title: Combined ultrasound and photoacoustic imaging to detect and stage deep vein thrombosis: phantom and ex vivo studies.
abstract: Treatment of deep venous thrombosis (DVT)--a primary cause of potentially fatal pulmonary embolism (PE)--depends on the age of the thrombus. The existing clinical imaging methods are capable of visualizing a thrombus but cannot determine the age of the blood clot. Therefore, there is a need for an imaging technique to reliably diagnose and adequately stage DVT. To stage DVT (i.e., to determine the age of the thrombus, and therefore, to differentiate acute from chronic DVT), we explored photoacoustic imaging, a technique capable of noninvasive measurements of the optical absorption in tissue. Indeed, optical absorption of the blood clot changes with age, since maturation of DVT is associated with significant cellular and molecular reorganization. The ultrasound and photoacoustic imaging studies were performed using DVT-mimicking phantoms and phantoms with embedded acute and chronic thrombi obtained from an animal model of DVT. The location and structure of the clots were visualized using ultrasound imaging, while the composition, and therefore age, of thrombi were related to the magnitude and spatiotemporal characteristics of the photoacoustic signal. Overall, the results of our study suggest that combined ultrasound and photoacoustic imaging of thrombi may be capable of simultaneous detection and staging of DVT.
authors.affiliation: University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas 78712, USA.
authors.forename: Andrei B
authors.initials: AB
authors.lastname: Karpiouk
authors.forename: Salavat R
authors.initials: SR
authors.lastname: Aglyamov
authors.forename: Srivalleesha
authors.initials: S
authors.lastname: Mallidi
authors.forename: Jignesh
authors.initials: J
authors.lastname: Shah
authors.forename: W Guy
authors.initials: WG
authors.lastname: Scott
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Rubin
authors.forename: Stanislav Y
authors.initials: SY
authors.lastname: Emelianov
mesh_terms: D000818:Animals; D054459:Elasticity Imaging Techniques / Q000295:instrumentation / Q000379:methods*; D007089:Image Enhancement / Q000379:methods*; D033401:Microscopy, Acoustic / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D018511:Systems Integration; D020246:Venous Thrombosis / Q000175:diagnosis*