JP3750972B2 - 3D ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-dimensional ultrasonic diagnostic apparatus that obtains three-dimensional information using a two-dimensional array probe formed by two-dimensionally arranging ultrasonic elements, and in particular, is configured using a large number of minute ultrasonic elements. The present invention relates to a three-dimensional ultrasonic diagnostic apparatus capable of reducing a burden during driving of a two-dimensional array probe or obtaining a three-dimensional volume image within a safe range and obtaining a two-dimensional tomographic image in real time.
[0002]
[Prior art]
Conventional ultrasonic diagnostic apparatuses are generally systems that display a cross-sectional image by scanning an ultrasonic beam in one plane. In recent years, many attempts have been made to collect diagnostic images while moving an ultrasonic probe that is an ultrasonic transmission / reception unit of an ultrasonic diagnostic apparatus to obtain three-dimensional information. The possibility of a new diagnosis is expected from the display. Actually, research to obtain a three-dimensional volume image by manually or mechanically moving a convex probe or a linear array probe for the abdomen, or a multi-plane probe for transesophagus with a mechanism for rotating an electronic sector probe. Research to obtain a three-dimensional volume image is underway.
[0003]
However, since it takes a considerable amount of time to reconstruct a three-dimensional volume image, compared to conventional cross-sectional image scanning, there is a problem that the movement cannot be captured when imaging a fast-moving part such as the heart. Is produced. For this reason, a two-dimensional array probe formed by two-dimensionally arranging ultrasonic elements is used to three-dimensionally scan an ultrasonic beam at a frame rate close to the real time (real time) of 30 frames / second. Development of a three-dimensional ultrasonic diagnostic apparatus that captures and displays a volume image is under research.
[0004]
[Problems to be solved by the invention]
Here, in such a three-dimensional ultrasonic diagnostic apparatus, even when a three-dimensional volume image is displayed, an image of a predetermined cross section (a cross section of interest) is displayed at substantially the same frame rate as a conventional two-dimensional cross section image. Although it is considered that there are many cases of observation, if a two-dimensional array probe is constantly scanned with a three-dimensional volume to obtain a three-dimensional volume image having the same image quality as a conventional two-dimensional tomogram, It is necessary to apply ultrasonic energy that is higher than that in the past, and the two-dimensional array probe may be damaged, causing a problem in the safety of the three-dimensional ultrasonic diagnostic apparatus.
[0005]
That is, the two-dimensional array probe is formed by two-dimensionally arranging a number of minute ultrasonic elements. For this reason, when trying to obtain a three-dimensional volume image having the same image quality as a conventional two-dimensional tomographic image and applying ultrasonic energy higher than conventional to each ultrasonic element over a long period of time, minute ultrasonic elements are more than conventional. Therefore, the two-dimensional array probe may be damaged, causing a problem in the safety of the three-dimensional ultrasonic diagnostic apparatus.
[0006]
In addition, when the three-dimensional volume image is to be obtained within the safe range of the ultrasonic radiation energy within the damage limit of the two-dimensional array probe or within the subject's internal temperature rise, the radiation energy must be reduced as compared with the conventional technique. Therefore, there arises a problem that the image quality is deteriorated.
[0007]
The present invention has been made in view of the above-described problems, and the required image quality 3 is achieved without damaging the two-dimensional array probe and without degrading the image quality using ultrasonic energy within the range of safety. It is an object of the present invention to provide a three-dimensional ultrasonic diagnostic apparatus capable of displaying a two-dimensional cross-sectional image while displaying a three-dimensional volume image.
[0008]
[Means for Solving the Problems]
The three-dimensional ultrasonic diagnostic apparatus according to the present invention includes a two-dimensional array probe formed by two-dimensionally arranging a plurality of ultrasonic elements, and a three-dimensional object. The two-dimensional array probe is driven and controlled to perform scanning intermittently, and two-dimensional scanning is performed at a scanning rate higher than the scanning rate at the time of the three-dimensional scanning during each of the three-dimensional scanning performed intermittently. As described above, a three-dimensional image is formed on the basis of ultrasonic information obtained by the control means for driving and controlling the two-dimensional array probe and the three-dimensional scanning performed intermittently. Image forming means for forming a two-dimensional image based on ultrasonic information obtained by two-dimensional scanning.
[0009]
Such a three-dimensional ultrasonic diagnostic apparatus considers a three-dimensional image as a reference image for observing a two-dimensional image, and intermittently scans the reference image at a sufficient scanning rate with a three-dimensional image. In addition to obtaining an image, during each intermittent three-dimensional scanning, a two-dimensional image is obtained by two-dimensional scanning at a scanning rate equal to or higher than the scanning rate at the time of the three-dimensional scanning.
