Patent ReferencesUltrasonic sector-scan probe Ultrasound scanner for tissue characterization Method and apparatus for ultrasonically scanning a subject with an ultrasound head Method and apparatus for adaptive focusing in a medical ultrasound imaging apparatus Ultrasonic diagnosis apparatus Apodization of ultrasound transmission Adaptive coherent energy beam formation using iterative phase conjugation Patent #: 4989143 InventorsAssigneeApplicationNo. 632924 filed on 12/24/1990US Classes:600/447, Electronic array scanning73/597, Velocity or propagation time measurement73/625, Having plural sonic type transmitter or receiver transducers600/441, Having B-scan and Doppler600/442Tissue attenuation or impedance measurement or compensationExaminersPrimary: Jaworski, Francis J.Assistant: Manuel, George Attorney, Agent or FirmForeign Patent References
International ClassA61B 008/00Foreign Application Priority Data1990-01-15 DEAbstractA method for generating an ultrasound image of a plane of a section of an examination subject having a non-uniform speed of sound distribution near the surface of the subject includes the steps of scanning the section plane line-by-line with a transducer array in an adaption phase and calculating values from the received, focussed echo signals which deviate from anticipated values which would arise given a uniform speed of sound distribution, the calculation being undertaken by a cross-correlation function of neighboring elementary transducers. Correction values are formed from the deviating values depending on the angle of incidence of the echo signals on the elementary transducers. In an imaging phase following the adaption phase, the delay values for focussing are modified dependent on the incident angle of the echo signals and dependent on the correction values for this incident angle. Image disturbances due to the non-uniform speed of sound distribution can thus be compensated even in the presence of thick, transducer-proximate disturbing layers in the examination subject. | |