JPH01221149A - Temperature distribution measuring device - Google Patents

Abstract

PURPOSE:To facilitate provision of a temperature distribution picture at a real time during heating, by providing a means to forming an ultrasonic reflection image, a means to store the base picture of an ultrasonic reflection image, a means to subtract a base picture and an ultrasonic reflection image formed at a real time, and a means to convert the picture element value of a picture obtained as a result of subtraction into a temperature value. CONSTITUTION:An ultrasonic probe 4 is adhered to an organism 1. The ultrasonic probe 4 is an ultrasonic vibrator, and is driven by means of a pulse from a pulse generator 5 for generating ultrasonic waves to emit ultrasonic waves in the organism. Thereafter, the ultrasonic probe receives reflection waves reflected by each tissue in the organism and sends the receiving signal to a receiving circuit 6. In the receiving circuit 6, processing, e.g. amplification, detection, is applied on the receiving signal and is sent to a digital scan converter 7, and is converted into an image signal, capable of being displayed, by means of picture display devices 13 and 14. An ultrasonic image formed during heating is subtracted by a subtracter 9 together with a base image read from a picture memory 8. The formed differential picture is sent to a converter 11, the value of each picture element is converted into a temperature value, which is displayed on a picture display device 14.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a temperature distribution measuring device suitable for hyperthermia (thermal therapy), which is known as a treatment method for cancer, malignant tumors, etc.

[Conventional technology]

In hyperthermia, it is important to heat only the affected area to a predetermined temperature (around 43°C). Therefore, it becomes necessary to measure the internal temperature distribution during treatment. Conventionally, as a device for measuring temperature during hyperthermia treatment, a device that measures temperature by inserting a temperature sensor such as a thermocouple or a thermistor into the body is known. Also, XI
It is also known to obtain a temperature distribution image by using an ICT device, a microwave CT device, or the like, and taking advantage of the fact that the image parameters obtained by these devices have temperature dependence.

[Problem to be solved by the invention]

However, there is a problem that temperature sensors such as thermocouples and thermistors can only obtain temperature information at specific measurement points, but not temperature distribution. When using an apparatus, a large-scale system is required, and there are drawbacks such as the need to interrupt heating and the time it takes to obtain a temperature distribution image. An object of the present invention is to provide a temperature measuring device that can obtain a temperature distribution image on a casing in real time during heating without interrupting heating.

[Means to solve the problem]

In order to achieve the above object, the temperature distribution measuring device according to the present invention includes a means for obtaining an ultrasonic reflection image, a means for storing a base image of the ultrasonic reflection image, and a means for storing the base image and the ultrasonic reflection image obtained in real time. and means for converting the pixel value of the image obtained as a result of the subtraction into a temperature value.

[For production]

Ultrasonic reflection images, that is, so-called ultrasound B-mode images obtained with ordinary ultrasound diagnostic equipment, represent the distribution of ultrasound reflection coefficients at each boundary of body tissues such as bones.6 As the temperature inside the body rises, As a result, the acoustic properties of the tissue change, which appears as a change in the ultrasound reflection image described above.Therefore, subtraction of two ultrasound images on the same tomographic plane obtained at different times is performed. For example, the pixel values of the resulting image will correspond to the temperature change over time. Therefore, by obtaining a base ultrasound image and accumulating it, it is possible to obtain it in real time. By subtracting this base image from the ultrasound image and converting the pixel values of the resulting image into temperature values, it is possible to obtain an image that represents the distribution of temperature changes from the time when the base image was obtained. Since we use a normal ultrasound B-mode image,
Compared to methods based on temperature dependence such as sound velocity, attenuation, and nonlinear parameters B/A, this method requires less processing time, allows you to easily obtain a temperature distribution image in real time, and does not require pump waves or other troublesome components. do not have.

【Example】

Next, one embodiment of the present invention will be explained with reference to the drawings. Figure 0 shows an embodiment in which the temperature distribution measuring device according to the present invention is combined with a hyperthermia device. Warm applicator 2
is attached, and electromagnetic waves from the heating energy generator 3,
Heating energy such as ultrasonic waves is applied to the living body 1 through the applicator 2, thereby warming the affected area and treating hyperthermia. In addition, instead of heating the living body 1 by injecting heating energy into the living body 1, it is also possible to warm the living body 1 by taking blood flowing through the living body 1 to the outside, warming it, and then sending it back to the living body 1. . On the other hand, an ultrasonic probe 4 is brought into close contact with the living body 1. This ultrasonic wave 10-p 4 is an ultrasonic transducer, which is driven by pulses from an ultrasonic pulse generator 5 to inject ultrasonic waves into the living body, and then reflects the waves from each tissue within the living body. It receives the waves and sends the received signal to the receiving circuit 6. The received signal undergoes processing such as amplification and detection in the receiving circuit 6, is sent to a DSC (digital scan converter) 7, and is converted to a video signal that can be displayed on an image display device 13, 14, etc. 6 Image display device 13 Since the video signal from the DSC 7 is sent as is, the obtained ultrasonic image is displayed in real time. The image memory 8 stores a base ultrasound image, and stores ultrasound images obtained before heating. The ultrasonic image obtained in real time during heating is subtracted from the base image read out from the image memory 8 in a subtracter 9 . The difference image obtained as a result of the subtraction is stored in the image memory 10 and further sent to the converter 11. This converter 11 converts the value of each pixel of the difference image obtained as a result of subtraction into a temperature value, and is composed of a RAM or the like. This converter 1
The conversion characteristic to be set to 1 is measured in advance and stored in a storage device such as a magnetic disk. This conversion characteristic is then set in the converter 11 as necessary. The converted image is buffered in the image memory 12 and displayed on the image display device 14, and is also sent to the main control device 17 and used as information for controlling the heating energy generating device 3. Furthermore, one or more temperature sensors 15 such as a thermocouple or thermistor are inserted into the living body 1, and the absolute value of the temperature near the temperature sensor 15 is measured by a temperature measuring device 16. A signal representing the absolute value of the temperature obtained by the temperature measuring device 16 is sent to the main controller 17 and used for calibrating the conversion characteristics of the converter 11, etc. Note that in order to remove speckle patterns in ultrasound images, an average image is used as both the base image to be stored in the image memory 8 and the real-time image to be subtracted from this, or the average image of the difference image after subtraction is used. The average image may be obtained by averaging a plurality of ultrasound images, or by averaging pixels within one image.

【Effect of the invention】

According to the temperature distribution measuring device of the present invention, a temperature distribution image can be easily obtained in real time without interrupting heating even during hyperthermia treatment. Therefore, when applied to hyperthermia treatment, it can contribute to improving the therapeutic effect.

[Brief explanation of the drawing]

The figure is a block diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Living body, 2... Warming applicator, 3... Warming energy generator, 4... Ultrasonic probe, 5...
... Pulse generator for ultrasonic generation, 6... Receiving circuit, 7
...DSC (digital scan converter), 8.1
o, 12... Image memory, 9... Subtractor, 11...
・Converter, 13.14... Image display device, 15...
Temperature sensor, 16... Temperature measuring device, 17... Main control device.

Claims (1)

[Claims] (1) means for obtaining an ultrasound reflection image; means for storing a base image of the ultrasound reflection image; means for subtracting the base image and the ultrasound reflection image obtained in real time; and means for converting pixel values of an image into temperature values.