Abstract: Shear wave imaging is provided in medical diagnostic ultrasound. A region is imaged to determine a location in which to calculate shear velocity. The shear velocity is estimated for the location. The imaging may guide the identification of the location, reducing the time to determine useful shear information. The estimate of shear may be validated, such as using cross-validation, to indicate the confidence level of the shear value. The shear velocity may be displayed relative to a scale of shear velocities associated with a type of tissue, such as tissue for an organ. The location on a scale may be more intuitive for a user.

Abstract: The shear modulus information is measured for sparse locations in a scanning field of view. For other locations, the shear modulus information is calculated as a function of the sparsely measured values and strain information. For example, shear modulus values are provided for every grid point in a field of view based on strain values for every grid point and on sparsely measured shear modulus values.

Abstract: Flow is represented by a synthesized or artificial pattern. Motion is visualized by apparent displacement of pixels from one frame to the next. An artificial pattern is introduced in order to present the flow. A changing parameter, such as velocity, is viewed as a function of multiple images or over time. The rate of change of the parameter is proportional to the perceived or actual motion. Humans perceive flow as a live stream, such as tap water pouring from a faucet or a stream in a creek. Flow associated with medical imaging is presented in a similar way, such that a pattern or other flow information persists over multiple images. The flow is synthesized by generating patterns and moving the generated patterns in the field of view. The direction and rate of motion of the pattern are a function of the direction and rate of the flow.

Abstract: Separate renderings are performed for data of a same medical imaging mode. The data is processed differently prior to rendering and/or rendered differently to enhance desired image information. For example, a same set of ultrasound B-mode data is rendered with opacity rendering and with maximum intensity projection or surface rendering. The surface or maximum intensity projection highlights strong transitions associated with bones. The opacity rendering maintains tissue information. Different sets of B-mode data may be separately rendered, such as one set processed to emphasize contrast agent response and another set processed to emphasize tissue. The separate renderings are aligned and combined. The combined rendering is output as an image.

Abstract: Complex response of tissue is calculated as function of a convolution relationship associated with measured strain with applied stress. In the Fourier or frequency domain, the convolution is a simple algebraic computation, such as multiplication. The complex response provides elasticity and viscosity information, assisting diagnosis. Complex compliance may be directly calculated from the strain and stress. Complex fluidity may be directly calculated from strain rate and stress.

Abstract: Using compression, tissue elasticity data from two or more different fields of view is acquired. Since different amounts of compression may be used for the different fields of view, the dynamic range of the elasticity data is updated. A panoramic elasticity image is generated from the updated elasticity data of multiple fields of view. A panoramic elasticity image represents the combined fields of view for the elasticity data.

Abstract: Systems and methods are described for tracking motion in a medical imaging system. The methods use landmark sets including hard landmarks and soft landmarks. The systems can include means for generating a landmark set, means for constructing a landmark set spatial relationship, means for computing a context similarity measurement, means for cost function construction, and means for cost function minimization and motion estimation. The invention provides advantages because, among other reasons, the use of a cost function of two or more variables, where the cost function is defined over members of the landmark set collection, and the cost function subject to at least two constraints and the landmark set stability in terms of context similarity measurements and spatial relationship provide effective and robust motion tracking.

Abstract: Measurements in diagnostic medical imaging are cross-referenced. A measurement made for one type of data is reflected in an image for another type of data. For example, a length is measured from ultrasound data. A line associated with the length is displayed on the ultrasound image. In a magnetic resonance image (MRI), the same line is displayed at a corresponding location. The same measurement may also be made with the MRI data and reflected in the ultrasound image. Each image shows both measurements in this example. The difference in the same measurements from different types of data may be useful for diagnosis. In the above example, the length is measured from ultrasound and from MRI. The difference between the two measured lengths may provide diagnostically useful information.

Abstract: Using compression, tissue elasticity data from two or more different fields of view is acquired. Since different amounts of compression may be used for the different fields of view, the dynamic range of the elasticity data is updated. A panoramic elasticity image is generated from the updated elasticity data of multiple fields of view. A panoramic elasticity image represents the combined fields of view for the elasticity data.

