JP5292179B2 - Ultrasonic diagnostic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To clearly display a medical device such as a puncture needle in an ultrasonic image. <P>SOLUTION: With a single ultrasonic beam, a point C that is the closest to an ultrasonic probe of the medical device is determined. Information concerning the form of the medical device to be used is preliminarily stored. Based on the pixel p(0) of the closest point C, a size d org in the direction along the ultrasonic beam of the medical device is taken, and information indicating that the medical device is present is provided to the pixels p(0) to p(b) in this section. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus suitable for observing medical devices such as puncture needles and forceps inserted into a subject.

  Methods are known that use ultrasound images to monitor and manipulate medical devices inserted into a subject. The following Patent Documents 1 to 3 describe a technique of using a puncture needle as a medical device and displaying it on an ultrasonic image.

JP 2000-185041 A JP 2004-208859 A JP 2007-1117566 A

  A medical device such as a puncture needle is displayed with high brightness on an ultrasound image because of high acoustic impedance. On the other hand, the farther from the ultrasonic probe, the sweeter the focus of the ultrasonic beam becomes, so that the dimension in the depth direction is displayed larger than the actual size. If the medical device is a puncture needle, the position farther from the probe, in many cases the thicker the tip of the needle, is displayed.

  An object of the present invention is to accurately represent the size of a medical device on an ultrasound image.

  A reception signal is obtained by transmitting and receiving ultrasonic waves from the ultrasonic probe. A point of the medical device closest to the ultrasonic probe is detected for one ultrasonic beam. On the other hand, shape information of the medical device to be used is stored. A range of a predetermined length based on the shape information of the medical device is set as a range actually occupied by the medical device from the nearest point of the detected medical device to the back direction along the ultrasonic beam. Image data is created so that this range can be identified from the surroundings.

  The most recent point of the medical device can be obtained accurately, while the back side is inaccurate to the extent of the actual medical device due to backscattering and the like. If there is shape information of the medical device being used, it can be estimated from the above-mentioned closest point that the range of dimensions according to the shape information is the range occupied by the actual medical device.

  In addition, the dynamic range for obtaining the closest point of the medical device and the normal dynamic range for obtaining ultrasonic information in the subject can be made different and changeable between them.

  Further, there is a difference between the range of the medical device obtained from the received ultrasonic signal and the range of the medical device obtained from the nearest point and the shape information. Since the latter is based on the nearest point, the deviation occurs in a portion far from the ultrasonic probe. The image of the medical device obtained from the received ultrasound signal of this part is actually a false image with no device present. The image data of the false image portion may be supplemented from image data of a region adjacent to the range of the medical device obtained from the received ultrasonic signal along one ultrasonic beam.

  According to the present invention, an accurate shape of a medical device can be represented.

It is a block diagram which shows schematic structure of the ultrasonic diagnosing device of this embodiment. It is the figure which showed the ultrasonic beam, the puncture needle, and the received signal waveform. It is a figure which shows the structure of the line data with which the information showing the position of a medical device was synthesize | combined. It is a figure which shows the relationship between a received waveform and the thickness of an actual medical device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an ultrasonic diagnostic apparatus 10 of the present embodiment. The ultrasonic diagnostic apparatus 10 includes an ultrasonic probe 12 that transmits ultrasonic waves to a living body as a subject and receives reflected waves from within the living body. The ultrasonic probe 12 is a probe for obtaining a tomographic image, and includes an ultrasonic transducer in which a plurality of ultrasonic vibration elements are arranged in one direction. The ultrasonic beam 14 is formed and scanned by controlling the drive timing of each vibration element. Transmission / reception of ultrasonic waves by the ultrasonic probe 12, that is, drive control of the ultrasonic transducer is performed by the transmitter / receiver 16. The received ultrasonic signal is sent to the beam forming unit 18 where phasing and addition are performed to form a reception beam, and an ultrasonic reception signal for each reception beam is sent to the beam processing unit 20. In the beam processing unit 20, line data of an ultrasonic image on the ultrasonic beam is generated based on the received reception signal. The processing in the beam processing unit 20 will be described in detail later. The line data is sent to the scan converter 22 where an ultrasonic diagnostic image is generated and sent to an output device such as a display device.

