公开(公告)号：US06263228B1

公开(公告)日：2001-07-17

申请号：US09141338

申请日：1998-08-27

申请人： Weiguo Zhang ,  David M. Kramer ,  Andrew Li

发明人： Weiguo Zhang ,  David M. Kramer ,  Andrew Li

IPC分类号： A61B505

CPC分类号： G01R33/4828 ,  G01R33/56563

摘要： A method and apparatus for producing water-dominant and fat-dominant MR signal data for use in constructing separate images from single-scan single-point Dixon MRI sequences is disclosed. The effects of field inhomogeneities are removed by quantitating the signal phase by taking the argument of the MR signal multiplied by itself. A region-growing algorithm guided by a polynomial model is used to unwrap the phase which is then used to separately generate water-pixel data and fat-pixel data for producing separate images. The invention can be used for constructing images from both 2-D and 3-D spin-echo and/or field-echo acquisitions.

摘要翻译： 公开了一种用于制造用于构建单扫描单点狄克逊MRI序列的分离图像的水占优势和脂肪占优势的MR信号数据的方法和装置。 通过将MR信号的自变量乘以自身来量化信号相位来消除场不均匀性的影响。 使用由多项式模型引导的区域增长算法用于展开相位，然后用于分开产生用于产生分离图像的水像像素数据和脂肪像素数据。 本发明可用于从2D和3-D自旋回波和/或场回波采集中构建图像。

公开(公告)号：US06603990B2

公开(公告)日：2003-08-05

申请号：US09925520

申请日：2001-08-10

申请人： Weiguo Zhang ,  David M. Kramer

发明人： Weiguo Zhang ,  David M. Kramer

IPC分类号： A61B5055

CPC分类号： G01R33/4828 ,  A61B5/055

摘要： A magnetic resonance imaging (MRI) method is disclosed for generating and identifying water and fat separated MR images. Image data is first acquired to obtain two echo images with the water and fat signals orthogonal in the first echo image, and parallel/anti-parallel in the second echo image. The effect of background field inhomogeneties are removed, and water and fat images are separated from each other. The separated water and fat images are identified according to the difference of their precessing frequencies.

公开(公告)号：US5652514A

公开(公告)日：1997-07-29

申请号：US621240

申请日：1996-03-25

申请人： Weiguo Zhang ,  David M. Kramer ,  David M. Goldhaber

发明人： Weiguo Zhang ,  David M. Kramer ,  David M. Goldhaber

IPC分类号： G01R33/54 ,  A61B5/055 ,  G01R33/565 ,  G01V3/00

CPC分类号： G01R33/56563

摘要： Methods and apparatus for correcting image artefacts caused by variations in the main magnetic field of an MRI system are disclosed, particularly for MRI with steady-state spin precession. For field correction in MRI with steady-state spin precession, the effects of the field changes can be corrected by quantifying the time course of the field drifts by repeated acquisition of the zero k-space lines. The change in the phase between consecutive zero k-space lines is used as an indicator of field variation and for correction of associated image artifacts. By using for field correction the zero k-space lines acquired using the imaging sequence itself, the steady-states of spin precession are undisturbed throughout the MRI data acquisition.

摘要翻译： 公开了用于校正由MRI系统的主磁场的变化引起的图像伪像的方法和装置，特别是对于具有稳态旋转进动的MRI。 对于具有稳态自旋进动的MRI中的场校正，可以通过重复采集零k空间线来量化场漂移的时间过程来校正场变化的影响。 使用连续零k空间线之间的相位变化作为场变化的指示符和用于校正相关联的图像伪像。 通过使用场校正，使用成像序列本身获取的零k空间线，自旋进动的稳态在整个MRI数据采集期间不受干扰。

公开(公告)号：US07218110B2

公开(公告)日：2007-05-15

申请号：US11217405

申请日：2005-09-02

申请人： Weiguo Zhang ,  David M. Kramer

发明人： Weiguo Zhang ,  David M. Kramer

IPC分类号： G01V3/00

CPC分类号： G01R33/56341

摘要： A method and a system for acquiring diffusion magnetic resonance images with compensation of the effects of eddy currents induced by the diffusion weighting (DW) gradient pulses. Prescan data are first acquired using the same DW sequence to be used for imaging. The prescan data are used to obtain eddy current parameters that model the effects of DW-induced eddy currents under the exact conditions under which DW images are to be acquired. The DW imaging sequence is then slightly modified according to the eddy current parameters and used to acquire DW image data with the effects of DW-induced eddy currents compensated.

