Analysis of three-dimensional photoacoustic imaging of a vascular tree in vitro

Abstract

We used photoacoustics in order to image a vasculature cast, which was obtained from a Wistar rat. The main objective was to investigate the imaging quality and the performance of the beamforming algorithm. For these purposes, the specimen was measured in several Intralipid™ 10% solutions and it was scanned with scanning steps of 100, 200, and 300 μm. The measurements were performed with a disk-shaped detector, with PVDF as an active material and four fibers for the light delivery. From the recorded signals, three-dimensional images of the cast were constructed.

Development of a catheter for combined intravascular ultrasound and photoacoustic imaging

“…[22][23][24] A number of scientific groups successfully use the photoacoustic technique for vascular applications. [25][26][27][28][29][30] Previously, we investigated the feasibility of IVPA imaging using commercially available IVUS imaging catheters. 15 The excised tissue samples were imaged with the IVUS catheter located inside of a lumen, while the vessel was externally irradiated, and the capability of the combined IVUS/IVPA imaging to detect and differentiate atherosclerotic plaques was demonstrated.…”

Photoacoustic Imaging of Brain Perfusion on Albino Rats by Using Evans Blue as Contrast Agent

“…As can be seen in Figure 1, in the region of green light (532 nm), haemoglobin presents an absorption coefficient (m a ) almost 1000 times higher than the bloodless dermis, while in the infrared (700-1064 nm) this drops to 100 times. As a result of that, a stronger PA signal could be generated from blood by using 20 mm and 0.5 mm depending on the wavelength and the detection system (Hoelen et al, 1998(Hoelen et al, , 2001Hoelen & de Mul, 2000;Pilatou et al, 2003b). Thus, the resolving power is comparable or even better than that of ultrasound and of several optical methods (Benaron et al, 1997;Coatney, 2001).…”

“…However, it has also been utilized for visualization of internal structures (tomography) and for quantitative estimation of internal local absorption patterns (tomometry). The technique has been applied for imaging breast tumors (Esenaliev et al, 1997;Kruger et al, 2000;Karabutov et al, 2001;Oraevsky et al, 2001a), skin vascular structures (Pilatou, 2003b), vascular abnormalities (Viator et al, 2002) and for imaging inflamed cancerous tissue (Jacques et al, 2000). Furthermore, the ability of photoacoustics has been demonstrated to determine tissue characteristics (Beard & Mills, 1997), make a depth profile of human skin (Paltauf & Schmidt-Kloiber, 2000), measure changes in the blood circulation (Kolkman, 2002;Pilatou, 2003a) and to image the brain of SpragueDawley rats (Wang et al, 2003).…”

In vivo volumetric imaging of subcutaneous microvasculature by photoacoustic microscopy

“…The spatial resolution of PA imaging is determined by the ultrasonic parameters [13], and, thus far, an imaging depth of 9 mm and a resolution of 10 µm [7] has been reported. Previously, three-dimensional (3D) PA images have been acquired from phantoms [7], ex vivo blood vessels [8], large in vivo human blood vessels [9], and in vivo animal brains [10]. However, imaging of both anatomy and functions of microvasculatures in three dimensions in vivo has not been reported yet.…”

“…Photoacoustic (PA) imaging [3,[7][8][9][10][11][12]] is a hybrid imaging modality based on optical absorption contrast and ultrasonic localization; it provides volumetric imaging of subcutaneous microvasculature with high spatial resolution at large depths. In PA imaging, a short laser pulse illuminates the biological tissue.…”