Abstract: This patent relates to an apparatus involving optical cameras, one or more, and computer graphic means for registering anatomical subjects seen in the cameras to computer graphic image displays of image data taken from CT, MRI or other scanning image means. One or more cameras may be set up to view the anatomical subject. The anatomical subject has been scanned previously by an imaging machine such as a CT scanner and the data has been stored in a computer with computergraphic readout. The computer has software which enables rotation translation and scaling of the anatomical subject seen in the image data. By registering the field of view of the camera or cameras with the corresponding graphic view of the image data, a registration of the optical view with the scanner image view can be made. In this way, points identifiable in the camera view can be located in the image data view and vice versa.

Abstract: A breast stabilization device includes a substantially rigid outer member and an inner member joined to the outer member. The inner member is configured to conform to the shape of the female breast. An opening is disposed through the outer and inner members, the opening being centered on the nipple/areolar complex of the breast and exposing at least a portion of the areola surrounding the nipple. A rigid rim may surround the periphery of the opening and may rise above the surface of the outer member. The device stabilizes the breast in an uncompressed or slightly expanded state to allow interventional and imaging procedures to be carried out without compressing the breast. The opening allows access to the breast through the areola and the rim allows one or more instruments to be attached thereto.

Abstract: An MRI system operates in a realtime mode to produce images rapidly for a physician performing a medical procedure. The location of the medical instrument used in the procedure is monitored by a locator system which produces an icon on the images to show where the instrument is positioned. Reference phantoms are used by the physician to confirm that the system is properly calibrated to accurately display the instrument location.

Abstract: The invention relates to MR guided intervention. For biopsies and similar interventions the challenge is to align a needle or other interventional device along an anticipated trajectory which hits a target point but does not intersect sensitive structures between the target and the surface. The invention includes the following method in order to position an MR visible device: collection of pre-intervention MR-images, establishing of an anticipated trajectory and an entry point by imaging of the MR-visible device and a thick slab positioned parallel to the surface and displaying of the MR localizer in the MR-image of the slab and moving the MR visible localizer to the entry point, imaging of two mutual orthogonal slices passing through the anticipated trajectory between the entry point and the target point and establishing an angle of entry by using for example a MR-visible pen and a targeting device.

Abstract: A frameless stereotaxis skull fiducial marker system uses custom-formed mouthpieces fitted to maxillary and mandibular teeth. A relatively thick medial portion of a tapered U-shaped bar is attached to a forward projecting connector on a mouthpiece. Thin distal ends of the rigid U-shaped bar support fiducial markers. The customized mouthpiece is stored for repeated use on a patient. The rigid bar may be connected to mouthpieces customized for several patients.

Abstract: A method is provided for correcting for effects of translational motion or movement of an object in MR imaging. In accordance with the method, an MR point source is joined to the object for translational movement in unison therewith, the point source being maintained in selectively spaced-apart relationship with the object. The method further comprises acquiring a set of k-space data representing images of the object and point source collectively, and deriving a function representing the square of the magnitude of the k-space data set. An inverse Fourier transform operation is applied to the derived function to generate a correlation function with a number of correlation components, a specified one of the correlation components comprising the cross-correlation of the object and the point source.

Abstract: A frameless stereotactic CT scanner includes a virtual needle display for planning image-guided interventional procedures. The virtual needle is useful for planning the introduction of an object such as a biopsy probe into a patient at an entry point along a trajectory to a target point within the patient. Using an imaging device, the patient is scanned to generate an image volume data set of an area of the patient. Using a stereotactic mechanical arm assembly mounted on one end to the imaging device, a surgical planning device is positioned adjacent the patient on the imaging device. A display includes a first transverse axial view of the patient taking through an image slice corresponding to the virtual needle entry point on the patient and, a second transverse axial view of the patient taken on an image slice of the image volume data set corresponding to a target point within the patient.

Abstract: In a method and apparatus for calibrating a navigation system in relation to image data of a magnetic resonance apparatus, positions of at least three markers arranged in an imaging volume of a magnetic resonance apparatus are determined with the navigation system in a first coordinate system, and are determined by means of magnetic resonance in a second coordinate system. From the positions of the markers in the two coordinate systems, a position and an orientation of the two coordinate systems to one another are determined. Localization data are transformed into the second coordinate system. An apparatus for conducting the method has at least one marker having a substance that can be detected using magnetic resonance technology, in spatial allocation to optical markings. A pickup coil can be spatially allocated to each marker.

Abstract: Medical apparatus for synthetic view point imaging includes an instrument insertable into the body of a patient. Using tissue image information defining an image of the patient's body, and defining the position of the distal end of the instrument within the body, synthetic images of the patient's body are synthesized having a viewpoint with a defined spatial relationship to the distal end of the instrument based on the image information and the determined position of the instrument.

Abstract: A fiducial positioning cup (86) has a hemispherical well (92) in its top and a central bore (94) from a bottom of the hemispherical well (92) to a base of the positioning cup (86). The fiducial cup (86) is then attached to the skin (88) of a patient. A needle (110) is passed through the fiducial positioning cup (86) to mark an area of the patient's skin (88) with a tattoo (112). Fiducials (84) are secured in the fiducial positioning cups (86). Magnetic resonance or other diagnostic images are taken. Once the images are taken, the fiducials (84) and fiducial positioning cups (86) are removed. The tattoo mark (112) remains. The fiducial positioning cups (86) are reattached when a stereotactic procedure is to be performed. The needle (110) is passed through the fiducial cups (86) and a tip of the needle (110) is aligned with the tattooed mark (112) on the patient's skin (88). The fiducial cup (86) is then lowered and centered over the tattooed mark (112).

