This invention is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2007-328919, filed on Dec. 20, 2007, the entire contents of which are incorporated herein by reference.
(1) Field of the Invention
This invention relates to an ultrasonic diagnostic apparatus and an ultrasonic image display apparatus. More particularly, the present invention relates to an ultrasonic diagnostic apparatus and an ultrasonic stress image acquisition method to be used for processing the strain of a heart or some other organ according to the ultrasonic reception signal acquired from a subject of examination.
(2) Description of the Related Art
An ultrasonic diagnostic apparatus is for acquiring an image of the interior of the body of a subject to be physically examined by irradiating an ultrasonic wave onto the subject from an ultrasonic oscillator and receiving and electrically processing the reflected wave. Such an apparatus is operated typically for diagnosing a living organ in terms of profile and function.
Stress echo techniques of putting a load of exercise or drug on a subject to be physically examined, collecting ultrasonic image data of the subject in the loaded state by exercise or drug and evaluating the mobility of the myocardium are being popularly employed for diagnosing the function of the heart of a subject (refer to, e.g., Jpn. Pat. Appln. Laid-Open Publication No. 2007-135994).
When a stress echo technique is employed for examining the heart of a subject, data on the heart need to be collected for a plurality of times from so many predetermined positions on predefined conditions. The image data acquired from each of the positions are referred to as a view (of the shot site). If a load of exercise is put on the heart of the subject, the heart is checked for its condition when the heart is at rest before the exercise, or in a pre-exercise phase, when the heart is bearing the load of the exercise, or in an intra-exercise phase, and when the heart is at rest once again after the exercise, or in a post-exercise phase. In a stress echo examination, data on each view are acquired in each phase. Conventionally, the conditions on which a predetermined view is acquired (strain processing conditions) in a phase are redefined each time after acquiring a view.
On the other hand, tissue strain imaging (TSI) techniques of mapping and displaying pieces of information acquired on the contraction in the direction of the long axis and on the stretch in the direction of the thickness of the heart during a cardiac contraction phase are being employed (refer to, e.g., Jpn. Pat. Appln. Laid-Open Publication No. 2007-044499). Image processing using a TSI technique is normally conducted after acquiring data from the subject. While there is a temporal margin from the time when data are acquired to the time when a TSI image is obtained, a strain processing image needs to be obtained within a short period of time when a real time TSI technique is employed for obtaining an image on the spot.
However, there arises a problem that it takes a relatively long time to obtain TSI image data when strain processing conditions are redefined each time after acquiring a view and more particularly when a TSI image needs to be obtained on a real time basis.
In view of the above-identified problem that strain processing conditions needs to be redefined each time when acquiring strain image data so that it takes a long time before obtaining a strain image, it is therefore the object of the present invention to provide an ultrasonic diagnostic apparatus and an ultrasonic stress image acquisition method that can quickly acquire a stress image subjected to a TSI imaging process (tissue strain imaging process).
In an aspect of the present invention, the above object is achieved by providing an ultrasonic diagnostic apparatus including: a condition defining/stress data acquiring section for defining predetermined strain processing conditions, radiating an ultrasonic wave to a tissue of a subject to be examined and acquiring stress image data according to the reception signal obtained from the reflected ultrasonic wave in the state of the tissue before bearing a load put thereon; a processing condition storing/defining section for storing the strain processing condition; an automatically defining/stress data acquiring section for automatically defining the strain processing condition stored in the processing condition storing/defining section and acquiring stress image data on the tissue in a loaded state of the tissue after bearing a load put thereon; a tissue strain data acquiring section for executing a tissue strain imaging process on the stress image data and acquiring tissue strain image data; and an image display section for displaying a stress image according to the tissue strain data.
Thus, according to the present invention, there are provided an ultrasonic diagnostic apparatus and an ultrasonic stress image acquisition method that can quickly acquire a stress image subjected to a TSI image process (tissue strain imaging process).
Now, the present invention will be described in greater detail by referring to the accompanying drawings that schematically illustrate preferred embodiments of the invention. Firstly, a case where four views of different sites of a tissue to be examined are obtained by shooting them in four phases before and after a load of exercise is put on the tissue will be described. In this case, four views, or Views 1 through 4, are obtained in each of the four phases, or Phases 1 through 4 as shown in
When, for example, a definition of an angle is a strain processing condition, it means that the views are obtained from different respective angles. While an angle may be automatically defined for each view as a strain processing condition, the operator can correct the angle.
When an ultrasonic diagnostic apparatus is operated by means of a stress echo method, predetermined strain processing conditions are defined and an ultrasonic wave is transmitted. Then, stress image data are obtained from the reflected ultrasonic wave and processed by way of a TSI image process (tissue strain image process) to obtain tissue strain image data. Thus, a stress image is obtained for each view.
The first embodiment automatically defines strain processing conditions input for each of the views in Phase 1 when corresponding views are obtained in each of Phases 1 through 4. The strain processing conditions of this embodiment include an angle, the pitch between two strain points and a color map.
