CN103006218B - The data processing method of cardiac magnetic resonance real-time film imaging and system - Google Patents

Abstract

The invention provides a data processing method and system for cardiac magnetic resonance real-time movie imaging. The method includes: acquiring a selected imaging level, and reading an image of the imaging level; acquiring a reference line set on the image; acquiring a dynamic change diagram of a signal profile of the reference line with acquisition time; Obtaining the time interval of the start and end of the end-expiration period from the dynamic change map; calculating the left ventricular diameter in the time interval through the dynamic change map, and determining the end-diastolic cardiac phase and the end-systolic cardiac phase according to the left ventricular diameter; An image corresponding to the end-diastolic cardiac phase and the end-systolic cardiac phase is extracted and saved. The data processing speed can be improved by adopting the invention.

Description

Data processing method and system for cardiac magnetic resonance real-time cine imaging

technical field

The invention relates to magnetic resonance imaging processing technology, in particular to a data processing method and system for cardiac magnetic resonance real-time movie imaging.

Background technique

Cardiac magnetic resonance cine imaging is a commonly used imaging method for measuring cardiac function in clinical practice. Generally, part of the K-space data is collected within one cardiac cycle. Since the complete k-space data is completed over multiple cardiac cycles, the method is sensitive to respiratory motion. In order to eliminate the influence of breathing movement on the imaging quality, the subjects need to hold their breath repeatedly during the scanning process. This requirement is difficult to achieve in patients with severe heart disease, respiratory disease and children, so this method has greater clinical limitations.

Cardiac magnetic resonance real-time cine imaging technology appropriately reduces the spatial resolution, adopts parallel imaging technology and special reconstruction algorithms (such as sliding window method, echo sharing method, etc.), and can complete the acquisition of all K-space data within one cardiac cycle , so the image quality is less affected by respiratory motion, and data acquisition can be realized in the free breathing state of the subject, which greatly improves the clinical application range of cardiac cine imaging.

However, respiratory motion in real-time cine imaging will cause the same slice in different cardiac phases and the spatial position mismatch between different slices, which will introduce errors for subsequent cardiac function measurements. In order to solve the problem of layer misalignment caused by respiratory motion in real-time cardiac magnetic resonance cine imaging, the usual method is to look through all the acquired images, and manually select the end diastolic phase at the end of expiration (ie, the minimum respiratory motion) by visual inspection. and end-systolic pictures. However, this processing method is cumbersome and time-consuming, which greatly reduces its clinical efficiency and application value.

Contents of the invention

Based on this, it is necessary to provide a data processing method for cardiac magnetic resonance real-time cine imaging with a faster processing speed to solve the problem of slow data processing.

At the same time, it is also necessary to provide a data processing system for cardiac magnetic resonance real-time cine imaging with a faster processing speed.

A data processing method for cardiac magnetic resonance real-time cine imaging, comprising:

acquiring a selected imaging level, and reading an image of the imaging level;

Obtain a reference line set on the image;

Acquiring a dynamic change diagram of the signal profile of the reference line with the acquisition time;

Obtain the time intervals of the beginning and end of the end-tidal period from the dynamic change diagram;

calculating the left ventricular diameter in the time interval through the dynamic change map, and determining the end-diastolic cardiac phase and the end-systolic cardiac phase according to the left ventricular diameter;

An image corresponding to the end-diastolic cardiac phase and the end-systolic cardiac phase is extracted and saved.

A data processing system for cardiac magnetic resonance real-time cine imaging, comprising:

The imaging level selection module is used to obtain the selected imaging level and read the image of the imaging level;

The reference line setting module is used to obtain the reference line set on the image;

The dynamic change map extraction module is used to obtain the dynamic change map of the signal profile of the reference line with the acquisition time;

The time interval determination module is used to obtain the time interval of the beginning and end of the end-tidal period from the dynamic change diagram;

The left ventricle diameter calculation module is used to calculate the left ventricle diameter in the time interval through the dynamic change map, and determine the end-diastolic cardiac phase and the end-systolic cardiac phase according to the left ventricle diameter;

The image saving module is used to extract and save images corresponding to the cardiac phases of the end diastole and the cardiac phases of the end systole.

