Abstract: An ultrasonic imaging method and apparatus are described for imaging the coronary arteries of the heart. The vascular system is infused with an ultrasonic contrast agent. A volumetric region of the heart wall including a coronary artery is three dimensionally scanned. A projection image of the volumetric region is produced from the scanning, providing a two dimensional contrast image of the coronary artery with the appearance of an angiogram. Preferably the coronary artery signals are segmented from contrast signals emanating from the myocardium and the heart blood pool so that the coronary arteries are clearly highlighted and distinct in the ultrasonic angiogram.

Abstract: An ultrasonic diagnostic imaging system is provided with synthesized transmit focus. Several beams are transmitted, each with a different transmit focus. Echoes received from the differently focused beams are combined to form a scanline with an extended focus. The echoes are preferably weighted and/or phase adjusted prior to being combined. Combining is performed in the r.f. domain before nonlinear processing of the signals such as amplitude detection. The resultant extended focus scanline exhibits the property of dynamic transmit focusing.

Abstract: An ultrasonic diagnostic imaging system and method are provided for producing r.f. interpolated image lines with reduced susceptibility to motion artifacts. A multiline beamformer receives multiple scanlines in response to each transmitted beam. Image lines are produced by r.f. interpolation of these multiline scanlines in a temporally consistent manner. In an illustrated embodiment, each image line is produced by tle interpolation of scanlines produced in response to at least two transmitted beams. In a preferred embodiment the interpolated image lines are produced by a [1 2 1] lateral filter.

Abstract: A method and apparatus are provided for interpolating image lines from ultrasonically obtained scanlines of an image region. The interpolated lines are preferably formed one-quarter and three-quarters of the distance between each pair of received scanlines by combining weighted samples of the adjacent scanlines in proportion to their distances from the interpolated lines. The received scanlines are preferably formed by a beamformer which samples the received lines at quadrature phases of the scanhead center frequency and filters the samples by combining successive samples of a related phase. The image lines are scan converted by computing a grid of weighted values between each pair of image lines, and using the closest value for each pixel in the ultrasound image.