JPS6244495B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic tomographic imaging device that obtains tomographic images within a body using an ultrasonic pulse echo method, and particularly relates to an ultrasonic tomographic imaging apparatus that obtains tomographic images in a body cavity by inserting a probe into a body cavity. It relates to a tomographic imaging device.

Conventionally, the method of inserting an ultrasound probe into a body cavity to observe a tomographic image of the body involves rotating one ultrasound transducer and performing rotational scanning, so-called radial scanning, to obtain a longitudinal cross-sectional tomographic image. There are two types of mechanical scanning methods that use an array transducer in which multiple ultrasonic transducers are arranged, and one that uses an electronic scanning method that electronically scans the ultrasound beam while keeping the transducers fixed (e.g., No. 85982 (Sho 53-85982). In the latter, a plurality of transducers are arranged along the longitudinal direction on the circumferential surface of a cylindrical probe, and by performing linear or sector-type electronic scanning, transducers are arranged parallel to the longitudinal direction of the probe. This is a method to obtain tomographic images of longitudinal sections.

Diagnosis of the prostate is a good example of observing a tomographic image by inserting a probe into a body cavity, and this case will be described below. When diagnosing the prostate using the latter method, a cylindrical probe is inserted into the rectum to obtain a longitudinal tomographic image (hereinafter referred to as longitudinal tomographic image) of the prostate in front of the rectum in real time. It can be displayed on a cathode ray tube. Since this method allows longitudinal tomographic images to be obtained in real time, it is extremely convenient for doctors to operate the probe themselves and make a diagnosis on the spot.
When recording necessary tomographic images as photographs, or when making a diagnosis based on recorded photographs,
It is not possible to tell which section the recorded tomogram is from just from the tomogram, which is extremely inconvenient for diagnosis. Therefore, it was extremely difficult to use it for mass medical examinations. Furthermore, with this method, it was not possible to observe a cross-sectional tomographic image (hereinafter referred to as a cross-sectional image) perpendicular to the axis of the probe.

SUMMARY OF THE INVENTION An object of the present invention is to provide an intrabody cavity ultrasonic tomographic imaging device that can obtain arbitrary longitudinal tomographic images and cross-sectional tomographic images, and also allows easy confirmation of the position of the cross-section in the obtained tomographic image. .

Another object of the present invention is to use ultrasonic waves for use in body cavities, which can automatically rotate a probe at a constant speed and continuously obtain longitudinal tomographic images of any cross section parallel to the longitudinal direction of the probe. To provide tomographic imaging equipment.

In the present invention, a probe having a plurality of transducers (array transducers) arranged in the longitudinal direction on the circumferential surface of a cylindrical body is rotated relative to its support by a motor. A longitudinal tomographic image of an arbitrary longitudinal section is displayed, and by detecting the rotation angle of the probe using the rotation of this motor, the sectional position of the longitudinal tomographic image is also displayed. Then, the rotation angle information of the probe is further supplied to the scan conversion circuit,
Display cross-sectional images if necessary. In this case, the position of the cross section is displayed, for example, as a linear marker on the longitudinal slice or as a distance from the body surface.

Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 1 shows a probe 1 and its support 2 in an embodiment of the present invention. The probe 1 has a plurality of transducers (hereinafter referred to as array transducers) 4 arranged along the longitudinal direction on a part of the circumferential surface of a cylindrical body (preferably a cylinder or cylindrical body) 3. The inner surface of the probe 4 is fixed to the ultrasonic absorber 5, and the ultrasonic beam is transmitted and received only on the outer surface. In reality, this surface is coated with a silicone rubber lens (not shown). The number of elements of the array vibrator 4 is, for example, 64, each of which is individually connected to a lead wire 6, and the lead wires 6 are bundled and pulled out from the support body 2 as a single cable 7, which will be described later. connected to an electronic scanning circuit.

