Abstract: An ultrasound system and method for variable transmission of ultrasonic signals are presented. With this method and system, ultrasonic beams can be transmitted into a region in response to a selected event in a reference signal by predicting a future occurrence of a selected event in a reference signal, transmitting a first set of ultrasonic beams into the region at the predicted future occurrence, and transmitting a second set of ultrasonic beams into the region at a selected time interval preceding the predicted future occurrence. Additional applications of the method and system are presented.

Abstract: An improvement to the method for harmonic imaging including the steps of (a) transmitting ultrasonic energy at a fundamental frequency and (b) receiving reflected ultrasonic energy at a harmonic of the fundamental frequency is provided. For the improvement, the transmitting step includes the step of transmitting a uni-polar waveform or a waveform characterized by an amplitude change rate of 8 or fewer times pre carrier cycle, said waveform comprising an envelope shape rising gradually to a respective maximum value and falling gradually from the respective maximum value.

Abstract: An RF ablation apparatus has a delivery catheter with distal and proximal ends. A handle is attached to the proximal end of the delivery catheter. The delivery catheter has an electrode deployment means where said electrode deployment means includes a retractable tip section comprising a deployable electrode with portion of one side having a sharp edge. The tip section has a non-deployed state when it is positioned in the delivery catheter. On the other hand, the tip section has a distended deployed state when it is advanced out of the distal end of said delivery catheter. The deployed tip section has a preformed shape while the farther distal deployed electrode defines an ablation target along with portion of the forward side having a sharp edge on said electrode. The forward edge of the deployed electrode has a slightly curvature or an essentially straight shape. Said deployable electrode has ultrasonic imaging capabilities.

Abstract: In performing harmonic echo imaging, the necessity of changing modes is obviated, maneuverability is improved, and diagnostic information of the kinetics of a blood flow is provided with high reliability. A diagnostic ultrasound system provides, by scanning a cross section of an object with an ultrasonic beam signal, a normal B-mode image (the first tomographic image) of a tissue and a harmonic-mode image (the second tomographic image) of distribution information of an ultrasonic contrast medium injected into the object. The distribution information is obtained based on a non-fundamental frequency component (e.g., second harmonics) other than a fundamental frequency component of the ultrasonic beam signal. The system comprises a unit for scanning an ultrasonic beam signal along the cross section to acquire an echo. The scanning unit controls the scan so that the beam signal is scanned automatically and alternately for each raster in both the normal B-mode and the harmonic-mode.

Abstract: An ultrasound method and system for measuring perfusion of a tissue of interest during an ultrasound examination is provided. Perfusion within a region of a tissue can be accurately quantified by measuring a concentration level of contrast agent in a first region before and after reducing the concentration level of contrast agent in a second region. The position of the second region overlaps the position of the first region such that any dimension of the second region differs from any corresponding dimension of the first region by less than a factor of two. With these concentration measurements, contrast agent flow into the first region can be calculated. A corresponding ultrasound image can be created that qualitatively displays perfusion of the tissue.

Abstract: It has been discovered that the incorporation of fluorinated gases, especially a perfluorocarbon such as octafluoropropane, into synthetic polymeric microparticles, significantly enhances echogenicity as compared with microparticles having air incorporated therein. The microencapsulated perfluorocarbon is manufactured with a diameter suitable for the targeted tissue to be imaged, for example, for intravenous or oral administration. In one embodiment, bioadhesive microparticles are formed for enhanced imaging of mucosal surfaces.

Abstract: An ultrasonic imaging apparatus devised to implement contrast imaging of enhanced S/N ratios. The apparatus comprises: an exciting unit for generating ultrasonic waves by stimulating a contrast medium introduced into a target object; a contrast image creating unit for creating a contrast image based on the ultrasonic waves generated through stimulation; an echo generating unit for generating echoes of the ultrasonic waves transmitted into the target object; an echo image creating unit for creating an echo image based on the generated echoes; and a display unit for superimposing the contrast image and the echo image for display.

Abstract: Apparatus and methods are disclosed for the detection and imaging of ultrasonic contrast agents. Ultrasonic apparatus is provided for coherent imaging of ultrasonic contrast agents, and for detecting harmonic contrast agents. The inventive apparatus includes a dual display for simultaneously viewing a real time image which displays the location of the contrast agent and a triggered contrast image. Methods of contrast agent detection and imaging include the measurement of perfusion rate characteristics, multizone contrast imaging, multifrequency contrast imaging, tissue perfusion display, and high PRF contrast image artifact elimination.

Abstract: The present invention relates generally to an ultrasound system and method, and more particularly to an excitation enhanced ultrasound system and method. The system employs at least one excitation signal as a "flashlight" for exciting ultrasonic microbubbles contained in an ultrasound contrast agent. The system further employs at least one ultrasound imaging signal for imaging structures and blood flow within an object. The excitation signal excites and expands the microbubbles which increase the amount of returned ultrasound imaging signals scattered and returned by an object. This process increases the signal to noise ratio of the returning imaging signal sufficiently to provide exciter weighted imaging, blood pool imaging, and harmonic imaging, facilitating improved diagnostic ultrasound and therapeutic ultrasound.

Abstract: A medical interventional instrument for use in a magnetic resonance imaging (MRI) or other imaging system, a method for designing such an instrument, and a method including the steps of positioning an instrument having a body with a contrast region (constructed in accordance with the invention) and a target in the imaging region of an imaging system and operating the imaging system to produce an image showing both the target and the contrast agent. The instrument has a carbon-fiber or glass-fiber composite (or zirconia) body which preferably carries a contrast agent which is appropriate to the particular imaging modality to be used with the instrument. The concentration and volume of the contrast agent are determined (preferably experimentally) to cause the instrument to be positively shown in an image produced by the imaging system, without obscuring or distorting unacceptably the image of the target (e.g., a typical target, such as human tissue) with which the contrast agent is to be imaged.

Abstract: A method and apparatus for directly identifying and characterizing input data derived from regions of interest in ultrasound images of organs in the presence of attenuation from interposed contrast agent, for the purpose of diagnosing abnormalities. The input data is classified into one of a number of classes depending upon the characteristics of that data, in order to distinguish normal conditions from abnormal conditions. The invention is based on the recognition that significant information relating to the health of tissue exists in regions of interest in ultrasound images in the presence of attenuation from interposed contrast agent. This information is in the form of backscatter speckle patterns that have "texture" characteristics that are distinguishable in healthy versus diseased tissue. The invention classifies such patterns as probably normal or abnormal by means of an analysis system that may include a neural network system.

Abstract: An echogenically enhanced medical device and method for manufacture are disclosed. A mask is applied to the surface of the medical device, and portions of bare metal are exposed through the mask. The masked device is subjected to a process which removes material from the exposed portions. The resulting depressions enhance echogenicity of the device under ultrasound. In a preferred embodiment the depressions comprise alternating rows of squares and diamonds disposed around the circumference of the device.