Using the method and system of this program, read the image on the imaging level, and set a reference line on the image, and obtain the dynamic change diagram of the signal profile of the reference line with the acquisition time, by calculating the left ventricular diameter within the time interval Determine the end-diastolic cardiac phase and the end-systolic cardiac phase, and quickly process the data of cardiac magnetic resonance real-time cine imaging without manual selection, making the processing easier and more efficient.

Description of drawings

Fig. 1 is the flowchart of the data processing method of cardiac magnetic resonance real-time cine imaging;

Figure 2 is an image at the imaging level;

Fig. 3 is a dynamic change diagram of the signal profile of the reference line with the acquisition time;

Figure 4 is a diagram of the dynamic changes in the diameter of the left ventricle;

Fig. 5 is a structural block diagram of a data processing system for cardiac magnetic resonance real-time cine imaging.

Detailed ways

In the process of cardiac magnetic resonance cine imaging, since the breathing motion will cause the same slice in different cardiac phases and the spatial position mismatch between different slices, it is necessary to select the end-diastole and systole at the end of expiration (that is, the minimum breathing motion) Final pictures.

The data processing method of cardiac magnetic resonance real-time cine imaging, referring to accompanying drawings 1 to 4, includes:

S10: Acquire the selected imaging level, and read the image of the imaging level. For cardiac magnetic resonance cine imaging, it is first necessary to collect K-space data during the cardiac cycle, select a certain imaging level, and automatically read all the images of the imaging level according to the scanning time sequence. In this solution, the selection of the imaging level is not limited, for example, the selection of the imaging level may be set by the user. In other embodiments, the image is a T2-weighted image.

S20: Acquire the reference line set on the image. In the resulting image, guide lines are set. Referring to Figure 2, the reference line passes through the chest wall, the center of the left ventricle, and the diaphragm; it can be understood that the reference line can only pass through the chest wall, the center of the left ventricle, or the diaphragm, which can reflect movement information. In this solution, the selection of the reference line is not limited, for example, the selection of the reference line may be set by the user.

S30: Obtain a dynamic change diagram of the signal profile of the reference line with the acquisition time. Combined with Figure 3, it is a pseudo-color map, the color represents the strength of the signal, the blue represents the weak signal strength, and the red represents the strong signal strength. Cardiac cine imaging is a T2-weighted image, so the blood signal in the heart cavity is high signal (red), the lungs are low signal (blue), and the signal of other organs (such as the liver) is centered. Expand the signal intensity corresponding to the reference line on all images on the slice (that is, expand the signal intensity of the reference line according to the imaging time), and then obtain the dynamic change map of the signal profile with the acquisition time. The vertical axis of the dynamic change diagram represents the signal profile of the reference line, and the horizontal axis represents the acquisition time, which includes multiple cardiac cycles.

S40: Obtain the time intervals of the start and end of the end-tidal phase from the dynamic change graph. The end-expiration period is the time interval corresponding to the lowest position of the chest wall or the highest position of the diaphragm in the dynamic change diagram. Since the respiratory motion cycle is longer than the cardiac cycle, the end-tidal period generally includes at least one complete cardiac cycle in the time interval.

S50: Calculate the left ventricle diameter in the time interval through the dynamic change map, and determine the cardiac phase at the end of diastole and the cardiac phase at the end of systole according to the diameter of the left ventricle. In the dynamic change map in the time interval, the left ventricular diameter in the dynamic change map is calculated. All obtained left ventricular diameter values are compared, and the largest left ventricular diameter is the end-diastolic cardiac phase, and the smallest left ventricular diameter is the end-systolic cardiac phase. With reference to Fig. 4, the calculation method of the left ventricle diameter is as follows: obtain the number of pixels of the blood signal in the left ventricle on the reference line, and calculate the number of pixels to obtain the diameter of the left ventricle. It can be seen that the method for calculating the left ventricular diameter is convenient and accurate.

