Abstract: A method for retrospectively correcting data prior to image reconstruction using an imaging system, wherein the method includes acquiring a first sinogram of a first slice of an object at a first axial field of view and a second sinogram of the first slice of the object at a second axial field of view different than the first axial field of view, determining at least one boundary of the object in the first sinogram and the second sinogram at the first slice, measuring a shift between the first sinogram and the second sinogram using the determined boundaries, and generating a corrected image using the measured shift.

Abstract: A method of calibrating detectors in a detector ring of a PET scanner, each detector including a plurality of crystals, the PET scanner having a field of view, is disclosed. The method comprises collecting timing data indicative of coincidence events occurring between each pair of crystals within the field of view. The method further comprises determining a detector adjustment value for each detector, determining a crystal adjustment value for each crystal in each detector, and discretizing the crystal adjustment value for each crystal to produce a discretized crystal adjustment value for each crystal. Lastly, the method comprises calibrating each detector by applying the discretized crystal adjustment value for each crystal in each detector to the collected timing data indicative of coincidence events.

Abstract: A method of calibrating detectors in a detector ring of a PET scanner, each detector including a plurality of crystals, the PET scanner having a field of view, is disclosed. The method comprises collecting timing data indicative of coincidence events occurring between each pair of crystals within the field of view. The method further comprises determining a detector adjustment value for each detector, determining a crystal adjustment value for each crystal in each detector, and discretizing the crystal adjustment value for each crystal to produce a discretized crystal adjustment value for each crystal. Lastly, the method comprises calibrating each detector by applying the discretized crystal adjustment value for each crystal in each detector to the collected timing data indicative of coincidence events.

Abstract: A method for retrospectively correcting data prior to image reconstruction using an imaging system, wherein the method includes acquiring a first sinogram of a first slice of an object at a first axial field of view and a second sinogram of the first slice of the object at a second axial field of view different than the first axial field of view, determining at least one boundary of the object in the first sinogram and the second sinogram at the first slice, measuring a shift between the first sinogram and the second sinogram using the determined boundaries, and generating a corrected image using the measured shift.

Abstract: A method of calibrating detectors in a detector ring of a PET scanner, each detector including a plurality of crystals, the PET scanner having a field of view, is disclosed. The method comprises collecting timing data indicative of coincidence events occurring between each pair of crystals within the field of view. The method further comprises determining a detector adjustment value for each detector, determining a crystal adjustment value for each crystal in each detector, and discretizing the crystal adjustment value for each crystal to produce a discretized crystal adjustment value for each crystal. Lastly, the method comprises calibrating each detector by applying the discretized crystal adjustment value for each crystal in each detector to the collected timing data indicative of coincidence events.

Abstract: An MRI system is provided with normal and quiet modes of operation. The quiet mode may be selected from an operator station, such as via a graphical user interface. When the quiet mode of operation is selected, configuration parameters are used for the particular pulse sequence to be executed in the examination. The configuration parameters for the quiet mode of operation may be derived from those of the normal mode of operation. The quiet mode of operation may, for example, employ gradient pulses having reduced amplitudes and slew rates as compared to those employed in the normal mode of operation. The reduced amplitudes and slew rates, along with changes in timing of the pulses and between pulses of the pulse sequence of the examination result in reduced acoustic noise for accommodating more sensitive patients.

Abstract: The present invention, in one form, is an x-ray CT system that modulates x-ray tube current as a function of gantry angle and reconstruction algorithm weighting coefficients. View indexes are stored in a table, and during scanning, values are periodically read from this table to determine weighting coefficients. An algorithm is applied to the weighting coefficients to generate an x-ray tube modulating factor. This modulating factor is then applied to the x-ray tube current to generate modulated x-ray tube current.