U.S. patent application number 13/081786 was filed with the patent office on 2011-07-28 for ultrasonic diagnostic apparatus and tomographic image processing apparatus.
Invention is credited to Akihiro Kawabata, Manabu Migita.
Application Number | 20110184288 13/081786 |
Document ID | / |
Family ID | 33475537 |
Filed Date | 2011-07-28 |
United States Patent
Application |
20110184288 |
Kind Code |
A1 |
Kawabata; Akihiro ; et
al. |
July 28, 2011 |
ULTRASONIC DIAGNOSTIC APPARATUS AND TOMOGRAPHIC IMAGE PROCESSING
APPARATUS
Abstract
A two-dimensional drawing module (25) (i) periodically reads
acoustic line data (S401), (ii) checks a scanning method of a
physical structure of a probe and acoustic line data, and (iii)
selects the optimum coordinate conversion algorithm (S402). After
that, the two-dimensional drawing module (25) (i) selects an
interpolation algorithm, based on a display rate (S403), (ii)
generates display data by performing a two-dimensional DSC process
using the selected coordinate conversion algorithm and the like
(S404a, 404b or 404c), (iii) performs a persistence process for the
display data (S405), a frame interpolating process for a "B mode"
image data (S406) and a display color conversion process (S407),
and (iv) transmits the display data after such processes as
described above to the display unit (14) (S408).
Inventors: |
Kawabata; Akihiro;
(Daito-shi, JP) ; Migita; Manabu; (Neyagawa-shi,
JP) |
Family ID: |
33475537 |
Appl. No.: |
13/081786 |
Filed: |
April 7, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10885704 |
Jul 8, 2004 |
7951082 |
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13081786 |
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Current U.S.
Class: |
600/440 |
Current CPC
Class: |
G01S 15/8977 20130101;
G01S 7/5206 20130101; G01S 7/52085 20130101; G01S 15/8979 20130101;
G01S 7/52071 20130101 |
Class at
Publication: |
600/440 |
International
Class: |
A61B 8/14 20060101
A61B008/14 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 9, 2003 |
JP |
2003-272595 |
Claims
1-24. (canceled)
25. An ultrasonic diagnostic apparatus comprising: an acoustic line
data generation unit configured to generate acoustic line data
based on ultrasonic echo signals acquired via a probe; a display
data generation unit configured to generate, for the generated
acoustic line data, at least two pieces of display data out of: (1)
a tomographic image or a blood flow image; (2) a time displacement
image of a tomographic image or a blood flow image in the same
acoustic line position; (3) a Doppler spectrum image; (4) a
three-dimensional description image of an object described by
volume data for a tomographic image or a blood flow image; and (5)
a cross-sectional image which is made by cutting, in a plane, an
object described by volume data for a tomographic image or a blood
flow image; a display unit configured to display an image
describing an inner state of a subject based on the generated at
least two pieces of display data; a memory unit configured to
memorize the acoustic line data or the volume data; and a memory
area control unit configured to control a memory area of said
memory unit, wherein said memory area control unit is configured to
retain the memory area having an amount required for generating the
display data, according to the at least two pieces of display data
generated by said display data generation unit.
26. An ultrasonic diagnostic method comprising: generating acoustic
line data based on ultrasonic echo signals acquired via a probe;
generating, for the generated acoustic line data, at least two
pieces of display data out of: (1) a tomographic image or a blood
flow image; (2) a time displacement image of a tomographic image or
a blood flow image in the same acoustic line position; (3) a
Doppler spectrum image; (4) a three-dimensional description image
of an object described by volume data for a tomographic image or a
blood flow image; and (5) a cross-sectional image which is made by
cutting, in a plane, an object described by volume data for a
tomographic image or a blood flow image; displaying an image
describing an inner state of a subject based on the generated at
least two pieces of display data; memorizing the acoustic line data
or the volume data in a memory unit; and controlling a memory area
of the memory unit, wherein in said controlling, the memory area
having an amount required for generating the display data is
retained according to the at least two pieces of display data
generated in said generating of at least two pieces of display
data.
27. A non-transitory computer-readable recording medium on which a
program is recorded, the program causing a computer to execute the
steps included in the ultrasonic diagnostic method according to
claim 26.
Description
BACKGROUND OF THE INVENTION
[0001] (1) Field of the Invention
[0002] The present invention relates to a signal processing
technology for echo signals acquired via a probe of an ultrasonic
diagnostic apparatus, in particular, to a data processing
technology for acoustic line data generated based on the echo
signals, and a data conversion technology from acoustic line data
to display data.
[0003] (2) Description of the Related Art
[0004] An ultrasonic diagnostic apparatus which is capable of
observing a subject without invasion and in real time has become an
essential existence in the medical field. Recently, while there
have been increasing attempts to improve the function of an
ultrasonic diagnostic apparatus, there have been efforts to reduce
the cost for operating the apparatus, as well.
[0005] As an example of such efforts to reduce the cost as
described above, an ultrasonic diagnostic apparatus which performs
a signal processing unit for generating acoustic line data in a
software achieved by a personal computer is suggested (for example,
refer to Japanese Laid-Open Patent publication No. H11-329).
[0006] FIG. 1 is a block diagram showing a functional structure of
a conventional ultrasonic diagnostic apparatus 100. As shown in
FIG. 1, the ultrasonic diagnostic apparatus 100 comprises: an
overall control unit 71, a signal processing unit 72, an acoustic
line data control unit 73, an acoustic line data memory unit 74, a
two-dimensional display control unit 75, a display unit 76, a
three-dimensional display control unit 77 and a three-dimensional
data memory unit 78.
[0007] The overall control unit 71 is a functional unit that
controls the overall operations of the ultrasonic diagnostic
apparatus 100, such as a micro computer equipped with ROM or
RAM.
[0008] The signal processing unit 72 performs a phasing addition
and a filter process for echo signals received via a probe, and
generates acoustic line data which indicates tomographic image
information.
[0009] The acoustic line data control unit 73 controls writing-in
and reading-out of the acoustic line data, generated by the signal
processing unit 72, into the acoustic line data memory unit 74.
And, the acoustic line data control unit 73 transmits the generated
acoustic line data to the two-dimensional display control unit
75.
[0010] The acoustic line data memory unit 74 is a memory apparatus
that memorizes acoustic line data following the direction of the
acoustic line data control unit 73, such as RAM.
[0011] The two-dimensional display control unit 75 receives
acoustic line data transmitted from the acoustic line data control
unit 73, and performs a two-dimensional coordinate conversion
process and an interpolating process for the acoustic line data.
And, the two-dimensional display control unit 75 generates display
data. And, the two-dimensional display control unit 75 transmits
the display data to the display unit 76 and the three-dimensional
display control unit 77.
[0012] The display unit 76 displays a tomographic image and the
like in a monitor (for example, CRT: not shown in figures), based
on the display data outputted by the two-dimensional display
control unit 75 or the three-dimensional display control unit
77.
[0013] The three-dimensional display control unit 77 takes in the
display data transmitted by the two-dimensional display control
unit 75, and generates volume data and image (written as a
"three-dimensional image" below) data that describes volume
data.
[0014] The three-dimensional data memory unit 78 is, for example,
RAM, and memorizes the volume data generated by the
three-dimensional display control unit 77.
[0015] Next, the operations performed by the ultrasonic diagnostic
apparatus 100 will be explained by classifying each representative
operational mode. Each operational mode will be further divided
into the two modes: a "live mode" and a "cine mode". Here, a "live
mode" means a mode that generates acoustic line data from echo
signals received via a probe (and further holds the generated
acoustic line data in the acoustic line data memory unit 74), and
displays a tomographic image and the like in real time. A "cine
mode" means a mode that reads out the acoustic line data, once held
in such "live mode" as described above, from the acoustic line data
memory unit 74 and displays the tomographic image and the like.
(B Mode)
[0016] A "B mode" is a mode that displays the strength of a
reflective wave with brightness.
[0017] A "live mode" of the "B mode" is a mode that processes echo
signals received via a probe, and displays a "B mode" image in the
display unit 76 in real time.
[0018] The operations performed by the "live mode" of the "B mode"
are as following.
[0019] Acoustic line data indicating tomographic image information
is generated by performing a phasing addition and a filter process
for echo signals received via a probe in the signal processing unit
72. The generated acoustic line data is memorized by the acoustic
line data memory unit 74, via the acoustic line data control unit
73; and at the same time, the generated acoustic line data is
transmitted to the two-dimensional display control unit 75.
[0020] The two-dimensional display control unit 75 (i) performs a
two-dimensional coordinate conversion process and an interpolating
process for acoustic line data, (ii) generates display data for
displaying a "B mode" image, and (iii) transmits the display data
to the display unit 76. The display unit 76 displays the "B mode"
image, based on the display data received from the two-dimensional
display control unit 75.
[0021] On the other hand, the "cine mode" of the "B mode" reads out
the acoustic line data memorized in the "live mode", and displays
the "B mode" image in the display unit 76, as well as such "live
mode" as described above.
