title: Calibrated Linear Array-Driven Photoacoustic/Ultrasound Tomography.
abstract: The anisotropic resolution of linear arrays, tools that are widely used in diagnostics, can be overcome by compounding approaches. We investigated the ability of a recently developed calibration and a novel algorithm to determine the actual radial transducer array distance and its misalignment (tilt) with respect to the center of rotation in a 2-D and 3-D tomographic setup. By increasing the time-of-flight accuracy, we force in-phase summation during the reconstruction. Our setup is composed of a linear transducer and a rotation and translation axis enabling multidimensional imaging in ultrasound and photoacoustic mode. Our approach is validated on phantoms and young mice ex vivo. The results indicate that application of the proposed analytical calibration algorithms prevents image artifacts. The spatial resolution achieved was 160 and 250 μm in photoacoustic mode of 2-D and 3-D tomography, respectively.
authors: Fraunhofer Institute for Biomedical Engineering (IBMT), Medical Ultrasound Group, St. Ingbert, Germany. Electronic address: Milan.oeri@ibmt.fraunhofer.de.
authors: Milan
authors: M
authors: Oeri
authors: Fraunhofer Institute for Biomedical Engineering (IBMT), Medical Ultrasound Group, St. Ingbert, Germany.
authors: Wolfgang
authors: W
authors: Bost
authors: Fraunhofer Institute for Biomedical Engineering (IBMT), Medical Ultrasound Group, St. Ingbert, Germany.
authors: Steffen
authors: S
authors: Tretbar
authors: Fraunhofer Institute for Biomedical Engineering (IBMT), Medical Ultrasound Group, St. Ingbert, Germany.
authors: Marc
authors: M
authors: Fournelle
mesh_terms: D000818:Animals; D016477:Artifacts; D002138:Calibration; D006257:Head / Q000000981:diagnostic imaging; D006321:Heart / Q000187:drug effects; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008168:Lung / Q000000981:diagnostic imaging; D051379:Mice; D023421:Models, Animal; D019047:Phantoms, Imaging; D061088:Photoacoustic Techniques / Q000379:methods*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*
keywords: Combined imaging; Image artifacts; Linear transducers; Photoacoustic tomography; Transducer calibration; Ultrasound tomography