摘要翻译： 一种用于获得扩散磁共振图像的方法和系统，其补偿由扩散加权（DW）梯度脉冲引起的涡流的影响。 首先采用相同的DW序列采集预扫描数据，以用于成像。 预扫描数据用于获得涡流参数，其模拟在获得DW图像的确切条件下DW诱导的涡流的影响。 然后根据涡流参数轻微修改DW成像序列，并用于补偿DW诱导的涡流影响的DW图像数据。

公开(公告)号：US5909119A

公开(公告)日：1999-06-01

申请号：US768993

申请日：1996-12-18

申请人： Weiguo Zhang ,  David M. Kramer ,  David M. Goldhaber ,  Ching Yao ,  Hsu Chang

发明人： Weiguo Zhang ,  David M. Kramer ,  David M. Goldhaber ,  Ching Yao ,  Hsu Chang

IPC分类号： G01R33/48 ,  A61B5/055 ,  G01R33/54 ,  G01N3/00

CPC分类号： G01R33/4828 ,  G01R33/4835

摘要： A method and apparatus for obtaining three MRI image data in a single data acquisition TR interval for use in constructing separate water and fat images by appropriate processing of the three images data is disclosed. The three image data are obtained in one exemplary embodiment by sandwiching a spin echo between two field echoes. The invention can also be used for multiple-echo and multiple-slice 3D scans.

摘要翻译： 公开了一种用于通过适当处理三个图像数据来构建单独的水和脂肪图像的单个数据采集TR间隔中的三个MRI图像数据的方法和装置。 在一个示例性实施例中，通过在两个场回波之间夹住自旋回波来获得三个图像数据。 本发明也可用于多回波和多层3D扫描。

公开(公告)号：US5928546A

公开(公告)日：1999-07-27

申请号：US920655

申请日：1997-08-29

申请人： David M. Kramer ,  Maurice W. Lee, Jr. ,  Ivanhoe E. Chaput ,  Maurice W. Lee, III

发明人： David M. Kramer ,  Maurice W. Lee, Jr. ,  Ivanhoe E. Chaput ,  Maurice W. Lee, III

IPC分类号： A47J37/06 ,  H05B3/00 ,  H05B1/02

CPC分类号： H05B3/0023 ,  A47J37/0611

摘要： An automatic circuit controller for cooking food interposed between electrodes connected with a source of AC by electrical resistance in which the resistance increases until the food is cooked and rapidly declines is formed by a current switching element in series in one wire of the AC source and a current sensing element in series in another wire of the AC source. The sensed current is rectified, reduced in voltage, converted from analog to digital and applied to a microprocessor connected with the switching element for controlling the current applied to the food by delaying the time into every half cycle in response to current measuring circuitry and a zero crossing detector for triggering the switching element on. The microprocessor detects the current peak of electrical resistance of the food and stops the cooking action when the current declines to a predetermined percent of the peak.

摘要翻译： 一种用于烹饪食物的自动电路控制器，其通过电阻连接到电极之间的电极进行烹饪，所述电阻通过电阻增加直到食物被烹饪并迅速下降，由AC电源的一根线中的电流开关元件形成，并且 电流感测元件串联在交流电源的另一根线中。 感测到的电流被整流，电压降低，从模拟转换成数字，并且应用于与开关元件连接的微处理器，用于通过将时间延迟到每半个周期以响应于当前测量电路而控制施加到食物的电流，零 用于触发开关元件的交叉检测器。 当电流下降到峰值的预定百分比时，微处理器检测食物的电阻的当前峰值并停止烹饪动作。

公开(公告)号：US5838430A

公开(公告)日：1998-11-17

申请号：US675655

申请日：1996-07-03

申请人： Dan Slater ,  David M. Kramer

发明人： Dan Slater ,  David M. Kramer

IPC分类号： G01B11/26 ,  G01B11/27 ,  G01C15/00

CPC分类号： G01B11/26 ,  G01B11/27 ,  G01C15/004

摘要： A high precision alignment apparatus is provided that utilizes a semiconductor laser device, such as a laser diode, to provide a source laser beam. The alignment apparatus permits the division of a pair of beam components from the source laser beam useful for either linear or planar alignment. A centroid measurement between the beam components provides a corrected reference point that accounts for the inherent instability of the source laser beam to yield a high level of alignment accuracy. For linear alignment purposes, the beam components are collinearly directed. In the alternative, for planar alignment purposes, the beam components may be either collinear or directed in opposite directions, and rotated to sweep respective planar regions. The laser alignment apparatus is capable of providing a level of accuracy heretofore achievable only with gas lasers, while maintaining the economical attributes of commercial semiconductor laser diodes.