The probe 1 is supported by a support body 2 so as to be rotatable in the circumferential direction. The contactor 1 is coupled to one rotating shaft 10a of a motor 9 fixed to the support 2 via a transmission shaft 8 within the cylindrical portion 2a of the support 2, and is rotationally driven in the circumferential direction by the motor 9. Ru. That is, when the motor 9 is driven while the support 2 is held in the hand, the probe 1 rotates relative to the support 2. A power supply cable 11 of the motor 9 is drawn out from the support 2 to the outside.

A support 2 is attached to the other rotating shaft 10b of the motor 9.
The shaft of a potentiometer 12 fixed to
The rotation angle of is detected. potentiometer 12
The rotation angle information detected is output as an electrical signal via a thin cable 13 drawn out from the support body 2.

When inserting the probe 1 into a body cavity, a thin rubber bag 14 is placed over the tip of the support 2 so that it is fixed, water 15 is poured inside the bag 14, and the array is inserted through an acoustic lens or coating material. It is desirable to improve the acoustic coupling between the vibrator 4 and the body surface.
In this case, there is an oxygen gas between the base of the probe 1 and the support 2 to prevent the water 15 from leaking into the support 2.
A ring 16 is interposed.

The support 2 is formed into a pistol shape, for example, so that it can be easily held by hand, and the transmission shaft 8, motor 9, potentiometer 12, etc. are provided in the cylindrical portion 2a of the support 2. Also cables 7, 1
1 and 13 and a water supply/drainage pipe (not shown) for the water 15 in the bag 14, etc., are drawn out from the end of the grip portion 2b of the support body 2.

If the probe as described above is used, longitudinal tomographic images of arbitrary longitudinal sections 20, 21, 22, etc. can be obtained in the process of rotating the probe 1 by the motor 9, as shown in FIG. Further, by selectively extracting only information corresponding to a certain scanning line of the ultrasonic beam while the probe 1 is rotating, it is also possible to obtain a cross-sectional image of a cross section such as 24. Furthermore, potentiometer 1
The cross-sectional position of the tomographic image can also be easily determined by the output of step 2.

FIG. 3 shows the overall configuration of an apparatus according to an embodiment of the present invention. As is well known, the electronic scanning circuit 30 includes a pulser for driving the transducer array 4 and a delay element for delaying the drive signal of the pulser or the reflected wave signal of the ultrasound from the body extracted from the transducer array. and an electronic switch for selecting each element of the transducer array 4. The reflected wave signals obtained as electrical signals from 4 are appropriately synthesized and extracted. Although linear scanning will be explained below as an example, sector scanning may of course be used. The main control circuit 31 controls the delay time of the delay elements in the electronic scanning circuit 30 and controls the electronic switches.

The reflected wave signal extracted as a video signal via the electronic scanning circuit 30 is transferred to an image memory 33 in a digital scanning conversion circuit 33 via an A/D converter 32.
0. The scan conversion circuit 33 is controlled by the main control circuit 31, and when displaying a longitudinal tomographic image, the reflected wave signal input via the A/D converter 32 is written into the image memory 330 for one arbitrary frame. . The contents of the image memory 330 are generally read out at a faster speed than when they were written, converted into a television video signal, and input to the television monitor 34.

The switch 35 is for controlling the motor 9, and is, for example, a foot switch or a switch attached like a trigger to the grip part 2b of the support body 2. The magnitude and polarity of the drive voltage supplied to the motor 9 from the motor drive circuit 36 are changed, so that the rotation speed and rotation direction of the probe 1 can be changed.

Therefore, if the probe 1 is rotated by an arbitrary angle under the control of the switch 35, a longitudinal tomographic image 4 of an arbitrary cross section in the direction of the rotation angle can be obtained as shown in FIG.
0 is displayed on the television monitor 34 in real time.

The rotation angle detection circuit 37 is connected to the potentiometer 1
This circuit supplies a constant DC voltage to the probe 2 and obtains an output voltage proportional to the rotation angle of the probe 1 via the potentiometer 12, and the output voltage is sent to the scan conversion circuit via the A/D converter 38. 33.

