摘要:
Systems and methods for identifying the relative contribution of fat and water signals in a magnetic resonance (“MR”) image including an algorithm operable for selecting an image signal model, selecting a scan parameter, forming a bias field estimate, applying a bias correction to a phase image, estimating the signal fraction of fat and water at each of a plurality of voxels, and forming a fat-suppressed image, a water-suppressed image, or a combination of a fat-based image and a water-based image. The (“MRI”) fat suppression systems and methods requiring only a single image acquisition including an algorithm operable for selecting a relative phase of approximately θ=π/2 or another suitable relative phase, employing an expectation maximization algorithm to classify the phase of the complex image, and projecting complex vectors into fat and water components to obtain fat and water images.
摘要翻译:用于识别在包括可用于选择图像信号模型的算法的磁共振(“MR”)图像中的脂肪和水信号的相对贡献的系统和方法,选择扫描参数,形成偏置场估计,将偏置校正应用于 相位图像,估计多个体素中的每一个的脂肪和水的信号分数,以及形成脂肪抑制图像,水分抑制图像或基于脂肪的图像和水基图像的组合。 (“MRI”)脂肪抑制系统和方法仅需要单个图像采集,包括可用于选择大约θ= pi / 2的相对相位的算法或另一合适的相对相位,采用期望最大化算法来分类 复杂的图像,并将复杂矢量投影到脂肪和水分中,以获得肥胖和水分图像。
摘要:
A computer-implemented method for reducing noise in an image includes receiving a first image in a computer system. The first image depicts an interior of an item and is generated using a technique that provides imaging at selected depths in the item. The first image represents a first interior section having a first thickness. The method includes determining a modification for the first image using a second image of the interior. The second image represents a second interior section encompassing the first interior section and has a second thickness greater than the first thickness. The method includes storing the modification in association with the first image.
摘要:
A system and a method for detecting an object, such as an explosive device or material, located within a closed article, such as a piece of luggage or a parcel. The system includes an acquisition subsystem for acquiring information pertaining to a specific object, a reconstruction subsystem for reconstructing acquired information pertaining to the specific object into image data, and a computer-aided detection subsystem adapted for identifying the specific object through the use of differential operators. The method includes obtaining image data of the one object, computing a differential operator for each voxel of the image data, computing eigenvalues and eigenvectors for each of the voxels, and computing a scalar function of the eigenvalues to ascertain whether each of the voxels represents a portion of the one object.
摘要:
A computer-implemented method for reducing noise in an image includes receiving a first image in a computer system. The first image depicts an interior of an item and is generated using a technique that provides imaging at selected depths in the item. The first image represents a first interior section having a first thickness. The method includes determining a modification for the first image using a second image of the interior. The second image represents a second interior section encompassing the first interior section and has a second thickness greater than the first thickness. The method includes storing the modification in association with the first image.
摘要:
Magnetic resonance imaging (“MRI”) systems and methods for acquiring multi-slice gradient echo images having a substantially constant T1-weighting including selecting a first scan having a desired contrast associated with T1-weighting and, given a first repetition time, TR1, and a first flip angle, flip1, associated with the first scan, selecting an effective repetition time, TReff, that provides the desired contrast. The MRI systems and methods also including holding the effective repetition time, TReff, substantially constant in relation to a second scan. The MRI systems and methods further including, given a second repetition time, TR2, determining a second flip angle, flip2, and, given the second flip angle, flip2, determining the second repetition time, TR2. The MRI systems and methods still further including performing the second scan using the second repetition time, TR2, and the second flip angle, flip2, and maximizing a signal-to-noise ratio, S/N, of the second scan.