As an angle is defined, the center for correcting the angle for a short axis image of a heart, for instance, is defined. The pitch between two strain points for a short axis image differs from the pitch between two strain points for a short axis image.
The expression that a color map is a strain condition means that the moving distance of each site showing an upper limit value or a lower limit value of strain values 0 to +60 or −20 to 0 for each view in a same phase is indicated by a color. With such an arrangement, how each site bears a load can be recognized easily. The range to be indicated by a same color is unequivocally defined.
Now, the operation of the embodiment of ultrasonic diagnostic apparatus will be described below by referring to the drawings particularly in terms of the operation of defining strain processing conditions when four views are obtained in each of the phases and a tissue (the heart) of the subject is made to bear a load of exercise.
Firstly, the four views of the heart will be described specifically. For example, View 1 is a cross sectional view of the heart taken along the long axis of the heart as shown in
If the strain processing conditions include the pitch between two strain points, the pitch refers to the distance D1 between Point 51 and Point 52 in
Referring now to
The strain processing conditions vary from view to view, although they remain substantially same in each phase. More specifically, the strain processing conditions of the stress image data P2V1, those of the stress image data P3V1 and those of the stress image data P4V1 are substantially same as those of the stress image data P1V1. So are the strain processing conditions of the stress image data in each of the other phases. Phases 1 through 4 typically refer to a phase immediately before a load of strain is put on the heart yet (and the heart is at rest), a phase in which the load of strain is being put on the heart, a phase in which the load of strain is moved away and a phase that comes when a predetermined period of time has passed since the time when the load of strain was moved away.
Now, referring to the flowchart of
While the strain processing conditions remain substantially same for a same view as pointed out above, the operator is prompted to input a command from the input section 26 for automatically defining the strain processing conditions obtained for View 1 in Phase 1 also for Phase 2, Phase 3 and Phase 4 or not. Then, the specified program is stored in the strain processing conditions storing/defining section 18. Assume here that the strain processing conditions for P1V1 through P1V4 are also automatically input and defined for P2V1 through P2V4, P3V1 through P3V4 and P4V1 through P4V4 in the following description of this embodiment.
When acquiring data for each view in Phase 1, the strain processing conditions used for the immediately preceding image are stored in the strain processing conditions storing/defining section 18 as effective conditions.
More specifically, Phase 1 is specified as i=1 in Step S202 and if View 1 is specified as j=1 in Step S203. Then, it is checked in Step S203 if i is greater than 1 or not. The process proceeds to Step S205 to store the strain processing conditions on which the stress image data for P1V1 are acquired in the strain processing conditions storing/defining section 18 because i=1.
Then, in Step S207, the strain image data for P1V1 are acquired and stored in the stress image data memory section 20.
Then, in Step S208, j=i+1 is defined and, in Step S209, it is checked if j becomes greater than 4 or not. If j is not greater than 4, the process proceeds to Step S204, where it is checked if i is greater than 1 or not. As long as i is not greater than 1, the strain processing conditions for acquiring stress image data are stored in the strain processing conditions storing/defining section 18 for each of Views 1 through 4 in Phase 1 (P1V1 through P1V4 in
If it is determined in Step S209 that j is greater than 4, the process moves to Step S210, where i is turned to i+1. In the next step, or Step S211, it is checked if i is greater than 4 or not. If i is equal to 2, the process returns from Step S211 to Step S203, where j=1 is defined. In the next step, or Step S204, it is checked if i is greater than 1 or not. Since i is greater than 1 now, the process moves to Step S206, where it is determined if strain processing conditions are automatically defined for the current i according to the strain processing conditions stored in Phase 1 or not.
If it is determined in Step S206 that strain processing conditions are automatically defined according to the strain processing conditions stored in Phase 1, they are then automatically defined and stress image data are acquired in Step S207.
If, on the other hand, it is determined in Step S206 that strain processing conditions are not automatically defined, the process returns to Step S205, where the current strain processing conditions are automatically stored, and then stress image data are acquired in Step S207.
Data for Views 1 through 4, or stress image data for P2V1 through P2V4 shown in
In this way, stress image data are acquired for each of the views in Phase 2 and the process proceeds from Step S209 to Step S210, where i is turned to 3. Then, the process returns from the next step, or Step S211, to Step S203 because i is now equal to 3. In Phase 3, the strain processing conditions of the views in Phase 1 are automatically defined as in Phase 2. In other words, the process proceeds from Step S206 to Step S207, where stress image data that correspond to all the views in Phase 3 (P3V1 through P3V4) are acquired.
As the data for all the views in Phase 3 are acquired, i is turned to 4 in Step S210 and the process returns from the next step, or Step S211, to Step S203 once again.
In Phase 4, the process proceeds through Steps S204, S206, S207, S208 and S209. Strain processing conditions are automatically defined in Step S206 as in Phase 1 and view data (stress image data) for P4V1, P4V2, P4V3 and P4V4 are acquired in Step S207.
In this way, stress image data P1V1 through P1V4, P2V1 through P2V4, P3V1 through P3V4 and P4V1 through P4V4 that correspond to the respective views listed in
In the next step, of Step S212, tissue strain image data are acquired from the sixteen stress image data by the TSI image processing section 22 shown in
Thus, with this embodiment, the heart is at rest in Phase 1 so that the operator can take time for defining conditions.
