Linear-array-based photoacoustic imaging of human microcirculation with a range of high frequency transducer probes

• Published in: Journal of biomedical optics Vol. 20; no. 5; p. 051021
• Main Authors: Zafar, Haroon, Breathnach, Aedán, Subhash, Hrebesh M, Leahy, Martin J
• Format: Journal Article
• Language: English
• Published: United States Society of Photo-Optical Instrumentation Engineers 01.05.2015
• Subjects: Biomedical materials; Forearm; Forearm - pathology; Healthy Volunteers; Hemoglobin; Human; Humans; Image Processing, Computer-Assisted - methods; Imaging; Imaging, Three-Dimensional - instrumentation; Imaging, Three-Dimensional - methods; Microcirculation; Microscopy, Acoustic - instrumentation; Microscopy, Acoustic - methods; Optics and Photonics; Oxygen - chemistry; Polyamide-imides; Reproducibility of Results; Skin - diagnostic imaging; Skin - pathology; Surgical implants; Three dimensional; Transducers; Ultrasonography - instrumentation; Ultrasonography - methods; high frequency ultrasound; photoacoustic; microcirculation imaging; linear-array transducer
• ISSN: 1083-3668; 1560-2281; 1560-2281
• DOI: 10.1117/1.JBO.20.5.051021

Photoacoustic imaging (PAI) with a linear-array-based probe can provide a convenient means of imaging the human microcirculation within its native structural context and adds functional information. PAI using a multielement linear transducer array combined with multichannel collecting system was used for in vivo volumetric imaging of the blood microcirculation, the total concentration of hemoglobin (HbT), and the hemoglobin oxygen saturation (sO2) within human tissue. Three-dimensional (3-D) PA and ultrasound (US) volumetric scans were acquired from the forearm skin by linearly translating the transducer with a stepper motor over a region of interest, while capturing two-dimensional images using 15, 21, and 40 MHz frequency transducer probes. For the microvasculature imaging, PA images were acquired at 800- and 1064-nm wavelengths. For the HbT and sO2 estimates, PA images were collected at 750- and 850-nm wavelengths. 3-D microcirculation, HbT, and sO2 maps of the forearm skin were obtained from normal subjects. The linear-array-based PAI has been found promising in terms of resolution, imaging depth, and imaging speed for in vivo microcirculation imaging within human skin. We believe that a reflection type probe, similar to existing clinical US probes, is most likely to succeed in real clinical applications. Its advantages include ease of use, speed, and familiarity for radiographers and clinicians.