Quantitative analysis on in vivo tumor‐microvascular images from optical‐resolution photoacoustic microscopy

Abstract

Optical‐resolution photoacoustic microscopy (OR‐PAM) has been shown to be an excellent imaging modality for monitoring and study of tumor microvasculature. However, previous studies focused mainly on the normal tissues and did not quantify the tumor microvasculature. In this study, we present an in vivo OR‐PAM imaging of the melanomas and hepatoma implanted in the mouse ear. We quantify the vessel growth by extracting the skeletons of both dense and thin branches of the tumor microvasculature obtained by Hessian matrix enhancement followed by improved two‐step multistencils fast marching method. Compared with the previous methods of using OR‐PAM for normal tissues, our method was more effective in extracting the binary vascular network in the tumor images and in obtaining the complete and continuous microvascular skeleton maps. Our demonstration of using OR‐PAM in improving microvasculature of tumors and quantification of tumor growth would push deep this technology for the early diagnosis and treatment of cancers.

Wide‐field monitoring and real‐time local recording of microvascular networks on small animals with a dual‐raster‐scanned photoacoustic microscope

“…The vascular density was represented as the ratio of all vessel pixels to the overall pixels of ROI by binarizing the image. The vascular tortuosity was assessed by measuring the ratio between the actual path length of a vessel segment in each subdomain and the linear distance between the two ends of the vessel . The PA intensity was determined by calculating the mean intensity of surrounding the specified point.…”

The role of Notch ligand, Delta-like ligand 4 (DLL4), in cancer angiogenesis—implications for therapy

“…This process is assisted by the basal membrane and the pericytes that cover the endothelial envelope. In the final stage, they accumulate with primary blood vessels and form tumour perfusion [3][4][5]. Significantly pathological tumour blood vessels are deficient.…”

Photoacoustic and ultrasound (PAUS) dermoscope with high sensitivity and penetration depth by using a bimorph transducer

“…Photoacoustic imaging (PAI), based on photoacoustic effect, is a hybrid biomedical imaging technology that combines high-contrast optical imaging and deeppenetration ultrasound imaging (USI) [1][2][3][4][5][6][7][8][9][10][11]. Photoacoustic microscopy (PAM) is an important application mode of PAI technology [12][13][14][15][16]. Conventional PAM systems based on a single-element ultrasonic transducer are increasingly being used in many biomedical applications [17,18], especially in clinical detection of skin diseases, such as precision assessment of psoriasis [19], port wine stain [20], skin melanoma [21] and basal cell carcinoma [22], all of which, demonstrate that PAM has significant potential for various biomedical applications and clinical research.…”