Label-free photoacoustic imaging of human palmar vessels: a structural morphological analysis

Abstract

We analysed the vascular morphology of the palm using a photoacoustic tomography (PAT) instrument with a hemispherical detector array. The three-dimensional (3D) morphology of blood vessels was determined noninvasively. Overall, 12 females and 11 males were recruited as healthy volunteers. Their ages were distributed almost evenly from 22 to 59 years. In all cases, many vascular networks were observed just beneath the skin and were determined to be veins anatomically. To analyse the major arteries, the layer containing the subcutaneous venous network was removed from the image. The analysis focused on the common and proper palmar digital arteries. We used the curvature of these arteries as a parameter to analyse their morphologies. There was no significant difference in the curvature between genders when comparing the subjects as a whole. The blood vessel curvature increased with age. Good agreement was found between the 3D numerical analysis results and the subjective evaluation of the two-dimensional (2D) projection image. The PAT system enabled visualization of the 3D features of blood vessels in the palm and noninvasive analysis of arterial tortuousness.

Image-guided filtering for improving photoacoustic tomographic image reconstruction

“…More importantly, as the noise is known to be existing in the high frequency components, it is able to eliminate noise effectively. In these cases, the Pearson correlation 88,89 (PC) between (a) and others was utilized to correlate these spectrums, which is known to be invariant to scale in the frequency spectrums to provide required normalization. The PC values given in Fig.…”

Photoacoustic imaging system visualizes restoration of peripheral oxygenation in psoriatic lesions

“…To address this need, we adopted a prototype PAI device (PAI-04; Canon Inc., Tokyo, Japan) that enables wide-field in vivo imaging of the peripheral vasculatures along with oxygenation status. [4][5][6] Psoriasis is a chronic inflammatory skin disease that affects 2%-3% of the general population. 7 There is a growing concern that psoriasis causes accelerated atherosclerosis, probably due to chronically elevated inflammatory cytokines.…”

Non‐invasive imaging in dermatology and the unique potential of raster‐scan optoacoustic mesoscopy

“…While macroscopic optoacoustic methods using broad illumination schemes and ultrasound detector arrays penetrate as deep as 3 cm and have been used for imaging larger vessels and pilot measurements of melanoma thickness, their resolution (typically 100-300 lm) is not sufficient for imaging the small dermal vasculature. [47][48][49] Microscopic optoacoustic devices, on the other hand, employ focused light to generate ultrasound signals from a very confined area. This allows for high-resolution imaging that resolves the superficial microvasculature.…”