公开(公告)号：US4899045A

公开(公告)日：1990-02-06

申请号：US197931

申请日：1988-05-24

申请人： David M. Kramer

发明人： David M. Kramer

IPC分类号： G01M11/00

CPC分类号： G01M11/31

摘要： An optical system for individually testing each one of a plurality of fibers for continuity. Each fiber having a proximal end and a distal end with a dichroic reflector at each distal end reflective of wavelengths respective to a source of testing light and transmissive to other wavelengths. The selection of which fiber is to be tested is only a matter of manipulating a rotator element which has the capacity to rotate the angle of polarization by 90 degrees. The polarization of the light determines the respective fiber to be tested.

摘要翻译： 一种用于单独测试多个光纤中的每一个以获得连续性的光学系统。 每个光纤具有近端和远端，每个远端具有二向色反射器，反射出与测试光源相对应的波长，并且可透射到其它波长。 要测试哪种纤维的选择只是操纵具有将偏振角旋转90度的能力的旋转元件的问题。 光的偏振决定了要测试的各个光纤。

公开(公告)号：US20080009701A1

公开(公告)日：2008-01-10

申请号：US11420224

申请日：2006-05-25

申请人： Hector E. Avram ,  James D. Hale ,  Ilya Simovsky ,  David M. Kramer

发明人： Hector E. Avram ,  James D. Hale ,  Ilya Simovsky ,  David M. Kramer

IPC分类号： A61B5/05

CPC分类号： G01R33/56341 ,  G01R33/5608 ,  G01R33/5615 ,  G01R33/5617 ,  G01R33/565 ,  G01R33/56509

摘要： In preferred embodiments, a fast spin echo imaging technique is provided that is insensitive to violations of the Carr Purcell Meiboom Gill (CPMG) condition. Diffusion gradients disrupt the CPMG condition, and, hence, the present fast spin echo method is compatible with diffusion measurements and diffusion weighted imaging. The preferred embodiments of the present technique involve splitting of spin echoes into echo pairs. Spin echoes are split by adjustment (in magnitude or duration) of an initial readout gradient pulse. A train of echo pairs is captured. A first image is constructed using the first echoes of each pair. Also, a second image is constructed using the second echoes of each pair. Hybrid radial Cartesian methods are used for constructing the first and second images. The first and second images are constructed independently of one another. Independent image construction renders the method insensitive to violation of the CPMG condition. Finally, the two images are combined to form a final image.

摘要翻译： 在优选实施例中，提供了对违反Carr Purcell Meiboom Gill（CPMG）条件不敏感的快速自旋回波成像技术。 扩散梯度破坏CPMG条件，因此，本发明的快速自旋回波方法与扩散测量和扩散加权成像兼容。 本技术的优选实施例涉及将自旋回波分解为回波对。 旋转回波通过初始读数梯度脉冲的调整（幅度或持续时间）分割。 一串回波对被捕获。 使用每对的第一个回波构建第一个图像。 此外，使用每对的第二回波来构建第二图像。 混合径向笛卡尔方法用于构建第一和第二图像。 第一和第二图像彼此独立构建。 独立的图像构造使得方法对违反CPMG条件不敏感。 最后，将两张图像合并形成最终图像。

公开(公告)号：US4908573A

公开(公告)日：1990-03-13

申请号：US293859

申请日：1989-01-05

申请人： Leon Kaufman ,  David M. Kramer ,  Ricardo Guzman

发明人： Leon Kaufman ,  David M. Kramer ,  Ricardo Guzman

IPC分类号： A61B5/055 ,  G01R33/36 ,  G01R33/54 ,  G01R33/56 ,  G06T1/00 ,  G06T11/00 ,  G06T15/08

CPC分类号： G01R33/4822 ,  G01R33/56 ,  G06T11/008 ,  G01R33/3607 ,  G01R33/4833

摘要： Variable voxel shifts required for shifting a 3D structure into a common oblique or contoured slice volume based on an existing 3D image are achieved by effecting variable f(x,y) phase shifts in corresponding frequency domain data parallel to a selected axis dimension and then reconstructing a new three-dimensional image having the 3D structure all located within a common oblique or otherwise contoured slice volume such that it may viewed in a single planar image display without loss of volume resolution. Equivalent convolution processes withing the spatial domain may also be empolyed. Oblique or curved reconstructions can thus be made using either originally acquired frequency domain data (used to construct the original image) or frequency domain data obtained by inverse Fourier transforming the available spatial domain data of the images themselves.