In other embodiments, the determination of the end-diastolic cardiac phase and the end-systolic cardiac phase can be carried out through this scheme: setting a threshold, the left ventricular diameter greater than the threshold is the end-diastolic cardiac phase, and the left ventricular diameter smaller than the threshold is the end-systolic cardiac phase . It can be understood that the selection of the threshold may be a range value or a value; the determination of the threshold may be acquired through experience accumulation, or may be set by a user. In this application, the size of the threshold is not limited.

S60: Extract and save images corresponding to the end-diastolic cardiac phase and the end-systolic cardiac phase. Extract images of corresponding phases and save them to specific folders for subsequent image analysis.

Using this scheme, read the image on the imaging level, and set a reference line on the image to obtain the dynamic change diagram of the signal profile of the reference line with the acquisition time, and determine the end-diastolic heart rate by calculating the left ventricular diameter within the time interval. Phase and end-systolic cardiac phase, quickly process the data of cardiac magnetic resonance real-time cine imaging, without manual selection, and the processing is easier and more efficient.

Further, the above-mentioned data processing method of cardiac magnetic resonance real-time cine imaging further includes: a step of selecting other imaging planes, and returning to read the images of the imaging planes. After completing the data processing at this level, the other imaging levels are processed according to the plan.

Based on the above-mentioned data processing method of cardiac magnetic resonance real-time cine imaging, a data processing system for cardiac magnetic resonance real-time cine imaging is also provided, referring to accompanying drawing 5, including:

The imaging level selection module 10 is configured to acquire the selected imaging level and read images of the imaging level. For cardiac magnetic resonance cine imaging, it is first necessary to collect K-space data during the cardiac cycle, select a certain imaging level, and automatically read all the images of the imaging level according to the scanning time sequence.

The reference line setting module 20 is configured to acquire the reference line set on the image. In the resulting image, guide lines are set. The reference line passes through the chest wall, the center of the left ventricle, and the diaphragm; it can be understood that the reference line may only pass through the chest wall, the center of the left ventricle, or the diaphragm and other organizational structures that can reflect motion information.

The dynamic change graph extraction module 30 is configured to obtain a dynamic change graph of the signal profile of the reference line with acquisition time.

The time interval determining module 40 is configured to obtain the time intervals of the start and end of the end-tidal phase from the dynamic change graph. The end-expiration period is the time interval corresponding to the lowest position of the chest wall or the highest position of the diaphragm in the dynamic change diagram. Since the respiratory motion cycle is longer than the cardiac cycle, the end-tidal time interval generally includes at least one complete cardiac cycle.

The direct calculation module 50 of the left ventricle is used to calculate the diameter of the left ventricle in the time interval through the dynamic change map, and determine the cardiac phase at the end of diastole and the cardiac phase at the end of systole according to the diameter of the left ventricle. In the dynamic change map in the time interval, the left ventricular diameter in the dynamic change map is calculated. All obtained left ventricular diameter values are compared, and the largest left ventricular diameter is the end-diastolic cardiac phase, and the smallest left ventricular diameter is the end-systolic cardiac phase.

In other embodiments, the end-diastolic cardiac phase and the end-systolic cardiac phase can be determined by setting a threshold determination unit (not shown in the figure): setting the threshold, the left ventricular diameter is greater than the threshold is the end-diastolic cardiac phase, and the left ventricular diameter Less than the threshold is the end-systolic cardiac phase. It can be understood that the selection of the threshold may be a range value or a value; the determination of the threshold may be acquired through experience accumulation, or may be set by a user. In this application, the size of the threshold is not limited.

The image saving module 60 is configured to extract and save images corresponding to the end-diastolic cardiac phase and the end-systolic cardiac phase. Extract images of corresponding phases and save them to specific folders for subsequent image analysis.

