JP2011050646A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a load on a user by automatically performing appropriate STC (Sensitivity Time Control). <P>SOLUTION: A control unit 14 determines the luminance distribution of an image which is based on an echo signal amplified by an amplifier 8 in a determination period, and when the luminance distribution is similar to the luminance distribution expressed by luminance distribution information described in an STC table, the control unit corrects the reference gain of each STC area by the correction amount of each STC area expressed by correction amount information which is related in the STC table with the luminance distribution information expressing the similar luminance distribution, thereby deciding the application gain of each STC area. When the luminance distribution information on the luminance distribution similar to the determined luminance distribution does not exist in the STC table, the control unit 14 determines the reference gain of each STC area as the application gain of each STC area. In the determination period, the control units 7, 13, 14 cause the amplifier 8 to amplify the echo signal by the reference gain with respect to the STC area where reflection waves during reception are reflected, and on and after a change timing after the termination of the determination period, the control units cause the amplifier to amplify the echo signal by the determined application gain with respect to the STC area where the reflection waves during reception are reflected. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ultrasonic diagnostic apparatus having an STC (sensitivity time control) function.

  The STC is a function that adjusts the gain when a corresponding echo signal is amplified according to the depth of the reflection position of the reflected wave. In order to realize this STC, the gain of the amplifier is changed in each of a plurality of divided regions set by dividing a scan region that is symmetrical to a scan by ultrasonic waves into a plurality of regions according to the depth. The gain for each divided area is a reference gain determined in the apparatus at the beginning of scanning. In an ultrasonic diagnostic apparatus having an automatic gain correction function in addition to the STC function, the gain corrected by the automatic gain correction function becomes the reference gain in the STC. Incidentally, the automatic gain correction function is a function for automatically correcting the amplification gain of the echo signal so as to adjust the image luminance to a predetermined value.

  Now, the amount of gain movement in the STC is set according to a user instruction. Thereby, the image luminance can be changed for each divided area according to the user's preference. In order to improve the convenience of this STC, the movement amount for each divided area set at the time when the instruction is given according to the user's separate instruction is stored, and the application is instructed by the user. Accordingly, a function of automatically performing STC by applying the stored movement amount is already realized.

JP 2009-178277 A

  However, the appropriate amount of movement for STC varies depending on the diagnostic site. For this reason, there are many cases where the stored movement amount is not appropriate for image display for a new diagnosis, and in such a case, the user has to adjust the movement amount again.

  The present invention has been made in view of such circumstances, and the object of the present invention is to automatically perform an appropriate STC in more scenes, thereby reducing the load on the user. It is to provide an ultrasonic diagnostic apparatus.

  An ultrasonic diagnostic apparatus according to an aspect of the present invention includes a transmission / reception unit that transmits an ultrasonic wave to a scan region of a subject, receives a reflected wave generated in the scan region according to the ultrasonic wave, and obtains an echo signal; Amplifying means for amplifying the echo signal with a set gain, and the structure of the scan region represented by the luminance according to the intensity of the echo signal amplified by the amplifying means A generation unit that generates an image, a correction amount information that represents a correction amount for each of a plurality of divided regions determined by dividing the scan region according to a distance from the transmission / reception unit, and a luminance that represents a luminance distribution Storage means for storing distribution information in association with each other, and brightness of an image generated by the generation means based on the echo signal amplified by the amplification means during a determination period A determination unit configured to determine a distribution; and the luminance distribution determined by the determination unit is similar to the luminance distribution represented by the luminance distribution information stored in the storage unit, and represents the similar luminance distribution. Reading means for reading out correction amount information stored in the storage means in association with luminance distribution information from the storage means, and when the correction amount information is not read by the reading means, the plurality of divided regions A predetermined reference gain for each is determined as it is as an applied gain of each of the plurality of divided regions, and when the correction amount information is read by the reading unit, the correction amount information represents the correction gain information. Applying each of the plurality of divided regions by correcting the reference gain of each of the plurality of divided regions with the correction amount of each of the plurality of divided regions Determining means for determining the gain, and amplifying the echo signal by the reference gain with respect to the divided area in which the reflected wave being received is reflected during the determination period, and the reflection being received after the change timing after the end of the determination period Control means for controlling the amplifying means to amplify the echo signal with an applied gain determined by the determining means for the divided area where the wave is reflected.

  According to the present invention, it is possible to automatically perform appropriate STC in more scenes, thereby reducing the load on the user.