The scan conversion circuit 33 has a built-in overlay memory 331 in addition to the image memory 330, and when displaying a longitudinal tomographic image, the output of this memory 331 is used to display the upper right image on the television monitor 34 as shown in FIG. A symbol pattern of a cross section of a region of interest in the living body, for example, a chestnut-shaped cross section pattern 42 of the prostate gland, is also displayed within a frame 41. Furthermore, the scan conversion circuit 33 has a function of displaying a linear angle marker 43 representing the rotation angle of the probe 1 on the pattern 42 according to the output of the rotation angle detection circuit 37. That is, when the probe 1 is inserted into the rectum, for example, so that the grip part 2b of the support body 2 is aligned with the midline of the body, the array transducer 4 of the probe 1 makes an angle of θ with respect to the grip part 2b. Assuming that the vertical tomographic image 40 on the television monitor 34 shown in FIG. 4 is rotated as shown in FIG.
represents a tomographic image of a longitudinal section in the direction of
It can be easily recognized by displaying it in the direction of the angle θ relative to the target. Therefore, if such an image on the television monitor 34 is recorded by photographing or the like, the cross-sectional position of the longitudinal tomographic image 40 can be seen at a glance from the display of the angle marker 43 during diagnosis by a doctor, and this can be helpful in diagnosis. Extremely useful.

It goes without saying that the cross-sectional position of the longitudinal tomographic image may be displayed not only by such a pattern but also by a numerical value of the angle.

Next, the case of obtaining a cross-sectional image will be explained.
The cross section position designation circuit 39 includes, for example, an up/down counter 390, an up switch 391, and a down switch 392.
When you press 1, the counter 390 counts up,
When the down switch 392 is pressed, it counts down, outputs one of the numbers equal to the number of scanning lines of the ultrasound beam, and sends it to the main control circuit 31 and the scan conversion circuit 33.

At this time, a vertical tomographic image 40 as shown in FIG. A marker 45 is displayed at the line position).

On the other hand, the main control circuit 31 controls the electronic scanning circuit 3 to move the scanning lines one by one at a repetition frequency of emitting ultrasonic pulses, that is, a rate frequency (for example, 4 kHz), so that a real-time longitudinal tomographic image can be obtained.
However, when a value specifying a scanning line, for example "20", is input from the output of the counter 390 in the cross-section position specifying circuit 39, the 20th scanning line (for example, 23 in FIG. ) is supplied to the scan conversion circuit 33. At this time, the scan conversion circuit 33
Then, the address of the image memory 330 is designated by the output of the rotation angle detection circuit 37. In this state, when the motor 9 is rotated by operating the switch 35 and the contactor 1 is continuously rotated, the electronic scanning circuit 3
0, a reflected wave signal of the cross section 24 as shown by the dotted line in FIG.

Therefore, if the contents of this image memory 330 are read out and supplied to the television monitor 34, a cross-layer image 50 will be displayed as shown in FIG. If the information on the longitudinal tomogram obtained at the beginning is transferred to the overlay memory 331 and displayed on the same screen together with the cross-sectional image 40 and the cross-sectional marker 45 as in the case of FIG. The cross-sectional position of the cross-sectional layer image 50 can be seen at a glance. Alternatively, as shown in FIG. 2, for example, a scale 25 is displayed on the circumferential surface of the probe 1, and the numerical value of the scale that matches the body surface is entered using the keys, and the scale position and the specified scanning line position are 5 at the top right as shown in Figure 5.
It can also be displayed numerically, such as 1. In this case, there is an advantage that the absolute distance from the body surface can be determined, and it is even more useful if this is used in combination with the above method. Since the scanning line of the ultrasonic beam in electronic scanning is moved at high speed, for example, at a rate of 4 kHz, the specified cross section need not be limited to one cross section. For example, as shown in FIG. 4, the cross-section position is specified so that two cross-section markers 45 and 46 are displayed, and the information of four equally spaced cross-sections between them is simultaneously stored in the memory in the scan conversion circuit 33. It is also possible to simultaneously display cross-sectional images of four sections on the same television monitor 34 as shown in FIG. In this case, on the right side, a longitudinal tomographic image, a marker indicating the position of the cross-sectional plane relative to the longitudinal tomographic image, and a distance from the body surface to each cross-sectional image are simultaneously shown.