Using this system, read the image on the imaging level, and set a reference line on the image, get the dynamic change diagram of the signal profile of the reference line with the acquisition time, and determine the end-diastole heart by calculating the left ventricular diameter within the time interval Phase and end-systolic cardiac phase, quickly process the data of cardiac magnetic resonance real-time cine imaging, without manual selection, and the processing is easier and more efficient.

In other embodiments, the data processing system for cardiac magnetic resonance real-time cine imaging further includes: another imaging level selection module (not shown in the figure), used to select other imaging levels and return to the imaging level selection module 10 . After completing the data processing at this level, the other imaging levels are processed according to the plan.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (2)

1. a data processing method for cardiac magnetic resonance real-time film imaging, comprising:

Obtain selected imaging aspect, read the image of described imaging aspect, described image is T2 weighted graph;

Obtain the reference line that described image is arranged, described reference line reflects the organizational structure of movable information through thoracic wall, left ventricle center and diaphragm;

Obtain the dynamic change figure of signal profile with acquisition time of described reference line, the y direction of described dynamic change figure represents the signal profile of reference line, and X direction is acquisition time, and comprises multiple cardiac cycle;

Obtain EEP from described dynamic change figure and terminate time interval;

The left ventricle diameter in described time interval is calculated by described dynamic change figure, and determine cardiac phase and end systole cardiac phase place diastasis according to described left ventricle diameter, the computational methods of described left ventricle diameter are: the pixel number obtaining left ventricle inner blood signal on reference line, calculate pixel number and obtain left ventricle diameter;

Extract cardiac phase and image corresponding to described end systole cardiac phase place preserving described diastasis; Described reference line is through thoracic wall, left ventricle center and diaphragm;

Described EEP is: time point corresponding when thoracic wall extreme lower position or diaphragm move to extreme higher position is interval; Described time interval at least comprises a cardiac cycle; Describedly determine cardiac phase and end systole cardiac phase place diastasis according to described left ventricle diameter, be specially: described left ventricle largest diameter be cardiac phase diastasis; What described left ventricle diameter was minimum is end systole cardiac phase place;

By setting threshold value, what left ventricle was greater than threshold value is cardiac phase diastasis, and what left ventricle diameter was less than threshold value is end systole cardiac phase place, and described threshold value is a value range or is a value.

2. a data handling system for cardiac magnetic resonance real-time film imaging, is characterized in that, comprising:

Imaging level selection module, for obtaining selected imaging aspect, read the image of imaging aspect, described image is T2 weighted graph;

Guide Settings module, for obtaining the reference line that image is arranged, described reference line reflects the organizational structure of movable information through thoracic wall, left ventricle center and diaphragm;

Dynamic change figure extraction module, for obtaining the dynamic change figure of signal profile with acquisition time of reference line, the y direction of described dynamic change figure represents the signal profile of reference line, and X direction is acquisition time, and comprises multiple cardiac cycle;

Time interval determination module, for obtaining EEP and the time interval terminated from dynamic variation diagram;

Left ventricle diameter computing module, for by the left ventricle diameter in dynamic change figure interval computation time, and determine cardiac phase and end systole cardiac phase place diastasis according to left ventricle diameter, the computational methods of described left ventricle diameter are: the pixel number obtaining left ventricle inner blood signal on reference line, calculate pixel number and obtain left ventricle diameter;

Image Saving module, for extracting cardiac phase and image corresponding to end systole cardiac phase place preserving diastasis;

Described reference line is through thoracic wall, left ventricle center and diaphragm;

Described EEP is: time point corresponding when thoracic wall extreme lower position or diaphragm move to extreme higher position is interval;

Described time interval at least comprises a cardiac cycle;

Describedly determine cardiac phase and end systole cardiac phase place diastasis according to described left ventricle diameter, be specially: described left ventricle largest diameter be cardiac phase diastasis; What described left ventricle diameter was minimum is end systole cardiac phase place;

By setting threshold value, what left ventricle was greater than threshold value is cardiac phase diastasis, and what left ventricle diameter was less than threshold value is end systole cardiac phase place, and described threshold value is a value range or is a value.