[0022] The operations performed by the "cine mode" of the "B mode"
are as follows.
[0023] The acoustic line data control unit 73 reads out the
acoustic line data memorized by the acoustic line data memory unit
74, and transmits the acoustic line data to the two-dimensional
display control unit 75. Here, the operations of the
two-dimensional display control unit 75 and the display unit 76 are
the same as those of the "live mode" of the "B mode".
(Color Mode)
[0024] A "color mode" is a mode that displays a blood flow image (a
tomographic image indicating the high and low of the blood flow
speed with a plurality of colors, which is also called a "color
flow mode"). The "live mode" of the "color mode" processes echo
signals received from a probe, and generates a blood flow image
(also called the "color mode" image), and displays the blood flow
image in the display unit 76 in real time.
[0025] The operations performed by the "live mode" of the "color
mode" are as follows.
[0026] The signal processing unit 72 performs a phasing addition, a
filter process, and a frequency analysis process for echo signals
received via a probe, and generates acoustic line data indicating
blood flow information. The generated acoustic line data is
memorized by the acoustic line data memory unit 74, via the
acoustic line data control unit 73; and at the same time, the
generated acoustic line data is transmitted to the two-dimensional
display control unit 75.
[0027] The two-dimensional display control unit 75 performs a
two-dimensional coordinate conversion process and an interpolating
process for acoustic line data, generates display data for
displaying a "color mode" image, and transmits the display data to
the display unit 76.
[0028] On the other hand, the "cine mode" of the "color mode" reads
out the acoustic line data memorized by the "live mode", and
displays the "color mode" image in the display unit 76, based on
the generated display data, as well as such "live mode" as
described above.
[0029] The operations performed by the "cine mode" of the "color
mode" are as follows.
[0030] The acoustic line data control unit 73 reads out the
acoustic line data memorized by the acoustic line data memory unit
74, and transmits the acoustic line data to the two-dimensional
display control unit 75. Here, the operations of the
two-dimensional display control unit 75 and the display unit 76 are
the same as those of the "live mode".
[0031] Also, in the operations performed by the "color mode", the
operations of the "B mode" are concurrently performed; and in
general, the "color mode" image is displayed overlapping the "B
mode" image.
(M Mode)
[0032] An "M mode" is a mode that displays a time displacement
image of tomographic image information in the same acoustic line
position in the display unit 76.
[0033] The "live mode" of the "M mode" processes echo signals
received via a probe to generate an "M mode" image, and displays
the "M mode" image in the display unit 76 in real time.
[0034] The operations performed by the "live mode" of the "M mode"
are as follows.
[0035] First, the signal processing unit 72 performs a phasing
addition and a filter process for echo signals received via a
probe, and generates acoustic line data.
[0036] Next, the generated acoustic line data is memorized by the
acoustic line data memory unit 74, via the acoustic line data
control unit 73; and at the same time, the generated acoustic line
data is transmitted to the two-dimensional display control unit
75.
[0037] The two-dimensional display control unit 75 performs a
two-dimensional coordinate conversion process and an interpolating
process for acoustic line data, and generates display data for
displaying an "M mode" image, that is, display data where
ultrasonic acoustic line information of the same acoustic line
position is arranged in the order of the time string. And, the
two-dimensional display control unit 75 transmits the display data
to the display unit 76. The display unit 76 displays the "M mode"
image according to the received display data.
[0038] On the other hand, the "cine mode" of the "M mode" reads out
the acoustic line data memorized by the "live mode", and generates
display data. And, the "cine mode" of the "M mode" transmits the
display data to the display unit 76. The display unit 76 displays
the "M mode" image, based on the received display data.
[0039] The operations performed by the "cine mode" of the "M mode"
are as follows.
[0040] First, the acoustic line data control unit 73 reads out the
acoustic line data memorized by the acoustic line data memory unit
74, and transmits the acoustic line data to the two-dimensional
display control unit 75.
[0041] Here, the operations of the two-dimensional display control
unit 75 and the display unit 76 are the same as those of the "live
mode" of the "M mode".
(Color M Mode)
[0042] A "color M mode" is a mode that displays a time displacement
image of blood flow information in the same acoustic line position.
The "live mode" of the "color M mode" processes echo signals
received via a probe, and displays the "color M mode" image in the
display unit 76 in real time.
[0043] The operations performed by the "live mode" of the "color M
mode" are as follows.
[0044] First, the signal processing unit 72 performs a phasing
addition, a filter process and a frequency analysis process for
echo signals received via a probe, and generates acoustic line data
indicating blood flow information.
[0045] Next, the generated acoustic line data is memorized by the
acoustic line data memory unit 74, via the acoustic line data
control unit 73; and at the same time, the generated acoustic line
data is transmitted to the two-dimensional display control unit
75.
[0046] The two-dimensional display control unit 75 performs a
two-dimensional coordinate conversion process and an interpolating
process for acoustic line data, and generates display data for
displaying a "color M mode" image, that is, display data where
blood flow acoustic line information of the same acoustic line
position is arranged in the order of the time string. And, the
two-dimensional display control unit 75 transmits the display data
to the display unit 76.
[0047] On the other hand, the "cine mode" of the "color M mode"
reads out the acoustic line data memorized by the "live mode", and
displays the "color M mode" image, based on the display data, in
the display unit 76.
[0048] The operations performed by the "cine mode" of the "color M
mode" are as follows.
[0049] First, the acoustic line data control unit 73 reads out the
acoustic line data indicating blood flow information memorized by
the acoustic line data memory unit 74, and transmits the acoustic
line data to the two-dimensional display control unit 75.
[0050] Here, the operations of the two-dimensional display control
unit 75 and the display unit 76 are the same as those of the "live
mode". Also, in the operations performed by the "color M mode", the
operations of the "M mode" are concurrently performed; and in
general, the "color M mode" image is displayed overlapping the "M
mode" image.
(Doppler Mode)
[0051] A "Doppler mode" is a mode that displays a time displacement
image of the Doppler spectrum of the same acoustic line
position.
[0052] The "live mode" of the "Doppler mode" processes echo signals
received via a probe, and displays the "Doppler mode" image in the
display unit 76 in real time.
[0053] The operations performed by the "live mode" of the "Doppler
mode" are as follows.
[0054] First, the signal processing unit 72 performs a phasing
addition, a filter process, and a Fourier analysis process for echo
signals received via a probe, and generates acoustic line data
indicating Doppler spectrum information.
[0055] Next, the generated acoustic line data is memorized by the
acoustic line data memory unit 74, via the acoustic line data
control unit 73; and at the same time, the generated acoustic line
data is transmitted to the two-dimensional display control unit
75.
[0056] The two-dimensional display control unit 75 performs a
two-dimensional coordinate conversion process and an interpolating
process for acoustic line data, and generates display data for
displaying a "Doppler mode" image, that is, display data where
Doppler spectrum acoustic line information of the same acoustic
line position is arranged in the order of the time string. And, the
two-dimensional display control unit 75 transmits the display data
to the display unit 76.
[0057] On the other hand, the "cine mode" of the "Doppler mode"
generates the display data by reading out the acoustic line data
memorized by the "live mode", and displays the "Doppler mode" image
in the display unit 76.
[0058] The operations performed by the "cine mode" of the "Doppler
mode" are as follows.
[0059] First, the acoustic line data control unit 73 reads out the
acoustic line data indicating Doppler spectrum information
memorized by the acoustic line data memory unit 74, and transmits
the acoustic line data to the two-dimensional display control unit
75. Here, the operations of the two-dimensional display control
unit 75 and the display unit 76 are the same as those of the "live
mode" of the "Doppler mode".
(3D Live Mode)
[0060] A "3D live mode" is a mode that simultaneously generates (a)
a tomographic image by processing echo signals received via a 3D
probe in real time, and (b) a three-dimensional image by a volume
rendering process, said volume being generated from a plurality of
tomographic image group which is a volume data set, and
simultaneously displays a tomographic image and a three-dimensional
image in the display unit 76.
[0061] The operations performed by the "3D live mode" are as
follows.
[0062] First, the signal processing unit 72 performs a phasing
addition and a filter process for echo signals received via a
probe, and generates acoustic line data. Next, the generated
acoustic line data is transmitted to the two-dimensional display
control unit 75, via the acoustic line data control unit 73.
[0063] The two-dimensional display control unit 75 performs a
two-dimensional coordinate conversion process and an interpolating
process for acoustic line data, and generates display data. And,
the two-dimensional display control unit 75 transmits the display
data to the display unit 76 and the three-dimensional display
control unit 77.
[0064] The three-dimensional display control unit 77 takes in the
display data, and generates volume data on the three-dimensional
data memory unit 78. And, the three-dimensional display control
unit 77 generates three-dimensional image data by a volume
rendering, and transmits the three-dimensional image data to the
display unit 76.
[0065] Finally, the display unit 76 simultaneously displays the
tomographic image and the three-dimensional image data.
