JPS59232540A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention is an ultrasonic diagnostic device, in particular, an electronic scanning type ultrasonic diagnostic probe that transmits an ultrasonic beam to an affected area, and images the affected area based on echoes reflected from the affected area. The present invention relates to an ultrasonic diagnostic device that displays images.

BACKGROUND ART Ultrasonic diagnostic equipment is well known that transmits an ultrasonic beam to an affected area within a subject and receives reflected echoes generated from differences in acoustic impedance of the affected area to observe arbitrary tomographic images within living tissue. Since it is possible to observe a desired tomographic image non-invasively, it is used for a wide range of diagnoses.

In the ultrasonic diagnostic device described above, a plurality of transducers for transmitting ultrasonic waves to the subject are arranged at predetermined intervals on the probe placed opposite to the subject, and the transducers are driven. Then, an ultrasonic beam is transmitted from the transducer toward the subject using a desired scanning method, such as linear scanning, sector scanning, compound scanning, or the like.

This transmitted ultrasound beam is reflected from the transmitting site,
By receiving this reflected echo and performing desired signal processing, a desired tomographic image of the subject is displayed on the image receiver. Therefore, by analyzing the tomographic image of the affected area, the disease can be diagnosed quickly and accurately.

However, in this type of device, the boundary between normal tissue and abnormal tissue in the diagnostic image displayed on the image receiver is not clear, and therefore accurate diagnosis cannot be made. It is known that the contrast resolution at the boundary between normal tissue and abnormal tissue, especially tumor tissue, depends on the reflectance of both tissues. This reflectance is due to the difference in acoustic impedance between adjacent tissues. It is a proportional coefficient, and is expressed as Za-ρC, where Za is the acoustic impedance, ρ is the density of the living tissue, and C is the speed of sound in the living tissue.

Here, both ρ and C are functions of temperature and depend on temperature changes in living tissue.

Generally, when an ultrasound beam is applied to normal tissue and abnormal tissue, especially tumor tissue, the absorption rate of ultrasound is higher in tumor tissue than in normal tissue. However, the temperature difference between the two tissues causes a difference in acoustic impedance. Corresponding to this difference in acoustic impedance, there is a difference in reflectance between the two tissues, and the boundary between the two tissues is identified and displayed with contrast corresponding to this difference in reflectance.

Therefore, the greater the temperature difference between normal tissue and tumor tissue, the more clearly it is possible to distinguish between the two tissues. Therefore, it is necessary to suppress the temperature rise of living tissues to about 42°C in a short period of time, that is, to about 5°C above normal temperature.
Even such an extremely small temperature difference can generate a difference in acoustic impedance that clearly distinguishes the boundary between normal tissue and abnormal tissue.

Purpose of the Invention The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to improve the contrast resolution of the boundary between normal tissue and abnormal tissue in diagnostic images by using ultrasound that can perform accurate diagnosis. The objective is to provide diagnostic equipment.

[Structure of the Invention] In order to achieve the second object, the present invention provides an electronic scanning ultrasound diagnostic probe that transmits an ultrasound beam to an affected area and receives reflected echoes from the affected area; A heating transducer that irradiates ultrasonic waves for heating, a first image memory that stores digital image signals based on reflected echoes before heating the affected area, and a digital image based on reflected echoes after heating the affected area. A second image memory that stores the signal, a subtracter that subtracts the corresponding digital image signal of one of the image memories from the other digital image signal, and an image receptor that displays an image of the affected area based on the subtracted value signal. , is characterized by increasing the contrast resolution between normal tissue and abnormal tissue of the affected area displayed as an image based on subtraction processing of digital image signals before and after heating the affected area.

Embodiment FIG. 1 shows a block configuration of an ultrasonic diagnostic apparatus according to the present invention, and FIG. 2 shows the main structure of a probe in the apparatus of the present invention.

In this embodiment, a diagnostic vibrating body 10 for transmitting an ultrasonic beam to a subject is held in the base frame 2 of the probe.

