Abstract: In order to spatially localize NMR Spectroscopic signals that are acquired at minimum time post excitation, a saturation selective spectroscopic imaging technique combines the use of saturation regions to define a region of interest; and RF pulse to generate a free induction decay (FID) signal; and phase encoding steps to spatially localize the signal within the non-saturated region.

Abstract: A multi-head SPECT-capable scintillation camera has one head collimated by a parallel hole collimator and one or more focussing collimators. The focussing collimators are advantageously cone beam collimators or (for scintillation cameras which have rectangular detectors) astigmatic collimators. The scintillation camera is used to acquire information about a relatively small body organ of interest, such as the heart or the brain. From this information, the spatial location of the organ is determined. Then, during rotation of the camera heads about the patient during a SPECT study, the positions of the focussing collimators are controlled so as to maintain the organ of interest in a predetermined position with respect to their field(s) of view. Thereafter, the data acquired during the SPECT study is used to form a SPECT image of the organ of interest. The SPECT image may then be displayed or outputted.

Abstract: The focus of a fan beam collimator is offset from the centerline.

Abstract: Two planar nuclear medicine images of a target organ are acquired using a focussing collimator at two different heights. An anatomic landmark associated with the target organ is computer-identified in each of the images, and the depth of the target organ is determined geometrically using the differences in size between the images of the identified landmark and the differences in height.

Abstract: Anatomical landmarks relating to a target organ which is to be studied in a nuclear medicine study are automatically identified by a computer. The landmarks are superimposed upon a nuclear medicine persistence image of the target organ. This facilitates technician identification of the target organ and also facilitates repeatability of, e.g., myocardial perfusion studies, which require that two studies be performed on a single patient at two different times.

Abstract: The long axis of the left ventricle is automatically identified by identifying, and correlating, local minima and maxima in images of slices of the left ventricle. Initially, the left ventricle is identified within a representative transverse slice of the left ventricle. The centerline of this slice is automatically computed and used as a reorientation axis, along which another (sagittal) slice of the left ventricle is reconstructed. The centerline of this sagittal slice is automatically computed, and is the long axis of the left ventricle. The accuracy of this identification is confirmed by reconstructing oblique transverse slices of the left ventricle and verifying that their centers are coincident.

Abstract: An energy window of a scintillation camera system is set to include only events which have been Compton-scattered within a slice of the body of a patient undergoing a SPECT examination. From events so acquired, a scatter image is reconstructed. The scatter image is processed to define therewithin a plurality of regions of constant attenuation coefficient. This information can be used during the normal image reconstruction process to eliminate artifacts caused by variation in attenuation coefficient.

Abstract: A nuclear medicine image is scanned and pixels of maximum and minimum intensity are identified and correlated with each other using constraints which are empirically determined to relate to the feature of interest (such as the heart). The information thus obtained is used to define a region of interest in which an anatomical feature of interest may be located, and to position a scintillation camera detector to carry out a nuclear medicine study at optimal positions.

Abstract: A modular package provides physical protection from shock, crushing and vibration. The modular package is reusable and expandable to fit a variety of sizes of printed circuit boards. In one embodiment, the package has an electrically conductive exterior and provides a faraday shield to protect the printed circuit board from damage by electrical fields.

Abstract: Light emitting diodes (LEDs) at fixed locations are placed at the entrance face of the scintillator within the detector head of a scintillation camera system. By energizing the LEDs, surrogate scintillation events may be generated and processed by the scintillation camera system. Information thus acquired can be used to maintain the photodetectors in a well-tuned state, to identify baseline shifts in the preamplifier channels and to determine system deadtime.

Abstract: A station assembly for use with a patient chair is disclosed. The station assembly includes a mounting bracket which can be attached to the patient chair. A first station arm and a second station arm are pivotally mounted to the mounting bracket such that they have nested translational paths when pivoted. Instrument stations are mounted to the station arms such that either station can be brought to either side of the patient chair by pivoting the station arms.

Abstract: A multi-isotope study is carried out using a plurality of imaging agents which are imaged simultaneously. The information obtained is weighted using as many energy weighting functions as there are isotopes. The weighting reduces "crosstalk" between each of the single-isotope images which are produced as a result of the study. This produces improved results in, for example, dual-isotope (Tc-99m and Tl-201) myocardial perfusion studies.

Abstract: A control system and circuit has a positive feedback characteristic but is nonetheless stable. Stability is achieved by superimposing a negative feedback loop with a short time constant and a positive feedback loop with a long time constant. The system and circuit are useful in situations where the sensor and the controlled variable (e.g. a heater) are well-coupled.

Abstract: A signal containing piled-up pulses from a scintillation camera head is sampled at a high frequency. Samples are summed to provide a time-integration of pulses which are sampled. When pulses pile up, the tail of the first pulse can be determined by extrapolation, permitting the first pulse to be energy-validated. The overlapping tail of the first pulse and the head of the second pulse are also time-integrated, and the area of the tail of the first pulse is subtracted from the time-integration so obtained. It is then possible to validate the second pulse.

Abstract: A fault detection circuit for a plurality of three-phase loads uses a wye-connected reference load as a benchmark. The voltages at the centerpoints of the loads to be monitored are monitored and the largest monitored voltage is identified. This largest voltage is compared with the voltage of the centerpoint of the reference load. The comparison is affected by faults which do not affect all loads equally (as by a short or open in one of the phases of one of the loads) and is unaffected by faults which do affect all loads equally (as by changes in voltage of one of the phases of the source).

Abstract: A scintillation crystal module of the type having a crystal housed in a backcap which is closed off by a glass window and sealed by an internal seal located between the window and the backcap is modified to include an external seal. The external seal is of moisture-impervious material and is attached to the outer surface of the backcap and the window and bridges over the boundary therebetween. The external seal may be made of an epoxy polyamid or a blocked urethane epoxy copolymer. The outer surface of the module may be sandblasted before the external seal is attached to the module, as by casting the adhesive in a suitable mold.

Abstract: A control panel, which includes a programmable electroluminescent touch screen, is mounted so as to be operable by the radiologist during a PTCA procedure. The system has the capability of displaying, for comparison purposes, synchronized comparable images of the arterial blood flow before and after the PTCA procedure. Synchronized image is achieved by adding or deleting video frames from the end of a patient's cardiac cycle.

Abstract: A housing for an electric device, such as a power transformer or an X-ray tube, comprises a tank which contains electric components of the device and which is filled with an insulating and/or cooling liquid, such as. A lid is arranged at a planar top portion of the tank and hermetically sealed thereto. The lid is at least partially flexible for enabling movement of the lid when the liquid expands and contracts due to heating and cooling, respectively. In a preferred embodiment, the lid comprises a gasket at its periphery and a rigid portion at its center. A frame can be provided for pressing the gasket against the tank. At the frame, at least one rod or spring can be fastened for guiding the movement of the lid perpendicular to the plane of the planar top portion.

Abstract: An MR imaging study precedes an MR spectroscopic study. Structural information from the imaging study is combined with MR spectra from the spectroscopic study to produce localized MR spectra.

Abstract: A control panel, which includes a programmable electroluminescent touch screen and a joystick, is mounted so as to be operable by the radiologist during a PTCA procedure. A bedside monitor displays fluoro and roadmap information during the procedure. The radiologist can adjust the relative weight of the roadmap information to the fluoro information by operating the joystick. The system automatically selects the appropriate roadmap based upon the angular orientation of the camera gantry, or alternatively selects the appropriate gantry position to correspond to that used to produce a satisfactory roadmap.