1 is a diagram showing a configuration of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The figure which shows the example of a setting of an STC area | region. The figure which shows an example of the data structure of an STC table. The figure which shows an example of luminance distribution information. The flowchart which shows the process sequence by the system control part in FIG. 1 regarding STC. The figure which shows an example of the result of having searched the histogram similar to the histogram produced | generated for every STC area | region from the STC table. The figure which shows an example of the correction value set produced | generated based on the search result shown in FIG. The figure which shows an example of the STC value set before changing according to a user instruction. The figure which shows an example of the STC value set after changing the STC value set shown in FIG. 8 according to a user instruction. The figure which shows the correction value set produced | generated according to the change of the STC value shown in FIG. 8 and FIG. The figure which shows a mode that the STC table shown in FIG. 3 was updated so that the correction value set shown in FIG. 10 might be reflected. The figure which shows a mode that the STC table shown in FIG. 3 was updated so that the correction value set which changed further the correction value set shown in FIG. 7 may be reflected.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of an ultrasonic diagnostic apparatus 100 according to the present embodiment.

  The ultrasonic diagnostic apparatus 100 includes a memory 1, a transmission delay circuit 2, a plurality of pulsers 3, a voltage setting unit 4, a transmission / reception switch (T / R SW) 5, a transducer group 6, a gain control unit 7, and a plurality of amplifiers 8. , A beamformer 9, a digital receiver (hereinafter referred to as DR) 10, a digital scan converter (hereinafter referred to as DSC) 11, a display unit 12, a sequence control unit 13, a system control unit 14, and a memory 15. In general, some elements such as the vibrator group 6 are provided in a probe separate from the apparatus main body, and other elements are provided in the apparatus main body.

  The memory 1 stores, for each transmission / reception timing, delay data related to a delay amount given to a transmission signal and a reception signal by the transmission delay circuit 2 and the beam former 9.

  The transmission delay circuit 2 sets a delay time for each of the m channels such that the m-channel ultrasonic signals transmitted from the transducer group 6 are converged to a predetermined part designated by the sequence control unit 13. The plurality of pulsars 3 correspond to each of the m channels. Each of the plurality of pulsars 3 generates a driving pulse having a delay time set by the transmission delay circuit 2 for the corresponding channel and having a voltage value set by the voltage setting unit 4. The voltage setting unit 4 sets a voltage value corresponding to the required transmission sound pressure in accordance with an instruction from the sequence control unit 13.

  The transmission / reception switch 5 selectively connects the plurality of pulsers 3 and the plurality of amplifiers 8 to the transducer group 6. When the transmission / reception switch 5 connects a plurality of pulsers 3 to the transducer group 6, m-channel drive signals generated by the pulser 3 are supplied to the transducer groups 6 via the transmission / reception switch 5.

  In the transducer group 6, ultrasonic transducers corresponding to the m channels are arranged one-dimensionally or two-dimensionally. An m-channel drive signal is applied to each of these ultrasonic transducers. Each ultrasonic transducer transmits an ultrasonic wave corresponding to the applied drive signal. Each ultrasonic transducer converts incident ultrasonic waves (reflected waves) into electrical reception signals (hereinafter referred to as echo signals).

  When the transmission / reception switch 5 connects a plurality of amplifiers 8 to the transducer group 6, m-channel echo signals obtained by the ultrasonic transducers of the transducer group 6 are input to the plurality of amplifiers 8, respectively. The gain control unit 7 sets the gains of the plurality of amplifiers 8 in accordance with instructions from the sequence control unit 13. The plurality of amplifiers 8 amplify each echo signal of each channel with the gain set by the gain control unit 7. Each of the amplified echo signals after being amplified is input to the beam former 9. The beam former 9 delays and adds a plurality of echo signals to obtain an echo signal related to a required reception beam. The DR 10 performs waveform processing such as filtering and edge processing on the echo signal obtained by the beam former 9. The DSC 11 converts the data obtained by the DR 10 into data suitable for display on the display unit 12. The display unit 12 displays a tomographic image, a volume image, and the like based on the data obtained by the DSC 11.

  The sequence control unit 13 loads delay data for each transmission / reception timing from the memory 1 and sets the delay data in the transmission delay circuit 2 and the beamformer 9. The sequence control unit 13 instructs the voltage setting unit 4 to set the desired transmission sound pressure. The sequence control unit 13 instructs the gain control unit 7 on the desired gain.