(Multi Planner Reconstruction (MPR) Mode)
[0066] An "MPR mode" is a display mode that observes volume data on
the three-dimensional data memory unit 78 as a three-dimensional
image or a cross-sectional image from an arbitrary viewpoint, said
volume data being generated by the "3D live mode".
[0067] The operations performed by the "MPR mode" are as
follows.
[0068] First, by using the volume data on the three-dimensional
memory unit 78 and according to the radial direction provided by
the overall control unit 71, the three-dimensional display control
unit 77 performs a volume rendering, and generates
three-dimensional image data. And, the three-dimensional display
control unit 77 transmits the three-dimensional image data to the
display unit 76.
[0069] Next, by using the volume data memorized on the
three-dimensional data memory unit 78, the three-dimensional
display control unit 77 generates cross-sectional image data whose
volume is sliced by a predetermined plate provided by the overall
control unit 71, and transmits the cross-sectional image data to
the display unit 76.
[0070] Finally, the display unit 76 performs a display, according
to the three-dimensional image data and the cross-sectional image
data.
[0071] Although specific explanations will be omitted here, the
"MPR mode" is capable of an operation to delete a part of the
volume data. In such case as described above, the "MPR mode"
generates and displays the three-dimensional image and the
cross-sectional image for the volume data other than the deleted
part.
[0072] A structure of the conventional ultrasonic diagnostic
apparatus can be briefly divided into the following two units: (i)
a signal processing unit that generates acoustic line data by
performing a phasing addition and a filter process for echo signals
received via a probe, and (ii) a backend unit that memorizes the
acoustic line data outputted from the signal processing unit and
reads out the acoustic line data to display.
[0073] As shown in FIG. 1, the backend unit includes the following
functional units: an acoustic line data control unit 73, an
acoustic line data memory unit 74, a two-dimensional display
control unit 75, a display unit 76, a three-dimensional display
control unit 77 and a three-dimensional data memory unit 78.
[0074] The problems of the backend unit 79 of the conventional
ultrasonic diagnostic apparatus 100 will be explained in detail as
follows.
[0075] The image quality of a two-dimensional tomographic image
outputted by the ultrasonic diagnostic apparatus 100 is greatly
influenced not only by the process algorithm of the signal
processing unit but also by the process algorithm of the backend
unit. In particular, the quality of the tomographic image and the
like is greatly influenced by the interpolating process for a
coordinate conversion, the frame interpolating process and the like
which are necessary in the process of converting acoustic line data
to display data
[0076] For example, the two-dimensional display control unit 75
needs a coordinate conversion to the display area of the display
unit 76, according to the physical form of the probe connected to
the ultrasonic diagnostic apparatus; however, a convex probe or a
sector probe and the like need a polar-orthogonal coordinate
conversion. In such polar-orthogonal coordinate conversion, the
acoustic line data which is original data does not appear on the
grid of the orthogonal coordinate. Thus, it is necessary to
generate the display data on the orthogonal coordinate by the
interpolating process.
[0077] Although there are various kinds of interpolating methods
for the interpolating process algorithm, such as a linear
interpolating method and an upsampling filter method, each method
has advantages and disadvantages.
[0078] In the case of the linear interpolating method, a
calculation cost is not necessary, but the image quality is not
very good. In the case of the upsampling filter method, the
calculation cost increases, depending on the number of filter taps,
but the image quality is improved from the linear interpolating
method.
[0079] Thus, in order to achieve as good an image quality as
possible by efficiently utilizing the hardware resource of the
apparatus within the limit, the quality of the tomographic image
should be optimized by enabling the dynamic change of the
interpolating process algorithm, depending on the physical form of
the probe and the frame rate of the tomographic image data
outputted by the signal processing unit. However, according to the
conventional structure, such functions as described above are
performed as a functional block which performs a solid process.
Thus, it is difficult to perform such processes as described
above.
[0080] The quality of the three-dimensional image outputted by the
ultrasonic diagnostic apparatus is greatly influenced by the
process algorithm of the backend unit, as well as the quality of
the two-dimensional tomographic image. The three-dimensional image
generation process requires the two processes of a volume
generation and rendering the generated volume. Such generation
process and rendering process are performed by the
three-dimensional display control unit 77.
[0081] Since the volume generation has the same problem as the one
described in the quality of the two-dimensional tomographic image,
the explanation will be omitted here.
[0082] As the volume rendering process performs the calculation
process of a mass volume, the balance between the rendering
algorithm which is related with the image quality and the
processing time is always essential.
[0083] Another problem is the functional block division of the
backend unit of the conventional ultrasonic diagnostic
apparatus.
[0084] FIG. 2 is a diagram showing the further specific functional
structures of the acoustic line data control unit 73 and the
acoustic line data memory unit 74.
[0085] As shown in FIG. 2, an individual functional block is
provided for each operational mode. The acoustic line data control
unit 73 includes: the "B mode" acoustic line data control unit 73a,
the "color mode" acoustic line data control unit 73b, the "M mode"
acoustic line data control unit 73c, the "color M mode" acoustic
line data control unit 73d and the "Doppler mode" acoustic line
data control unit 73e.
[0086] The acoustic line data memory unit 74 includes: the "B mode"
acoustic line data memory unit 74a, the "color mode" acoustic line
data memory unit 74b, the "M mode" acoustic line data memory unit
74c, the "color M mode" acoustic line data memory unit 74d and the
"Doppler mode" acoustic line data memory unit 74e.
[0087] Here, in the case of the "B mode", only the "B mode"
acoustic line data memory unit 74a is used among the blocks
included in the acoustic line data memory unit 74; and the other
blocks are not used
[0088] Also, in the case of the "color mode", only the two blocks
of the "B mode" acoustic line data memory unit 74a and the "color
mode" acoustic line data memory unit 74b are used; and it is the
same in the case of the other operational modes.
[0089] In addition, depending on the operational mode of the
ultrasonic diagnostic apparatus, not only the use situation of the
acoustic line data memory unit 74, but also the use situation of
the three-dimensional data memory unit 78 differs. For example, in
the case of displaying only the "B mode" image, the
three-dimensional data memory unit 78 is not used at all.
[0090] Moreover, the coordinate conversions of the two-dimensional
display control unit 75 and the three-dimensional display control
unit 77 are essentially the same; however, at present they are
performed as different functional blocks.
[0091] As described above, the functional block division of the
backend unit of the conventional ultrasonic diagnostic apparatus is
inefficient; and as a result, the cost is increased. Japanese
Laid-Open Patent publication No. H11-329 discloses an ultrasonic
diagnostic apparatus which comprises a personal computer and a
software that performs a signal process. And, the Japanese
Laid-Open Patent publication No. H11-329 further discloses a fast
performance of a signal process by the use of a CPU of a
higher-efficiency, and a multiple process of a plurality of
functional modules by implementing and multitask-operating the
software in an object-oriented manner.
[0092] However, such problem as described above is not solved; and
the advantage of the ultrasonic diagnostic apparatus comprising a
software is not fully utilized.
SUMMARY OF THE INVENTION
[0093] An object of the present invention, in view of the above
problem, is to provide the ultrasonic diagnostic apparatus which
has an improved image quality and a flexible extendability, and to
reduce the cost of the backend unit.
[0094] In order to achieve such object as described above the
ultrasonic diagnostic apparatus according to the present invention
comprises: an acoustic line data generation unit operable to
generate acoustic line data, based on echo signals acquired via a
probe, display data generation unit operable to generate display
data for the generated acoustic line data, and a display unit
operable to display an image describing an inner state of a
subject, based on the generated display data, wherein the display
data generation unit (i) changes the quality of the image
describing the inner state of the subject, and (ii) generates
display data after the change, according to the generation amount
of the acoustic line data, per unit time, or the number of display
frames of the image describing the inner state of the subject, per
unit time.
[0095] Thus, it is possible to realize the function of the backend
unit of the conventional ultrasonic diagnostic apparatus by
efficiently utilizing the resource. Consequently, the cost of the
apparatus can be reduced; and as high an image quality as the
resource permits can be acquired.
[0096] Also, the operational mode of the present ultrasonic
diagnostic apparatus has at least one of the following modes: a "B
mode", a "color mode", an "M mode", a "color M mode", a "Doppler
mode", a "3D live mode" and an "MPR mode".
[0097] In addition, in order to achieve such object as described
above, the tomographic image processing apparatus according to the
present invention comprises: an acoustic line data acquisition unit
operable to acquire acoustic line data based on ultrasonic echo
signals acquired via a probe; and a display data generation unit
operable to generate display data for the acquired acoustic line
data, wherein the display data generation unit (i) changes the
quality of the image describing the inner state of the subject,
according to the generation amount of the acoustic line data, per
unit time, or the number of display frames of the image describing
the inner state of the subject, per unit time, and (ii) generates
display data after the change.
[0098] Thus, it is possible to realize the function of the backend
unit of the conventional tomographic image processing apparatus by
efficiently utilizing the resource. Consequently, the cost of the
apparatus can be reduced; and as high an image quality as the
resource permits can be acquired.