[0010]
As a result, three-dimensional scanning of the two-dimensional array probe can be performed intermittently, so that it is sufficient for the reference image without giving ultrasonic energy for a long time until safety becomes a problem for the two-dimensional array probe. A three-dimensional image can be obtained intermittently at the scanning rate. Also, when obtaining a two-dimensional image, the two-dimensional array probe is scanned at a scanning rate higher than the scanning rate at the time of three-dimensional scanning. A two-dimensional image can be obtained.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the three-dimensional ultrasonic diagnostic apparatus according to the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a block diagram of a three-dimensional ultrasonic diagnostic apparatus according to an embodiment of the present invention.
[0012]
In FIG. 1, the three-dimensional ultrasonic diagnostic apparatus according to the embodiment includes a two-dimensional array probe 1 in which a number of minute ultrasonic elements are two-dimensionally arranged and a two-dimensional array probe 1. An image acquisition processing unit 2 that forms a three-dimensional volume image or a two-dimensional tomographic image based on an echo signal that is taken in three-dimensionally or three-dimensionally, and a controller 7 that controls the entire three-dimensional ultrasonic diagnostic apparatus. A three-dimensional volume image or two-dimensional tomographic image formed by a pointing device 8 such as a mouse device, a trackball device or a keyboard, and an image acquisition processing unit 2, and a cathode ray tube (CRT) or a liquid crystal display unit (LCD) And a scan converter 9 that controls display on the display unit 10.
[0013]
The image acquisition processing unit 2 includes a two-dimensional beamformer 4 that adjusts a delay time so that a two-dimensional tomographic sound field such as a B-mode image is formed on each transducer element, and a three-dimensional volume sound field. In this way, the three-dimensional beamformer 3 that adjusts the delay time and the ultrasonic transducers of the two-dimensional array probe 1 are driven by ultrasonic transmission pulses, and the reflected waves generated by the difference in the acoustic impedance of the living tissue A transmission / reception unit 5 that receives an echo signal, a two-dimensional tomographic image such as a B mode, or a three-dimensional structure such as a living tissue is reconstructed from a three-dimensional echo signal, and a three-dimensional display technique such as volume rendering is used. An image processing unit 6 for processing a three-dimensional image.
[0014]
In FIG. 1, the two-dimensional beamformer 4 and the three-dimensional beamformer 3 are illustrated as separate blocks. However, these are functionally separated for the sake of explanation, and are the same on the hardware. It may be a block.
[0015]
Next, the operation of the three-dimensional ultrasonic diagnostic apparatus according to the embodiment having such a configuration will be described.
[0016]
First, FIG. 2 and FIG. 3 show sector type and linear type 3D / 2D tomographic sound field models, respectively. The three-dimensional sound field is one in which all elements can be received simultaneously by the two-dimensional array probe 1, and the two transmission / reception areas of the two-dimensional array probe 1 are orthogonal to each other at the center of the transmission / reception area, for example. Is divided into four equal parts, and divided reception is performed such that ultrasonic waves are transmitted and received for each of the divided areas, the corresponding three-dimensional sound field of the reception element group is obtained. In the case of the two-dimensional tomographic sound field indicated by oblique lines in FIGS. 2 and 3, a plurality of columns of elements are arranged in order to reduce the expansion of the sound field in the x direction of the two-dimensional array probe 1 or in the lens direction. Two-dimensional beam forming is performed using elements.
[0017]
Note that the two-dimensional tomographic sound field is parallel to the x direction, but if it is parallel to the y direction, one or more elements in the y direction are used.
[0018]
Next, FIG. 4 shows a time-series timing chart of the two-dimensional scan and the three-dimensional scan of the three-dimensional ultrasonic diagnostic apparatus. In the three-dimensional ultrasonic diagnostic apparatus, as shown in the scan sequence (transmission / reception sequence) in FIG. 4A, the three-dimensional scan is intermittent such as nth, (n + 1) th, (n + 2) th, etc. The controller 2 collects images so that the two-dimensional scan is performed at a high frame rate (continuously) such as 1 s, 2 s, 3 s, 4 s, 5 s... The two-dimensional array probe 1 is driven and controlled via the transmission / reception unit 5 of the processing unit 2.
