System and method for image improvement using electrocardiogram synchronization for multiple moving pulsed X-ray source tomosynthesis devices

Abstract

The present invention discloses a system and method for improving image acquisition of multiple motion pulse X-ray source tomosynthesis imaging devices by generating ECG waveform data using an electrocardiogram (ECG) device. Once a representative cardiac cycle is determined, the system will acquire images only during the resting period of the heartbeat. The real-time ECG waveform is used as ECG synchronization for image improvement. The imaging device avoids ECG peak pulses to better image the chest, lungs and breasts under the influence of the cyclical motion of the heart. Therefore, smoother data acquisition and much higher data quality can be achieved. The multiple motion pulse X-ray source tomosynthesis machine has distributed multiple X-ray sources across a wide scanning angle. During the resting period of a heartbeat, multiple X-ray exposures are acquired from the X-ray source at different angles. The machine itself has the ability to acquire up to 60 actual projection images in about two seconds.

Description

[0001] This application claims the priority of the following applications: Provisional Application Serial No. 63182426 filed on April 30, 2021; Provisional Application Serial No. 63226508 filed on July 28, 2021; Provisional Application Serial No. 63170288 filed on April 2, 2021, Provisional Application Serial No. 63175952 filed on April 16, 2021, Provisional Application Serial No. 63194071 filed on May 27, 2021; Provisional Application Serial No. 63188919 filed on May 14, 2021; Provisional Application Serial No. 63225194 filed on July 23, 2021; Provisional Application Serial No. 63226508 filed on July 28, 2021; Provisional Application Serial No. 63170288 filed on April 2, 2021, Provisional Application Serial No. 63175952 filed on April 16, 2021, Provisional Application Serial No. 63194071 filed on May 27, 2021 Provisional application serial number 63209498 filed on June 11; provisional application serial number 63214913 filed on June 25, 2021; provisional application serial number 63220924 filed on July 12, 2021; provisional application serial number 63222847 filed on July 16, 2021; provisional application serial number 63224521 filed on July 22, 2021; and U.S. application serial number 17149133 filed on January 24, 2021, which U.S. application subsequently claims priority to provisional serial number 62967325 filed on January 29, 2020, and the contents of the above applications are incorporated by reference. Technical Field

[0002] The present invention relates to a system and method for a multiple motion pulsed X-ray source tomosynthesis imaging device for acquiring images of the lungs affected by a periodically moving heart. Background Art

[0003] Digital tomosynthesis systems typically use an X-ray source mounted at one end of a rotatable arm assembly and a digital X-ray flat panel detector mounted at the other end. Tomosynthesis can be used to screen for early signs of breast cancer in women and lung cancer in asymptomatic ordinary people. When performing tomosynthesis, the X-ray source will need to move in an arc around the breast or lungs. While the X-ray source moves around the breast or lungs, a series of low-dose X-ray images are acquired at different angles. The collected data set allows reconstruction of parallel planes. Each plane is clearly visible, and those out-of-plane tissue images are blurred. Generally, wider sweep angles will generate more data projections and result in better 3D resolution, but it takes longer. Data processing is manufacturer-specific because different reconstruction algorithms may be used. However, due to the periodically moving heart, the heartbeat significantly affects the quality of X-ray imaging data used for lung imaging. Therefore, when the object moves, if an X-ray image exposure is being performed, a blurred image is inevitable. However, conventional systems have only a single X-ray source when the heart is at rest, which has limited coverage and slow speed. A single X-ray source can only be in a certain position at a certain angle when the heart is at rest. Furthermore, if such a single source system accelerates data acquisition, data may be lost at certain angles, and reconstruction may suffer from motion artifacts and / or limited viewing angle artifacts. There is prior art in the use of gated ECG synchronization for cardiac related imaging with computed tomography (CT), such as the prior art in US20040077941A1. Summary of the invention

[0004] In a first aspect, a method for performing multiple motion pulse source tomosynthesis imaging includes: using an electrocardiogram (ECG) sensor to capture an ECG waveform; evaluating the ECG waveform to verify a signal from the ECG sensor; using the ECG waveform as a basis for triggering multiple X-ray tomosynthesis sources; and scanning an object using multiple pulse sources of a tomosynthesis imaging device triggered by the ECG waveform.

