JP2002153472A - Image diagnostic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire both of OCT images and ultrasonic images by one diagnosis. SOLUTION: A probe 10a provided with an ultrasonic wave transducer 51 and an OCT scanning part 140 in the inside is inserted to the forceps port of an endoscope and the inside of the celom of a patient is observed. Ultrasonic wave signals are oscillated by an ultrasonic wave signal processor 50, an object is irradiated with ultrasonic waves from the ultrasonic wave transducer 51 on the basis of the signals and measurement is performed. Simultaneously, the light source of an OCT device is driven, the object is irradiated with signal light Ls and the measurement is performed. Further, the probe 10a is rotated by driving a centerless motor 20 and radial scanning is performed. On the basis of information obtained by the scanning, the ultrasonic images and the OCT images are acquired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image diagnostic apparatus, and more particularly, to an image diagnostic apparatus capable of acquiring subject information by a plurality of means.

[0002]

2. Description of the Related Art An ultrasonic diagnostic imaging apparatus has many advantages such as less burden on a patient, almost harmlessness unlike X-ray diagnosis, much information to be obtained, and inexpensive equipment. Widely used in the field of medical diagnosis.

[0003] This ultrasonic image diagnostic apparatus oscillates ultrasonic waves by applying an ultrasonic probe to an observation part of a patient, and obtains information in the body based on echoes reflected from the body. Many of these ultrasonic diagnostic imaging apparatuses perform a sector scan or a linear scan to obtain a B-mode image, that is, a two-dimensional cross-sectional image.

In the field of endoscopes, ultrasonic probes that are inserted into forceps ports of endoscopes are widely used, and B-mode images of inner walls in body cavities, that is, two-dimensional cross-sectional images are obtained. It is used for observation.

On the other hand, in recent years, O
CT (Optical Coherence Tomography) diagnostic imaging device,
In particular, an OCT image diagnostic apparatus that obtains an optical tomographic image of a tissue to be measured by measuring the light intensity of low coherence light interference light by heterodyne detection is being applied to medical diagnosis. Details of the OCT image diagnostic apparatus are described in "O Plus E Vol. 21, No. 7 P. 802-804" (by Masamitsu Haruna).

[0006] This OCT image diagnostic apparatus is an SLD (Supe
r Luminescent Diode) to divide the low-coherence light emitted from the light source into signal light and reference light, slightly shift the frequency of the reference light or signal light by a piezo element, etc., and make the signal light incident on the tissue to be measured. Let the reflected light and reference light reflected at a predetermined depth of the tissue to be measured interfere,
The light intensity of the interference light is measured by heterodyne detection,
The tomographic information is acquired, and by slightly moving a movable mirror or the like disposed on the optical path of the reference light to slightly change the optical path length of the reference light, the optical path length of the reference light and the optical path length of the signal light are changed. The information corresponding to the depth of the measured tissue can be obtained.

With such an OCT image diagnostic apparatus, a subject can be observed with a high resolution of about several tens of μm. For this reason, early cancer diagnosis and the like can be performed. Therefore, a method of guiding a signal light and a reflected light of the signal light with a probe that can be inserted into a forceps port of an endoscope apparatus to acquire an optical tomographic image in a body cavity. Is being developed. For example, "OPTICS LETTER Vol.24, No19 P1358 ~ P1360" (by And
rew M Rollins and Rujchai Ung-arunyawee) have an optical fiber that guides the signal light through the forceps port of the endoscope device, and a mirror that is disposed at the tip of the optical fiber and reflects the signal light at right angles. And an OCT image diagnostic apparatus that performs a radial scan by rotating the mirror and displays a radial optical tomographic image that displays the body cavity wall in a sliced state.

[0008]

However, in the case of an ultrasonic diagnostic imaging apparatus, several tens of millimeters from the inner wall surface in a body cavity.
It can be imaged to a depth of mm, but the frequency of ultrasonic waves used practically for diagnosis is several MHz to several tens of MHz.
Therefore, the resolution can be increased only up to about several 100 μm.

On the other hand, the OCT diagnostic imaging apparatus is an imaging technique using light, and therefore has a high resolution of about several tens of μm. However, when used in a body cavity, it is 1 to 2 m from the inner wall surface.
It can only be imaged to a depth of about m.

[0010] The present invention provides an OCT image,
An object of the present invention is to provide an image diagnostic apparatus capable of acquiring both images with an ultrasonic image and acquiring information up to a high depth, and acquiring high-resolution information at a low depth. is there.

