Abstract: A method for facilitating a reduction in reconstructed image noise in a computed tomography imaging system. The method includes generating projection data, characterizing a noise distribution of the projection data, performing an adaptive noise reduction operation on the projection data using the noise distribution characterization, and filtering the projection data.

Abstract: A system and method are disclosed that use the steady-state free precessing (SSFP) technique for MR imaging to allow the acquisition of MR angiography images in which the acquisition is not time dependent upon the first passage of a contrast agent. The technique includes applying a pulse sequence with refocusing S− signals from a train of RF pulses to a desired field-of-view (FOV) in a patient in which a contrast bolus has been injected. An SSFP image of the desired FOV is acquired, together with an S− SSFP mask image of the desired FOV. The S− SSFP mask image is subtracted from the SSFP image in order to reconstruct an image with improved visualization of the arterial and venous structures and reduce mis-registration artifacts.

Abstract: There is therefore provided, in one aspect, a method for imaging an object utilizing a computed tomographic (CT) imaging system having a rotating gantry, a multislice detector array on the rotating gantry and using at least n>1 rows of detector channels, and a radiation source on the rotating gantry configured to project a beam of radiation towards the multislice detector array through an object to be imaged. The method includes helically scanning the object with the CT imaging system at a pitch p>n to acquire projection data from the n rows of detector channels; applying a combined helical weight and conjugate weight to at least a portion of the acquired projection data to produce virtual projection data compensating for incomplete helical row data of the acquired projection data; and reconstructing an image of the object utilizing the acquired projection data and the virtual projection data.

Abstract: A method for reconstructing a computed tomographic (CT) image of an object is provided. The method includes initializing a CT imaging system in a step-and-shoot mode, scanning an object to generate a plurality of adjacent axial scans, wherein the distance between the adjacent axial scans is approximately equal to a projected detector height at the detector iso-center, and reconstructing an image of the object using the adjacent axial scans.

Abstract: An MRI apparatus and method for reducing wrap around artifacts during image reconstruction is provided. An RF coil and control configuration includes a center coil and at least one pair of end RF coils configured to encode and excite spins over an adjustable field-of-view (FOV). The adjustable FOV has at least two size designations in response to an FOV size request input. The control connected to the RF coil assembly is capable of switching between the FOV size designations by switching power to activate a center coil alone or the center coil in conjunction with the end coils in unison.

Abstract: A mobile medical image scanner and teleradiology system are incorporated into an ambulance or other vehicle to permit a patient to be diagnosed while en route to a treatment facility such as a trauma center. The system obtains medical image data while the patient is being transported in the vehicle and transmits the medical image data to a receiver at a location which is remote from the vehicle. At the remote location, the transmitted medical image data is displayed in a humanly discernable manner and interpreted by a qualified physician, who then communicates diagnostic information to the technicians in the vehicle and/or to the treating physicians at the treatment facility. By providing diagnostic information back to the treating physicians prior to the patient's arrival at the treatment facility, the patient can be routed directly to the operating room, or the intensive care unit as necessary, thereby saving valuable time.

Abstract: The present invention provides a detector for a multi-slice CT system. The detector includes a scintillator for receiving and converting high frequency electromagnetic energy directly to electrons. The detector is further configured to directly conduct the electrons. The detector comprises a compound formed of scintillator bulk and a conducting material capable of converting high frequency energy to electrons as well as conduct electrons. The CT system also provides for a gantry having an output for projecting high frequency electromagnetic energy toward the detector and a data acquisition system for receiving electrons directly from the detector. A method to provide imaging electrons to a CT system is also provided.

Abstract: Methods and apparatus for reducing motion-induced artifacts in CT imaging is described. The imaging system scans a patient's heart to obtain a plurality of projection views, a differential projection is determined from the projection views, a weighting function is applied to the differential projection to minimize motion artifacts, and an inconsistency index is determined from the differential projection, and the inconsistency index is used to locate an image reconstruction location. This method directly measures the mechanics of the heart, rather than an electrical signal and utilizes projection data to select the best locations to minimize image artifact.

Abstract: One embodiment of the present invention is a detector for detecting x-rays of an imaging system. The detector has a plurality of photodetectors; and a plurality of scintillator elements optically coupled to the plurality of photodetectors. The scintillator elements have sides separated from adjacent scintillator elements by gaps; and a cast reflector mixture in the gaps between the sides of the scintillator elements. The cast reflector mixture include a first powdered material having a higher Z and a higher density than titanium dioxide, and a refractivity index sufficient to effectively scatter and reflect light within the cast reflector mixture.

Abstract: The present invention discloses a method of aligning scintillator crystalline structures for computed tomography imaging and a system of use. Crystal seeds are deposited inside a glass melt and are then grown to form a plurality of layer crystallites. While growing the crystallites, a field is applied to align each crystallite structure in a uniform orientation. As a result, the crystallites are configured to reduce light scattering and improve the overall efficiency of the CT system. A CT system is disclosed implementing a scintillator array having a plurality of scintillators, each scintillator being formed of a plurality of uniformly aligned crystallites. Each crystallite includes a receiving surface and an exiting surface configured perpendicular to an x-ray beam. Further, the receiving surface and the exiting surface are connected by a plurality of surface walls arranged parallel to the x-ray beam.