[0005] In a second aspect, an imaging system includes: an ECG sensor for generating an ECG waveform from an object; a tomosynthesis imaging device with multiple pulsed X-ray sources; and a processor coupled to the ECG sensor and the imaging device to perform tomosynthesis imaging by: using the ECG sensor to capture the ECG waveform; evaluating the ECG waveform to verify the signal from the ECG sensor; using the ECG waveform as a basis for triggering one or more X-ray sources; and scanning the object using a multiple motion pulse source tomosynthesis imaging system triggered by the ECG waveform.

[0006] On the other hand, a system and method for improving image acquisition of multiple motion pulse X-ray source tomosynthesis imaging devices use an electrocardiogram device to generate ECG waveform data. Once a representative cardiac cycle is determined, the system will only acquire images during the resting period of the heartbeat. The real-time ECG waveform is used as ECG synchronization for image improvement. The multi-source imaging device avoids ECG peak pulses to better image the lungs under the influence of the periodic motion of the heart. Therefore, smoother data acquisition and much higher data quality can be achieved. Multi-source tomosynthesis machines have been distributed to multiple X-ray sources across a wide angle. During the resting period of a heartbeat, X-ray exposure comes from the X-ray source from different angles. Depending on the strength of the motor, for multiple motion pulse X-ray source tomosynthesis imaging devices, up to 60 projections of the actual image acquisition process can usually be completed in as fast as two seconds. Adding restrictions on the resting period of the heartbeat improves image quality, but it also slightly slows down image acquisition.

[0007] The advantages of the system may include one or more of the following. The first advantage is that the exposure from multiple pulsed X-ray sources spans a large angle when the heart is at rest. The second advantage is that the motion source position is programmable, so data is not lost. The third advantage is that the multiple motion sources can run much faster. Other advantages may occur when multiple motion pulsed X-ray source tomosynthesis imaging devices can quickly capture images with improved resolution when synchronized with ECG signals. Therefore, real-time imaging and 4D imaging can also be performed at multiple motion pulsed X-ray source tomosynthesis imaging devices. It has a much lower dose than that in CT. When the heart rate is low, the interval between heartbeats is almost constant, and each mechanical contraction of the heart is almost the same (for example, sinus rhythm in the case of a heart rate of less than 65 times), and the heart image taken in any way will have high diagnostic quality. The system provides high-resolution images when synchronized with the ECG signal (such as when the heart rate changes suddenly and intermittently due to arrhythmia) to obtain tomosynthesis imaging data while the heart is in a certain position that is essentially spatially stationary. One embodiment uses prospective gating, in which the ECG signal is used to trigger data acquisition by the detector array at a point in time when the heart is fairly still (typically during diastole), so that the radiographs used to reconstruct the image correspond to a time when the heart is fairly still. The imaging window is typically centered between about 60% and about 80% of the duration of a representative cardiac cycle (phase). Different window widths and phases, including multiple phases, may be selected based on the selection of the scanning protocol.

[0008] The resulting system is ideal for X-ray lung or breast imaging. The lung has regions with rest and moving phases, where the rest phases of different regions follow at different points in time. The method and tomosynthesis imaging device are of the type in which multiple X-ray sources are moved around the lung. The system obtains multiple projections during a limited sweep angle of the X-ray source around the object to be examined. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A timing diagram of X-ray exposure and motor speed over one cardiac cycle for a multiple motion pulse source tomosynthesis imaging system is shown.

[0010] Figure 2 A multiple moving pulsed X-ray source tomosynthesis imaging system is shown.

[0011] Figure 3 The angular span of a multiple moving pulsed X-ray source tomosynthesis imaging system during a cardiac cycle is shown. DETAILED DESCRIPTION

[0012] The present invention will be described in detail by way of example with reference to the accompanying drawings in the following paragraphs. Throughout the description, the preferred embodiments and examples shown should be considered as exemplary rather than limiting the present invention. As used herein, "the present invention" refers to any one of the embodiments of the present invention described herein and any equivalents. In addition, references to various features of the "present invention" throughout the document do not mean that all claimed embodiments or methods must include the referenced features.

[0013] Therefore, for example, it will be appreciated by those skilled in the art that diagrams, schematic diagrams, diagrams, etc. represent conceptual views or processes that embody the system and method of the present invention. The functions of the various elements shown in the figure can be provided by using dedicated hardware and hardware capable of executing related software. Similarly, any switch shown in the figure is only conceptual. Their functions can be performed by the operation of program logic, by dedicated logic, by the interaction of program control and dedicated logic, or even manually, and specific techniques can be selected by the entity that realizes the present invention. It is also understood by those skilled in the art that the exemplary hardware, software, process, method and / or operating system described herein are for illustrative purposes, and are therefore not intended to be limited to any specific designated manufacturer.

