Four-dimensional photoacoustic imaging of moving targets.
Photoacoustic imaging provides optical contrast with improved tissue penetration and spatial resolution compared to pure optical techniques. Three-dimensional photoacoustic imaging is particularly advantageous for visualizing non-planar light absorbing structures, such as blood vessels, internal organs or tumours. We have developed a fast 3-D photoacoustic imaging system for small animal research based on a sparse array of ultrasonic detectors and iterative image reconstruction. The system can acquire 3-D images with a single laser-shot at a frame rate of 10 Hz. To demonstrate the imaging capabilities we have constructed phantoms made of a scanning point source and a rotating line object and imaged them at a rate of 10 frames per second. The resulting 4-D photoacoustic images depicted well the motion of each target. Comparison of the perceived motion in the images with the known velocity of the target showed good agreement. To our knowledge, this is the first report of single-shot high frame-rate 3-D photoacoustic imaging system. With further developments, this system could bring to bear its inherent speed for applications in small animal research, such as motion tracking of tumour outline during respiration, and rapid monitoring of contrast agent kinetics.
Ephrat
Pinhas
P
Imaging Program, Lawson Health Research Institute, St. Joseph's Health Care, 268 Grosvenor Street, London, Ontario N6A 4V2, Canada.
Roumeliotis
Michael
M
Prato
Frank S
FS
Carson
Jeffrey J L
JJ
D000162:Acoustics; D003287:Contrast Media / Q000494:pharmacology; D003952:Diagnostic Imaging / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007700:Kinetics; D033401:Microscopy, Acoustic / Q000379:methods; D009038:Motion; D009369:Neoplasms / Q000175:diagnosis* / Q000473:pathology; D055095:Optics and Photonics; D010363:Pattern Recognition, Automated / Q000379:methods; D019047:Phantoms, Imaging; D041622:Tomography, Optical / Q000379:methods
D003287:Contrast Media