High Resolution Ultrasound Superharmonic Perfusion Imaging: In Vivo Feasibility and Quantification of Dynamic Contrast-Enhanced Acoustic Angiography.
Mapping blood perfusion quantitatively allows localization of abnormal physiology and can improve understanding of disease progression. Dynamic contrast-enhanced ultrasound is a low-cost, real-time technique for imaging perfusion dynamics with microbubble contrast agents. Previously, we have demonstrated another contrast agent-specific ultrasound imaging technique, acoustic angiography, which forms static anatomical images of the superharmonic signal produced by microbubbles. In this work, we seek to determine whether acoustic angiography can be utilized for high resolution perfusion imaging in vivo by examining the effect of acquisition rate on superharmonic imaging at low flow rates and demonstrating the feasibility of dynamic contrast-enhanced superharmonic perfusion imaging for the first time. Results in the chorioallantoic membrane model indicate that frame rate and frame averaging do not affect the measured diameter of individual vessels observed, but that frame rate does influence the detection of vessels near and below the resolution limit. The highest number of resolvable vessels was observed at an intermediate frame rate of 3 Hz using a mechanically-steered prototype transducer. We also demonstrate the feasibility of quantitatively mapping perfusion rate in 2D in a mouse model with spatial resolution of ~100 μm. This type of imaging could provide non-invasive, high resolution quantification of microvascular function at penetration depths of several centimeters.
Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, USA.
Brooks D
BD
Lindsey
Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, USA.
Sarah E
SE
Shelton
Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, USA.
K Heath
KH
Martin
Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, USA.
Kathryn A
KA
Ozgun
Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, USA.
Juan D
JD
Rojas
Sunnybrook Health Sciences Centre, Toronto, ON, Canada.
F Stuart
FS
Foster
Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Raleigh, NC, USA. padayton@email.unc.edu.|Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. padayton@email.unc.edu.
Paul A
PA
Dayton
D000792:Angiography / Q000379:methods*; D000818:Animals; D002642:Chick Embryo; D049033:Chorioallantoic Membrane / Q000098:blood supply / Q000000981:diagnostic imaging; D003287:Contrast Media / Q000494:pharmacology*; D045423:Microbubbles / Q000627:therapeutic use*; D055420:Perfusion Imaging / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*
D003287:Contrast Media
Angiogenesis; High frequency; Low flow imaging; Microbubble; Perfusion; Quantitative imaging; Superharmonic; Ultrasound