[0011]

An image diagnostic apparatus according to the present invention has light guiding means for guiding signal light, which is low coherence light, to a subject, and the subject is provided with the signal light guided by the light guiding means. And OCT image acquisition means for acquiring an optical tomographic image of the subject using interference between reflected light from a predetermined depth and reference light having a slight frequency difference from the signal light, and irradiating the subject with ultrasonic waves. An irradiating means, and an ultrasonic image acquiring means for acquiring an ultrasonic image of the object based on a reflected wave of the ultrasonic wave radiated by the irradiating means from the object; The means constitutes a search unit integrally fixed to each other, and the search unit is contained in a hollow flexible case to constitute a probe.

Here, the light guiding means means a fiber that guides the signal light from the proximal end to the distal end of the probe, a rod lens provided at the distal end of the fiber, a mirror, and the like.

In the image diagnostic apparatus according to the present invention, the OC
It is desirable that the T image acquiring unit and the ultrasonic image acquiring unit acquire an image of the same region of the subject.

Further, in the diagnostic imaging apparatus according to the present invention, the probe may be inserted into a forceps port of the endoscope.

[0015] Further, the exploration unit may be configured to perform a radial scan by rotating around a longitudinal direction of the probe in order to acquire an image, wherein a rotational angle of the rotational movement is detected by a single rotary encoder. Alternatively, assuming that the linear scanning is performed by moving in parallel in the longitudinal direction of the probe, the moving distance of the parallel movement may be detected by a single linear encoder.

In the diagnostic imaging apparatus according to the present invention, the search section is provided in parallel with the central axis of the probe, and guides the signal light to the vicinity of the subject. A lens that condenses the light, a mirror provided at the tip of the rod lens, and a mirror that polarizes the signal light in the perpendicular direction, and an ultrasonic transducer attached to the optical fiber and irradiating the object with ultrasonic waves,
The optical fiber may be held by a bearing in the case.

Here, the optical fiber means a combination of a fiber body, a sheath covering the fiber, and the like.

Here, a part of the optical fiber may be connected to a centerless motor disposed outside the case and rotated by the centerless motor.
It may be connected to a driving means arranged outside the case and may be translated by the driving means.

[0019]

The image diagnostic apparatus according to the present invention having the above-described configuration is capable of combining the OCT image acquiring means and the ultrasonic image acquiring means to obtain several tens mm from the inner wall surface of the luminal organ by one observation. , And high-resolution information of several tens μm in a range of 1 to 2 mm from the inner wall surface.

Since the OCT image acquiring means and the ultrasonic image acquiring means can acquire an image of the same area of the subject, a plurality of pieces of information of the same area can be obtained at the same time.

Further, since the probe of the image diagnostic apparatus according to the present invention can be used by being inserted into the forceps port of the conventional endoscope, the function of the image diagnostic apparatus according to the present invention can be applied to the conventional endoscope. Can be granted.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a first embodiment of an image diagnostic apparatus according to the present invention.

The diagnostic imaging apparatus according to the present embodiment includes a probe 10a for observing the inside of a body cavity of a patient, an ultrasonic information acquiring section for acquiring ultrasonic information, and an optical tomographic information acquiring section 100 for acquiring optical tomographic information. A computer 160a for imaging each information acquired by the ultrasonic information acquiring unit and the optical tomographic information acquiring unit 100, and a monitor 170 for displaying an image generated by the computer 160a.

The ultrasonic information acquisition unit includes an ultrasonic signal processing device 50 for generating an ultrasonic signal and an ultrasonic signal processing device 5 for generating an ultrasonic signal.
And an ultrasonic transducer 51 for generating an ultrasonic wave based on the signal generated by the ultrasonic transducer 51. A probe 1 is provided between the ultrasonic signal processing device 50 and the ultrasonic transducer 51.
0a, the cable 52 and the terminal 53, the probe 10
A cable 54 is connected between the terminal 53 at the base end and the ultrasonic signal processing device 50.

The ultrasonic signal processing device 50 has both the function of an oscillator for oscillating an ultrasonic signal and the function of a receiver for receiving an ultrasonic signal.

The cable 52 is connected to a terminal 53 provided around the base end of the optical fiber described later.
4 is in contact with the terminal 53. Thus, even when the optical fiber performs a rotational movement, the cable 52 and the cable 54 are always in contact with each other, so that the ultrasonic signal is transmitted without interruption.

