Program Information
Development and Characterization of a Temporally Stable Tissue-Mimicking Photoacoustic-Ultrasonic Phantom
T Mitcham1 , J Lynch2 , J Cook3 , S Emelianov3 , R Bouchard1*, (1) UT MD Anderson Cancer Center, Houston, Texas, (2) CIRS, Inc., Norfolk, Virginia, (3) University of Texas at Austin, Austin, TX
Presentations
SU-E-I-26 Sunday 3:00PM - 6:00PM Room: Exhibit HallPurpose: To quantify the tissue-mimicking properties and temporal stability of a novel tissue-mimicking photoacoustic-ultrasonic (PAUS) imaging phantom.
Methods: Nine phantoms containing titanium wire targets were formulated from a Zerdine base with varying degrees of Intralipid and India ink dye to generate distinct scattering and absorption characteristics. India ink was included in three concentrations (0.01%, 0.005%, or 0.0025% by mass), while Intralipid comprised 12.5%, 25%, or 37.5% of the sample by mass. These scattering/absorption agents were combined in a 3x3 matrix to generate unique properties for each phantom. Speed-of-sound (SOS), acoustic absorption and optical scattering/absorption measurements were obtained for each formulation to characterize tissue-mimicking properties. PAUS imaging was performed on each phantom at four time points, in approximately 2-month intervals, to assess temporal stability. Images were analyzed to provide data regarding target signal strength, target contrast, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). All PAUS imaging was performed on a Vevo 2100-LAZR system (FUJIFILM VisualSonics Inc., Toronto, Canada) at 808 nm using a 20-MHz US transducer.
Results: Each phantom formulation provided unique acoustic absorption and optical scattering/absorption; the range of tested formulations provided scattering/absorption/SOS characteristics that accurately mimic tissue. Examination of the longitudinal PAUS data demonstrates that none of the phantoms experienced significant temporal change over the 6-month testing period. Target signal, contrast, SNR, and CNR changed less than 10% from the initial baseline for an individual phantom through 2, 4, and 6-month follow-up imaging sessions.
Conclusion: This work indicates that the investigated phantom formulations accurately approximate tissue for photoacoustic-ultrasonic imaging purposes. Additionally, adequate temporal stability is demonstrated over a six-month period, allowing for construction of a long-term tissue-mimicking PAUS imaging phantom that could be utilized for preclinical technical development or clinical quality assurance purposes in the future.
Funding Support, Disclosures, and Conflict of Interest: John Lynch is an employee of CIRS, Inc.
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