[0019]
As shown in FIG. 4 (b), the image processing unit 6 of the image collection processing unit 2 collects each anisotropy collected after the end of the three-dimensional scan of the nth, (n + 1) th, (n + 2) th, etc. 3D image data is reconstructed (resampled) into isotropic 3D data for performing 3D display processing, and volume reconstruction processing, MIP processing, etc. are performed on the reconstructed data. By performing the three-dimensional image processing, a three-dimensional volume image is formed and supplied to the scan converter 9. The scan converter 9 performs a predetermined display process on the three-dimensional volume image and supplies it to the display unit 10. In addition, after the two-dimensional scan, the image processing unit 6 performs a two-dimensional tomography instantaneously (in real time) by performing a B-mode process or the like performed by a conventional ultrasonic diagnostic apparatus on the two-dimensional image data. An image is formed and supplied to the display unit 10 via the scan converter 9.
[0020]
As a result, a two-dimensional tomographic image obtained by a two-dimensional scan performed between the n-th three-dimensional scan and the (n + 1) -th three-dimensional scan is displayed on the display unit 10 as shown in FIG. , The (n−1) -th three-dimensional scan and the three-dimensional volume image are superimposed and displayed on the display unit 10. Further, as shown in FIG. 4A, a two-dimensional tomographic plane in three-dimensional data, that is, a three-dimensional volume image obtained by, for example, the (n + 1) th three-dimensional scan, Since the tomographic plane of the two-dimensional tomographic image 6s between the two-dimensional tomographic image 7s is included, this tomographic plane is also displayed as a two-dimensional tomographic image 6d as shown in FIG.
[0021]
By performing such superposition display, the time difference between the displayed three-dimensional volume image and the two-dimensional tomographic image displayed on the three-dimensional volume image is large, but the real-time property of the two-dimensional tomographic image can be ensured. it can.
[0022]
Note that, even if the real-time property is sacrificed to some extent, if it is necessary to correct this time lag, for example, as shown in FIGS. You can do it.
[0023]
Next, it is conceivable that the tomographic plane of the two-dimensional tomographic image to be displayed superimposed on the three-dimensional volume image displays a tomographic plane at the tomographic position described below.
[0024]
First, as indicated by hatching in FIG. 2 or FIG. 3, a tomographic plane perpendicular to the center line of the probe surface, that is, a two-dimensional tomographic image of the central cross section of the three-dimensional volume image, as in the conventional one-dimensional probe. Always display.
[0025]
Next, as shown in FIG. 6 (a), for example, a hepatocellular carcinoma is fixedly displayed on a three-dimensional volume image, and only the cross-section in that is translated in an arbitrary direction as shown in FIG. 6 (b). Alternatively, as shown in FIG. 6C, there is a clinical need to rotate and tilt the image for observation. Normally, cancer cells are spherical, but in order to make the explanation easy to understand, FIGS. 6A to 6C are assumed to be cubes.
[0026]
Therefore, secondly, when the two-dimensional array probe 1 is fixed at a position where hepatocellular carcinoma can be observed, and the pointing device 8 is operated by a hand not holding the two-dimensional array probe 1, this operation is performed. A two-dimensional tomographic image of the tomographic plane specified by is displayed. Actually, when the degree of freedom of designation of the two-dimensional tomographic plane increases, the feeling of discomfort with the operation feeling of the conventional one-dimensional probe increases, so that it is limited to, for example, turning and shifting in the y direction shown in FIG. 2 or FIG. It is considered that the interpretation (interpretation) of the image is easier.
[0027]
Next, such movement of the two-dimensional tomographic plane is not a problem when shifting in the front direction as shown in FIGS. 6A and 6B, but as shown in FIG. When the three-dimensional tomographic plane is rotated, the tomographic plane is viewed from an oblique line of sight, so it may be difficult to see if the rotation angle is deep. Therefore, thirdly, when the tomographic plane is viewed from an oblique line of sight as shown in FIG. 7A, the tomographic plane is viewed from the front as shown in FIG. Change the viewing direction of the three-dimensional volume image. As a result, even when the tomographic plane to be observed is rotated, the tomographic plane can always be displayed as viewed from the front.
[0028]
As is apparent from the above description, the three-dimensional ultrasonic diagnostic apparatus of the present embodiment intermittently drives the two-dimensional array probe 1 to obtain a three-dimensional volume image at a predetermined intermittent frame rate, A two-dimensional tomographic image is obtained in real time by partially driving the two-dimensional array probe 1 at a frame rate higher than the frame rate for obtaining this three-dimensional volume image. As a result, a three-dimensional volume image can be intermittently obtained without applying ultrasonic energy for a long time until safety becomes a problem with respect to the two-dimensional array probe 1, and substantially the same frame as the conventional one. A two-dimensional tomographic image can be obtained at a rate (real time). Therefore, the necessary three-dimensional volume image is displayed without damaging the two-dimensional array probe 1 and without degrading the image quality using ultrasonic energy within the range of safety, and the two-dimensional cross section in real time. An image can be displayed.