The computer 160a generates an ultrasonic image based on the waveform of the ultrasonic signal received by the ultrasonic signal processing device 50.

The optical tomographic image acquisition section 100 converts the low coherence light emitted from the light source section 110 into a reference light Lr and a signal light Lr.
fiber-coupled optics 120 for splitting and combining into s
And an optical path delay unit 130 arranged on the optical path of the reference light Lr to change the optical path length of the reference light Lr, a scanning unit 140 for scanning a living tissue or the like by the signal light Ls, and reflected by a predetermined surface of the subject. Interference light L between the reflected signal light Ls' and the reference light Lr
and a photodetector 150 for detecting the intensity of c.

The light source unit 110 includes a light source 111 composed of an SLD or the like and emitting low coherence light, and a condenser lens 11 for condensing low coherence light emitted from the light source 111.
2 is provided.

The fiber coupling optical system 120 includes a light source 111
Divides the low coherence light emitted from the light into the signal light Ls and the reference light Lr, and combines the signal light Ls ′, which is reflected light of the signal light Ls from a predetermined deep portion of the subject, with the reference light Lr, A fiber coupler 121 for obtaining the interference light Lc and a piezo element 12 for causing a slight frequency shift in the reference light Lr
2, a fiber 123 connecting the light source unit 110 and the optical path delay unit 130 via the fiber coupler 121, and a fiber 124 guiding the light between the light detection unit 150 and the scanning unit 140 via the fiber coupler 121. .

The optical path delay unit 130 converts the reference light Lr emitted from the fiber 123 into a parallel light, and a condensing lens 131 for making the reflected reference light Lr incident on the fiber 123, and in the horizontal direction in FIG. The reference light mirror 132 changes the optical path length of the reference light Lr by moving the reference light Lr, and the driving unit 133 moves the reference light mirror 132 in the horizontal direction.
And

The scanning section 140 has a fiber 141 disposed at the center thereof. At the tip of the fiber 141, the signal light Ls guided by the fiber 141 and the signal light Ls' reflected by the lesion are condensed. Rod lens 142
And a mirror 143 that reflects the signal lights Ls and Ls ′ in a right angle direction is fixed. The fiber 124
Light is guided between the optical fiber 141 and the fiber 141 via the lens 125.

The computer 160 generates an optical tomographic image based on the light intensity of the interference light Lc detected by the light detector 150.

The inside of the probe 10a is provided with an OCT scanning section 140 at the center, and is inserted to the vicinity of the tip inside the probe 10a. Around the fiber 141,
A flexible sheath 144a is provided. On the rear surface of the mirror 143, an ultrasonic transducer 51 for irradiating ultrasonic waves in a direction opposite to the reflection direction of the mirror 143, that is, in a direction opposite to the scanning direction of the optical scanning unit is provided.

Here, the position where the ultrasonic transducer is disposed is not limited to the above position. For example, if the position such as the tip of the mirror 143 does not hinder the scanning of the signal light Ls of the optical scanning section, It may be arranged at any position. In addition, the relationship between the scanning direction of the signal light Ls and the irradiation direction of the ultrasonic wave is not limited to the one that irradiates in the opposite direction, and may be any direction, for example, the same direction.

The sheath 144a into which the fiber 141 is inserted at the center is supported by a plurality of bearings 21 inside the probe 10. The proximal end side of the sheath 144a protrudes from the probe 10, and the sheath 144a
The base end of “a” is connected to the centerless motor 20. The centerless motor 20 has a function of a rotary encoder, and a signal indicating the rotation angle detected by the rotation angle detection unit of the centerless motor 20 is sent to the computer 160a via the signal line 22.

Next, the operation of the image diagnostic apparatus according to the present embodiment configured as described above will be described.

When observing the inside of the patient's body cavity, the probe 10a is inserted into the forceps port of the endoscope, the endoscope is inserted into the patient's body cavity, and the image displayed on the monitor of the endoscope is displayed. Based on
The distal end of the insertion portion of the endoscope is visually guided to a desired site.

When the observation is started, the ultrasonic signal processor 5
0 causes an ultrasonic signal to oscillate. This ultrasonic signal
The signal is transmitted to the ultrasonic transducer 51 via the cable 54, the terminal 53 at the base end of the fiber 141, and the cable 52.

