Abstract: An incubator arrangement and radiofrequency (RF) coil are provided for use in a Magnetic Resonance Imaging (MRI) system. The incubator arrangement comprises an enclosure adapted to support a subject in a magnet of the MRI system during imaging and a radiofrequency coil disposed within the enclosure. The RF coil is adapted to provide visual and physical access to the subject, and further adapted to obtain a selected signal to noise ratio.

Abstract: An insertable intracavity probe for use in Magnetic Resonance Imaging (MRI) and therapy of a region of interest proximal to a cavity, the probe having a substantially rigid probe shell for insertion into the cavity. The probe shell is adapted to incorporate at least one device for imaging the region of interest. A guide track is incorporated in the probe shell and is adapted to guide at least one biopsy or therapy device to the region of interest during imaging. Intracavity regions include cervical, rectal, and other regions associated with internal cavities of a patient.

Abstract: A rotating body coil assembly for use with an open MR magnet for imaging at least a portion of a subject comprises a resonant structure configured to rotate about the subject and to permit access to the subject during imaging. The body coil assembly comprises first and second end ring assemblies positioned on opposing sides of the imaging space. The first and second end ring assemblies are each configured to energize the body coil assembly. A plurality of element assemblies are disposed between and connecting the first and second end ring assemblies for providing structural support and electrical isolation of the body coil assembly. A base assembly is coupled to the first and second end ring assemblies and at least one of the element assemblies.

Abstract: An MRI system acquires NMR tracking data from a tracking coil imbedded in a medical device which is guided by a physician using real time anatomic images produced from image data acquired by the MRI system. A Hadamard magnetic resonance tracking sequence is used to update the tracking coil location which is indicated on the anatomic image. The Hadamard sequence uses four different acquisition, but tracking coil location is updated after each acquisition, using the new acquisition and three previously acquired acquisitions.

Abstract: An MRI system repeatedly performs a pulse sequence during a time interval &Dgr;T in which a surge of blood flows through a vessel whose compliance is to be measured. Two spaced-apart slices are simultaneously excited by each pulse sequence and the transverse magnetization is flow-encoded before an NMR signal is acquired in the presence of a readout gradient pulse. The change in phase of the NMR signal is used to detect when the wave arrives at each slice location, and from this information blood vessel compliance may be calculated.

Abstract: A scan control device located in the bore of an MRI system magnet includes tracking coils and a display. Location and alignment of the scan control device is tracked by the MRI system using signals acquired from the tracking coils. These signals are also used to update the scan parameters such that the scan plane of the image acquired by the MRI system is controlled by the scan control device location and orientation. The image is produced on the display to provide an attending physician with interactive control of the image from the magnet bore.

Abstract: An MRI system acquires NMR tracking data from a tracking coil imbedded in an ablation device which is guided by a physician using real time anatomic images produced from image data acquired by the MRI system. The same tracking coil is energized by an RF power source to deliver energy which ablates tissue after the device is guided into proper position.

Abstract: An imaging method and system generates images of non-planar portions of a three dimensional data point array wherein the non-planar portion corresponds to a non-planar object. The method includes selecting at least two different intermediate imaging planes, each selected plane including at least a portion of the object to be imaged, generating cross-sectional views perpendicular to each intermediate plane, selecting a viewing plane, projecting the cross-sectional views onto the viewing plane to generate transition value sets, and combining the transition value sets to generate values for each pixel in a display.

Abstract: The present invention is capable of more accurately tracking an invasive device in a subject's body in the presence of eddy current inducing structures. Current patterns applied to the tracking system's transmit coils are modified to compensate for the effect of the eddy currents. The current supplied to the coils is a linear combination of the current needed to create the desired electromagnetic field in the region of interest; and one or more error terms. These terms are determined experimentally during system calibration and are mathematically modeled as a series of exponential functions having a given amplitude and time constant. The error terms in the current applied to the transmit coils cancel the magnetic fields created by eddy currents within the tracking region and result in an actual electromagnetic field which is close to the desired ideal electromagnetic field.

Abstract: An MRI system receives scan parameters from an operator which define the prescribed pulse sequence to be used in acquiring image data. The amplitude and slew rate of gradient pulses in the pulse sequence are calculated based on their prescribed areas to have optimal duration without exceeding physiologic gradient slew rate limits and to produce the pulse area required by the scan parameters.

Abstract: An invasive probe for mapping the walls of a lumen employs a real-time tracking means and a wall distance measurement means. As the probe is advanced within the lumen, the real-time tracking means provides three-dimensional coordinates of the probe's position and orientation. Concurrent with probe localization, the distance between the probe and the lumen walls is measured. Both the probe position and the wall distance measurement are sent to a data acquisition system which in turn provides a graphic or numeric display to the operator. Probe tracking can be performed with radio-frequency, magnetic resonance, ultrasonic techniques or the like. If desired, lumen wall distance measurements can be performed with magnetic resonance or ultrasound methods. Lumen wall distance measurements can also be performed with mechanical devices such as balloons and/or expanding structures.

