Abstract: A method of mounting a CT imager on a gantry: determining a center of rotation of a rotor of the gantry; siting a plurality of mounting elements at predetermined positions with respect to the center of rotation; and attaching the mounting elements to the rotor while keeping the mounting elements at the predetermined positions.

Abstract: A nuclear medicine camera having an X-ray imaging capability. The camera comprises at least one gamma camera mounted on a gantry and an X-ray CT imager mounted on the same gantry. The at least one gamma camera and the X-ray imager are capable of simultaneously rotating about a common axis at different rotation rates.

Abstract: A nuclear medicine camera having an X-ray imaging capability, comprising: a gantry having a stationary portion and at least one rotating portion; at least one gamma camera mounted on a said at least one rotating portion and capable of being rotated together at a common first rotation rate about an axis, said at least one gamma camera being capable of acquiring nuclear imaging data for reconstructing a tomographic nuclear image; and an X-ray CT imager having an X-ray source mounted on said at least one rotating portion and being capable of acquiring X-ray imaging data for reconstructing an X-ray image; said X-ray CT imager being mounted closer to said stationary portion than said at least one gamma camera.

Abstract: A method of mounting a CT imager on a gantry: determining a center of rotation of a rotor of the gantry; siting a plurality of mounting elements at predetermined positions with respect to the center of rotation; and attaching the mounting elements to the rotor while keeping the mounting elements at the predetermined positions.

Abstract: A method of producing a nuclear medicine image of a subject, comprising: acquiring nuclear imaging data suitable to produce a nuclear tomographic image, said nuclear image data being acquired by a gamma camera head rotating about the subject; acquiring X-ray imaging data suitable to produce an X-ray tomographic image for attenuation correction of the gamma camera image, said X-ray imaging data being acquired by detectors irradiated by an X-ray source rotating around the subject; reducing the sensitivity of gamma camera head while the X-rays are produced; and reconstructing an attenuation corrected nuclear medicine image utilizing the nuclear imaging data and X-ray imaging data.

Abstract: A nuclear medicine camera having an X-ray imaging capability, comprising: a gantry having a stationary portion and at least one rotating portion; at least one gamma camera mounted on a said at least one rotating portion and capable of being rotated together at a common first rotation rate about an axis, said at least one gamma camera being capable of acquiring nuclear imaging data for reconstructing a tomographic nuclear image; and an X-ray CT imager having an X-ray source mounted on said at least one rotating portion and being capable of acquiring X-ray imaging data for reconstructing an X-ray image; said X-ray CT imager being mounted closer to said stationary portion than said at least one gamma camera.

Abstract: Apparatus for producing attenuation corrected nuclear medicine images of patients, comprising: at least one gamma camera head that acquires nuclear image data suitable to produce a nuclear tomographic image at a first controllable rotation rate about an axis; at least one X-ray CT imager that acquires X-ray data suitable to produce an attenuation image for correction of the nuclear tomographic image at a second controllable rotation rate about the axis; and a controller that controls the data acquisition and first and second rotation rates to selectively provide at least one of the following modes of operation: (i) a movement gated NM imaging mode in which the second rotation rate is substantially higher than the first rotation rate and the data from each view of the X-ray acquisition is associated with one of a plurality of respiration gated time periods; (ii) a cardiac gated NM imaging mode in which the second rotation rate is substantially higher than the first rotation rate and the data from each view

Abstract: Apparatus for producing attenuation corrected nuclear medicine images of patients, comprising: at least one gamma camera head that acquires nuclear image data suitable to produce a nuclear tomographic image at a first controllable rotation rate about an axis; at least one X-ray CT imager that acquires X-ray data suitable to produce an attenuation image for correction of the nuclear tomographic image at a second controllable rotation rate about the axis; and a controller that controls the data acquisition and first and second rotation rates to selectively provide at least one of the following modes of operation: (i) a movement gated NM imaging mode in which the second rotation rate is substantially higher than the first rotation rate and the data from each view of the X-ray acquisition is associated with one of a plurality of respiration gated time periods; (ii) a cardiac gated NM imaging mode in which the second rotation rate is substantially higher than the first rotation rate and the data from each view of

Abstract: A method of producing a nuclear medicine image of a subject comprising the steps of acquiring nuclear image data suitable to produce a nuclear tomographic image, the data being acquired by at least one gamma camera head (12, 14) rotating about the subject at an average first rate, acquiring x-ray imaging data suitable to produce an x-ray tomographic image for attenuation correction of the gamma camera image, the data being acquired by an array of detectors (20) irradiated by an x-ray source (18) rotating around the subject at an average second rate which is within a factor of 10 of the first rate, and reconstructing an attenuation corrected nuclear medicine image utilizing the nuclear imaging data and x-ray imaging data.

Abstract: A system for recording fewer of the events that are caused by unwanted photons with greater stability. The system locally determines the energy spectrum and fits for each pixel of the image the determined energy spectrum with a modified trial function composed of: a photopeak component of known energy shape, Compton scatter components having theoretically derived energy shapes and, when applicable, also measured or calculated energy spectra of other unwanted photons. The modified trial function also takes into consideration unknown local deviations in the outputs of electronic components. The amplitude of the photopeak distribution resulting from the fit is used to obtain the local content of wanted interactions in the image. This enables removal of Compton contamination and also the contamination caused by interaction of the gamma photons with lead components.

Abstract: A system for recording fewer of the events that are caused by unwanted photons with greater stability. The system locally determines the energy spectrum and fits for each pixel of the image the determined energy spectrum with a modified trial function composed of: a photopeak component of known energy shape, Compton scatter components having theoretically derived energy shapes and, when applicable, also measured or calculated energy spectra of other unwanted photons. The modified trial function also takes into consideration unknown local deviations in the outputs of electronic components. The amplitude of the photopeak distribution resulting from the fit is used to obtain the local content of wanted interactions in the image. This enables removal of Compton contamination and also the contamination caused by interaction of the gamma photons with lead components.

Abstract: A system for recording fewer of the events that are caused either by Compton scatter photons or by gamma radiation interacting with lead. The system locally determines the energy spectrum and fits the determined energy spectrum with a trial function composed of a photopeak component of known energy shape, but unknown magnitude and a Compton scatter component having a theoretically derived energy shape and an unknown magnitude for each pixel of the image. The trial function is locally fitted to the measured energy spectrum to obtain the values of both the Compton Coefficient and the gamma radiation interacting with lead. This enables removal of Compton contamination and also the contamination caused by interaction of the gamma photons with lead components.

Abstract: Correction for Compton scattering is effected by analysis of the energy spectra. More particularly, a measured energy spectrum is constructed per location from detected counts that are stored according to their measured energy as well as according to the location of gamma ray infingement on a scintillating detector. The measured spectrum comprises scattered and unscattered photons. A physically correct trial function enables the separation of overlapping contributions of scattered and unscattered photons. The trial function includes multiple collision terms that are preferably constructed using the Nishina-Klein equations describing photon Compton scatter probability distributions. The count of unscattered photons per location is derived from the measured spectrum by locally fitting to the trial function. The count of the unscattered photons per location is used to produce the improved images with reduced artifacts caused by Compton scatter.