The ultrasonic signal is transmitted to the ultrasonic transducer 51.
Is converted into ultrasonic waves, and the object is irradiated with ultrasonic waves. The ultrasonic wave reflected at the deep part of the subject is converted into an electric signal by the ultrasonic transducer 51, and the ultrasonic signal is received by the ultrasonic signal processing device 50. The ultrasonic signal processing device 50 transmits the received ultrasonic signal to the computer 160a via the cable 55.

Further, the irradiation direction of the ultrasonic wave is moved by rotating the fiber 141 by the centerless motor 146, and a radial scan is performed with the longitudinal direction of the fiber 141 around the subject as an axis.

At the same time, low coherence light for obtaining an optical tomographic image is emitted from the light source unit 110. The low coherence light emitted from the light source 111 is condensed by the condensing lens 112 and introduced into the fiber 123.

The low coherence light transmitted through the fiber 123 is converted by the fiber coupler 121 into a reference light Lr traveling in the fiber 123 toward the optical path delay unit 130 and a signal light traveling in the fiber 124 toward the scanning unit 140. Ls
And divided into The reference light Lr is modulated by the piezo element 122 provided on the optical path, and the reference light Lr and the signal light Ls
Generates a slight frequency difference Δf.

The signal light Ls guided to the fiber 124
Is incident on the fiber 141 via the lens 125,
The light enters the subject from the tip of the fiber 141 via the rod lens 142 and the mirror 143. Of the signal light Ls incident on the subject, the signal light Ls ′ reflected at a predetermined depth of the subject is reflected by the mirror 143, the rod lens 142,
The fiber 124 via the fiber 141 and the lens 125
Returned to. The signal light Ls ′ returned to the fiber 124 is multiplexed in the fiber coupler 121 with the reference light Lr returned to the fiber 123 described later.

On the other hand, the reference light Lr modulated by the piezo element 122 passes through the fiber 123 and passes through the optical path delay unit 13.
The light enters the reference light mirror 132 via the zero condenser lens 131, is reflected by the reference light mirror 132, passes through the condenser lens 131 again, and is returned to the fiber 123. The reference light Lr returned to the fiber 123 is multiplexed by the fiber coupler 121 with the signal light Ls ′ described above.

The signal light Ls 'and the reference light Lr multiplexed by the fiber coupler 121 are again coaxially overlapped, and the signal light Ls' and the reference light Lr interfere with each other to form an interference light Lc, thereby generating a beat signal.

Since the reference light Lr and the signal light Ls' are low coherence lights having a short coherence distance, the low coherence light is split into the signal light Ls and the reference light Lr. When the optical path length before reaching the fiber coupler 121 is equal to the optical path length until the reference light Lr reaches the fiber coupler 121, the two lights interfere with each other, and the frequency difference (Δf) between the two interfering lights is strong or weak. Is generated.

The photodetector 150 detects the light intensity of the beat signal from the interference light Lc, performs heterodyne detection, detects the intensity of the signal light Ls' reflected from a predetermined depth of the subject, and outputs the signal processing unit 160a Output to

Further, by rotating the fiber 141 by the centerless motor 146, the irradiation direction of the signal light Ls is moved, and radial scanning is performed with the longitudinal direction of the fiber 141 around the subject as an axis. After that, the reference light mirror 132 is moved in the optical axis direction (horizontal direction in the drawing) by the driving unit 133 so that the reference light Lr is
The optical path length before reaching 1 changes. Therefore, the optical path length of the signal light Ls (Ls ′) that interferes with the reference light Lr also changes, so that the depth at which tomographic information around the subject is acquired also changes. Here, the radial scanning is performed again. By repeating such an operation until the signal light reaches a predetermined depth, tomographic information around the subject can be obtained.

The signal processing section 160 a generates an ultrasonic image based on the signal transmitted from the ultrasonic signal processing apparatus 50, and generates an OCT image based on the tomographic information around the subject detected by the light detecting section 150. Generate An ultrasonic image and an OCT image taken by radial scanning are displayed on a monitor 17.
0 and is displayed on the screen of the monitor 170.

According to the image diagnostic apparatus of the present invention configured as described above, the image of the region up to the high depth captured by the ultrasonic device and the high-resolution image of the low depth region captured by the OCT device are displayed. Since an image can be obtained by one shot, information on the subject can be obtained efficiently.

In the present embodiment, the probe including the ultrasonic transducer and the scanning section of the OCT apparatus is used by being inserted into the forceps port of the endoscope, but the ultrasonic transducer is inserted into the endoscope insertion section main body. And a scanning unit of the OCT apparatus.

Next, a second embodiment of the present invention will be described. FIG. 2 is a diagram showing a schematic configuration of a second embodiment of the diagnostic imaging apparatus according to the present invention. The image diagnostic apparatus according to the present embodiment is such that the centerless motor according to the first embodiment is changed to a linear drive device to perform linear scanning. The description of the same elements as those in the first embodiment shown in FIG. 1 will be omitted unless particularly necessary.

The ultrasonic transducer 51 generates the signal light L
s is radiated in the same direction as the optical path toward the subject. In addition, fiber 1
The sheath 144b into which the 41 has been inserted is supported by the plurality of supports 31 inside the probe 10b. The proximal end of the sheath 144b protruding from the probe 10 is connected to the linear driving device 30, and is moved back and forth in the longitudinal direction of the probe 10. The linear driving device 30 has a function of a linear encoder, and a signal indicating the moving distance detected by the moving distance detecting unit of the linear encoder is:
The signal is sent to the computer 160b via the signal line 32.

The probe 10b is inserted through the forceps port of the endoscope to perform a linear scan, thereby obtaining ultrasonic waves and OCT.
, A linear cross-sectional image of the subject can be obtained.

In the present embodiment, similarly to the first embodiment, an ultrasonic transducer and a scanning section of an OCT apparatus may be incorporated in an endoscope insertion section main body.

Further, in the diagnostic imaging apparatus of the present invention,
One probe may perform both radial scanning and linear scanning, and a three-dimensional image may be generated by combining radial scanning and linear scanning.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of an image diagnostic apparatus according to the present invention;

FIG. 2 is a schematic configuration diagram of a second embodiment of the diagnostic imaging apparatus according to the present invention.

[Explanation of symbols]

 10a, 10b Probe 20 Centerless motor 30 Linear drive device 50 Ultrasonic signal processing unit 51 Ultrasonic transducer 100 Optical tomographic image acquisition unit 110 Light source unit 120 Fiber coupling optical system 130 Optical path delay unit 140 Scanning unit 150 Signal processing unit 160a, 160b Computer 170 monitors

Claims (8)

[Claims] A light guide unit configured to guide a signal light, which is a low coherence light, to a subject, wherein the signal light guided by the light guide unit is reflected from a predetermined depth of the subject, and OCT for obtaining an optical tomographic image of the subject by using interference between signal light and reference light having a slight frequency difference
Ultrasound image having image acquisition means and irradiation means for irradiating the object with ultrasonic waves, and acquiring an ultrasonic image of the object based on reflected waves of the ultrasonic waves emitted by the irradiation means from the object Acquisition means, comprising a search section in which the tip of the light guide means and the irradiation means are integrally fixed to each other, the search section is contained in a hollow flexible case, An image diagnostic apparatus comprising a probe. 2. The image diagnostic apparatus according to claim 1, wherein the OCT image acquiring unit and the ultrasonic image acquiring unit acquire an image of the same area of the subject. 3. The image diagnostic apparatus according to claim 1, wherein the probe is inserted through a forceps port of an endoscope. 4. The probe section performs radial scanning by rotating around a longitudinal direction of the probe in order to acquire an image, and a rotation angle of the rotating movement is detected by a single rotary encoder. 2. The diagnostic imaging apparatus according to claim 1, wherein the diagnostic imaging is performed. 5. The probe section performs a linear scan by moving in parallel in a longitudinal direction of the probe to acquire an image, and a moving distance of the parallel movement is detected by a single linear encoder. The diagnostic imaging apparatus according to claim 1, wherein the diagnostic imaging apparatus is a diagnostic imaging apparatus. 6. An optical fiber that is provided in parallel with a central axis of the probe, guides the signal light to the vicinity of the subject, and is provided at a tip of the optical fiber to detect the signal light. A rod lens for condensing, a mirror provided at the tip of the rod lens, for polarizing the signal light in a right angle direction, and an ultrasonic transducer attached to the optical fiber and irradiating the object with ultrasonic waves. 2. The diagnostic imaging apparatus according to claim 1, wherein the optical fiber is held by a bearing in the case. 7. An image diagnostic apparatus according to claim 6, wherein a part of said optical fiber is connected to a centerless motor disposed outside said case, and is rotated by said centerless motor. 8. An image diagnostic apparatus according to claim 6, wherein a part of said optical fiber is connected to a driving means disposed outside said case and is translated by said driving means.