The diagnostic vibrating body 10 has a main substrate 14 and diagnostic vibrators]Oa arranged on the main substrate at predetermined intervals, and can perform a desired scanning method based on a command from a wave transmission controller 16. An ultrasound beam is transmitted from the diagnostic transducer] Oa toward the affected area of the subject. The reflected echo reflected from the affected area of the subject is received by the diagnostic transducer based on the command from the wave reception controller 18, and the received signal is sent to the logarithmic amplifier 20.
is amplified.

A characteristic feature of the present invention is that a warming camera element is provided that heats the affected tissue by irradiating heating ultrasonic waves onto the subject, and the reflected echo signal before heating and the post-warming By digitally subtracting the reflected echo signal, the contrast resolution of the boundary between normal tissue and abnormal tissue in the diagnostic image is increased, and a clear diagnostic image is obtained.

In this embodiment, a heating vibrating body 24 is provided on the base frame 14 of the probe so as to be tiltable so as to surround the diagnostic vibrating body 10. A heating vibrator 24a is disposed at a predetermined position. and,
The heating transducer 24a irradiates heating ultrasonic waves toward the subject based on a command from the heating wave transmission controller 26.

In this embodiment, in order to perform arithmetic processing on the received signal before heating the affected area and the received signal after heating, each of these received signals is converted from an analog signal to a digital signal in the A/D converter 28. The digital signal before heating the affected area is stored in the first image memory 30, and the digital signal after heating is stored in the second image memory 32.

In this embodiment, both the first and second image memories 30.
32 is formed in a matrix memory type. As a result, the corresponding signals of both image memo 'J30.32 can be accurately aligned, and signal processing can be made more accurate.

In the present invention, in order to increase the contrast resolution between normal tissue and abnormal tissue, a subtracter 34 is provided for subtracting the corresponding digital image signal of one of the two image memories 30, 32 from the other digital image signal. In the embodiment, the subtractor 31I is configured to subtract the digital memory before heating from the digital memory after heating at high speed, and this subtraction process causes a temperature difference between the normal tissue and the abnormal tissue. The area where the acoustic impedance has changed, that is, the area where the acoustic impedance has changed, is characteristically emphasized. This emphasized subtraction value signal is converted from a digital signal to an analog signal at high speed by the D/A converter 36, and the tomographic image of the affected area is transmitted to the diagnostic image receptor 38 on the one hand by the converted analog signal. The image is displayed at the resolution, and on the other hand, it is photographed and recorded by the photographing receiver 40.

In this embodiment, as described above, as a result of high-speed signal processing, it is possible to reproduce the subtracted diagnostic image and the pre-warming diagnostic image in real time.

On the other hand, in this example, when ultrasound is irradiated to the affected area, the temperature distribution of the affected area is determined and used as diagnostic aid material, and on the other hand, the temperature of the affected area is monitored to ensure that it does not become abnormally high, and A temperature calculator 42 and a temperature distribution display 44 are provided so that the irradiation amount of the ultrasonic beam can be optimally controlled.

That is, the temperature calculator 42 calculates the temperature of each part of the affected area based on the subtracted value signal of the digital signals of the first image memory 30 and the second image memory 32 from the subtracter 34. The result of this calculation is displayed on the temperature distribution display 44.As mentioned above, normal tissue and tumor tissue have different absorption rates of the ultrasound beam, The temperature distribution of the affected area will indicate an abnormality in the affected area,
Therefore, by using this temperature distribution together with the ultrasonic diagnostic image displayed on the diagnostic image receptor 38, the diagnosis can be made more accurately.

Furthermore, by monitoring the temperature distribution of the affected area displayed on the temperature distribution display 44, abnormal heating can be detected and desired measures can be taken against it. The temperature information calculated by the device 42 is fed back to the heating ultrasonic beam irradiation amount control device, which automatically prevents abnormal temperature rises in the affected area and maintains the optimal irradiation amount. The affected area is heated.

The device of this embodiment has the above configuration, and its operation will be explained below.

