Reliability assessment on intravascular photoacoustic imaging of lipid: ex vivo animal and human sample validation

Abstract

Although the lipid-detecting IVPA imaging system has been developed in resolution, speed, and catheter size, there is no parameterization study of the reliability on the IVPA imaging for lipid diagnosis. Here, the sensitivity, specificity, and accuracy were calculated to assess the reliability of the IVPA imaging of lipid. Abdominal aortas from six rabbits with atherosclerosis, were subjected to the IVPA imaging and Oil Red O staining, and 75 groups of IVPA as well as corresponding histological images were obtained. Similarly, 125 groups of IVPA and histological results were obtained from five human carotid plaque samples. The sensitivity, specificity, and accuracy, calculated from the statistical data, were 96.8%, 83.3%, 94.6% and 97.3%, 72.7%, 95.2%, respectively. The numerical values of sensitivity, specificity, and accuracy demonstrated the reliability of IVPA imaging on distinguishing the lesions vessel with lipid-rich plaque, which provided the foundation for IVPA translation to clinical application.

Current Strategies of Photoacoustic Imaging Assisted Cancer Theragnostics toward Clinical Studies

“…Endogenous contrast agents are mainly natural chromophores present in the organism, such as melanin, heme, hemoglobin, lipids, and water. Indeed, endogenous contrast agents for PA is a label-free strategy that enabled high-sensitivity detection of functional changes of angiogenesis without affecting the physiological processes of the organisms and the approval of regulatory authorities. − Nevertheless, endogenous agents could not provide an ideal signal source for molecular imaging with high contrast in some circumstances. It is necessary to add an exogenous contrast medium to improve the PA signal intensity of biological tissue.…”

Review on Laser Technology in Intravascular Imaging and Treatment

“…Lei et al achieved the IVPA system with the lateral resolution of 13 μm and the ultrafine imaging catheter with a diameter of 0.7 mm ( Fig. 5D ) [ 101 , 102 ]. Fiber optic technologies take advantages of the flexibility and compactness of the optical fiber, which facilitate the miniaturization of catheter size [ 45 ].…”

“…Recently, Wang et al displayed the distribution and the relative concentration of lipid by the tapered fiber-based IVPA/US imaging catheter, which provides more parameters for the accurate assessment of atherosclerotic plaque [ 103 ]. Lei et al assessed the reliability of the IVPA/US imaging of lipid by a parametric study [ 102 ]. The sensitivity, specificity, and accuracy of the IVPA/US imaging were 96.8%, 83.3%, 94.6% and 97.3%, 72.7%, 95.2%, respectively, in rabbit abdominal aorta and human plaque.…”

Photoacoustic Tomography Appearance of Fat Necrosis: A First-in-Human Demonstration of Biochemical Signatures along with Histological Correlation

“…Photoacoustic (PA) tomography, a hybrid optical imaging modality, is based on the light-induced ultrasound waves providing the contrast of optical imaging combined with the high spatial resolution of ultrasound [ 5 ]. Its ability to provide the distribution of endogenous chromophores, such as blood oxygenation [ 6 ], water [ 7 ], lipid [ 7 , 8 , 9 , 10 ] and recently collagen [ 11 , 12 ], makes it attractive as a potential adjunct tool to various aspects of ultrasound. This is particularly useful in regions abundant with these chromophores, such as superficial soft tissues and the breast, or in fat-containing and fibrotic/necrotic conditions, such as fat necrosis.…”