Now, the second embodiment will be described below by referring to
The strain processing conditions of this embodiment typically include A (angle) and B (color map). While A (angle) is automatically defined just like B, it needs to be corrected sometime later.
The process of this embodiment also proceeds basically according to the flowchart shown in
The operator inputs a program for automatically defining strain processing conditions from the input section 26 in Step S201 shown in
Thus, strain processing conditions (A: angle, B: color map) of each of the views are stored in Phase 1. In Phase 2, the strain processing conditions of each of the views in the immediately preceding phase, or Phase 1, are automatically defined for the corresponding view in Phase 2 and the strain processing condition B is stored. For example, A (angle) and B (color map) of View 1 in Phase 1 are automatically defined as the strain processing conditions of P2V1 and the strain processing condition B that is used for acquiring the P2V1 data is stored.
In Phase 3, the strain processing conditions of each of the views in Phase 1 are automatically defined for the corresponding view in Phase 3 but the strain processing conditions for the corresponding view in Phase 3 are not stored. For example, only A (angle) and B (color map) of View 1 in Phase 1 are automatically defined as the strain processing conditions of P3V1 but the strain processing conditions that are used for acquiring P3V1 data are not stored.
In Phase 4, the strain processing condition A of each of the views in Phase 1 and the strain processing condition B of each of the views in Phase 2 are automatically defined for the corresponding view in Phase 3 but the strain processing conditions for the corresponding view in Phase 4 are not stored. For example, A of View 1 in Phase 1 and B of View 1 in Phase 2 are automatically defined as the strain processing conditions of P4V1.
Now, the processing operations after Step S202 in
If it is determined in Step S209 that i is equal to 1 (Phase 1) and j is greater than 4, i is turned to 2 in Step S210 and the process returns from Step S211 to Step S203 and then proceeds to the processing operations in Phase 2. The process moves from Step S204 to Step S206 and the strain processing conditions A and B for the corresponding view in Phase 1 are automatically defined for the current view in Phase 2. Although not shown in
Subsequently, stress image data for Views P2V1 through P2V4 are acquired in Step S207.
In Phase 3, the strain processing conditions A and B of the corresponding view are automatically defined as the strain processing conditions A and B of the current view. However, the strain processing conditions A and B of the current view in Phase 3 are not stored. Stress image data of each of the views (P3V1 through P3V4) in Phase 3 are acquired in Step S207.
As i is turned to 4 in Step S210 and the process returns from Step S211 to Step S203, j is defined as 1 in Step S203 and the strain processing conditions corresponding to P4V1 are defined and stress image data are acquired for the view.
In Phase 4, the strain processing condition A in Phase 1 is also defined as the strain processing condition A in Phase 4 but the strain processing condition B in Phase 2 is defined as the strain processing condition B in Phase 4. The strain processing conditions A and B of the current view in Phase 4 are not stored.
For example, if i=4 and j=1, the process moves from Step S204 to Step S206, where it is determined that strain processing conditions are to be automatically defined or not. (1) A and (5) B are automatically defined for P4V1 as shown in
In Phase 4, strain processing conditions are automatically defined for each of the views in Step S206 and stress image data are acquired in Step S207 and stored in the stress image data memory section 20 for the view. After the stress image data of P4V1 through P4V4 are acquired and stored, the process moves to Step S212, where the TSI image processing section 22 executes a TSI image process on those data and the corresponding images are displayed on the display section 24 in Step S213.
Note that the strain processing condition A (angle) of each of the views in Phase 1 is automatically defined as the strain processing condition of each of the views in Phase 4 while the strain processing condition B (color map) of each of the views in Phase 2 is defined as the strain processing condition of each of the views in Phase 4.
With this embodiment, Phase 2 and on are those in which the tissue bears a load and the diagnosis needs to be given within a limited period of time. However, the time necessary for the definitions can be made very short to a great advantage for a diagnosis.
While the tissue to be examined is the heart of the subject in the above description of the embodiments, the present invention can be applied to any other tissue. While the embodiments are described above in terms of an instance of putting a load of exercise on the heart of the subject of physical examination, the present invention can also be applied to instance of putting a load of drug of the heart of the subject of physical examination.
While the strain processing conditions include an angle, the pitch between two strain points and a color map or an angle or a color map in each of the above-described embodiments, strain processing conditions are by no means limited thereto.
While stress image data are acquired in four phases and four views are acquired in each of the phases in the above-described embodiments, the present invention is by no means limited thereto and some other number of phases and/or some other number of views may be selected for the purpose of the present invention.
The present invention is by no means limited to the above-described embodiments particularly in terms of storing strain processing conditions, automatically defining strain processing conditions and selecting parameters and some other arrangement may be appropriately selected for the purpose of the present invention.
Obviously, many modifications and variations of this invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims, this invention may be practiced otherwise than as specification.
Number | Date | Country | Kind |
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2007-328919 | Dec 2007 | JP | national |