First, a desired wave transmission command signal is supplied from the wave transmission controller 16 to the ultrasonic diagnostic probe placed opposite to the subject, and the ultrasonic wave is transmitted from the diagnostic transducer 10a of the diagnostic vibrator 10 in a desired scanning manner. radiated by. On the other hand, the reflected echo from the affected area within the subject is received by the diagnostic transducer 10a according to a reception command from the reception controller 18, and the received reception signal is amplified at high speed by the logarithmic amplifier 20. Furthermore, the analog signal is converted at high speed into a digital signal by the A/D converter 28, and this signal is stored in a matrix memory in the first image memory 30.

This stored digital signal is then sent to the D/A converter 3.
6, the signal is converted into an analog signal at high speed, and an image of the ultrasound radiation site within the subject is displayed based on this signal. Therefore, by adjusting the movement of the ultrasonic diagnostic probe while observing this diagnostic image, the affected area within the subject can be accurately detected. As mentioned above, the image projected on this diagnostic image receptor 38 has a low contrast resolution between normal tissue and abnormal tissue in the affected area, so it is difficult to diagnose the exact condition of the affected area. In the embodiment, as a means for increasing the contrast resolution, heating ultrasonic waves are emitted from the heating transducer 24a to the affected area by operating the heating wave transmission controller 26.

As a result, the temperature difference between the normal tissue and the abnormal tissue in the affected area increases, and the boundary between the normal tissue and the abnormal tissue in the diagnostic image displayed on the diagnostic image receptor 38 becomes slightly clearer. In this example, in order to further clarify this, a digital signal based on the received ultrasound signal before heating is stored in the first image memory, and a digital signal based on the received ultrasound signal after heating is stored in the first image memory. Each matrix is stored in the second image memory 32, and the digital signal of the first image memo IJ 30 is converted from the digital signal of the second image memory to the subtracter 3/I for each matrix portion. subtract,
This subtraction value signal is rapidly converted into an analog signal by the D/A converter 36, and based on this signal, a clear diagnostic tomographic image is displayed on the diagnostic image receiver 38. This clear image is then recorded on the photographing receiver 40.

On the other hand, as described above, the temperature distribution of the affected area is calculated by the temperature calculator 42 based on the subtracted value signal of the subtracter 34,
The irradiation amount of the heating ultrasonic beam is controlled based on the calculated value signal of the trench.

As described in detail, according to the present invention, it is possible to improve the contrast resolution of the boundary between normal tissue and abnormal tissue in a diagnostic image, thereby making the diagnostic image clearer. It is possible to quickly and accurately diagnose diseases.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of an ultrasonic diagnostic apparatus according to the present invention, and FIG. 2 is a configuration diagram of main parts of an ultrasound probe of the ultrasonic diagnostic apparatus according to the present invention. ]O... Vibrating body 24 for diagnosis... Vibrating body 30 for heating - First image memory 32 - Second image memory 34... Subtractor 38... Diagnostic image receptor 40... Photographing Image receptor 42 ... Temperature calculator 44 ... Temperature IW distribution display device. Applicant Aloka Co., Ltd.

Claims (1)

[Claims] (1) An electronic scanning ultrasound diagnostic probe that sends an ultrasound beam to the affected area and receives reflected echoes from the affected area, and a heating system that emits heating ultrasound to the affected area. a first image memory that stores digital image signals based on reflected echoes before warming the affected area, and a second image memory that stores digital image signals based on reflected echoes after warming the affected area; Subtraction processing of digital image signals before and after heating the affected area includes a subtracter that subtracts one corresponding digital image signal of the image memory from the other digital image signal, and an image receptor that displays an image of the affected area based on the subtraction value signal. An ultrasonic diagnostic device characterized by increasing the contrast resolution between normal tissue and abnormal tissue of an affected area displayed as an image based on the above. (2. In the device described in claims ()), the first
, a temperature calculator that calculates the temperature distribution of the affected area by calculation based on the digital image signal of the second image memory; and a temperature distribution display that displays the temperature distribution of the affected area based on the temperature calculation value signal of the temperature calculator. An ultrasonic diagnostic device featuring: