Abstract: A magnetic resonance imaging apparatus comprises a data acquisition system with motion compensation means for acquiring an image data set in respect of a moving object within an imaging region, the image data set comprising a plurality of acquisitions each in respect of one or more slice planes. Further there are means for averaging, on a slice-by-slice basis, said plurality of acquisitions to generate a single, average image set of said moving object. Also means are provided for calculating the actual scan location of all of said slice planes from all of said acquisitions, means for averaging a selected set of slice planes to generate a single, average image set of a static object within said imaging region. This averaging results in a high image quality in respect of the moving object (12) because for the static object, slice locations change for each acquisition.

Abstract: A magnetic resonance imaging apparatus comprises a data acquisition system with motion compensation means for acquiring an image data set in respect of a moving object within an imaging region, the image data set comprising a plurality of acquisitions each in respect of one or more slice planes. Further there are means for averaging, on a slice-by-slice basis, said plurality of acquisitions to generate a single, average image set of said moving object. Also means are provided for calculating the actual scan location of all of said slice planes from all of said acquisitions, means for averaging a selected set of slice planes to generate a single, average image set of a static object within said imaging region. This averaging results in a high image quality in respect of the moving object (12) because for the static object, slice locations change for each acquisition.

Abstract: An object of this invention is to provide a Navigator Echo method applicable even when an elongated navigator region and a region of interest to be imaged have a mutually overlapping part. A control section of an MRI apparatus decides, based on a measured signal obtained from a first reception pulse emanated in response to a first transmission pulse which excites a first region to monitor the breathing movement of a subject, whether or not a second region of the subject to be imaged and the first region have a mutually overlapping part, corrects, when the decision result shows that there is an overlapping part, the measured signal obtained from the first reception pulse, and controls a reconstruction unit so as to reconstruct the image of the second region based on the measured signal obtained from a second reception pulse emanated in response to a second transmission pulse which excites the second region and the corrected measured signal.

Abstract: In order to reduce the cost for isolation between a surface coil and a body coil installed on a magnet assembly side, an RF shield for a surface coil is disposed between a body coil installed on a magnet assembly side of an MRI apparatus and a surface coil body not installed on the magnet assembly side. The reception by the body coil of RF pulses transmitted from the surface coil body is suppressed by the RF shield for the surface coil. Since an induced voltage in the body coil drops to a great extent, a switch provided on the body coil side no longer requires a component resistant to high voltage and high current. Thus, the apparatus can be simplified and the cost can be reduced. As a result, the reliability of the apparatus is improved.

Abstract: In order to reduce the cost for isolation between a surface coil and a body coil installed on a magnet assembly side, an RF shield for a surface coil is disposed between a body coil installed on a magnet assembly side of an MRI apparatus and a surface coil body not installed on the magnet assembly side. The reception by the body coil of RF pulses transmitted from the surface coil body is suppressed by the RF shield for the surface coil. Since an induced voltage in the body coil drops to a great extent, a switch provided on the body coil side no longer requires a component resistant to high voltage and high current. Thus, the apparatus can be simplified and the cost can be reduced. As a result, the reliability of the apparatus is improved.

Abstract: An image processing system having a server which applies image processing to a medical image sent by a subscriber via a generally available network, such as the “internet”, and sends the results of the image processing back to that subscriber or to another subscriber as instructed upon verification of the legitimacy of the instructions. In this manner, the processing load is reduced and medical images are made more readily and easily accessible.

Abstract: For the purpose of providing an image processing method for properly performing filtering, a local region is defined containing a pixel of interest in an original image (504); pixel groups are defined in the region in a plurality of modes (506); a pixel group mode which best fits a structure of the original image in the local region is selected (508, 510); and an average pixel value of the pixel group which contains the pixel of interest is used as a new pixel value for the pixel of interest.

Abstract: For the purpose of accurately calculating the average value M of original complex observed signals S from an absolute-value image produced by the complex observed signals S, in Step A1, the average value Ma of pixel values |S| of the absolute-value image in a local region is calculated by: Ma=?|S|/k, wherein the number of pixels in the local region is represented as k. In Step A2, the average value M of the original complex observed signals S is calculated by the following equation: M=?·ƒ?1 (Ma/?), wherein ƒ?1 (Ma/?) is an inverse function of the function Ma/?=ƒ(M/?) represented as: Ma/?=??{|M/?+(X+iY)|exp{?(X2+Y2)/2}/2?}dX dY.

Abstract: For the purpose of enhancing a difference between pixels relating to a substantial structure in an image and other pixels, with each pixel constituting an image defined as a pixel of interest, the variance of pixel values is determined in a local region to which the pixel of interest belongs (508); and the pixel value of the pixel of interest is maintained when the variance of pixel values is significantly larger than the variance of noise, otherwise the pixel value of the pixel of interest is suppressed (510, 512).