Abstract: A system for computer graphic determination and display of a patient's anatomy, as from CT or MR scanning, and stored along with associated equipment in an object field including the patient's anatomy. A first digitizing camera structure produces a signal representative of its field-of-view which defines coordinates of index points in its field-of-view. A second digitizing camera structure produces similar output for an offset field-of-view. The two camera positions are defined with respect to the patient's anatomy so that the fields-of-view of the cameras include both the patient's anatomy and the equipment, but are taken from different directions. Index markers are for fixing points in the fields of view and accordingly locate equipment relative to said patient anatomy. The index markers are provided by variety of structures including, light sources in various forms as reflectors, diodes, and laser scanner structures to provide a visible grid, mesh or cloud of points.

Abstract: Chemical shift imaging with spectrum modeling (CSISM) models the general chemical shift spectrum as a system with N distinct peaks with known resonant frequencies and unknown amplitudes. Based on the N peak spectrum model, a set of nonlinear complex equations is set up that contains N+1 unknowns of two kdnds: the magnitudes of the N peaks, and a phasor map caused by main magnetic field inhomogeneity. Using these equations, the timing parameters for shifting the 180.degree. RF refocusing pulses for acquiring spin-echo images are optimally chosen. Corresponding timing parameters for other pulse sequences can also be optimized similarly. Using the chosen timing parameters, a plurality of images are acquired. Next, acquired image data are automatically processed to solve the complex linear equations. First, the phasor map is found by fitting various phasor map values over a small number of pixels, or "seeds", that are picked sparsely in a field of view.

Abstract: The invention provides a device for correlating the internal location of an anatomical point of a human or animal patient with a location on the external body contours of the patient.

Abstract: A detachable cap for use in determining the location of the center of the imageable portion of a fiducial marker is disclosed. The lower portion of the cap has three arms and a boss for providing a detachable connection with an implanted base portion to which an imaging marker can be attached. The upper portion of the cap includes a divot-like depression that is configured to mate with a ball whose center can be determined. The ball, marker, and divot are configured so that the center of the ball, when mated to the divot, is coincident with the center of the marker when it is attached to the base in place of the cap. Knowledge of the location of the center of the ball when it is brought into engagement with the divot of the cap can be used to determine the location of the center of the marker when it is attached to the base.

Abstract: In a method for determining the time curve of the basic field of a nuclear magnetic resonance tomography apparatus under switched gradients, a phase-encoding gradient Gvx is prefixed to a readout gradient Gox. The time position of the signal maximum of a nuclear magnetic resonance signal S under the readout gradient Gox is determined. This is repeated n times with different gradient time surfaces of the phase-encoding gradient. The curve of the phase position over the temporal position of the signal maxima yields the phase error that occurs due to fluctuations of the basic magnetic field.

Abstract: A system is disclosed for monitoring the position of a medical instrument with respect to a patient's body and for displaying at least one of a plurality of prerecorded images of said body responsive to the position of said medical instrument. In one embodiment the system includes a reference unit secured from movement with respect to the patient's body such that said reference unit is substantially immobile with respect to a target operation site. The system also includes a remote unit for attachment to the medical instrument. A field generator may be associated with one of the units for generating a position characteristic field in an area including the target operation site. One or more field sensors may be associated with either of the units responsive to the presence of the position characteristic field for producing one or more sensor output signals representative of said sensed field.

Abstract: A system is disclosed for monitoring the position of a medical instrument with respect to a patient's body and for displaying at least one of a plurality of prerecorded images of said body responsive to the position of said medical instrument. In one embodiment the system includes a reference unit secured from movement with respect to the patient's body such that said reference unit is substantially immobile with respect to a target operation site. The system also includes a remote unit for attachment to the medical instrument. A field generator may be associated with one of the units for generating a position characteristic field in an area including the target operation site. One or more field sensors may be associated with either of the units responsive to the presence of the position characteristic field for producing one or more sensor output signals representative of said sensed field.

Abstract: A patient is secured to a subject support (10). A stereotaxic wand (40) is inserted into a tool guide (60). The wand has a tip portion (44), a portion extending along a pointing axis (46) of the wand, an offset portion (42) which is offset from the pointing axis of the wand, and at least two wand emitters (48, 50), mounted in alignment with the pointing axis of the wand. The two emitters selectively emit wand signals which are received by three receivers (14) mounted to a frame assembly (12). The tool guide includes a bore (66) extending along a guide axis. The bore is configured for selectively receiving a tool and the tip portion of the wand. An entry point and a trajectory are identified by the surgeon with the wand in the guide. More specifically, a trajectory and location of the wand are superimposed on a diagnostic image on a monitor (30).

Abstract: An automatic computer implemented technique which may be used for identifying markers and determining the centroids of fiducial markers (e.g., cylindrical fiducial markers) attached to the head in magnetic resonance (MR) and X-ray computed tomography (CT) volume images is disclosed. This technique may be referred to as image space localization. A first portion of the technique identifies many candidate voxel points included in a bright area of the image which may correspond to candidate markers. A second portion of the technique selects from the identified candidate voxels a predetermined number of candidate points of the image volume that are most likely to lie within an actual fiducial marker. The centroid for each of these markers is then determined. The method finds markers whose images are of a higher intensity than their surroundings and which have a given shape and size.