Visualization of tumor-related blood vessels in human breast by photoacoustic imaging system with a hemispherical detector array

Abstract

Noninvasive measurement of the distribution and oxygenation state of hemoglobin (Hb) inside the tissue is strongly required to analyze the tumor-associated vasculatures. We developed a photoacoustic imaging (PAI) system with a hemispherical-shaped detector array (HDA). Here, we show that PAI system with HDA revealed finer vasculature, more detailed blood-vessel branching structures, and more detailed morphological vessel characteristics compared with MRI by the use of breast shape deformation of MRI to PAI and their fused image. Morphologically abnormal peritumoral blood vessel features, including centripetal photoacoustic signals and disruption or narrowing of vessel signals, were observed and intratumoral signals were detected by PAI in breast cancer tissues as a result of the clinical study of 22 malignant cases. Interestingly, it was also possible to analyze anticancer treatment-driven changes in vascular morphological features and function, such as improvement of intratumoral blood perfusion and relevant changes in intravascular hemoglobin saturation of oxygen. This clinical study indicated that PAI appears to be a promising tool for noninvasive analysis of human blood vessels and may contribute to improve cancer diagnosis.

Photoacoustic imaging depth comparison at 532-, 800-, and 1064-nm wavelengths: Monte Carlo simulation and experimental validation

“…Therefore, first near-infrared window (NIR-I) (700 to 900 nm) is widely used for sample illumination in PAI rather than visible (400 to 600 nm) region for deep tissue imaging. [23][24][25][26] Although imaging depth is increased in NIR-I, it comes with a cost of a bulky, inefficient, expensive two-stage [Ti:sapphire, dye, or optical parametric oscillator (OPO)] laser needed to generate the light in this window. Recently, a second window of near-infrared region (NIR-II, 900 to 1200 nm) has been used for PAI.…”

Photoacoustic imaging system visualizes restoration of peripheral oxygenation in psoriatic lesions

“…Editor I appreciate Dr. Ferreira's thoughtful comments on my short piece about MUDS. 1,2 Importantly, and correctly, she stresses that using the term 'medically unexplained' to patients can perpetuate symptoms and cause heightened anxiety and depression. One needs to be careful to not give patients the impression that their symptoms are hopeless because they are physically unexplained.…”

Optoacoustic model-based inversion using anisotropic adaptive total-variation regularization

“…Since the texture within the blood vessels is affected by the random distribution of the red-blood cells within the blood vessels, its elimination by A 2 TV may be considered as an acceptable price for better visualization of the blood-vessel morphology. In deeptissue OAT systems, sub-millimeter vasculature imaging has been suggested as a potential diagnostic tool and has been demonstrated in the human extremities [39,40] and breast [41]. We note that while some OAT systems can also produce images of the tissue bulk, characterized by low frequencies and representative of the density of the microvasculature and fluence map, such systems require transducers capable of detecting ultrasound frequencies considerably below 1 MHz [6].…”