  The system control unit 14 instructs the sequence control unit 13 to apply a sequence to be applied, and causes the transmission / reception circuit 2, the voltage setting unit 4, the gain control unit 7, and the beam former 9 to perform a scanning operation according to the sequence. Control. Further, the system control unit 14 controls each operation of the DR 10 and the DSC 11 in order to display an image corresponding to a sequence to be applied on the display unit 12. Further, the system control unit 14 determines, as a reference gain, the gain of the amplifier 8 for adjusting the luminance of the image displayed on the display unit 12 to a predetermined luminance based on the data obtained by the DR 10. The functions of the system control unit 14 for these controls may be the same as those employed in existing ultrasonic diagnostic apparatuses. The system control unit 14 of the present embodiment further includes the following additional functions for STC. One of the additional functions determines the luminance distribution of the image displayed on the display unit 12 based on the data obtained by DR10 during a predetermined determination period. One of the additional functions described above is described in the STC table in association with the similar luminance distribution when a luminance distribution similar to the determined luminance distribution is included in the STC table stored in the memory 15. The correction amount information is read from the memory 15. One of the additional functions described above is that the gain applied by the amplifier 8 (hereinafter referred to as “applied gain”) remains as the reference gain when the correction amount information cannot be read, and the correction amount information can be read. In this case, the gain is determined as the gain corrected with the correction amount represented by the correction amount information from the reference gain. One of the additional functions instructs the sequence control unit 13 to use the gain of the amplifier 8 in the determination period as a reference gain, and to use the gain of the amplifier 8 as an applied gain after the change timing after the end of the determination period. One of the additional functions is to set the gain correction amount of the amplifier 8 according to the user's designation. Another of the above additional functions is that an entry that correlates the correction amount information indicating the set correction amount and the luminance distribution information indicating the determined luminance distribution is stored in the STC table stored in the memory 15. Let

  The memory 15 stores an STC table.

  Next, the operation of the ultrasonic diagnostic apparatus 100 configured as described above will be described.

  First, in the present embodiment, as shown in FIG. 2, each of the areas (hereinafter referred to as STC areas) set by dividing the scan area into eight according to the depth thereof is reflected in the reflected wave from that area. The STC is realized by individually setting the gain of the amplifier 8 when the corresponding echo signal is input to the amplifier 8.

  On the other hand, the STC table has a data structure as shown in FIG. The STC table can include a plurality of entries, and each entry represents luminance distribution information and correction value information in association with each other. As shown in FIG. 4, the luminance distribution information is composed of a set of information each representing a histogram of image luminance in each STC region. The correction value information represents a correction amount related to each STC region. Note that the STC table may take a state in which no entry is included.

  FIG. 5 is a flowchart showing a processing procedure of the system control unit 14 related to STC.

  In step Sa1, the system control unit 14 sets the gain of the amplifier 8 to the reference gain. That is, if automatic gain correction is performed, the system control unit 14 determines the luminance of the image displayed on the display unit 12 based on the data obtained by the DR 10, and the gain is such that the predetermined luminance is obtained. Set the reference gain as If automatic gain correction is not performed, a reference gain is set as a predetermined gain. The system control unit 14 notifies the sequence control unit 13 of the set reference gain. The reference gain may be set as the same value regardless of the STC area, or may be set individually for each STC area.

  In step Sa2, the system control unit 14 instructs the sequence control unit 13 to start scanning. In response to this instruction, the sequence control unit 13 starts control of the transmission delay circuit 2 and the beamformer 9 for repeatedly scanning the scan area according to a predetermined sequence. Further, the sequence control unit 13 instructs the gain control unit 7 to set the gain of the amplifier 8 as the reference gain during the initial determination period after the start of scanning. Thus, in the determination period, scanning is performed without performing STC.

  In step Sa3, the system control unit 14 measures a luminance histogram for each of the STC regions based on the data obtained in the DR 10, and generates a current histogram set.

  In step Sa4, the system control unit 14 searches the STC table for a histogram set similar to the histogram set generated in step Sa3. In step Sa5, the system control unit 14 checks whether or not there is a corresponding histogram set.

  If there is a similar histogram set, the system control unit 14 proceeds from step Sa5 to step Sa6. In step Sa6, the system control unit 14 reads out correction value information associated with the corresponding histogram set, and obtains a correction value set represented by the correction value information. After that, the system control unit 14 proceeds to Step Sa9.

  On the other hand, if there is no similar histogram set, the system control unit 14 proceeds from step Sa5 to step Sa7. In step Sa7, the system control unit 14 searches the STC table for a histogram similar to the histogram generated in step Sa3 for each STC region.