[0014] Figure 1An X-ray imaging system timing diagram with a typical ECG diagram is shown, which illustrates a typical cardiac cycle for an ECG signal waveform, including the cardiac contraction phase (also known as cardiac systole) and the cardiac relaxation phase (also known as cardiac diastole) of the heart. The portions of the ECG signal marked as P, R, and T are called P waves, R waves, and T waves, which are usually the most prominent and highest amplitude features of the entire ECG signal. The cardiac cycle is usually defined as starting with a P wave and continuing until the next P wave appears. The R to R interval (also known as the "RR interval") is defined as starting with an R wave and continuing until the next R wave appears. The graphical representation of the ECG signal includes a T wave and a P wave. Analyzing the ECG signal relative to the T wave and the P wave allows more accurate phase information to be associated with the projection data when the heart rate changes. Multiple motion pulsed X-ray source tomosynthesis imaging systems can be programmed in a way that X-ray exposure occurs only during cardiac rest.

[0015] The X-ray source 6 is passed around the patient or object, thus generating multiple pulse exposures. In a preferred embodiment, the X-ray source 6 moves a total of about 4 to 5 inches from its original position after each exposure. In addition, the X-ray source 6 can also be programmed to be in any position. In a preferred embodiment, in order to ensure that all heart motion is accounted for and has been accounted for, all ECG heart beats need to be considered as a sequence of data points.

[0016] A cardiac cycle or a heartbeat is an average time of about two seconds for each complete contraction of the heart. Therefore, the total duration of the ECG can be in about two seconds or much shorter. There are groups of pulses that last about 0.1 to 0.2 seconds. For example, if the window length for collecting cardiac cycle data at rest is 0.3 to 0.4 seconds, multiple motion pulse X-ray source tomosynthesis imaging systems 5 can run their cycles several times. X-ray images are taken during diastole when the heart is at its maximum expansion. When the heart contracts, no X-ray images are taken. The next set of X-ray images is taken when the heart is fully expanded. This will be called gated tomosynthesis imaging. In order to accommodate the movement between one heartbeat and another, multiple motion pulse X-ray source tomosynthesis imaging systems 5 are synchronized by the ECG waveform. This can result in real-time reconstruction of high-resolution images.

[0017] Turning now to ECG details, the R wave is the most important ECG signal for cardiac imaging. It is the electrical activity of the heart's ventricles, i.e., R wave, P wave, and T wave. The amplitude of these waves corresponds to the amount of blood that the ventricles pump into the heart's arteries. It can also be detected by surface ECG. According to one embodiment of the present invention, the X-ray source pulse rate, pulse width, and intensity are controlled by synchronizing with the R wave of the ECG signal of the patient's heartbeat. The benefit of ECG gating is that the heart will move only during half of the cardiac cycle (i.e., during diastole). The potential for improving the diagnostic performance of screening, detecting nodules earlier, and avoiding low-quality image data will provide additional benefits to medical professionals.

[0018] Systole is the electrical contraction of the heart muscle that forces blood out of the heart. Diastole is the relaxation phase of the heart, during which the heart muscle is stretched to receive the incoming blood flow. The trace above illustrates an electrocardiogram (ECG) waveform taken from the top of the heart at rest in a normal sinus rhythm. Arrhythmias or abnormal rhythms of the heart can cause these heart cycles to be irregular or cause parts of the heart cycle to occur outside the atria, so that only certain parts of the ECG are stationary at any given moment. These irregularities can form artifacts that blur the resulting tomosynthesis image. Imaging at the systolic phase is not ideal due to the movement of the heart.

[0019] Preferably, the diastolic phase is used to capture channel ECG waveform data from the subject's heart at rest. ECG waveforms of R waves, P waves, and T waves can be captured in just a few heartbeat cycles and recorded into a computer. After averaging or other algorithms, a single resting time period can be determined. After selecting the resting time period, the gating parameters are set.

[0020] Reference is made to the multi-pulse X-ray source tomosynthesis system 5 Figure 2 , each X-ray source 6 is located on an independent motor table. All X-ray source exposure timings and motor table speeds are programmable. In the timing diagram, when the first motor table speed 2 reaches a constant speed, the first X-ray source exposure 1 is triggered. The next motor table will move and the next X-ray source exposure will be triggered in the same way. In this example, there are five X-ray sources 6 and five motor tables. When the last motor table speed 4 temporarily reaches a constant, the last X-ray source exposure 3 is triggered.

