Abstract: A method for shaping an RF pulse for use with an MRI system includes shaping an RF pulse for use with an MRI system that uses an RF coil. The RF pulse is shaped to reduce changes in B1 amplitude and in an off-resonance effect with respect to Larmor frequency as a function of distance from the RF coil.

Abstract: A system for NMR/MRI, having X, Y, Z directions, includes an RF coil having a B0 static magnetic field in the Z direction and a transverse B1 RF magnetic field in the XY directions. Currents in the RF coil are distributed so that the transverse B1 field is substantially uniform in the XY plane.

Abstract: A method for shaping an RF pulse for use with an MRI system includes shaping an RF pulse for use with an MRI system that uses an RF coil. The RF pulse is shaped to reduce changes in B1 amplitude and in an off-resonance effect with respect to Larmor frequency as a function of distance from the RF coil.

Abstract: A detector system adapted for monitoring a radiation treatment system comprising a pulsed beam radiation source for treating a body with a given beam intensity and beam configuration, with pulse times and intervals between pulses less than 100 milliseconds, using at least one monitoring radiation source located inside or outside the body, the detector system comprising; a) a detector designed to detect radiation from the monitoring source, and subject to interference radiation from the beam source; and b) control circuitry that creates a data record of radiation received by the detector, to provide information about the body; wherein, when the detector detects radiation in real time during operation of the beam, the data record selectively excludes data for radiation received by the detector during the pulses, as opposed to data for radiation received by the detector between pulses.

Abstract: A combination MRI and radiotherapy system comprising: a) an MRI system for imaging a patient receiving radiotherapy, comprising a magnetic field source suitable for generating a magnetic field of strength and uniformity useable for imaging, capable of being ramped up to said magnetic field in less than 10 minutes, and ramped down from said magnetic field in less than 10 minutes; b) a radiation source configured for applying radiotherapy; and c) a controller which ramps the magnetic field source down to less than 20% of said magnetic field strength when the radiation source is to be used for radiotherapy, and ramps the magnetic field source up to said magnetic field strength when the MRI system is to be used for imaging.

Abstract: System and methods for image guided surgery is provided. The surgical tracking system can include at least one sensor configured to acquire a marker signal associated with a first location of a marker within a body and to output a first signal indicative of the first location, and also further configured to acquire a device signal associated with a second location of a movable imaging device and to output a second signal indicative of the second location. The movable imaging device can be configured to generate a plurality of sequential images. The surgical tracking system can further include at least one processor configured to receive the first signal, the second signal, and the plurality of sequential images, and to generate a plurality of composite images where at least one of the plurality of composite images include a visual indication of the first location on at least one of the plurality of sequential images.

Abstract: A hybrid radioactive and impedance tracking system for tracking a target in a human or animal body, comprising: a) a radioactive tracking subsystem for tracking the target; b) an impedance tracking subsystem for tracking the target; and c) a processor that uses data from the radioactive tracking subsystem in combination with data from the impedance tracking system to estimate a position of the target.

Abstract: A detector system adapted for monitoring a radiation treatment system comprising a pulsed beam radiation source for treating a body with a given beam intensity and beam configuration, with pulse times and intervals between pulses less than 100 milliseconds, using at least one monitoring radiation source located inside or outside the body, the detector system comprising; a) a detector designed to detect radiation from the monitoring source, and subject to interference radiation from the beam source; and b) control circuitry that creates a data record of radiation received by the detector, to provide information about the body; wherein, when the detector detects radiation in real time during operation of the beam, the data record selectively excludes data for radiation received by the detector during the pulses, as opposed to data for radiation received by the detector between pulses.

Abstract: A system for delivery of a capsule to a target location within a subject body including a capsule including a locomotion element and a gamma emitting radioactive source, a radiation tracking subsystem capable of locating the gamma emitting radioactive source in three dimensions, and a locomotion control subsystem capable of controlling movement of the capsule by effecting movement of the locomotion element, based, at least partly, on a location of the gamma emitting radioactive source provided by the radiation tracking subsystem.

Abstract: Apparatus for determining the position of a selected object relative to a moving reference frame, the apparatus including at least one reference frame transceiver assembly firmly attached to the moving reference frame, at least one object transceiver assembly firmly attached to the selected object, an inertial measurement unit firmly attached to the selected object, an inertial navigation system firmly attached to the moving reference frame, and a tracking processor coupled with the object transceiver assembly, with the inertial measurement unit and with the inertial navigation system, the object transceiver assembly communicating with the reference frame transceiver assembly using magnetic fields, the inertial measurement unit producing IMU inertial measurements of motion of the selected object with respect to an inertially fixed reference frame, the inertial navigation system producing INS inertial measurements of motion of the moving reference frame with respect to the inertially fixed reference frame, the

Abstract: A method for reducing respiratory motion caused artifacts in magnetic resonance imaging. The respiration cycle amplitude of the patient is divided into a plurality of intervals. Each interval is assigned a preferred encoding pulse. If the preferred encoding pulse has been used the next sequential (higher or lower) unused phase encoding pulse of a valve that is .+-.50% of the originally preferred phase encoding pulse is used.

Abstract: An unique external averaging system for reducing the coherence of acquired data used for magnetic resonance imaging. The averaging is done after the acquisition of substantially complete matrices of data.

Abstract: A method of acquiring data for use in providing magnetic resonance images (MRI) wherein prior to stabilization of the system, data is acquired using phase encoding gradient pulses far removed from zero. Immediately after system stabilization data proximate and equal to the zero value phase encoding gradient pulse is acquired.

Abstract: Method and apparatus for improving the signal-to-noise ratio in magnetic resonance imaging systems using echo acquisition modes. The bandwidth of the received signals are reduced along with the amplitude of the view gradient and the sampling time. Since the signal-to-noise ratio is proportional to one over the square root of the bandwidth, this results in an increased signal-to-noise ratio.

Abstract: Improved T2 values and signal to noise ratio obtained by magnetic resonance image synthesization. Each measured echo signal intensity is divided by a correcting factor that is a function of the echo number to obtain corrected echo signal intensity. A characteristic curve is best fitted to the corrected intensity values and the intensity values of the curve are used.

Abstract: A magnetic resonance (MR) system and method for determing absolute image intensities (MR numbers) comparable to "CT" numbers by removing the dependence of the intensity measurement on system dependent parameters. The dependence of the intensity measurement on system parameters is removed by determining the absolute gain of the receiver portion of the MR system. The absolute gain is a function of the loaded gain and the unloaded gain of the receiver system, the loaded gain is divided by the unloaded gain to provide a normalization factor which is multiplied by output data to provide the absolute values of intensity of absolute MR numbers.

Abstract: Arrangements for selectively exciting sections of bodies being imaged in NMR systems wherein the rotating magnetic fields are shaped with envelopes defined by the sum of a sinc function and a cosine function.