  FIG. 1 shows a state where a puncture needle 26 as a medical device has entered the scanning range of an ultrasonic beam. The puncture needle 26 is supported by an adapter (not shown) fixed to the ultrasonic probe 12, for example, so that only the axial movement of the needle itself is allowed. However, the present invention is not limited to this, and a free orientation may be taken within the ultrasonic scanning plane, and any orientation may be taken in three dimensions.

  The medical device such as the puncture needle 26 is formed of a material having high acoustic impedance such as metal, and the reception signal from the puncture needle 26 has high reception intensity. When the puncture needle 26 is in the scanning range 24, the reception signal sent from the beam forming unit 18 to the beam processing unit 20 has high reception intensity by the puncture needle. This received signal is sent to a line data generation unit 28 for generating line data, and distribution data of the reflection intensity of the ultrasonic wave on the beam is created for each ultrasonic beam. Generally, it is created as distribution data of luminance data so that the intensity of reflected ultrasonic waves corresponds to the luminance on the image. On the other hand, the received signal sent from the beam forming unit 18 is branched before being subjected to processing such as gain adjustment in the line data generating unit 28 and sent to the medical device determining unit 30. As described above, the medical device has a high acoustic impedance, and a high-intensity portion of the received signal is determined as the medical device.

  FIG. 2 is a diagram illustrating waveforms of the ultrasonic beam 14, the puncture needle 26, and the reception signal. The spread of the focus of the ultrasonic beam with respect to the ultrasonic beam 14 is schematically indicated by reference numeral 32. As shown in the figure, the focus is wide in the vicinity of the ultrasonic probe 12, and once narrowed, it is expanded again. The position where the puncture needle 26 is inserted is assumed to be a position having a certain distance from the ultrasonic probe 12. Therefore, in observing the puncture needle 26, the focus is broadened as the distance from the ultrasonic probe 12 increases. Reflected by the surface of the puncture needle 26 facing the ultrasonic probe 12 (hereinafter referred to as the front surface), this becomes high intensity and appears in the received waveform 34. This high intensity range a is determined by the threshold value TH. That is, a predetermined threshold value TH for discriminating between the waveform of the living body portion and the waveform of the puncture needle portion is determined in advance, and the portion exceeding this threshold value is set as the position of the puncture needle 26. In the figure, the focus of the ultrasonic beam is drawn widely for easy understanding, the width a of the reflected wave from the front surface of the actual puncture needle is sufficiently small, and the received waveform 34 first exceeds the threshold value TH. There is no practical problem with the position as the front surface of the puncture needle 26. That is, this position is the closest point (nearest point) C of the puncture needle 26 on one ultrasonic beam.

  The data synthesis unit 36 synthesizes data indicating the position of the puncture needle 26 determined by the medical device determination unit 30 with the data generated by the line data generation unit 28 to generate combined line data. An example of the structure of the combined line data is shown in FIG. One row of FIG. 3 shows data of one pixel, the upper one bit is a bit (position information bit) 38 indicating the position of the puncture needle 26, and the subsequent bits are bits indicating the luminance of the pixel ( (Luminance information bits) 40. The position information bit 38 is set to “1” for a pixel belonging to the range a in FIG. 2 that represents the position of the puncture needle determined by the medical device determination unit 30, and the position of the puncture needle is indicated. In the example of FIG. 3, the flag is set for all pixels exceeding the threshold TH, but the flag may be set only for the pixel closest to the ultrasonic probe. This synthesized data is sent to the scan converter 22.

  In the scan converter 22, a diagnostic image is generated by the diagnostic image generation unit 44 based on the combined data generated by the beam processing unit 20 and information on the shape of the puncture needle stored in the device information storage unit 42. . The device information storage unit 42 stores information regarding the shape of the medical device, and at least the thickness of the puncture needle 26 is stored. In the diagnostic image generation unit 44, luminance data is generated so that the number of pixels corresponding to the thickness of the puncture needle from the closest point C is displayed at the maximum luminance. The pixels following the pixel corresponding to the thickness of the puncture needle may have high luminance on the composite data due to ultrasonic backscattering or the like, and the processing will be described below.