[0021] In the timing diagram, the entire X-ray exposure from the first X-ray source exposure 1 to the last X-ray source exposure 3 lasts about less than one second. For example, a typical exposure time for such a source is about 40 ms, so five X-ray sources will require at least about 200 ms or 0.2 s. This will generally fit within the resting period of the diastolic phase of the heart. The length of the resting period can vary based on a variety of factors, including the patient's physical condition and physiological function. Therefore, after selecting the resting period, additional gating parameters are set.

[0022] In one embodiment, each motor of the tomosynthesis imaging system is operated to drive one of the drive assemblies to rotate about a pivot point while the other drive assembly is stationary. The X-ray source 6 generates X-rays when an object is in position between the source and the X-ray flat panel detector 7 . Figure 3 A representation of the movement of the source is shown by arrows in , where the source is at a certain position. A motor moves the x-ray source across the heart. The patient breathes naturally while the device acquires ECG synchronized images. Typically, rotation and translation (and deformation) of a rigid body and its components results in image degradation and loss of spatial resolution and image contrast, but the data acquired during the passage of the x-ray source through various positions allows reconstruction and viewing of multiple parallel planes that can be reconstructed to provide a three-dimensional image. Data from each plane can be used to construct a single view of the anatomical structure. Alternatively, image processing software can analyze multiple slices from one or more planes and create a three-dimensional image from these partial views.

[0023] P wave, R wave, T wave represent the electrical signals in the heart. P wave indicates the beginning of atrial contraction, and is followed by a negative deflection representing atrial repolarization. The interval between P wave and R wave is usually called PR interval. Normal PR interval measurement is 0.12 to 0.20 seconds. The interval between two consecutive R waves represents the duration of ventricular contraction. For cardiac imaging under ECG synchronous gating, ECG leads are attached to the body near the patient's chest wall or attached to the body using a chest strap ECG device so that the ECG signal can be received by the medical device.

[0024] The T wave is shown in an electrocardiogram and represents the phase of the cardiac cycle in which the electrical activity of the myocardium opposes that of its action potential. For convenience, it is shown as a line with an arrow. However, the T wave is not intended to represent the signal level of the electrocardiogram.

[0025] Figure 2A novel x-ray imaging system is shown, which uses multiple moving pulsed x-ray sources to perform efficient and ultra-fast 3D radiography. There are multiple pulsed x-ray sources 6 mounted on a moving structure to form a source array. The multiple x-ray sources 6 move simultaneously relative to the object at a constant speed as a group on a predefined arc track. Each individual x-ray source 6 can also move quickly around its static position at a small distance. When the x-ray source 6 has a speed equal to the group speed but with an opposite moving direction, the x-ray source 6 and the x-ray flat panel detector 7 are triggered by an external exposure control unit so that the source remains temporarily stationary. This results in a greatly reduced source travel distance for each x-ray source 6. 3D scanning can cover a much wider sweep angle in a much shorter time, and image analysis can also be performed in real time. This type of x-ray imaging system utilizes much more x-ray sources 6 than other types of x-ray imaging systems to achieve much higher scanning speeds. Since multiple sources are used, it is necessary to ensure that each x-ray source 6 is working properly so that the entire machine is running.

[0026] refer to Figure 1 In the timing diagram, in one embodiment, when the vibration motor has a direction opposite to that of the sweep motor but has the same speed as that of the sweep motor, the X-ray source exposure 1 is triggered. However, during the cardiac time period, the lung position area is affected by the heartbeat, so if the exposure does not occur during the rest period of the heartbeat, image blur is inevitable. The multiple pulse X-ray source tomosynthesis imaging system 5 with ECG synchronization performs the following operations: first, using an ECG sensor to capture an ECG waveform; second, evaluating the ECG waveform to verify the signal from the ECG sensor; third, using the ECG waveform as a basis to trigger the X-ray source exposure and motion speed control; finally, scanning the object and acquiring an X-ray image based on the trigger provided by the ECG waveform.

[0027] In one embodiment, the vibration motor provides low vibration energy to adjust the movement of the multiple pulsed X-ray sources when the heart is at rest. The real-time ECG waveform is used as ECG synchronization for image improvement. The real-time data acquisition of the multiple motion pulsed X-ray source tomosynthesis imaging system 5 will only acquire images during the resting period of the heartbeat. The real-time ECG waveform is used as ECG synchronization for image improvement. The real-time ECG waveform is used as ECG synchronization for image improvement.

[0028] The sweep motor rotates the arm in an arc to allow the source to be positioned sequentially between angles, thereby providing X-ray exposures during time intervals. Depending on the patient's requirements, exposures to the target can be scanned at a regular rate, a variable rate, or a pulsed exposure. This is part of a preferred embodiment for 4D imaging using multiple pulsed X-ray sources, which also synchronizes the real-time heart cycle ECG signal with the image acquisition process. The ECG signal will drive an actuator (such as a solenoid or a sweep motor) to move the arm at the speed of the heartbeat while the rest of the arm is stationary. The arm and the X-ray source move together while a series of positions are pulsed during the time interval, and imaging data is acquired within a given time interval. Due to the ECG synchronization during this entire movement, all images are acquired while the heart is moving smoothly. If the heart stops moving, imaging will stop. The patient's real-time ECG signal is used to synchronize image acquisition by moving the arm and X-ray source 6 simultaneously with the patient's heartbeat. The patient's real-time ECG signal is used to synchronize image acquisition by moving the arm and X-ray source simultaneously with the patient's heartbeat.

[0029] X-ray source 6 generates an X-ray beam that passes through the patient's breast, lung or body tissue. X-ray flat panel detector 7 acquires a data set that includes multiple real-time data acquired at different angles. For each motion source X-ray source, an ECG waveform is available. Using an ECG waveform synchronizer to synchronize ECG for image improvement can be achieved using actual ECG signals to obtain the correct timing point for each data acquisition process. The ECG waveform synchronizer sends a signal to each data acquisition controller to control the movement of the X-ray source to perform precise timing of data acquisition. The ECG waveform generator generates a heartbeat trigger signal that triggers the entire data acquisition system to start data acquisition during the rest period of the cardiac cycle and stops data acquisition when the cardiac cycle moves. This results in the elimination of blurred images caused by cardiac cycle motion artifacts. Each ECG waveform data synchronization allows seamless data acquisition to run much faster than the prior art. Therefore, the total scanning speed is much faster than the prior art. This will provide better quality images with stable data.

[0030] The support frame structure holds an array of multiple X-ray sources 6. The array is mounted on the support frame structure so that each X-ray source is disposed at one end of a rotatable arm assembly and so that each X-ray source can be independently rotated to different angular positions. Each arm assembly supports a corresponding X-ray flat panel detector. Multiple arm assemblies may be provided with a single support frame structure. In this arrangement, the corresponding arm assembly, the corresponding X-ray flat panel detector, and the corresponding X-ray source may be positioned adjacent to each other so as to allow radiation from the corresponding X-ray source to pass through a portion of the subject during acquisition of a given tomosynthesis data set. In some embodiments, more than one X-ray source may be activated simultaneously. In one example, up to four or six X-ray sources may be activated simultaneously. In another example, eight X-ray sources may be activated simultaneously. In another example, sixteen X-ray sources may be activated simultaneously. A processing unit with FPGA logic, a processor, or a computer controls the activation of the individual X-ray sources and coordinates the operation of all X-ray sources in a time-division multiplexed manner.

[0031] Figure 3 The total scanning sequence from different sources on different motors at different angles and different times is shown. Source A, Source B, Source C, Source D, Source E are sources on different motors, and the X-ray exposure from A, B, C, D, E will occur at Figure 1 Those exposures are from different angles. After the first five exposures, each of the multiple motors will move to the next position and make another five exposures in another heartbeat period. In this case, there are five motors. Therefore, in this example, a total of 25 exposures can be achieved in five heartbeat periods. Depending on the required exposure time for each source, 25 exposures can be achieved in less than five heartbeats.

[0032] The X-ray sources 6 can be independently powered and controlled for multiple exposures. Because they are located on a rotatable X-ray arm assembly, each source can be pointed to a different position and expose the object sequentially at different angles to create a corresponding number of data sets. Different data sets can be processed to generate images of specific image viewing angles and 3-dimensional (3D) image volumes. Based on the above characteristics, the images acquired by each pulsed X-ray source can be combined into a corresponding 3D data set to form a combined data set with high-quality images to improve the accuracy of the final diagnostic imaging results. It should be noted that the combined data set may also contain spatially related information of two or more different projection data sets to achieve a true 3-dimensional representation of the desired data set. When the projection data sets overlap, the spatially related information of each data set is retained in the composite 3D data set for diagnostic purposes.