Abstract: The present invention provides a detector for a CT imaging system. The detector includes a focused scintillator for receiving and converting high frequency electromagnetic energy to light energy. The detector further includes a photodiode positioned adjacent to the scintillator and configured to receive light energy discharged through a light exiting surface of the scintillator. The detector also includes electrical leads to transmit signals from the photodiode to a data processing unit for image construction. The CT system also provides for a gantry having an output for projecting high frequency electromagnetic energy toward the scintillator. A method of use and method of fabricating the tapered scintillators of the tapered scintillator array are also disclosed.

Abstract: A method for MRI signal analysis of an area of a biological tissue comprising: a) providing a biological tissue, wherein physiological activity is taking place in an area thereof; b) acquiring sequential magnetic resonance images, at least during a portion of time in which the physiological activity is taking place, of said area and of at least a portion of the tissue in a vicinity of the area; c) constructing, responsive to at least one pixel-related parameter value of the images, a pixel parameter space; and d) separating the pixel parameter space into at least two subspaces.

Abstract: A method and apparatus for correcting ghost artifacts that are related to orthogonal perturbation magnetic fields is disclosed. The technique includes acquiring MR data and an MR reference scan, each in the presence of orthogonal perturbation magnetic fields. However, the region of interest for the MR reference scan is limited to a relatively narrow band within the imaging subject. Preferably, the narrow band is selected in the vicinity of the magnet iso-center and parallel to the readout direction. Alternatively, the narrow band can also be selected in the limited region where the orthogonal perturbation fields are either minimal or constant along the phase encoding direction, and parallel to the readout direction. The selection of the relatively narrow band is accomplished by either spatially saturating surrounding regions, or using a two-dimensional spatially selective RF pulse.

Abstract: A method is described for controlling x-ray exposure during gated cardiac scanning, including the steps of detecting a first cardiac signal; starting scanning after a pre-selected wait time after detecting the first cardiac signal; and stopping the scanning after a first to occur of passage of a pre-selected data collection time and detection of a second cardiac signal.

Abstract: A coil for a magnet used in magnetic resonance imaging (MRI) systems, the coil including a grooved resilient former and an electrical conductor disposed around the former, wherein the former includes a sheet of flexible material having a tubular shape.

Abstract: In one aspect, the present invention relates to tube-spit detection and correction. In an exemplary embodiment, and once a sample of projection data has been collected, the projection data is preprocessed in accordance with known preprocessing algorithms including applying a detector primary speed correction to the projection data. Such primary speed correction removes contamination of previous signal sample from the current sample. After primary speed correction, tube-spit detection is performed on the sample. Such detection can be performed using many different methods. Generally, the objective is to determine whether the x-ray source experienced a drop in power. If a tube-spit event is not detected, then processing proceeds with further preprocessing and image reconstruction. If a tube-spit event is detected, then a tube spit correction is performed. Generally, the objective of tube-spit correction is to remove image artifacts due to the occurrence of a tube-spit event.

Abstract: One aspect of the present invention is a CT imaging method. An object is scanned at a selected helical pitch to acquire a set of attenuation measurement. For each angle of a fan beam of radiation, a direct and a conjugate set of attenuation measurements are identified that each include at least two measurements closest to a plane of reconstruction. Measurements are arranged in pairs, including a short pair and a long pair, using direct and conjugate measurements. Direct measurements are weighted in accordance with their distance from the plane of reconstruction. Direct measurements of the short and long pairs are blended according to a blending function that weights the short pair contribution to zero at a point at which the selected direct pair and the selected conjugate pair have a same z-axis location. The weighted and blended data is used to reconstruct an image of the object.

Abstract: To reduce the computational load in comparison to the iso-center shift described above, instead of selecting the z-axis of the coordinate system as the iso-center for reconstruction, the gantry iso-center of one of the detector rows (e.g., one of the center rows) is selected as the reconstruction iso-center. In this arrangement, the detector row for which the iso-center is based need not to undergo protection shift, since the defined reconstruction iso-center is the row iso-center. Data from the other detector rows is shifted relative to the selected detector row. When the gantry iso-center of one of the detector rows (e.g., one of the center rows) is selected as the reconstruction iso-center, the reconstructed image will be shifted along y′-axis relative to the original compensation schemes described above. To ensure the images generated with both schemes are identical in location, an adjustment can be added in the backprojection process.

Abstract: The present invention is, in one embodiment, a method for multi-slice, computed tomography imaging. The method includes steps of moving an x-ray source through a trajectory; projecting an x-ray cone beam from the moving x-ray source through an object towards a curved detector; and determining contributions of segments along the trajectory to voxels in a reconstruction volume of the object, including compensating the determined contributions for curvature of the detector and x-ray cone beam geometry.

Abstract: The present invention is directed to a method and apparatus for administering computed tomography (CT) imaging scans with reduced radiation dosage. The present invention includes an algorithm that allows for reduction of the sampling rate and tube current to acquire a first set of angular views. A second set of angular views is then created using interpolation from the first set of angular views. The sets of angular views are then combined to form a final set of angular views that are used to create an aliasing-free image of the scan subject. The present invention is particularly applicable for scanning centralized small objects such as the heart or the head and also is particularly useful in acquiring imaging data of pediatric patients.