  In step Sa8, the system control unit 14 adopts an STC correction value associated with the corresponding histogram for the STC area having the corresponding histogram, and generates a correction value set using “0” for the other STC areas. . For example, if the search result in step Sa7 is as shown in FIG. 6, the system control unit 14 generates a correction value set as shown in FIG. That is, for example, since there is no similar histogram for the first STC region, the STC correction value for the first STC region is set to “0”. Since the histogram of the second entry is similar for the second STC region, “7”, which is the correction value for the second STC region in the second entry, is used as the STC correction value for the second STC region. adopt. After generating the correction value set in this way, the system control unit 14 proceeds to step Sa9.

  In step Sa9, the system control unit 14 corrects the reference gain set at that time using the correction value set obtained in step Sa6 or the correction value set generated in step Sa8, and performs STC. A set of values (hereinafter referred to as STC values) representing the gain of the amplifier 8 is determined. Here, the STC value is an integer in the range of 0 to 127, and the larger the value is, the larger gain is applied and the luminance of the image is increased.

  In step Sa10, the system control unit 14 instructs the sequence control unit 13 to start STC with notification of the STC value set to be determined in step Sa9. In response to this instruction, the sequence control unit 13 performs STC by sequentially changing the gain of the amplifier 8 to a value corresponding to the STC value set in synchronization with the scan sequence. As the STC is started in this way, the gain of the amplifier 8 is no longer the reference gain, and thus the determination period ends. However, the determination period may be ended at an arbitrary timing after the generation of the histogram set in step Sa3 until the STC is started.

  In this state where the STC is being performed, the system control unit 14 waits for an instruction to change the STC value or an instruction to end the scan in steps Sa11 and Sa12. The system control unit 14 individually accepts the change of the STC value for each of the STC areas.

  If the STC value change instruction is given by the user using an operation device (not shown), the system control unit 14 proceeds from step Sa11 to step Sa13. In step Sa13, the system control unit 14 changes the STC value set in accordance with a user instruction, and notifies the sequence control unit 13 of the changed STC value set. Then, the sequence control unit 13 subsequently changes the gain of the amplifier 8 based on the changed STC value set.

  In step Sa14, the system control unit 14 generates a correction value set reflecting the result of the change in the STC value. Further, in step Sa15, the system control unit 14 writes an entry in which the correction value information representing the correction value set generated in this way is associated with the luminance distribution information representing the histogram set generated in step Sa3 in the STC table.

  Specifically, it is assumed that the STC value set before the change is as shown in FIG. 8, and the STC value set after the change is as shown in FIG. In this case, the STC values for the third, fourth and fifth STC regions are changed by +5, -2 and -5, respectively. If the correction value set of the fourth entry in FIG. 3 is acquired and applied in step Sa6, the system control unit 14 changes the above change to the correction value set of the fourth entry in FIG. Is added to generate a correction value set as shown in FIG. When a new correction value set is generated by changing the correction value set acquired in step Sa6 as described above, the correction value set acquired in step Sa6 with the entry including the correction value information indicating the correction value set is generated. Overwrite the entry that contained the correction value information that represents it. That is, in this case, the existing entry is updated according to the current STC adjustment. Thereby, for example, the STC table is updated from the state shown in FIG. 3 to the state shown in FIG.

  On the other hand, the STC value set set based on the correction value set as shown in FIG. 7 generated in step Sa8 is applied to perform STC, and the STC values for the 4th and 5th STC regions are If the values are changed by +4 and −5, respectively, the system control unit 14 generates a correction value set obtained by adding the above change to the correction value set shown in FIG. When a new correction value set is generated by changing the correction value set generated in step Sa8 as described above, an entry including the correction value information indicating it is additionally stored in the STC table. Thereby, for example, the STC table is updated from the state shown in FIG. 3 to the state shown in FIG.

  If the user gives an instruction to end scanning using an operation device (not shown), the system control unit 14 proceeds from step Sa12 to step Sa16. In step Sa16, the system control unit 14 stops all operations for STC and scanning. Then, the system control unit 14 ends the process of FIG.

  As described above, according to the ultrasonic diagnostic apparatus 100, if a luminance distribution similar to the luminance distribution of an image obtained without performing STC is registered in the STC table, the STC is associated with the similar luminance distribution. The STC is automatically performed by applying each STC correction value of the correction value set registered in the table to each STC region. Accordingly, if a typical luminance distribution obtained in repeated diagnosis and an appropriate correction value set when an image of the luminance distribution is obtained are associated with each other and registered in the STC table in advance, such a diagnosis is performed. It is not necessary for the user to adjust the STC every time the operation is performed, and the burden on the user is greatly reduced.