  FIG. 4 shows the relationship between the received waveform 34 and the stored puncture needle thickness dorg. The horizontal axis represents the number of pixels from the ultrasonic probe. Of the pixels whose reception waveform 34 exceeds the threshold TH, the pixel closest to the ultrasonic probe is p (0), and the farthest pixel is p (n). Pixel p (0) corresponds to the closest point C described above. The range from the pixel p (0) to the pixel p (n) represents the thickness decho of the puncture needle 26 that appears as an ultrasonic image. As described above, when the length corresponding to the actual thickness dorg of the puncture needle 26 is taken from the pixel p (0) (nearest point C), it reaches only the pixel p (b) before the pixel p (n). May not. A section from the pixel p (b + 1) to the pixel p (n) is a false image dpse that appears as an ultrasonic image but has no substance. The luminance information of the pixels in this section is replaced with the luminance information of the pixel p (n + 1) or subsequent pixels, and complementation is performed. Further, the pixel before pixel p (0) (left in the figure) may be used for complementation.

  When the position of the medical device can be identified, that is, when the closest point (C) is detected, the manifestation position of the multiple reflection artifact caused by the medical device can be identified. When the distance from the ultrasonic probe surface to the medical device is d, the position where multiple reflection occurs between the medical device and the probe surface is 2d, 3d,. Therefore, the pixel at the predicted multiple reflection occurrence position is complemented based on the luminance value of the pixel adjacent to this position, and the artifact due to multiple reflection can be eliminated.

  In addition, the reception dynamic range can be changed when the medical device is detected and when the tomographic image is acquired. At the time of tomographic image acquisition, the dynamic range is adjusted to be optimized for a highly reflective material in the living body. A medical device generally reflects ultrasound more strongly than a strong reflective material in a living body, but is saturated in a dynamic range optimized for a strong reflective material in a living body, Discrimination may be difficult. In order to avoid this, it is possible to provide a circuit that receives a dynamic range wider than the reflection of a general biomaterial, and to regularly perform ultrasonic scanning for detecting the position of the medical device. This circuit can be incorporated into the beam forming unit 18 in the ultrasonic diagnostic apparatus of FIG.

  DESCRIPTION OF SYMBOLS 10 Ultrasonic diagnostic apparatus, 12 Ultrasonic probe, 14 Ultrasonic beam, 20 Beam processing part, 22 Scan converter, 26 Puncture needle, 38 Position information bit, 40 Luminance information bit, 42 Device information storage part.

Claims (3)

An ultrasound probe that transmits and receives ultrasound to and from the subject;
An image data creation unit for processing signals received by the ultrasound probe and creating ultrasound image data;
A device information storage unit for storing shape information of a medical device inserted into the subject;
An ultrasonic diagnostic apparatus comprising:
The image data creation unit
A closest point detection unit for detecting a point closest to the ultrasonic probe of the medical device for one ultrasonic beam transmitted and received by the ultrasonic probe;
A device range setting unit that sets a range of a predetermined length based on the shape information of the device from the detected closest point along the ultrasonic beam as a range occupied by the medical device;
An identification processing unit that creates image data so that a set medical device range can be identified from the surroundings;
Having
Ultrasonic diagnostic equipment. The ultrasonic diagnostic apparatus according to claim 1,
The image data creation unit is a dynamic range changing unit for transmitting and receiving ultrasonic waves in different dynamic ranges for detecting the nearest point and obtaining ultrasonic information in the subject.
An ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1, wherein:
For each ultrasonic beam, a false image range that specifies a false image range that is a difference range between the range of the medical device obtained from the received ultrasonic signal and the range set by the device range setting unit A specific part,
A complementing unit that supplements the image data of the false image range with image data of a region adjacent to the range of the medical device obtained from the received ultrasonic signal;
An ultrasonic diagnostic apparatus.

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