Abstract: An invasive probe for determining the morphological characteristics of walls of a lumen employs a real-time tracking means and an optical spectral measurement means. As the probe is advanced within the lumen, the real-time tracking means provides three-dimensional coordinates of the probe's position and orientation. Concurrent with probe localization, measurement of the spectral properties of the lumen wall are made by detecting the reflectance and/or absorption of light at the lumen wall. Both the probe position and the spectral measurement are sent to a data acquisition system which in turn provides an graphic or numeric display to the operator. Probe tracking can be performed with radio-frequency, magnetic resonance, ultrasonic techniques or the like. If desired, spectral measurements can be made in the visible, ultra-violet or infra-red spectral bands to provide optimized detection of chemical species of interest.

Abstract: Secondary data set information is incorporated into a primary data set (such as a digital image) retaining a desired dynamic range and retaining the original primary set data quality. The secondary data set information is `smuggled` into the least significant bits of the primary data set to result in an enhanced data set. If desired, the primary data word can be shifted toward the most significant bit. The enhanced data set may be viewed as if it were the original primary data set with existing playback devices, however it now includes additional `smuggled` information which may be played back in coordination with the primary data set information. One example is flow-direction information `smuggled` into an angiographic image. The least significant bits of the enhanced data words may be used to select the color map and color code the images. A user-adjustable intensity threshold can also be employed to select between color maps.

Abstract: One or more flexible magnetic Resonance (MR) receive coils are constructed of a flexible material and connected to a flexible base to produce a module. Each module has the coils overlapping by a predetermined amount to minimize coupling between the coils. The modules may be connected by attachment means placed at predefined locations to cause overlap of adjacent coils such that the coupling is minimized. Balanced-unbalanced ("baluns") may be used to couple each receive coil to its lead cable connecting it to the MR imaging electronics. The baluns effectively isolate the coils from the cables and each other to optimize signal-to-noise ratio of the received signal.

Abstract: A magnetic resonance (MR) imaging method uses chemical shift and/or slice selective inversion pulse to create angiograms of coronary arteries. In one embodiment blood is doped with a contrast enhancement agent and a sequence of slice selective and chemical shift selective inversion pulses are applied. Detection RF pulses then generate an image signal. In another embodiment two sequential chemical shift inversion pulses are applied followed by detection RF pulses for imaging.

Abstract: One or more flexible magnetic Resonance (MR) receive coils are constructed of a flexible material and connected to a flexible base to produce a module. Each module has the coils overlapping by a predetermined amount to minimize coupling between the coils. The modules may be connected by attachment means placed at predefined locations to cause overlap of adjacent coils such that the coupling is minimized. Balanced-unbalanced ("baluns") may be used to couple each receive coil to its lead cable connecting it to the MR imaging electronics. The baluns effectively isolate the coils from the cables and each other to optimize signal-to-noise ratio of the received signal.

Abstract: An optical coupling is incorporated into an invasive device used in magnetic resonance (MR) imaging. The coupling is incorporated into the invasive device between an imaging or tracking RF coil, and the MR receiver. The optical coupling has a first transducer circuit coupled to the RF which converts between optical and electrical signals. An optical fiber is coupled to the first transducer circuit and extends out of the invasive device to medical imaging equipment. Near this equipment, a second transducer circuit converts optical signals to electrical, and electrical signals to optical, just opposite that of the first transducer circuit. The present invention thereby replaces long lead wires which can cause heating during MR imaging, and may distort an MR image.

Abstract: A patient isolation device is used as a safety device to provide electrical insulation between medical electronic equipment and portions of the equipment which come in contact with the patient. In one implementation of the patient isolation device, an RF coil is incorporated in a catheter connected to medical electronic equipment which tracks the position of the catheter. Typically, there is also medical imaging electronics to provide internal images of the subject along with an indication of the location of the catheter. Typically, the signal from the RF coil is provided to a preamplifier to amplify the signal. The isolation device is placed between the RF coil and the preamplifier such that MR response signals may pass through to the preamplifiers but in the event of a short or electrical malfunction the line voltage will not pass backward into the RF coil causing damage to the patient.

Abstract: An interactive surgery planning and display system mixes live video of external surfaces of the patient with interactive computer generated models of internal anatomy obtained from medical diagnostic imaging data of the patient. The computer images and the live video are coordinated and displayed to a surgeon in real-time during surgery allowing the surgeon to view internal and external structures and the relation between them simultaneously, and adjust his surgery accordingly. In an alternative embodiment, a normal anatomical model is also displayed as a guide in reconstructive surgery. Another embodiment employs three-dimensional viewing.

Abstract: A temperature monitoring system employs a temperature detection means incorporated into an invasive device intended to be placed within a body during a magnetic resonance procedure. The temperature monitoring system is used to monitor temperature rises in tissue arising from the creation of electric fields within the tissue. These electric fields are created by the application of RF pulses during the course of a magnetic resonance procedure which induce electrical current in the invasive device. It the detected temperature rise exceeds a selected threshold, the temperature monitoring system can cause the magnetic resonance imaging system to either reduce RF power or terminate the procedure. An optical coupling may be used between the imaging or tracking RF coil and the MR receiver to eliminate heating induced by the application of RF pulses during the procedure.