Abstract: Flow information (e.g., velocity and acceleration) and/or pressure gradient information are determined with ultrasound. Both velocity and acceleration are simultaneously estimated using a model and least squares analysis. Anti-aliasing of velocity information may be provided using the model and least squares analysis. Pressure gradient is calculated from velocity information automatically, more likely providing consistent measurements. Consistency may be increased further by automatically positioning a region of interest in either a multidimensional spatial image or a spatial-temporal image. A parametric image of pressure gradient for each spatial location within the image is generated as well as a delta pressure curve. Any single one or combinations of two or more of the features described above may be used.

Abstract: A difference between a detected motion and a reference motion is automatically displayed. The reference motion is a modeled motion of an organ, a base line motion of an organ or another portion of an organ. A deviation in motion amplitude, angle or both angle and amplitude from a reference set may more easily identify abnormal or normal motion of the organ.

Abstract: Methods and systems for detecting a border in a medical image are provided. A boundary is chosen as a connected curve whose tangent is substantially perpendicular to the gradient of the image everywhere along the curve. As an alternative to a tangent, a normal or other border direction may be used. At a given point within the image, the tangent to the boundary and the image gradient direction are orthogonal. Using an initial boundary detection, the boundary associated with the minimum cost or associated with the closest boundary where the boundary tangent and the image gradient directional are orthogonal for locations along the boundary is identified. By refining an initial border location to minimize divergence from the boundary tangent being orthogonal to the image gradient direction or by identifying a border based on the orthogonal relationship, accurate border detection may be provided in ultrasound images as well as other medical images.

Abstract: Motion of a region of interest is tracked in medical imaging. For example, velocity information, such as colored Doppler velocity estimates independent of tracking from one image to another image, are used to indicate an amount of motion between the images. The velocity assisted tracking may be used for one dimensional tracking (e.g., for M-mode images), for tracking in two dimensional images, or for tracking between three dimensional representations. As an alternative or additional example, physiological signal information is used to assist in the tracking determination. A physiological signal may be used to model the likely movement of an organ being imaged to control or adjust matching search patterns and limits. The modeling may also be used to independently determine movement or for tracking. The independently determined tracking is then combined with tracking based on medical data or other techniques.

Abstract: Flow is represented by a synthesized or artificial pattern. Motion is visualized by apparent displacement of pixels from one frame to the next. An artificial pattern is introduced in order to present the flow. A changing parameter, such as velocity, is viewed as a function of multiple images or over time. The rate of change of the parameter is proportional to the perceived or actual motion. Humans perceive flow as a live stream, such as tap water pouring from a faucet or a stream in a creek. Flow associated with medical imaging is presented in a similar way, such that a pattern or other flow information persists over multiple images. The flow is synthesized by generating patterns and moving the generated patterns in the field of view. The direction and rate of motion of the pattern are a function of the direction and rate of the flow.

Abstract: Methods and systems for detecting a border in a medical image are provided. A boundary is chosen as a connected curve whose tangent is substantially perpendicular to the gradient of the image everywhere along the curve. As an alternative to a tangent, a normal or other border direction may be used. At a given point within the image, the tangent to the boundary and the image gradient direction are orthogonal. Using an initial boundary detection, the boundary associated with the minimum cost or associated with the closest boundary where the boundary tangent and the image gradient directional are orthogonal for locations along the boundary is identified. By refining an initial border location to minimize divergence from the boundary tangent being orthogonal to the image gradient direction or by identifying a border based on the orthogonal relationship, accurate border detection may be provided in ultrasound images as well as other medical images.

Abstract: Systems and methods are described for tracking motion in a medical imaging system. The methods use landmark sets including hard landmarks and soft landmarks. The systems can include means for generating a landmark set, means for constructing a landmark set spatial relationship, means for computing a context similarity measurement, means for cost function construction, and means for cost function minimization and motion estimation. The invention provides advantages because, among other reasons, the use of a cost function of two or more variables, where the cost function is defined over members of the landmark set collection, and the cost function subject to at least two constraints and the landmark set stability in terms of context similarity measurements and spatial relationship provide effective and robust motion tracking.

Abstract: The present invention relates generally to a medical device, and more particularly to ultrasound apparatus and methods for the identification and characterization of tissues, tissue transitions and tissue constituent structures.