[0029]
Finally, the above-described embodiment is an example of the present invention. Therefore, the present invention is not limited to this embodiment. For example, in the description of the above-described embodiment, the three-dimensional volume image and the two-dimensional tomographic image are displayed so as to overlap each other. The two-dimensional tomographic image may be displayed separately. In addition to this, it is a matter of course that various modifications can be made according to the design or the like as long as they do not depart from the technical idea according to the present invention.
[0030]
【The invention's effect】
The three-dimensional ultrasonic diagnostic apparatus according to the present invention prevents damage without giving ultrasonic energy up to a level where safety is a problem, and also uses ultrasonic energy within the range of safety to improve image quality. The necessary three-dimensional volume scanning / display can be performed without lowering the image quality, and real-time display can be performed at substantially the same frame rate as that in the conventional case at the target disease site that requires detailed examination.
[Brief description of the drawings]
FIG. 1 is a block diagram of a three-dimensional ultrasonic diagnostic apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a three-dimensional / two-dimensional scan target area when a sector scan type two-dimensional array probe is provided in the three-dimensional ultrasonic diagnostic apparatus of the embodiment.
FIG. 3 is a diagram illustrating a three-dimensional / two-dimensional scan target region in the case where a linear scan type two-dimensional array probe is provided in the three-dimensional ultrasonic diagnostic apparatus of the embodiment.
FIG. 4 is a diagram for explaining processing / display timing of a three-dimensional volume image and a two-dimensional tomographic image of the three-dimensional ultrasonic diagnostic apparatus according to the embodiment.
FIG. 5 is a diagram for explaining other processing / display timings of a three-dimensional volume image and a two-dimensional tomographic image of the three-dimensional ultrasonic diagnostic apparatus according to the embodiment.
FIG. 6 is a diagram for explaining an overlay display of a three-dimensional volume image and a two-dimensional tomographic image and a tomographic plane moving operation in the three-dimensional ultrasonic diagnostic apparatus of the embodiment.
FIG. 7 is a diagram for explaining a problem when the tomographic plane is rotated by the operation of moving the tomographic plane and a display form for displaying the rotated tomographic plane in front.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Two-dimensional array probe, 2 ... Image acquisition process part, 3 ... Three-dimensional beam former, 4 ... Two-dimensional beam former, 5 ... Transmission / reception part, 6 ... Image processing part, 7 ... Controller, 8 ... Pointing device, 9 ... Scan converter, 10 ... display section

Claims (6)

A two-dimensional array probe formed by two-dimensionally arranging a plurality of ultrasonic elements;
The two-dimensional array probe is driven and controlled so as to intermittently perform three-dimensional scanning of an object, and during each three-dimensional scanning performed intermittently, at a scanning rate equal to or higher than the scanning rate at the time of the three-dimensional scanning. Control means for driving and controlling the two-dimensional array probe to perform two-dimensional scanning;
A three-dimensional image is formed based on the ultrasonic information obtained by the three-dimensional scanning performed intermittently, and 2 based on the ultrasonic information obtained by the two-dimensional scanning performed between the three-dimensional scanning. A three-dimensional ultrasonic diagnostic apparatus comprising image forming means for forming a three-dimensional image. The image forming unit forms a three-dimensional image based on the ultrasonic information obtained by the intermittent three-dimensional scanning, and performs the scanning based on the ultrasonic information obtained by the three-dimensional scanning. The three-dimensional ultrasonic diagnostic apparatus according to claim 1, wherein a two-dimensional image of timing is formed. 3. The three-dimensional ultrasonic diagnostic apparatus according to claim 1, further comprising a superimposed display unit that superimposes the two-dimensional image on the three-dimensional image formed by the image forming unit and displays the superimposed image on the display unit. . 4. The three-dimensional ultrasonic diagnostic apparatus according to claim 3, wherein the superimposing display unit superimposes and displays a two-dimensional image corresponding to a central section of the three-dimensional image on the display unit. A cross-section specifying means for specifying a cross-section of a two-dimensional image relative to the ultrasonic probe surface of the two-dimensional array probe;
4. The three-dimensional ultrasonic diagnostic apparatus according to claim 3, wherein the superimposing display unit displays the two-dimensional image of the cross section designated by the cross section designating unit on the display unit so as to overlap the three-dimensional image. 6. The three-dimensional ultrasonic diagnostic apparatus according to claim 5, wherein the superimposed display means displays on the display means so that a two-dimensional image of the cross section designated by the cross section designation means is always located in front.

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