[0099] Moreover, the present invention can be realized as an
ultrasonic diagnostic method or a tomographic image processing
method which has steps of the characteristic functional structure
of the ultrasonic diagnostic apparatus or the tomographic image
processing apparatus and a program which includes all the steps of
such methods as described above. And, needless to say, the program
can be distributed via a record medium such as a CD-ROM and the
like or a transmission medium such as the Internet and the
like.
[0100] Thus, according to the present invention, depending on the
generation amount, per unit time, of acoustic line data or the
number of frames, per unit time, of an image describing the inner
state of a subject which is displayed by the display step, the
quality of an image describing the inner state of the subject can
be changed; and by efficiently utilizing the resource, as high an
image quality as the resource permits can be acquired.
[0101] Specifically, by flexibly changing (a) an interpolation
algorithm of a two-dimensional DSC process, (b) the necessity or
unnecessity of a frame persistence process, (c) the rate of a
weighted addition of the process, (d) the necessity or unnecessity
of a frame interpolation process and (e) the number of frames to
generate in the process, a high image quality can be realized.
[0102] Furthermore, as for the image quality of a three-dimensional
image as well, by flexibly changing (a) an interpolation algorithm
of a three-dimensional DSC process, (b) a sample pitch of a volume
rendering, (c) an interpolation algorithm, and (d) a rendering
algorithm, a high image quality can be realized.
[0103] Finally, the functional block division of the backend unit
of the ultrasonic diagnostic apparatus, as well as the
two-dimensional DSC process and the three-dimensional DSC process,
is performed by a host processor. Also, the acoustic line data
control and the volume data control that differ, depending on the
operational mode of the ultrasonic diagnostic apparatus are
performed by the host processor and the main memory of the host
processor, thus a system that is functionally simple and of a low
cost can be built.
[0104] Consequently, the practical effects of the present invention
are considered substantial.
Further Information About Technical Background to this
Application
[0105] The disclosure of Japanese Patent Application No.
2003-272595 filed on Jul. 9, 2003 including specification, drawings
and claims is incorporated herein by reference in its entirety.
BRIEF DESCRIPTION OF THE DRAWINGS
[0106] These and other objects, advantages and features of the
invention will become apparent from the following description
thereof taken in conjunction with the accompanying drawings that
illustrate a specific embodiment of the invention. In the
Drawings:
[0107] FIG. 1 is a block diagram showing a functional structure of
the conventional ultrasonic diagnostic apparatus;
[0108] FIG. 2 is a functional structure diagram of the conventional
acoustic line data control unit and the acoustic line data memory
unit;
[0109] FIG. 3 is an outside drawing of the ultrasonic diagnostic
apparatus according to the present invention;
[0110] FIG. 4 is a schematic structure diagram of the ultrasonic
diagnostic apparatus according to the first and second
embodiments;
[0111] FIG. 5 is a schematic diagram of the software function of
the backend unit according to the first embodiment;
[0112] FIG. 6 is an overall flow showing an operational flow of the
backend unit according to the first embodiment;
[0113] FIG. 7 is a flow chart of the "B mode" of the
two-dimensional drawing module according to the first
embodiment;
[0114] FIG. 8(a) is a brief diagram showing an interpolation
performed using the nearest neighbor interpolating method;
[0115] FIG. 8(b) is a brief diagram showing an interpolation
performed using the linear interpolating method;
[0116] FIG. 8(c) is a brief diagram showing an interpolation
performed using the upsampling filter method;
[0117] FIG. 9 is a flow chart showing an operational flow of the "M
mode" of the two-dimensional drawing module according to the first
embodiment;
[0118] FIG. 10 is a schematic diagram of a software function of the
backend unit according to the second embodiment; and
[0119] FIG. 11 is a flow chart showing a flow of the procedure of
the three-dimensional processing module according to the second
embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0120] The embodiments according to the present invention will be
explained in detail with reference to the figures as following.
First Embodiment
[0121] FIG. 3 is an outside drawing of the ultrasonic diagnostic
apparatus 10 according to the present invention. FIG. 4 is a block
diagram showing a functional structure of an ultrasonic diagnostic
apparatus 10 according to the first embodiment. As shown in FIG. 4,
the ultrasonic diagnostic apparatus 10 comprises: a signal
processing unit 11, an overall control unit 12, a host memory 13, a
display unit 14 and an input unit 16. Also, a backend unit 15
includes the overall control unit 12, the host memory 13 and the
display unit 14.
[0122] Here, the "backend unit" is a functional unit that performs
an image process for generated acoustic line data (in this case,
the functional unit between the probe and the unit where the
acoustic line data is generated based on the acquired echo signals
via the probe is called a "front end unit").
[0123] The signal processing unit 11 performs a phasing addition
and a filter process for echo signals received via the probe, and
generates acoustic line data.
[0124] The overall control unit 12 is a functional unit that
controls the whole ultrasonic diagnostic apparatus 10, such as a
microcomputer equipped with ROM, RAM and the like. In such case as
described above, each function of the backend unit 15 is performed
according to the control program performed by the overall control
unit 12. Also, the host memory 13 can be the main memory or a part
of the microcomputer.
[0125] In addition, the overall control unit 12 performs an
"acoustic line data-display data conversion process" of converting
the acoustic line data to display data by performing the following
processes for the acoustic line data: a coordinate conversion
process, an interpolating process, a frame interpolating process, a
frame persistence process and a display color conversion process.
At the same time, the overall control unit 12 has the host memory
13 memorize the acoustic line data outputted from the signal
process unit 11.
[0126] The host memory 13 memorizes the acoustic line data
outputted from the signal processing unit 11, according to the
direction of the overall control unit 12. Moreover, the host memory
13 provides a work area that is necessary for the "acoustic line
data-display data conversion process" performed by the overall
control unit 12. The input unit 16 is a functional unit that
receives operations from a user, such as a keyboard and a
switch.
[0127] Also, the ultrasonic diagnostic apparatus 10 as shown in
FIG. 4 can be formed by attaching an expansion card that realizes a
signal processing unit 11 to an expansion slot of a general
personal computer.
[0128] FIG. 5 is a block diagram showing a structure of a software
which realizes the function of the backend unit 15 as shown in FIG.
4. As shown in FIG. 5, the backend unit 15 includes respective
software function as follows: an I/O module 21, a cine memory
control module 22, a playback module 24 and a two-dimensional
drawing module 25 (respective function of the I/O module 21-the
two-dimensional drawing module 25 will be described later
corresponding to each display mode). In such case as described
above, the cine memory control module 22 performs a writing-in and
reading-out for the cine memory 23.
[0129] Next, the operations of the backend unit 15 as shown in FIG.
4 will be explained in relation to the display mode of the
ultrasonic diagnostic apparatus 10. FIG. 6 is a whole flow showing
the operational flow of the backend unit 15.
[0130] First, the overall control unit 12 checks whether or not a
user has set a display mode. In the case the user has set a display
mode (S301: Yes), according to the set (S302), either of the
following processes is repeated until the ultrasonic diagnostic
apparatus 10 finishes its diagnosis (S301-S308): the "B mode"
display process (S303), the "color mode" display process (S304),
the "M mode" display process (S305), the "color M mode" display
process (S306) and the "Doppler mode" display process (S307).
[0131] The functions and operations of each display mode (in
addition, a "live mode" and a "cine mode") of the backend unit 15
will be explained as following.
(B Mode)
[0132] The operations performed by the "live mode" of "B mode" are
as follows.
[0133] The I/O module 21 acquires acoustic line data from the
signal processing unit 11, and has the cine memory 23 of the host
memory 13 memorize the acoustic line data via the cine memory
control module 22. Also, the I/O module 21 performs a grouping of
the acoustic line data included in a frame of a "B mode" image, and
transmits the acoustic line data, per frame, to the two-dimensional
drawing module 25.
[0134] The cine memory control module 22 is a module that reserves
a cine memory according to the operational mode on the host memory
13 and performs an input/output operation for the reserved cine
memory 23.
[0135] The two-dimensional drawing module 25 is periodically
activated, and performs a two-dimensional Digital Scan Convert
(DSC) process to acoustic line data transmitted from the I/O module
21. And, the two-dimensional drawing module 25 converts the
acoustic line data to display data, and transmits the display data
to the display unit 14.
[0136] Here, the "two-dimensional DSC process" means a series of
processes for generating a tomographic image as follows: a
coordinate conversion process, an interpolating process, a frame
interpolating process, a frame persistence process, and a display
color conversion process.
[0137] Finally, the display unit 14 displays a "B mode" image in
the display, according to the display data received from the
two-dimensional drawing module 25.
[0138] On the other hand, the operations performed by the "cine
mode" of the "B mode" are as following.
[0139] The playback module 24 reads out the acoustic line data
memorized by the cine memory 23 in the "live mode", via the cine
memory control module 22. Then, the playback module 24 performs a
grouping of the acoustic line data which forms a frame of the "B
mode" image, and transmits the acoustic line data, per frame, to
the two-dimensional drawing module 25.