As described in detail above, according to the present invention, longitudinal tomographic images within a body cavity can be obtained in real time by electronic scanning, and longitudinal tomographic images at any required angle can be continuously and automatically obtained by simply operating a switch. Furthermore, the cross-sectional position is displayed as a linear marker or numerical value on the same screen as the tomographic image, for example.
Therefore, even when this image is recorded as a photograph, the position of the cross section can always be known by looking at the recorded data.

Further, by displaying the image graphically, the anatomical positional relationship of the obtained longitudinal tomographic images can be intuitively recognized.

Furthermore, according to the present invention, a cross-sectional image can be immediately obtained as the probe rotates by specifying a necessary cross-sectional position on a longitudinal tomographic image with a marker. Moreover, the position of the cross section can also be displayed as a linear marker displayed on the longitudinal tomographic image or as a distance from the body surface.

As described above, according to the present invention, both longitudinal tomographic images and cross-sectional tomographic images with clear anatomical positional relationships can be obtained, which is extremely useful for diagnosis.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the configuration of a probe and its support portion according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the principle of the present invention, and FIG. 3 is an embodiment of the present invention. The configuration diagram of the entire apparatus according to the example, and FIGS. 4 to 6 are diagrams showing display examples in the present invention. DESCRIPTION OF SYMBOLS 1... Ultrasonic probe, 2... Support body, 3... Cylindrical body, 4... Vibrator, 9... Motor, 12... Potentiometer, 30... Electronic scanning circuit, 33...
. . . Digital scan conversion circuit, 34 . 46
...Transverse section position marker, 50...Transverse layer line.

Claims (1)

[Claims] 1. An ultrasonic probe in which a plurality of transducers are arranged along the longitudinal direction of a cylindrical body, and a plurality of different ultrasonic beams from the transducers of this probe in a longitudinal section. a scanning section that obtains a longitudinal tomographic image from the transmitted signal; a first memory section that records the longitudinal tomographic image; a rotating section that rotates the probe; and a signal corresponding to an ultrasound beam selected from among the plurality of different ultrasound beams supplied from the scanning section in accordance with the rotation angle of the probe by the rotating section. a second memory section for recording and forming a cross-layer image;
a display unit that displays a cross-sectional marker at a position corresponding to the selected ultrasound beam on the longitudinal tomographic image read out from the memory unit, and displays the cross-sectional tomographic image read out from the second memory unit; An ultrasonic tomographic imaging device for use in body cavities, which is characterized by: 2. The display section has a means for displaying a tomographic image of an arbitrary longitudinal section parallel to the longitudinal direction of the probe, and a means for displaying the rotation angle of the probe as a line marker on a symbol pattern of a cross section of the region of interest in the body. 2. The intra-body cavity ultrasonic tomography apparatus according to claim 1, further comprising means for displaying or numerically displaying the rotation angle. 3. The display section includes a means for displaying tomographic images of one or more arbitrary cross sections perpendicular to the longitudinal direction of the probe, and a means for displaying the position of the cross section as a linear marker on the tomographic image of the longitudinal section. 2. The intrabody cavity ultrasonic tomography apparatus according to claim 1, further comprising means for numerically displaying the position of the cross section as a distance from the body surface. 4. The intrabody cavity ultrasonic tomographic imaging apparatus according to claims 1 to 3, wherein the display section displays the cross-sectional position on the same screen as the tomographic image. 5. The ultrasonic tomographic imaging device for use in a body cavity according to claim 1, wherein the cylindrical body of the probe has a scale displayed on its outer peripheral surface along the longitudinal direction.