title: Flow measurements in a blood-perfused collagen vessel using x-ray micro-particle image velocimetry.
abstract: Blood-perfused tissue models are joining the emerging field of tumor engineering because they provide new avenues for modulation of the tumor microenvironment and preclinical evaluation of the therapeutic potential of new treatments. The characterization of fluid flow parameters in such in-vitro perfused tissue models is a critical step towards better understanding and manipulating the tumor microenvironment. However, traditional optical flow measurement methods are inapplicable because of the opacity of blood and the thickness of the tissue sample. In order to overcome the limitations of optical method we demonstrate the feasibility of using phase-contrast x-ray imaging to perform microscale particle image velocimetry (PIV) measurements of flow in blood perfused hydrated tissue-representative microvessels. However, phase contrast x-ray images significantly depart from the traditional PIV image paradigm, as they have high intensity background, very low signal-to-noise ratio, and volume integration effects. Hence, in order to achieve accurate measurements special attention must be paid to the image processing and PIV cross-correlation methodologies. Therefore we develop and demonstrate a methodology that incorporates image preprocessing as well as advanced PIV cross-correlation methods to result in measured velocities within experimental uncertainty.
authors.affiliation: Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia, United States of America.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Antoine
authors.forename: Cara
authors.initials: C
authors.lastname: Buchanan
authors.forename: Kamel
authors.initials: K
authors.lastname: Fezzaa
authors.forename: Wah-Keat
authors.initials: WK
authors.lastname: Lee
authors.forename: M Nichole
authors.initials: MN
authors.lastname: Rylander
authors.forename: Pavlos
authors.initials: P
authors.lastname: Vlachos
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D001783:Blood Flow Velocity; D003094:Collagen / Q000737:chemistry*; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D055806:Microvessels / Q000033:anatomy & histology / Q000502:physiology; D008954:Models, Biological; D009369:Neoplasms / Q000098:blood supply; D012212:Rheology / Q000295:instrumentation / Q000379:methods*; D059629:Signal-To-Noise Ratio; D059016:Tumor Microenvironment; D014965:X-Rays
chemical_list: D003094:Collagen