Abstract: For the purpose of providing an image processing method for efficiently performing filtering, a local region containing a pixel of interest is defined in a plurality of modes in an original image (502); sequentially for the region in the plurality of modes, the variance of pixel values is obtained and a decision is made whether the value of the variance falls within a predetermined range (504, 506, 508 512, 514); and an image is produced using as a new pixel value for the pixel of interest an average value of pixel values of the region for which the value of the variance first falls within the range (508, 510, 524).

Abstract: For the purpose of providing an image processing method for determining the variance of noise in an image, a residual sum of squares of pixel values is determined for each of a plurality of local regions defined over the entire image (502-508); a histogram thereof is obtained (510); and the variance of noise is determined based on the value of the residual sum of squares that gives a peak of the histogram (512, 514).

Abstract: For the purpose of improve rendering capability for a blood vessel, an MR. image producing method comprises: window-processing MR signals using a window function f(k) that has a “value less than one” at a center (O) and in its proximate region in a k-space and on a periphery and in its proximate region in the k-space, and has a value larger than the “value less than one” between the regions in which the window function has the “value less than one;” and applying Fourier-transformation processing to the window-processed MR signals to obtain an MR image.

Abstract: For the purpose of improve rendering capability for a blood vessel, an MR image producing method comprises: window-processing MR signals using a window function f(k) that has a “value less than one” at a center (O) and in its proximate region in a k-space and on a periphery and in its proximate region in the k-space, and has a value larger than the “value less than one” between the regions in which the window function has the “value less than one;” and applying Fourier-transformation processing to the window-processed MR signals to obtain an MR image.

Abstract: For the purpose of acquiring the magnetic resonance signal having a small Maxwell term, a flow encode gradient Gr having the first half and the second half in which the gradient of the respective halves is reversed and having an equal absolute value of the gradient is applied in the readout gradient direction in a time period coincident with the time period when the spin is rephased by means of the slice gradient, and a flow encode gradient having the first half and the second half in which the gradient of the respective halves is reversed and having an equal absolute value of the gradient is applied in the slice gradient direction in a time period coincident with the time period when the spin is dephased by means of the readout gradient.

Abstract: In order to provide a magnetic resonance signal receiving method and apparatus for performing imaging with good quality and an magnetic resonance imaging apparatus employing such a magnetic resonance signal receiving apparatus, gradient magnetic fields Gs1k and Gs2k for dephasing spins are applied with their strengths varied after each spin echo is received in line scanning.

Abstract: For the purpose of acquiring the magnetic resonance signal having a small Maxwell term, a flow encode gradient Gr having the first half and the second half in which the gradient of the respective halves is reversed and having an equal absolute value of the gradient is applied in the readout gradient direction in a time period coincident with the time period when the spin is rephased by means of the slice gradient, and a flow encode gradient having the first half and the second half in which the gradient of the respective halves is reversed and having an equal absolute value of the gradient is applied in the slice gradient direction in a time period coincident with the time period when the spin is dephased by means of the readout gradient.

Abstract: For the purpose of enhancing a difference between pixels relating to a substantial structure in an image and other pixels, with each pixel constituting an image defined as a pixel of interest, the variance of pixel values is determined in a local region to which the pixel of interest belongs (508); and the pixel value of the pixel of interest is maintained when the variance of pixel values is significantly larger than the variance of noise, otherwise the pixel value of the pixel of interest is suppressed (510, 512).

Abstract: For the purpose of providing an image processing method for efficiently performing filtering, a local region containing a pixel of interest is defined in a plurality of modes in an original image (502); sequentially for the region in the plurality of modes, the variance of pixel values is obtained and a decision is made whether the value of the variance falls within a predetermined range (504, 506, 508 512, 514); and an image is produced using as a new pixel value for the pixel of interest an average value of pixel values of the region for which the value of the variance first falls within the range (508, 510, 524).

Abstract: For the purpose of accurately calculating the average value M of original complex observed signals S from an absolute-value image produced by the complex observed signals S, in Step A1, the average value Ma of pixel values |S| of the absolute-value image in a local region is calculated by:

Abstract: For the purpose of providing an image processing method for properly performing filtering, a local region is defined containing a pixel of interest in an original image (504); pixel groups are defined in the region in a plurality of modes (506); a pixel group mode which best fits a structure of the original image in the local region is selected (508, 510); and an average pixel value of the pixel group which contains the pixel of interest is used as a new pixel value for the pixel of interest.