound and multispectral optoacoustic tomography for imaging tumour hypoxia

Optoacoustic imaging has demonstrated potential for imaging tumour micovasculature and hypoxia but provides limited information on haemodynamics. Conversely, dynamic contrast enhanced ultrasound (DCE-US) is widely used to evaluate perfusion. This study describes a novel method of co-registering optoacoustic tomography images with DCE-US images to demonstrate, in preclinical cancer models, the value of combining the two imaging modalities. Imaging results showed the importance of the combinative imaging approach for interpreting optoacoustic images, demonstrating that not all regions which lack an optoacoustic blood-signal are entirely avascular; some are just poorly perfused. Furthermore, significant differences of potential biological importance were observed between the microbubble time intensity curve parameters of image regions that lacked, versus those which possessed, an optoacoustic blood-signal.