[0033] The X-ray flat panel detector 7 has the ability to acquire images when multiple pulsed X-ray sources are scanning in motion or during the resting period of a heartbeat. When the heart is at rest, one X-ray source 6 rotates around the object at a constant distance from the object to form an arc trajectory. During the heartbeat, when the other pulsed X-ray source is static. Before all static pulses are delivered for each heartbeat, the sequence repeats itself. Because the X-ray pulses come from different angles, the real-time image acquisition process can be completed in about two seconds. At this time, different data acquisition patterns can also be used. It will be useful to use other patterns to acquire other tomosynthesis images. Those skilled in the art can determine which patterns should be applied based on the purpose of imaging.

[0034] The ECG pulse should be detected first and synchronized with the multiple pulse X-ray sources. The operator needs to set the appropriate position and time point for the heart cycle in a computer program with a real-time ECG waveform. It will tell the system to acquire images at specific positions in a time series based on data from the ECG sensor when the heart is about to be in a resting position. In other words, when the heart rate is relatively low, if the X-ray image is acquired when the heart is at rest, it will have good quality. If there is no synchronization, the data acquisition from multiple sources will have different positions relative to the stationary breast or lungs. This means that they cannot be reconstructed into a single view. A representative cardiac cycle means the full range of the periodic motion of the heart; the signal of a representative cardiac cycle means the entire time period of the periodic motion of the heart. According to the present invention, a multiple pulse X-ray source tomosynthesis system 5 is provided for obtaining images of moving objects (including the heart) by using multiple pulse X-ray sources arranged in a certain pattern around an axis extending from the center of the patient's body to the periphery of the patient's body.

[0035] ECG data is acquired using an ECG sensor. A representative cardiac cycle is determined by averaging multiple cardiac cycles of an actual patient. Images are acquired only during the resting period of a representative cardiac cycle. ECG signals are captured by analog or digital electrodes on the patient's body surface. ECG leads have three electrodes. Two electrodes are located near the heart to detect the electrical signals of the heart. ECG data can be further processed by an analog-to-digital converter and then passed to an image processing system. First, we need to process the ECG waveform in order to obtain a synchronization signal for image acquisition. There are many ECG waveform processing methods described in medical imaging that can be used to achieve this purpose. Once a representative cardiac cycle is determined, the future position of the next representative cardiac cycle can be predicted and appropriate exposure adjustments can be made in advance. By capturing images during cardiac diastole, we can improve image quality and reduce radiation dose during tomosynthesis imaging. Because we need to capture data during a specific phase and control the moving X-ray source and camera to be stationary in space at a certain angle and duration, multiple motion pulse X-ray source tomosynthesis 5 imaging devices can be used to generate high-quality tomosynthesis imaging data.

[0036] Multiple motion pulse source tomosynthesis imaging systems 5 can use ECG signals / waveforms to synchronize with the motion of the imaged object to capture images at specific moments of the cardiac cycle, from which motion artifacts are eliminated or reduced. The specific moment of the cardiac cycle depends on the heart rate, and it can be determined based on the initial or previous average RR interval. After capturing at a specific moment in the cardiac cycle, a computer reconstruction algorithm can then be used to correct for motion artifacts of the patient or object. The average RR interval (the ratio of one heartbeat to another) can be completed within one minute. Therefore, during a high heart rate period, additional tomosynthesis image acquisition using a smaller window width or window can be performed during the same period. The average RR interval will depend on the speed of the movement. If the heart moves slower, the average RR interval will be longer.

[0037] In one embodiment, ECG synchronization for image acquisition uses the cardiac time interval between two heartbeats (cardiac cycle). When cardiac images are obtained with the same cardiac cycle, each X-ray image exposure is performed at the same phase of the cardiac cycle. Therefore, each projection data set acquired during a different cardiac cycle phase can be used to generate a high-quality final reconstructed image. The technology relies on gated synchronization to acquire the entire projection data set during different phases of the cardiac cycle using a gated window (diastole). The rate at which projection data sets are acquired becomes limited by the periodicity of the cardiac cycle. The motion source system should not acquire projection data sets that overlap or may cause other overlaps.