[0140] The playback module 24 is periodically activated. By making
the activation cycle changeable, the playback speed of the "B mode"
image can be arbitrarily changed.
[0141] The operations performed by the two-dimensional drawing
module 25 and the display unit 14 are the same as the "live mode"
of the "B mode".
[0142] Also, as described above, the two-dimensional drawing module
25 can flexibly change the algorithm of the interpolating process,
the operation of the frame interpolating process and the like,
according to the acquisition rate (frame rate) of the acoustic line
data outputted from the signal processing unit 11, and according to
the display rate with which the two-dimensional drawing module 25
itself transmits the display data to the display unit 14. Here, the
operations performed by the two-dimensional drawing module 25 will
be explained in further detail using a flow chart.
[0143] FIG. 7 is a flow chart showing a flow of the operations
performed by the two-dimensional drawing module 25 in the display
mode of the "B mode".
[0144] First, the two-dimensional drawing module 25 periodically
reads the acoustic line data forming a frame of the "B mode" image
(S401). Although it is not shown in FIG. 6, in the case where the
frame rate of the acoustic line data generated by the signal
processing unit 11 is low, as the time space in which the acoustic
line data is transmitted becomes long, it is possible to lower the
rate (lengthening the time space) with which the acoustic line data
is read. As a result, it is possible to lower the renewal rate (the
number of display frames per unit time) of the display data in the
display unit 14, and to reduce the burden of the two-dimensional
drawing module 25 according to the overall control unit 12.
[0145] Next, the two-dimensional drawing module 25 checks (a) the
scanning method of the physical structure of the probe and (b) the
scanning method of the acoustic line data, and selects the
coordinate conversion algorithm suitable for the two scanning
methods (a) and (b) as described above (S402). For example, in the
case of the sector-convex type probe, the "polar-orthogonal
coordinate conversion process" is selected; and in the case of the
linear type probe, the "orthogonal-orthogonal coordinate conversion
process" is selected.
[0146] Next, the two-dimensional drawing module 25 selects the
interpolation algorithm for the two-dimensional DSC process,
according to the renewal rate of the display data (S403). As the
criteria for selecting the interpolation algorithm, the processing
cycle of the interpolation algorithm which is a selection candidate
is shorter than the renewal cycle of the display data, and the CPU
occupancy of the overall control unit 12 is considered. And, the
interpolation algorithm of the highest image quality is selected
among the interpolation algorithms fulfilling such selection
conditions as described above.
[0147] As described above, the renewal rate of the display data can
be decided, according to the frame rate of the acoustic line data.
Thus, it can be considered that the interpolation algorithm is
selected according to the frame rate of the acoustic line data.
[0148] As the interpolation algorithm, for example, there are the
nearest neighbor interpolating method, a linear interpolating
method and an upsampling filter method. However, other
interpolating methods can be used, as well.
[0149] The comparison of the processing time of each interpolation
algorithm is as follows:
the nearest neighbor interpolating method <the linear
interpolating method <the upsampling filter method (1)
The upsampling filter method has the highest image quality; on the
other hand, the processing burden is the biggest. Here, the outline
of such respective interpolating method as described above will be
explained as follows.
[0150] FIGS. 8(a)-(c) are diagrams for explaining the outline of
respective interpolation in the case where an interpolation is
performed by such respective interpolating method as described
above. As the subject for the interpolation, FIGS. 8(a)-(c) show
the examples of interpolating the value of brightness in an
arbitrary position (for convenience, a position in an arbitrary
".times." coordinate is provided here). Also, the black dot " "
indicates the data (original data) used in the interpolation
process.
[0151] The outline of respective interpolation is shown as follows:
FIG. 8(a) for the case where the interpolation is performed by the
nearest neighbor interpolating method; FIG. 8(b) for the case where
the interpolation is performed by the linear interpolating method;
and FIG. 8(c) for the case where the interpolation is performed by
the upsampling filter method. In the case where the nearest
neighbor interpolating method is used as shown in FIG. 8(a), as the
brightness suddenly changes in the position of P1, the image
becomes discontinuous and lacks smoothness. In addition, in the
case where the linear interpolating method is used as shown in FIG.
8(b), a relatively smooth image can be acquired around P2; however,
it becomes a so-called edgy image in the position of P3.
Furthermore, in the case where the upsampling filter method is used
as shown in FIG. 8(c), as a smooth continuous interpolation is
performed, a natural image which does not have any discrepancies as
a whole can be acquired.
[0152] Then, the two-dimensional drawing module 25 (i) performs a
two-dimensional DSC process using the selected coordinate
conversion algorithm and interpolation algorithm, and (ii)
generates display data (S404a, 404b or 404c).
[0153] Next, the two-dimensional drawing module 25 performs a
persistence process of the display data (S405). The persistence
process means performing the weighted addition of the present "B
mode" image data and the past "B mode" image data (IIR filter
process), and has effects to decrease the spike noise which occurs
only in single frame. Thus, an image with the appearance of little
roughness can be acquired.
[0154] However, in the case where the renewal rate of the display
data of the display unit 14 is low, the overlapping movements of
the "B mode" image of the long period can be displayed, causing the
visibility of the subject to deteriorate. Thus, the two-dimensional
drawing module 25 determines the necessity or unnecessity of the
persistence process and the rate of the weighted addition in the
case of performing the persistence process, according to the
renewal rate of the display data of the display unit 14.
[0155] In addition, the two-dimensional drawing module 25 newly
generates a "B mode" image data between the present "B mode" image
data and the past "B mode" image data by using the frame
interpolation (S406). In the case where the renewal rate of the
display data of the display unit 14 is low, the frame interpolation
has effects to prevent the "B mode" image for display from
advancing frame by frame and to make it look smooth. Thus, the
two-dimensional drawing module 25 selects the necessity or
unnecessity of the frame interpolation and determines the number of
the frames to generate by interpolating, in the case of performing
the frame interpolation, according to the renewal rate of the
display data of the display unit 14.
[0156] Here, in the frame persistence process and the frame
interpolating process, as well as the interpolation algorithm, it
can be considered that making a decision according to the renewal
rate of the display data means making a decision according to the
frame rate of the acoustic line data.
[0157] Finally, the two-dimensional drawing module 25 performs a
display color conversion process (S407). The display color
conversion process includes a gamma control interfacing with the
display characteristics of the display which is connected to the
display unit 14, improvement of the contrast of the "B mode" image
and the application of the color map. Then, the two-dimensional
drawing module 25 transmits the display data (B mode image) to the
display unit 14 (S408). Such processes as described above are
repeated while the diagnosis of the present ultrasonic diagnostic
apparatus continues (S401-S409).
[0158] Although the case where the frame interpolation process and
the frame persistence process are performed after the coordinate
conversion process is explained above, such processes can be
performed for acoustic line data before the coordinate conversion
process. Specific explanations will be omitted here.
[0159] Here, in consideration with the communication of the
ultrasonic echo, in order for the ultrasonic echo transmitted from
the probe to reflect within the subject and get received by the
probe, it takes time corresponding to the speed with which the
ultrasonic echo is transmitted within the subject and the depth of
the part where the ultrasonic echo is reflected within the subject.
In other words, per one acoustic line data, it takes time
corresponding to the depth for scanning within the subject.
[0160] And, in order to scan for one frame, it takes as much time
as the number of acoustic line data which forms one frame. The
number of the acoustic line data which forms one frame is decided
by the frame width and the density of the acoustic line data.
[0161] When the above is taken into consideration, the following
steps can be performed according to the depth, width and density in
scanning the subject: selection of the interpolation algorithm
(S403), determining the necessity or unnecessity of the frame
persistence process and the rate of the weighted addition (S405),
and determining the necessity or unnecessity of the frame
interpolating process and the number of the frames to generate
(S406).
[0162] In such procedures as described above, the following
processes can be performed not only individually, but also in
association with each other: selection of the interpolation
algorithm (S403), determining the necessity or unnecessity of the
frame persistence process (S405) and determining the necessity or
unnecessity of the frame interpolating process and the number of
the frames to generate (S406).
[0163] In other words, considering the case where such functions as
described above are all performed by single processor, in the case
where the frame rate of the tomographic image data is extremely
fast, and the renewal rate of the display data must be speeded up,
even if the nearest neighbor interpolating method is selected as
the interpolation algorithm, there might be a case where the
processing performance of the overall control unit 12 is not good
enough in order to perform the frame persistence process and the
frame interpolating process. In such case as described above, the
frame persistence process and the frame interpolating process are
omitted; and the number of the frames to generate in the frame
interpolating process is reduced.
(Color Mode)
[0164] The operations performed by the "live mode" of the "color
mode" are as follows.
[0165] I/O module 21 acquires acoustic line data indicating blood
flow information from the signal processing unit 11, and memorizes
the acoustic line data in the cine memory 23, using the cine memory
control module 22. And, the I/O module 21 performs a grouping of
the acoustic line data forming a frame of a "color mode" image, and
transmits the acoustic line data, per frame, to the two-dimensional
drawing module 25.
