公开(公告)号：WO1987002821A1

公开(公告)日：1987-05-07

申请号：PCT/GB1986000655

申请日：1986-10-24

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  MATTSON, Rodney, A. ,  DeMEESTER, Gordon, D.

IPC: G21K01/02

CPC classification number: A61B6/032 ,  G21K1/025

Abstract: An off-focal radiation (40) collimator which includes a plurality of radiation absorbing elements (41) supported in spaced relationship with respect to one another in a housing (43) such that each element is aligned along radii extending from the focal spot (25) of a radiation source. The off-focal collimator is preferably disposed between the radiation source and a primary beam collimator (24). The off-focal collimator also acts as a radiation beam compensator. By varying the spatial density of the radiation absorbing elements (41) by a function of location within the housing, the radiation beam can be shaped to any desired profile.

公开(公告)号：WO1987000924A1

公开(公告)日：1987-02-12

申请号：PCT/GB1986000458

申请日：1986-07-31

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  HAACKE, Mark, E.

IPC: G01N24/08

CPC classification number: G01R33/58 ,  G01R33/561 ,  G01R33/565 ,  G01R33/56509 ,  G01R33/5676

Abstract: A reference object (24) is disposed in an image region (20) with a subject (22) to be examined. The reference object has known parameters such as relaxation time, spin density, dimensions, and position. Magnetic resonance signals in which the spatial position of resonating nuclei is encoded in the relative phase and frequency thereof are sampled and temporarily stored in a view memory (56). A Fourier transform (60) is performed to convert the stored signals view into a representation of at least the positions and spin density of the resonating magnetic dipoles of the subject and reference object. The parameters of the reference object measured from the image representation are compared or inverse transformed back to data space for comparison with actual parameters of the reference object or thresholds. Based on the comparison, the resonance signals or the image representation are adjusted. For example, the magnetic resonance signals are rotated (78) through a phase correction to correct for offsets in the phase encoding. As other examples, the spin density may be adjusted, low magnitude data discarded, spatially offset data shifted, or the like. Alternately, the reference object may be interconnected with the subject to undergo movement therewith. The position of the reference object is then utilized to select views in which the movement of the subject is within preselected ranges or to approximately correct for the motion. The image can be shifted to a selected location or interpolated.

公开(公告)号：WO1991013367A1

公开(公告)日：1991-09-05

申请号：PCT/GB1991000281

申请日：1991-02-22

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  PROVOST, Terence, J.

IPC: G01R33/56

CPC classification number: G01R33/56545 ,  G01R33/56

Abstract: A fully sampled data set is generated and stored in a fully sampled memory (42). An undersampled data set corresponding to a portion of the same field of view as the fully sampled data set is generated and stored in an undersampled data memory (62). The fully sampled data set includes a frequency encoded data line corresponding to each of the phase encode gradient steps or angles required to span the selected field of view with a selected resolution. The undersampled data set includes data lines with only a fraction of the phase encoding steps or angles. The fully sampled data set is Fourier transformed (44) into a fully sampled image representation (50) and stored in a fully sampled image memory (46). The undersampled data is Fourier transformed (44) into an undersampled image representation (66) and stored in an undersampled image memory (64). The undersampled image from the views of the undersampled data set between boundaries (58a, 58b) includes a representation of the tissue (52a, 52b, 54) within these boundaries as well as a representation from tissue (52c, 52d) outside of the boundaries superimposed thereon. Portions (72, 74) of the fully sampled image representing tissue outside of the undersampled image are translated and combined (86) and subtracted (88) from the undersampled image representation to generate a corrected undersampled image (90) for display on a video monitor (48). In this manner, a portion of fully sampled image representation that is free of roll-over artifacts is utilized to correct an undersampled, incomplete image representation of the same region that includes the roll-over artifacts.

公开(公告)号：WO1987001200A1

公开(公告)日：1987-02-26

申请号：PCT/GB1986000450

申请日：1986-07-30

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  PATTANY, Pradip, Mathuradas ,  NAYLER, Graham, Leslie

IPC: G01N24/08

CPC classification number: G01R33/56509 ,  G01F1/716 ,  G01R33/482 ,  G01R33/56308 ,  G01R33/56316

Abstract: A main magnetic field coil (10) and control (12) cause a generally uniform main magnetic field through an image region. A resonance excitation control (22) causes an R.F. coil (20) to generate excitation pulses (100). An inversion pulse control (24) causes the R.F. coil to generate a first 180 degree inversion pulse (102) after the excitation pulse and a second 180 degree inversion pulse (106) immediately preceding the excitation pulse. A slice gradient control (32) and a read gradient control (34) cause a gradient coil (30) to generate complementary slice selection gradients (112, 114) and complementary read gradient profiles (120, 122; 124, 126) on either side of the first inversion pulse in such a manner that the effective first moment in time is substantially zero. By time shifting one or both of the slice selection and read gradients (Figures 4 and 5), resonating nuclei in the selected slice can be phase encoded. A transform algorithm (40) transforms resonance signals received by the R.F. coil into image representations. A first memory (54) receives real and imaginary components of the image representations when the read and slice selection gradients are not shifted and a second memory (56) receives real and imaginary components of the image representations when one or both of the read and slice selection gradients are time shifted. From the arctangent of the real and imaginary components, first and second phase maps are calculated for storage in first and second phase memories (62, 64). The intensity of each pixel of the phase maps varies with phase shift, hence velocity. By subtracting (66) the two phase maps, correction is made for any stationary artifacts.