[0038] The ECG waveform of the heartbeat is used to determine the periodic motion of the heart in ECG synchronization. With ECG synchronization, image quality improvements can be achieved in several ways. The first way is to acquire data only when the object is at rest, which is less likely to cause blurring due to periodic motion. It will reduce unnecessary multiple imaging exposures, which in turn reduces radiation dose. Second, by having better synchronized data, there are more opportunities to reconstruct high-resolution three-dimensional (3D) volume images. The higher the data quality, the easier it is to reconstruct. In addition, reduced radiation dose means reduced breast tissue necrosis and reduced lung tissue lesions, which are the main causes of false positive diagnoses in radiologists' reports.

[0039] Current systems detect R waves in the ECG waveform, which can be used as a basis for image data acquisition. ECG synchronization for image improvement works with multi-source imaging devices and avoids ECG peak pulses for better lung imaging under the influence of the heart's cyclical motion. Therefore, high data quality can be achieved using a multiple pulse source tomosynthesis system with distributed multiple X-ray sources across a wide angle. During the resting period of one heartbeat, X-ray exposures come from the X-ray sources from different angles.

[0040] In an embodiment of the present invention, a multiple pulse source tomosynthesis imaging system may be a moving X-ray source assembly with: multiple X-ray sources arranged in a pattern to span a wide viewing angle when in motion; an X-ray detector array; and an ECG synchronization unit coupled to the moving X-ray source assembly. The ECG synchronization unit is used to control the timing of the X-ray exposure so that there is no X-ray exposure at the peak heart beat. Therefore, the image data set acquired during the heart rest will have high quality. When the object moves, if an X-ray image exposure is being performed, a blurred image is inevitable. The moving X-ray source tomosynthesis imaging device may use ECG synchronization at the peak of the X-ray pulse of the heartbeat. In one embodiment, a heart rate of approximately 65 beats per minute (bpm) can be tracked by the ECG, and the frame rate will increase when the heart rate is lower because the imaging window can be larger. The multiple moving pulse X-ray source tomosynthesis imaging device uses real-time ECG synchronization.

[0041] In addition, as used herein, an element or step recited in the singular and followed by the word "a" or "an" should be understood as not excluding a plurality of said elements or steps, unless such exclusion is explicitly stated. In addition, the reference to "one embodiment" of the present invention is not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the described features. Also as used herein, the expression "reconstructing an image" is not intended to exclude embodiments of the present invention in which data representing an image is generated but a visual image is not generated. However, many embodiments generate (or are configured to generate) a visual image.

[0042] Various modifications and alterations of the present invention will be apparent to those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims. It should be noted that the steps recited in any method claim below do not necessarily need to be performed in the order in which they are recited. One of ordinary skill in the art will recognize variations in performing the steps based on the order in which the steps are recited. In addition, the lack of mention or discussion of a feature, step, or component provides a basis for a claim in which an absent feature or component is excluded by proviso or similar claim language.

[0043] Although the present invention is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects, and functions described in one or more of the individual embodiments are not limited to their applicability to the specific embodiment with which they are described, but rather may be applied alone or in various combinations to one or more of the other embodiments of the present invention, whether or not such embodiments are described and whether or not such features are present as part of the described embodiments. Therefore, the breadth and scope of the present valve should not be limited by any of the above-described exemplary embodiments.

[0044] Unless expressly stated otherwise, the terms and phrases used in this document and their variations should be interpreted as open-ended and not restrictive. As examples of the foregoing: the term "including" should be interpreted as meaning "including but not limited to" or the like; the term "example" is used to provide an illustrative example of the items under discussion, rather than an exhaustive or limiting list thereof; the term "a" or "an" should be interpreted as meaning "at least one", "one or more", or the like; and adjectives such as "conventional", "traditional", "normal", "standard", "known", and terms of similar meaning should not be interpreted as limiting the items described to a given time period or to items available as of a given time, but instead, they should be interpreted as covering conventional, traditional, normal, or standard technologies available or known now or at any time in the future. Therefore, where this document refers to technologies that are obvious or known to a person of ordinary skill in the art, such technologies cover those technologies that are obvious or known to a person of ordinary skill in the art now or at any time in the future.

[0045] In some cases, the presence of broad words and phrases (such as "one or more", "at least", "but not limited to", or other such phrases) should not be understood to mean that narrower cases are intended or required to be used where such broad phrases may not be present. Use of the term "module" does not imply that the components or functionality described or claimed as part of a module are all configured in a common package. In fact, any or all of the various components of a module, whether control logic or other components, may be combined in a single package or maintained separately, and may further be distributed across multiple locations.