[0166] The two-dimensional drawing module 25 is periodically
activated, and performs a two-dimensional DSC process for the
acoustic line data transmitted from the I/O module 21. And, the
two-dimensional drawing module 25 converts the acoustic line data
to display data, and transmits the display data to the display unit
14.
[0167] The two-dimensional DSC process of the "color mode" includes
the following processes: a coordinate conversion process, an
interpolating process, a frame interpolating process, a frame
persistence process and a display color conversion process.
[0168] Finally, the display unit 14 displays the "color mode" image
in the display.
[0169] On the other hand, the operations performed by the "cine
mode" of the "color mode" are as follows.
[0170] The playback module 24 reads out the acoustic line data
indicating the blood flow information which is memorized by the
cine memory 23 in the "live mode", using the cine memory control
module 22. Then, the playback module 24 performs a grouping of the
acoustic line data forming the frame of the "color mode" image, and
transmits the acoustic line data, per frame, to the two-dimensional
drawing module 25.
[0171] The playback module 24 is periodically activated. By making
the activation cycle changeable, the playback speed of the color
mode image can be arbitrarily changed.
[0172] The operations performed by the two-dimensional drawing
module 25 and the display unit 14 are the same as the live mode of
the "color mode".
[0173] Also, in the "color mode", the process of the "B mode" is
simultaneously performed; and in general, the "color mode" image is
displayed overlapping the "B mode" image in the display unit
14.
[0174] Here, as well as the "B mode", the two-dimensional drawing
module 25 can flexibly change the algorithm of the interpolating
process, the operation of the frame interpolating process and the
like, according to (a) the acquisition rate (frame rate) of the
acoustic line data indicating the blood flow information which is
outputted from the signal processing unit 11 and (b) the display
rate with which the two-dimensional drawing module 25 itself
transmits the display data to the display unit 14.
(M Mode)
[0175] The operations performed by the "live mode" of the "M mode"
are as follows.
[0176] I/O module 21 acquires acoustic line data indicating
tomographic image information in the same acoustic line position
from the signal processing unit 11, and memorizes the acoustic line
data in the cine memory 23, using the cine memory control module
22. Then, the I/O module 21 transmits the acoustic line data to the
two-dimensional drawing module 25. The two-dimensional drawing
module 25 holds a fixed area for the acoustic line data of one
picture in the "M mode".
[0177] The two-dimensional drawing module 25 is periodically
activated, and writes the acoustic line data transmitted from the
I/O module 21 in the next area to the previous write-in area within
the holding acoustic line data area. Then, the two-dimensional
drawing module 25 performs a two-dimensional DSC process for the
holding acoustic line data, and converts the acoustic line data to
display data. And, the two-dimensional drawing module 25 transmits
the display data to the display unit 14.
[0178] The two dimensional DSC process of the "M mode" includes the
following processes: a coordinate conversion process, an
interpolating process and a display color conversion process.
Finally, the display unit 14 displays an "M mode" image in the
display.
[0179] On the other hand, the operations performed by the "cine
mode" of the "M mode" are as follows.
[0180] The playback module 24 reads out the acoustic line data
memorized in the "live mode" from the cine memory 23, via the cine
memory control module 22. Then, the playback module 24 transmits
the acoustic line data to the two-dimensional drawing module. The
playback module 24 is periodically activated. By making the
activation cycle changeable, the playback sweep rate of the "M
mode" image can be arbitrarily changed. The operations performed by
the two-dimensional drawing module 25 and the display unit 14 are
the same as the "live mode" of the "M mode".
[0181] Here, as well as the "B mode", the two-dimensional drawing
module 25 can flexibly change the algorithm of the interpolating
process, according to (a) the acquisition rate (sweep rate) of the
acoustic line data in the same acoustic line position which is
outputted from the signal processing unit 11 and (b) the display
rate with which the two-dimensional drawing module 25 itself
transmits the display data to the display unit 14. Thus, the
operations performed by the two-dimensional drawing module 25 in
the "M mode" will be explained in further detail by using a flow
chart.
[0182] FIG. 9 is a flow chart showing a flow of the operations
performed by the two-dimensional drawing module 25 of the "M
mode".
[0183] First, the two-dimensional drawing module 25 periodically
reads the acoustic line data which forms an "M mode" image (S501).
Although it is not shown in FIG.9, in the case where the rate of
the acoustic line data generated by the signal processing unit 11
is slow, that is, the sweep rate of the "M mode" image is slow, as
the time space where the acoustic line data is transmitted becomes
longer, as well as the "B mode", the rate for reading the acoustic
line data can be decreased (the time space can be lengthened).
[0184] Next, the two-dimensional drawing module 25 selects the
"orthogonal-orthogonal conversion process" as the coordinate
conversion algorithm (S502). In the "M mode" the
"orthogonal-orthogonal coordinate conversion" process is always
performed.
[0185] Next, the two-dimensional drawing module 25 selects the
interpolation algorithm of the two-dimensional DSC process,
according to the renewal rate of the display data of the display
unit 14 (S503). As the criteria for selecting the interpolation
algorithm, the processing time in the interpolation algorithm which
is a selection candidate is shorter than the renewal cycle of the
display data, and the CPU occupancy of the overall control unit 12
is considered. The interpolation algorithm of the highest image
quality is selected among the interpolation algorithms which
fulfill such selection conditions as described above.
[0186] As described above, the renewal rate of the display data can
be decided according to the sweep rate of the "M mode" image. Thus,
it can be considered that the interpolation algorithm is selected
according to the sweep rate of the "M mode" image.
[0187] As the interpolation algorithm, there are the nearest
neighbor interpolating method (S504a), a linear interpolating
method (S504b) and an upsampling filter method (S504c). However,
other methods can be used, as well.
[0188] Finally, the two-dimensional drawing module 25 performs a
display color conversion process (S505). The display color
conversion process includes: a gamma control interfacing with the
display characteristics of the display which is connected to the
display unit 14, improvement of the contrast of the "M mode" image
and the application of the color map. After that, the
two-dimensional drawing module 25 transmits the display data (M
mode image) to the display unit 14 (S506).
[0189] Then, in the case where the diagnosis of the "M mode"
continues, such processes as described above are repeated
(S501-S507).
(Color M Mode)
[0190] The operations performed by the "live mode" of the "color M
mode" are as follows.
[0191] I/O module 21 acquires acoustic line data indicating blood
flow information in the same acoustic line position from the signal
processing unit 11, and memorizes the acoustic line data in the
cine memory 23, using the cine memory control module 22. Then, the
I/O module 21 transmits the acoustic line data to the
two-dimensional drawing module 25.
[0192] The two-dimensional drawing module 25 holds a fixed area for
the acoustic line data of one picture in the "color M mode".
[0193] The two-dimensional drawing module 25 is periodically
activated, and writes the acoustic line data transmitted from the
I/O module 21 in the next area to the previous write-in area within
the holding acoustic line data area. Then, the two-dimensional
drawing module 25 performs a two-dimensional DSC process to the
holding acoustic line data, and converts the acoustic line data to
display data. And, the two-dimensional drawing module 25 transmits
the display data to the display unit 14. Here, the two-dimensional
DSC process includes the following series of processes: a
coordinate conversion process, an interpolating process and a
display color conversion process.
[0194] Finally, the display unit 14 displays a "color M mode" image
in the display.
[0195] On the other hand, the operations performed by the "cine
mode" of the "color M mode" are as follows.
[0196] The playback module 24 reads out the acoustic line data
indicating the blood flow information which is memorized by the
cine memory 23 in the "live mode", using the cine memory control
module 22. Then, the playback module 24 transmits the acoustic line
data to the two-dimensional drawing module 25.
[0197] The playback module 24 is periodically activated. By making
the activation cycle changeable, the playback sweep rate of the
"color M mode" can be arbitrarily changed. The operations performed
by the two-dimensional drawing module 25 and the display unit 14
are the same as the "live mode".
[0198] Also, in the "color M mode" the process of such "M mode" as
described above is simultaneously performed; and in general, the
"color M mode" image is displayed overlapping the "M mode" image in
the display unit 14.
[0199] Here, as well as the "M mode", the two-dimensional drawing
module 25 can flexibly change the algorithm of the interpolating
process, according to (a) the acquisition rate (sweep rate) of the
acoustic line data indicating the blood flow information which is
outputted by the signal processing unit 11 and (b) the display rate
with which the two-dimensional drawing module 25 itself transmits
the display data to the display unit 14.
(Doppler Mode)
[0200] The operations performed by the Doppler mode are as
follows.
[0201] I/O module 21 acquires acoustic line data indicating Doppler
spectrum information from the signal processing unit 11, and
memorizes the acoustic line data in the cine memory 23, using the
cine memory control module 22. Then, the I/O module 21 transmits
the acoustic line data to the two-dimensional drawing module
25.