公开(公告)号：WO1987001199A1

公开(公告)日：1987-02-26

申请号：PCT/GB1986000453

申请日：1986-07-30

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  MISIC, George, J. ,  HOLLAND, Neil, G. ,  HURST, Gregory, C. ,  PATRICK, John, L., III ,  ORLANDO, Paul, T.

IPC: G01N24/04

CPC classification number: G01R33/3628 ,  G01R33/341

Abstract: A resonance exciting coil (C) excites magnetic resonance in nuclei disposed in an image region in which a main magnetic field and transverse gradients have been produced. A flexible receiving coil (D) includes a flexible plastic sheet (40) on which one or more loops (20) are adhered to receive signals from the resonating nuclei. Velcro straps (46) strap the flexible sheet and the attached coil into close conformity with the surface of the portion of the patient to be imaged. An impedance matching or coil resonant frequency adjusting network (50) is mounted on the flexible sheet for selectively adjusting at least one of an impedance match and the peak sensitivity resonant frequency of the receiving coil. A preamplifier (52) amplifies the received signals prior to transmission on a cable (24). A selectively variable voltage source (70) applies a selectively adjustable DC bias voltage to the cable for selectively adjusting at least one of the impedance match and the LC resonant frequency of the receiving coil. The received signals are amplified by an amplifier (82) and processed by an image processor (30) to form man-readable images of the examined region of the patient for display on a video display (32) or the like.

公开(公告)号：WO1992009234A1

公开(公告)日：1992-06-11

申请号：PCT/GB1991002051

申请日：1991-11-20

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  PERUSEK, Allan, J.

IPC: A61B06/03

CPC classification number: G01T1/1648 ,  A61B6/037 ,  A61B6/4266

Abstract: A patient is supported along a longitudinal axis of a stationary patient table (10). An outer gantry (20) is mounted to move on rails (22) parallel to the longitudinal axis. The outer gantry supports a large diameter outer race (46) of a large diameter bearing (42). An inner race (44) of the large diameter bearing doubles as a structural outer frame for an inner gantry (30) which defines a patient receiving aperture (36) centrally therethrough. The large diameter bearing enables the inner gantry to rotate about the longitudinal axis. A motor (68) selectively adjusts an angular position of a first detector head (32) about a first axis (62) that lies in a plane transverse to the longitudinal axis through the large diameter bearing. A second motor (78) selectively adjusts an angular position of a second detector head (34) about a second axis (72) also lying in the plane. The motors (86 and 96) along with associated drive mechanisms selectively move the first and second camera heads, independently, toward and away from the longitudinal axis.

公开(公告)号：WO1990011045A1

公开(公告)日：1990-10-04

申请号：PCT/GB1990000397

申请日：1990-03-16

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  LINDSTROM, Walter, W. ,  DINEWITZ, Isaac

IPC: A61B05/08

CPC classification number: A61B6/481 ,  A61B5/0275 ,  A61B5/0813 ,  A61B6/032 ,  A61B6/507

Abstract: A patient is disposed within a scan circle or examination region (62) of a CT scanner (B). As the patient starts breathing air from a xenon gas supply means (A), a flow image and a lambda image are created and stored in a flow image memory (90) and a lambda image memory (92). The flow and lambda images, as well as a standard CT image, are displayed in quadrants of a video monitor (102). A joystick (106) enables the operator to designate a region of interest on the displayed image representations. Corresponding flow and lambda values are retrieved from the flow and lambda image memories for each spatial location or pixel within the region of interest. The flow and lambda values are loaded into a flow vs. lambda image memory (112) which is addressed in one direction by the flow values and in another by the lambda values to create a count of the flow and lambda value pairs. The information in the flow vs. lambda image memory is displayed as a histogram in one quadrant of the video display. The joystick further enables the operator to designate a section of the histogram as white matter and another portion as grey matter. A statistical analysis circuit (122) analyses the designated white matter and grey matter data to determine average flow and lambda values for each. These average flow and lambda values are displayed numerically with appropriate headings on the video display monitor.