[0046] In addition, the various embodiments set forth herein are described in terms of exemplary block diagrams, flow charts, and other illustrations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives may be implemented without limitation to the illustrated examples. For example, the block diagrams and their accompanying descriptions should not be construed as mandating a particular architecture or configuration.

Claims

1. A method for performing tomosynthesis imaging of multiple moving pulsed X-ray sources, wherein include: Using an electrocardiogram (ECG) sensor to capture ECG waveforms; evaluating the ECG waveform to verify a signal from the ECG sensor; using the ECG waveform as a basis for moving each of the motor stages and triggering a plurality of pulsed X-ray tomosynthesis sources; as well as by scanning the object and acquiring images using a plurality of motion pulse source tomosynthesis imaging devices triggered by the ECG waveform, wherein multiple pulsed X-ray sources in motion are used by positioning a primary motor stage and one or more secondary motor stages to predetermined initial positions; sweeping the elementary motor table at a predetermined constant speed by the elementary motor; oscillating each of the secondary motor stages in a predetermined sequence via a corresponding secondary motor based on the ECG waveform; electrically activating an X-ray source and an X-ray flat panel detector when the secondary motor stage moves in a direction opposite to the direction of the primary motor stage and at a selected speed of the primary motor stage; and Image data is acquired from the X-ray source using the X-ray flat panel detector.

2. The method according to claim 1, include: A virtual 3-dimensional (3D) model is generated using the sequence of data points.

3. The method according to claim 1, include: A 3D surface with a predetermined point density towards the center of the heart is generated at each heartbeat.

4. The method according to claim 1, include: The number of 3D models required for a predetermined image quality specified by the clinical protocol is determined.

5. The method according to claim 1, include: Noise is removed and real-time activity data is acquired that meets one or more ECG criteria during diastole.

6. The method according to claim 1, include: Capture a gated tomosynthesis image from the imaging system.

7. The method according to claim 1, include: X-ray exposures from multiple X-ray sources are captured at different angles during the resting phase of the heartbeat.

8. The method according to claim 1, include: Capture at least 60 projection images within two seconds.

9. The method according to claim 1, include: Motor actuation and X-ray exposure are sequenced during the diastolic cycle.

10. A tomosynthesis imaging system with multiple moving pulsed X-ray sources, wherein include: an electrocardiogram (ECG) sensor for generating an ECG waveform from an object; as well as A multiple moving pulsed X-ray source tomosynthesis imaging device, the device comprising: an X-ray exposure control unit; a predefined track; a source array, the source array comprising a plurality of pulsed X-ray sources mounted on a moving structure, wherein each of the plurality of pulsed X-ray sources moves simultaneously around an object at a constant speed of the group on the predefined track, and when an individual X-ray source has a speed equal to the group speed but in an opposite moving direction, the individual X-ray source is triggered by the exposure control unit; and an X-ray flat panel detector for receiving an X-ray flux and for generating imaging data; and a processor coupled to the ECG sensor and the imaging device to perform tomosynthesis imaging by: Using an electrocardiogram (ECG) sensor to capture ECG waveforms; evaluating the ECG waveform to verify a signal from the ECG sensor; using the ECG waveform as a basis for moving each of the motor stages and triggering a plurality of pulsed tomosynthesis sources; and Images are acquired by scanning the object and using a multiple motion pulse source tomosynthesis imaging device triggered by the ECG waveform.

11. The system according to claim 10, in, The X-ray source is stationary during an X-ray pulse trigger exposure duration based on the ECG waveform.

12. The system according to claim 10, in, The X-ray flat panel detector is used to acquire 3D radiographic image projection data based on the ECG waveform using a predetermined sweep for a predetermined time, and wherein image analysis is performed in real time during scanning.

13. The system according to claim 10, in, The X-ray source is randomly activated from one of the sources in the array using a random firing scheme based on the ECG waveform.

14. The system of claim 10, wherein a 3D X-ray radiographic image is reconstructed based on each image with an angled geometry of the X-ray source.

15. The system according to claim 10, wherein include: A virtual 3-dimensional (3D) model is generated using the sequence of data points.

16. The system according to claim 10, wherein include: A 3D surface with a predetermined point density towards the center of the heart is generated at each heartbeat.

17. The system according to claim 10, wherein include: The number of 3D models required for a predetermined image quality according to the clinical scenario is determined.

18. The system according to claim 10, wherein include: Noise is removed and real-time activity data is acquired that meets one or more ECG criteria during diastole.

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