[0202] The two-dimensional drawing module 25 holds a fixed area for
the acoustic line data of one picture in the "Doppler mode".
[0203] The two-dimensional drawing module 25 is periodically
activated, and writes the acoustic line data transmitted from the
I/O module 21 in the next area to the previous write-in area within
the holding acoustic line data area. Then, the two-dimensional
drawing module 25 performs a two-dimensional DSC process for the
holding acoustic line data, and converts the acoustic line data to
a display data. And, the two-dimensional drawing module 25
transmits the display data to the display unit 14.
[0204] The two-dimensional DSC process of the "Doppler mode"
includes the following processes: a coordinate conversion process,
an interpolating process and a display color conversion
process.
[0205] Finally, the display unit 14 displays the "Doppler mode"
image in the display.
[0206] On the other hand, the operations performed by the "cine
mode" of the "Doppler mode" are as follows.
[0207] The playback module 24 reads out the acoustic line data
indicating the Doppler spectrum information which is memorized by
the cine memory 23 in the "live mode", using the cine memory
control module 22. Then, the playback module 24 transmits the
acoustic line data to the two-dimensional drawing module 25.
[0208] The playback module 24 is periodically activated. By making
the activation cycle changeable, the playback sweep rate of the
Doppler mode image can be arbitrarily changed. The operations
performed by the two-dimensional drawing module 25 and the display
unit 14 are the same as the "live mode" of the "Doppler mode".
[0209] Here, as well as the "M mode", the two-dimensional drawing
module 25 can flexibly change the algorithm of the interpolating
process, according to the (a) acquisition rate (sweep rate) of the
acoustic line data indicating the Doppler spectrum information
which is outputted from the signal processing unit 11, and (b) the
display rate with which the two-dimensional drawing module 25
itself transmits the display data to the display unit 14.
[0210] Thus, the functions and operations of the software performed
by the overall control unit 12 in each operational mode are
described as above. There are some functional blocks that are used
in some operational modes, but not in other operational modes.
[0211] For example, in the "live mode" of any operational mode, the
I/O module 21 is used, but the playback module 24 is not used. In
the "cine mode" the I/O module 21 is not used, but the playback
module 24 is used.
[0212] Also, the functional block which performs the frame
persistence process and the frame interpolating process in the
two-dimensional drawing module 25 is used in the "B mode" and the
"color mode", but is not used in the other operational modes.
[0213] As the conventional ultrasonic diagnostic apparatus 100, in
the case where each functional block is implemented separately, the
functional blocks that are not used are wasteful. However, such
plurality of unused functional blocks can be formed to be performed
by a single processor of the overall control unit 12. Then, by
forming a structure where the process of the processor is provided
only to the operating functional blocks, the waste is avoided; and
the processing ability of the overall control unit 12 can be
efficiently utilized.
[0214] Although only the case where each operational mode
individually operates has been described, so far, it is possible to
simultaneously perform a plurality of operational modes by
combining, for example, the "B mode" and the "M mode", and the
"color mode" and the "Doppler mode", and display two or more images
in a row in the display unit 14. In such case as described above,
for example, in the combination of the "B mode" and the "M mode",
generally the display renewal rate of the "M mode" image is more
important than the display renewal rate of the "B mode" image in
terms of the usability of the display.
[0215] Thus, in the case where the processes of the "B mode" and
the "M mode" are performed by a single processor of the overall
control unit 12, the display data of the "B mode" image and the "M
mode" image is generated by the two-dimensional drawing module 25,
and in the case where there is a shortage in the processing ability
of the processor, for example, the process of the "B mode" can be
performed in the double cycle of the process of the "M mode". By
forming such structure as described above, as usable a display as
possible can be achieved within the limit of the processing ability
of the overall control unit 12.
[0216] Finally, the method of the cine memory control module 22 to
reserve the area for the cine memory 23 in the host memory 13 will
be explained.
[0217] In the "B mode", the "M mode" and the "Doppler mode",
respectively, only the acoustic line data of the "B mode", the "M
mode" and the "Doppler mode" is memorized in the cine memory
23.
[0218] On the other hand, in the "color mode" and the "color M
mode", the acoustic line data of both the "B mode" and the "color
mode" or the acoustic line data of both the "M mode" and the "color
M mode" is memorized in the cine memory 23.
[0219] In addition, in the case where a plurality of operational
modes such as the "B mode" and the "M mode" are combined and
performed simultaneously, the acoustic line data of the number of
kinds according to the plurality of operational modes is memorized
in the cine memory 23.
[0220] Thus, depending on the operational mode of the ultrasonic
diagnostic apparatus, the use situation of the cine memory 23
differs. If the overall control unit 12 dynamically reserves the
cine memory 23 in the host memory 13, according to the operational
mode of the ultrasonic diagnostic apparatus, via the cine memory
control module 22, without wasting the memory area which
corresponds to the unused operational mode, all the area of the
host memory 13 which can be used as the cine memory 23 can be
efficiently utilized.
[0221] By forming the ultrasonic diagnostic apparatus with such
structure as described above, in the two-dimensional DSC process,
it is possible to flexibly change the algorithm of the
interpolating process, the frame interpolating process and the
like. And, by efficiently utilizing the resource, the image of high
image quality can be acquired as far as the resource permits.
[0222] Moreover, by dynamically reserving the cine memory area, the
host memory area can be efficiently utilized; and the cost of the
system can be reduced.
Second Embodiment
[0223] While the ultrasonic diagnostic apparatus 10 according to
the first embodiment enables the display of the two-dimensional
tomographic image, the ultrasonic diagnostic apparatus 20 according
to the second embodiment enables the display of the image which
three-dimensionally displays the inner state of the subject. Also,
the structure of the ultrasonic diagnostic apparatus 20 according
to the second embodiment is similar to that of the ultrasonic
diagnostic apparatus 10 according to the first embodiment. Thus,
only the different functional structure will be explained; and the
common functional structure will be omitted here. In addition, as
well as the first embodiment, the function of the backend unit of
the ultrasonic diagnostic apparatus 20 according to the second
embodiment is achieved as a software performed by the overall
control unit 32 (refer to FIG. 10 described below).
[0224] FIG. 10 is a block diagram showing a structure of the
software function performed by the overall control unit 32
according to the second embodiment. As shown in FIG. 10, the
backend unit includes: I/O module 51, the cine memory control
module 52, the cine memory 53, the three-dimensional processing
module 54 and the two-dimensional drawing module 55.
[0225] Next, the functions and operations of the software performed
by the overall control unit 32 according to the second embodiment
will be explained for each operational mode of the ultrasonic
diagnostic apparatus 20.
(3D Live Mode)
[0226] I/O module 51 acquires acoustic line data from the signal
processing unit 11, and memorizes the acoustic line data in the
cine memory 53, via the cine memory control module 52. Then, the
I/O module 51 performs a grouping of the acoustic line data which
forms a frame of the tomographic image, and transmits the acoustic
line data, per frame, to the two-dimensional drawing module 55.
[0227] Also, when the acquisition of a tomographic image data group
which forms a volume is completed, the three-dimensional processing
module 54 performs a three-dimensional DSC process (such as a
coordinate conversion process and an interpolating process) for the
acoustic line data forming the volume, and converts the acoustic
line data to a volume data. Then, the three-dimensional processing
module 54 generates three-dimensional image data (image data
describing a volume) by performing a volume rendering process for
volume data, and transmits the three-dimensional image data to the
two-dimensional drawing module 55.
[0228] Also, the volume data generated by the three dimensional DSC
process is memorized in the cine memory 53, via the cine memory
control module 52; and the last piece of the volume data is held
for using in the "MPR mode".
[0229] The two-dimensional drawing module 55 is periodically
activated, and performs a two-dimensional DSC process for the
acoustic line data of the tomographic image frame or the
three-dimensional image data generated by the three-dimensional
processing module 54. And, the two-dimensional drawing module 55
converts the above mentioned acoustic line data and
three-dimensional image data to display data, and transmits the
display data to the display unit 14.
[0230] The two-dimensional DSC process of the "3D live mode"
includes: a coordinate conversion process, an interpolating
process, a frame interpolating process, a frame persistence process
and a display color conversion process.
[0231] Finally, the display unit 14 displays the tomographic image
and the three-dimensional image data in the display.
[0232] Also, the cine memory control module 52 reserves a cine
memory amount corresponding to an operational mode on the host
memory 13, and performs an input/output operation for the reserved
cine memory 53.
[0233] Here, as described above, the operations performed by the
three-dimensional processing module 54 must be able to flexibly
change, according to (a) the acquisition rate (volume rate) of the
acoustic line data forming the volume which is outputted from the
signal processing unit 11 and (b) the acquisition amount (data size
forming the volume).
[0234] The operations performed by the three-dimensional processing
module 54 will be explained in further detail using a flow chart as
following. FIG. 11 is a flow chart showing the operational flow
performed by the three-dimensional processing module 54 in the "3D
live mode".