Abstract translation: 患者被放置在CT扫描器（B）的扫描圆圈或检查区域（62）内。 当患者开始从氙气供应装置（A）呼吸空气时，产生流动图像和λ图像并将其存储在流动图像存储器（90）和λ图像存储器（92）中。 流量和λ图像以及标准CT图像显示在视频监视器（102）的象限中。 操纵杆（106）使得操作者能够在所显示的图像表示上指定感兴趣的区域。 对于感兴趣区域内的每个空间位置或像素，从流和λ图像存储器检索相应的流和λ值。 流和λ值被加载到流对λ图像存储器（112）中，其通过流值在一个方向上被寻址，另一个方向被λ值寻址，以创建流量和λ值对的计数。 流量与λ图像存储器中的信息在视频显示的一个象限中显示为直方图。 操纵杆进一步使操作员能够将直方图的一部分指定为白色物质，另一部分指定为灰质物质。 统计分析电路（122）分析指定的白质和灰质数据，以确定每一个的平均流量和λ值。 这些平均流量和λ值在视频显示监视器上以适当的标题数字显示。

公开(公告)号：WO1987000922A1

公开(公告)日：1987-02-12

申请号：PCT/GB1986000451

申请日：1986-07-30

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  BLAKELEY, Douglas, M. ,  KERSHAW, Carolyn, A. ,  GANGAROSA, Raymond, E., M., D.

IPC: G01N24/08

CPC classification number: G01R33/5673 ,  A61B5/7239 ,  A61B5/7285 ,  A61B6/541

Abstract: A magnetic resonance imaging apparatus (A) generates a uniform main magnetic field, gradient fields transversely thereacross, excites resonance in nuclei within an image region, receives radio frequency signals from the resonating nuclei, and reconstructs images representative thereof. Electrodes (30) monitor the cardiac cycle of a patient (B) being imaged and an expansible belt (32) monitors the respiratory cycle. A carrier signal from a generator (52) is modulated with the respiratory signals. The modulated carrier signals are combined (60) with the cardiac signals and converted to a light signal by a light source (62). A fiber optic cable (36) conducts the light signals to a light receiver (70). Band pass filters (72, 100) separate the received cardiac and respiratory encoded carrier signals. A zero detector (80) provides a scan initiation signal in response to a preselected portion of the cardiac cycle. The respiratory encoded carrier signal is demodulated by demodulator (102) and a comparator (116) blocks or enables the processing of image data during a selected window of the respiratory cycle. A window adjustment means (118) adjusts the respiratory window as a function of phase encoding of the resonating nuclei.

公开(公告)号：WO1987000921A1

公开(公告)日：1987-02-12

申请号：PCT/GB1986000452

申请日：1986-07-30

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  MISIC, George, J.

IPC: G01N24/04

CPC classification number: G01R33/3678 ,  G01R33/3614 ,  G01R33/3621

Abstract: An interface for interfacing a transmitter (C), a receiver (F) and a common probe assembly, for example in a magnetic resonance spectrometer comprising a first RF switch (10) for selectively passing and blocking the passage of RF signals between the transmitter and a first probe port (30); a phase shift means (20) connected between the first probe port and a second probe port (34), a second RF switch (40) for selectively passing and blocking the passage of RF signals between the second probe port and the receiver; and control means (G) which operates the RF switches so that when one blocks RF signals, the other passes RF signals and vice versa.

Abstract translation: 用于例如在磁共振光谱仪中的发射器（C），接收器（F）和公共探头组件接口的接口，所述磁共振光谱仪包括第一RF开关（10），用于选择性地通过和阻止RF信号在发射器和 第一探测端口（30）; 连接在第一探测端口和第二探测端口（34）之间的相移装置（20），用于选择性地通过和阻止第二探测端口和接收器之间的RF信号通过的第二RF开关（40） 以及控制装置（G），其操作RF开关，使得当一个阻塞RF信号时，另一个通过RF信号，反之亦然。

公开(公告)号：WO1992009907A1

公开(公告)日：1992-06-11

申请号：PCT/GB1991002050

申请日：1991-11-20

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  PLUMMER, Steven, J. ,  YORK, Davil, L.

IPC: G01T01/169

CPC classification number: G21K1/025 ,  E05Y2900/402 ,  G01T1/1648

Abstract: An outer gantry (20) is movably mounted on wheels to move along tracks (22). An inner gantry (30) rotatably mounted on the outer gantry includes at least a pair of guide rods (56, 58) on which detector heads (32, 34) are slidably mounted. Motors (92, 102) selectively translate the detector heads along the guide rods. A chain and sprocket arrangement (116, 114; 128, 126) constrains the heads against canting and maintains opposite sides of the detector heads in alignment as the detector heads move and as the inner gantry rotates. Each detector head includes a roller bearing track or channel portion (140) on which a horizontal track portion (142) of a collimator (144) is hung vertically. A collimator connecting assembly (150) connects a bottom portion of the collimator to the detector head and secures it against further horizontal movement. A collimator cart (200) includes an analogous roller track portion (202) for supporting the collimators by the collimator guide track portion as collimators are moved between the detector head and like track portion (192) of a detector storage rack (190).