| Patent application number | Description | Published |
|---|
| 20080267484 | Ultra Low Radiation Dose X-Ray CT Scanner - A line scan cone beam CT imaging system irradiates an object with an x-ray cone beam for multiple views. A projection data set of the object is acquired at each view. Between views, the cone beam and detector array are translated along parallel lines in opposite directions. An image is generated by converting the cone beam projection data set of the real object into a parallel-beam projection data set corresponding to a virtual object and using a total variation minimization image reconstruction algorithm to reconstruct a virtual image of the virtual object. The reconstruction algorithm includes the constraint that the Fourier transform of the reconstructed virtual image matches the known Fourier coefficients in the set of converted parallel-beam projections of the virtual object. The constructed virtual image is then transformed into an image of the real object. | 10-30-2008 |
| 20090161932 | Method For Prior Image Constrained Image Reconstruction - A method for reconstructing a high quality image from undersampled image data is provided. The image reconstruction method is applicable to a number of different imaging modalities. Specifically, the present invention provides an image reconstruction method that incorporates an appropriate prior image into the image reconstruction process. Thus, one aspect of the present invention is to provide an image reconstruction method that requires less number of data samples to reconstruct an accurate reconstruction of a desired image than previous methods, such as, compressed sensing. Another aspect of the invention is to provide an image reconstruction method that imparts the signal-to-noise ratio of a prior image to the desired image being reconstructed. Another aspect of the invention is to provide an image reconstruction method that, when practiced in the field of x-ray imaging, allows for exposing a subject to substantially less radiation dose than is required in conventional x-ray imaging techniques. | 06-25-2009 |
| 20090161933 | METHOD FOR DYNAMIC PRIOR IMAGE CONSTRAINED IMAGE RECONSTRUCTION - A method for reconstructing a high quality image from undersampled image data is provided. The image reconstruction method is applicable to a number of different imaging modalities. Specifically, the present invention provides an image reconstruction method that incorporates an appropriate prior image into the image reconstruction process. Thus, one aspect of the present invention is to provide an image reconstruction method that requires less number of data samples to reconstruct an accurate reconstruction of a desired image than previous methods, such as, compressed sensing. Another aspect of the invention is to provide an image reconstruction method that produces a time series of desired images indicative of a higher temporal resolution than is ordinarily achievable with the imaging system. For example, cardiac phase images can be produced with high temporal resolution (e.g., 20 milliseconds) using a CT imaging system with a slow gantry rotation speed. | 06-25-2009 |
| 20090175523 | Method For Image Reconstruction Using Sparsity-Constrained Correction - An image reconstruction method applicable to a number of different imaging modalities including magnetic resonance imaging (MRI), x-ray computed tomography (CT), positron emission tomography (PET), and single photon emission computed tomography (SPECT) is disclosed. A sparsifying image is reconstructed from a series of acquired undersampled data to provide a priori knowledge of a subject being imaged. An iterative reconstruction process is further employed to iteratively determine a correction image for a given image frame that, when subtracted from the sparsifying image, produces a quality image for the image frame. | 07-09-2009 |
| 20090274355 | Method for Prior Image Constrained Progressive Image Reconstruction - A method for reconstructing a high quality image from undersampled image data is provided. The image reconstruction method is applicable to a number of different imaging modalities. Specifically, the present invention provides an image reconstruction method that incorporates an appropriate prior image into an iterative image reconstruction process as well as utilizing an image frame from a previous time frame to constrain the reconstruction of a current image frame. | 11-05-2009 |
| 20100128958 | METHOD FOR PRIOR IMAGE CONSTRAINED IMAGE RECONSTRUCTION IN CARDIAC CONE BEAM COMPUTED TOMOGRAPHY - An image reconstruction method for cardiac cone beam CT is provided, in which data acquired as truncated projections using current cardiac flat panel detectors is reconstructed to form a high quality image of a desired cardiac phase. An iterative method is utilized to reconstruct a prior image from all of the acquired truncated data without cardiac gating. Subsequently, a reconstruction method, in which the prior image is utilized in a prior image constrained reconstruction method, is utilized to reconstruct images for each individual cardiac phase. The objective function in such a prior image constrained reconstruction method is modified to incorporate the conditions used in the production of the prior image so that the data truncation problem is properly addressed. | 05-27-2010 |
| 20100310144 | Method for Dynamic Prior Image Constrained Image Reconstruction - A method for reconstructing a high quality image from undersampled image data is provided. The image reconstruction method is applicable to a number of different imaging modalities. Specifically, the present invention provides an image reconstruction method that incorporates an appropriate prior image into the image reconstruction process. One aspect of the invention is to provide an image reconstruction method that produces a time series of desired images indicative of a higher temporal resolution than is ordinarily achievable with the imaging system, while mitigating undesired image artifacts. This is generally achieved by incorporating a limited amount of additional image data into the data consistency condition imposed during a prior image constrained image reconstruction. For example, cardiac phase images can be produced with high temporal resolution using a state-of-the-art multi-detector CT system with either fast gantry rotation speed or CT imaging system with a slow gantry rotation speed. | 12-09-2010 |
| 20110286646 | Method For Radiation Dose Reduction Using Prior Image Constrained Image Reconstruction - A method for reconstructing an image of a subject with a medical imaging system is provided. Image data is acquired with the medical imaging system, typically in an undersampled manner. A prior image constrained compressed sensing (PICCS) image reconstruction method is then implemented to reconstruct images of the subject being imaged. The prior image used in such a method is produced from so-called averaged image data. The averaged image data is produced by effectively averaging signal information associated with a plurality of different slice locations along a direction orthogonal to the plane parallel to the slice locations. Weightings are calculated from images reconstructed in a conventional manner from the acquired image data, and these weightings are employed to produce the averaged image data. By producing a prior image in this manner, a higher signal-to-noise ratio is achievable, allowing trade-offs with factors such as radiation dose in x-ray imaging. | 11-24-2011 |