[0235] First, when the acquisition of a tomographic image data
group which forms a volume is completed by the I/O module (S601),
the three-dimensional processing module 54 selects a coordinate
conversion algorithm and decides the volume size (S602). For
example, in the case of a 3D probe that mechanically sways a sector
convex type probe, a "polar-orthogonal coordinate conversion
process" is selected. In the case of a 2D phased array type 3D
probe, an "orthogonal-orthogonal coordinate conversion process" is
selected.
[0236] Next, the three-dimensional processing module 54 selects the
interpolation algorithm of the three-dimensional DSC process,
according to the data size that forms the volume rate and the
volume (S603). As the criteria for selecting the interpolation
algorithm, the processing time of the interpolation algorithm which
is a selection candidate is shorter than the volume acquisition
cycle of the signal processing unit 11, and the CPU occupancy of
the overall control unit 32 is considered. Then, the interpolation
algorithm of the highest image quality is selected among the
interpolation algorithms which fulfill such selection conditions as
described above. As the interpolation algorithm, there are the
nearest neighbor interpolating method, a linear interpolating
method and an upsampling filter method. However, other
interpolating methods can be used, as well.
[0237] Then, by using the selected and determined coordinate
conversion algorithm, volume size and interpolation algorithm, the
three-dimensional DSC process is performed and the volume data is
generated (S604a, S604b or S604c).
[0238] Next, the three-dimensional processing module 54 decides the
sample pitch of the volume rendering, according to the volume rate
and the volume size (S605). The sample pitch is closely related to
the rendering processing time and the image quality. By making the
sample pitch big, the processing time can be shortened, but the
image quality is deteriorated.
[0239] As the criteria for selecting the sample pitch, the
rendering processing time in the sample pitch that is a selection
candidate is shorter than the volume acquisition cycle of the
signal processing unit 11, and the CPU occupancy of the overall
control unit 32 is considered. The smallest value is selected among
the sample pitches that fulfill such selection conditions as
described above.
[0240] Next, the three-dimensional processing module 54 selects the
interpolation algorithm of the sample value of the volume
rendering, according to the volume rate and the volume size (S606).
The selection of the interpolation algorithm is the same as the
three-dimensional DSC process, thus the explanation will be omitted
here.
[0241] Next, the rendering algorithm is decided by the 3D display
mode (S607). As the rendering algorithm, there are a ray casting
rendering method and a Maximum/Minimum Intensity Projection (MIP)
rendering method. However, the rendering algorithm is not limited
to such methods as described above, and other rendering methods can
be used.
[0242] Here, the three-dimensional processing module 54 changes the
operation of the algorithm, according to the volume rate and volume
size. For example, in the volume rendering, as a technique to
improve the quality of the three-dimensional image to be generated,
there are a diffuse reflection shading and a depth shading.
However, if such shadings as described above are applied, the
burden of the process increases. Thus, the three-dimensional
processing module 54 makes the rendering processing time shorter
than the volume acquisition cycle of the signal processing unit 11,
and considers the CPU occupancy of the overall control unit 32.
And, the three-dimensional processing module 54 selects the
applicable technique within these restrictions.
[0243] Next, the three-dimensional processing module 54 performs
the volume rendering by the sample pitch, the interpolation
algorithm and the rendering algorithm selected and determined as
described above, and generates three-dimensional image data
(S608).
[0244] Finally, the three-dimensional processing module 54
transmits the generated three-dimensional image data to the
two-dimensional drawing module 55 (S609). Thus, while the diagnosis
by the "3D live mode" continues, such processes as described above
are repeated (S601-S610).
[0245] Also, as the two-dimensional DSC process and the
three-dimensional DSC process include many common processes, the
modules can be shared. Such mutual modules can be easily
implemented because of the flexibility of the software. And, the
waste that the equal functional blocks are redundantly implemented
can be avoided.
[0246] Moreover, a structure that generates and displays a
cross-sectional image, instead of a three-dimensional image, by
slicing volume data by a predetermined plate can be used, as well.
In this case, the sample pitch and the interpolation algorithm of
the sample value for generating a cross-sectional image can be
decided, according to the volume rate, as well. However, the
specific explanations will be omitted here.
[0247] Here, in consideration with the communication of the
ultrasonic echo via the probe, in order to scan single frame data
forming a part of volume, as described in the first embodiment, it
takes time corresponding to the depth, width and density in
scanning the subject. Then, in the case of the 3D probe
mechanically swaying the sector convex type probe, the time the
probe takes for single sway is decided by the swaying degree and
the swaying rate. And, scanning of frames continues during the time
the probe takes for single sway. Thus, the frame data group is made
by such scanning of frames for forming a volume.
[0248] When the above is taken into consideration, it is possible
that the acquisition rate (volume rate) and the acquisition amount
(data size for forming a volume) of the acoustic line data forming
a volume that is outputted from the signal processing unit 11
depend on (i) the depth, width and density in scanning the subject,
(ii) the swaying degree of the probe and (iii) the swaying rate of
the probe. Moreover, it can be considered that the following steps
depend on (i) the depth, width and density in scanning the subject,
(ii) the swaying degree of the probe and (iii) the swaying rate of
the probe: selection of the interpolation algorithm for the
three-dimensional DSC process (S603), determining the sample pitch
for the volume rendering (S605), selection of the interpolation
algorithm (S606) and selection of the rendering algorithm
(S607).
(Multi Planner Reconstruction (MPR) Mode)
[0249] In the case of transiting to the "MPR mode", the cine memory
53 holds the volume data generated in the "3D live mode".
[0250] The three-dimensional processing module 54 is performed in
the case where the three-dimensional image and the cross-sectional
image need to be renewed such as the case where the mode is
transited to the "MPR mode", and the radial direction for observing
the volume data and the cut surface are changed by a user's
operation.
[0251] First, the three-dimensional processing module 54 reads
volume data from the cine memory 53, via the cine memory control
module 52, and generates three-dimensional image data
(two-dimensional image data describing a volume) and a
cross-sectional image by the volume rendering process. And, the
three-dimensional processing module 54 transmits them to the
two-dimensional drawing module 55.
[0252] Also, the two-dimensional drawing module 55 is periodically
activated, and performs a two-dimensional DSC process for the
three-dimensional image data or the cross-sectional image data.
And, the two-dimensional drawing module 55 converts them to display
data, and transmits the display data to the display unit 14.
[0253] Finally, the display unit 14 displays the three-dimensional
image data and the cross-sectional image data in the display.
[0254] In the "MPR mode", either of the image quality of the
three-dimensional image and the cross-sectional image or the
renewal response is prioritized. And, the sample pitch for the
volume rendering and generating the cross-sectional image is
determined. Then, the interpolation algorithm of the sample value
is selected; and the rendering algorithm is changed.
[0255] Finally, the method of the cine memory control module 52 to
reserve the area for the cine memory 53 in the host memory 13 will
be explained.
[0256] In the "3D live mode", the cine memory 53 is reserved and
controlled by dividing into the area for memorizing the acoustic
line data of the tomographic image information and the area for
holding the volume data. On the other hand, in the "MPR mode", the
cine memory 53 is reserved and controlled by dividing into the area
for holding the volume data and the work area used for cutting off
a part of volume data. Thus, the cine memory control module 52
performs the optimum memory control according to the operational
mode.
[0257] As described above, by using the ultrasonic diagnostic
apparatus according to the second embodiment, (a) the algorithm of
the interpolating process in the three-dimensional DSC process and
(b) the algorithm of the rendering and the interpolating process in
the volume rendering can be flexibly changed. Therefore, the image
of as a high picture quality as the resource permits can be
acquired by efficiently utilizing the resource.
[0258] As well as the first embodiment, by dynamically reserving
the cine memory area, the host memory area can be efficiently
utilized. Thus, the cost of the system can be reduced.
[0259] Although in both the first and second embodiments, as the
most suitable structure where the present invention exhibits its
effects, the structure which implements each function of the
backend unit 15 as a software operated by the overall control unit
12 is described, the present invention is not limited to such
structure as described above.
[0260] For example, in the case where the two-dimensional DSC
processing unit is implemented by a hardware, the through-put of
the process may be different, due to the difference of the
interpolation algorithm, depending on the implementation. In this
case, the present invention can be applied.
[0261] Although only some exemplary embodiments of this invention
have been described in detail above, those skilled in the art will
readily appreciate that many modifications are possible in the
exemplary embodiments without materially departing from the novel
teachings and advantages of this invention. Accordingly, all such
modifications are intended to be included within the scope of this
invention.
INDUSTRIAL APPLICABILITY
[0262] The ultrasonic diagnostic apparatus and the method according
to the present invention are beneficial as the ultrasonic
diagnostic apparatus and the like capable of flexibly and easily
dealing with the diversification of the function of the backend
unit of the ultrasonic diagnostic apparatus. Also, such ultrasonic
diagnostic apparatus and method as described above are suitable for
the ultrasonic diagnostic apparatus and the like capable of
inspecting not only human bodies but also animals and goods without
any invasion and destruction.
* * * * *