  Further, according to the ultrasonic diagnostic apparatus 100, when the STC value is changed according to a user instruction, a correction value set for obtaining an STC value set including the changed STC value, and the STC at that time Since it is automatically registered in the STC table in association with the luminance distribution of the image obtained in a state where the image processing is not performed, the STC table is automatically learned in consideration of the actual STC performance in the ultrasonic diagnostic apparatus 100. Thereby, the burden of the user for registration to an STC table does not arise.

  This embodiment can be variously modified as follows.

  (1) An SCT table may be prepared in association with each of a plurality of usage conditions, and the STC table corresponding to the usage conditions of the ultrasonic diagnostic apparatus 100 may be referred to. The usage conditions include a user who uses the ultrasonic diagnostic apparatus 100, a part of a subject to be examined, a mounting situation of exchangeable probes for transmitting ultrasonic waves and receiving reflected waves (for example, plural types of probes) It is conceivable that at least one of scan modes for acquiring an echo signal relating to each position in the scan region, or a combination of a plurality of them. In this way, it is possible to automatically perform an appropriate STC in consideration of circumstances for each use condition such as user preferences.

  (2) The automatic gain correction function may not be provided.

  (3) The amplifier 8 may have a multi-stage configuration, and automatic gain correction and STC may be performed by separate amplifiers.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Memory, 2 ... Transmission delay circuit, 3 ... Pulser, 4 ... Voltage setting part, 5 ... Transmission / reception switch, 6 ... Vibrator group, 7 ... Gain control part, 8 ... Amplifier, 9 ... Beam former, 10 ... Digital receiver (DR), 11 ... digital scan converter (DSC), 12 ... display unit, 13 ... sequence control unit, 14 ... system control unit, 15 ... memory, 100 ... ultrasonic diagnostic apparatus.

Claims (3)

Transmitting and receiving means for transmitting an ultrasonic wave to a scan area for a subject, receiving a reflected wave generated in the scan area according to this, and obtaining an echo signal;
Amplifying means for amplifying the echo signal with a set gain capable of changing and setting the gain;
Generating means for generating an image representing the structure of the scan region with a luminance corresponding to the intensity of the echo signal amplified by the amplifying means;
Correction amount information representing a correction amount and luminance distribution information representing a luminance distribution are stored in association with each other for each of a plurality of divided regions determined by dividing the scan region according to the distance from the transmission / reception means. Storage means for
A determination unit that determines a luminance distribution of an image generated by the generation unit based on the echo signal amplified by the amplification unit during a determination period;
When the luminance distribution determined by the determination unit is similar to the luminance distribution represented by the luminance distribution information stored in the storage unit, the storage is associated with the luminance distribution information representing the similar luminance distribution. Reading means for reading correction amount information stored in the means from the storage means;
When the correction amount information is not read by the reading means, a reference gain predetermined for each of the plurality of divided areas is determined as it is as an applied gain for each of the plurality of divided areas; and When the correction amount information is read by the reading unit, the reference gains of the plurality of divided regions are corrected by the correction amounts of the plurality of divided regions represented by the correction amount information, and the plurality of divided regions are corrected. Determining means for determining the respective applied gains of the divided regions;
In the determination period, the echo signal is amplified by the reference gain with respect to the divided area where the reflected wave being received is reflected, and after the change timing after the end of the determination period, the divided area where the reflected wave being received is reflected And a control means for controlling the amplifying means so as to amplify the echo signal with the applied gain determined by the determining means. Setting means for setting the correction amount according to a user's specification;
In response to the setting of the correction amount by the setting means, the storage means associates correction amount information representing the set correction amount and luminance distribution information representing the luminance distribution determined by the determination means with each other. The ultrasonic diagnostic apparatus according to claim 1, further comprising a writing unit that writes data to the head. The storage means includes a user who uses the ultrasonic diagnostic apparatus, a part of the subject to be examined, a mounting state of an exchangeable probe for transmitting the ultrasonic wave and receiving the reflected wave, or the scan. Storing the correction amount information in association with a use condition including at least one of scan modes for acquiring the echo signal for each position in the region;
The reading unit represents a luminance distribution similar to the luminance distribution determined by the determination unit from the correction amount information stored in the storage unit in association with the current use condition of the ultrasonic diagnostic apparatus. The ultrasonic diagnostic apparatus according to claim 1, wherein correction amount information associated with the luminance distribution information is read out.

Images