KR20110028916A - A new method to measure necrotic core and calcium content in coronary plaques using intravascular ultrasound radiofrequency-based analysis - Google Patents

Abstract

PURPOSE: A device and a method for measuring components of an atheromatous plaque in a blood vessel using an ultrasound image in the blood vessel are provided to supply a similar clinical measuring result to an existing method. CONSTITUTION: A method for measuring components of an atheromatous plaque in a blood vessel using an ultrasound image in the blood vessel comprises the following steps. An ultrasound image in a blood vessel including areas around the blood vessel is obtained using an ultrasound image photographing device in the blood vessel(S710). An area between the first and second boundary lines is set as an inspection area(S740). The ratio of dangerous components to the entire components in the inspection area is measured.

Description

A new method to measure necrotic core and calcium content in coronary plaques using intravascular ultrasound radiofrequency-based analysis}

The present invention uses the vascular ultrasound image as a method of measuring the amount of necrotic core and calcium among the components of atherosclerosis in blood vessels.

Ultrasound systems are one of the important diagnostic systems that are used in a variety of applications. In particular, ultrasound systems are widely used in the medical field because they have nondestructive properties for the subject. Modern high performance ultrasound systems have been used to form two-dimensional or three-dimensional images of the internal shape of a subject (eg, internal organs of a patient).

Generally, ultrasonic systems include probes, beam formers, signal processors, processors, displays, and inputs. The probe for transmitting and receiving the ultrasonic signal includes a plurality of conversion elements for converting the ultrasonic signal and the electrical signal. Each transducer of the probe generates an ultrasonic signal separately, and several transducers may simultaneously generate an ultrasonic signal. The ultrasonic signal transmitted from each conversion element is reflected at the discontinuous surface (the reflector surface) of the acoustic impedance inside the object. Each converter converts the individually reflected ultrasonic signal into an electrical signal to form a received signal. The beam former performs focusing and reception focusing of an ultrasonic signal in consideration of the focusing point of the object and the position of each conversion element. The signal processor performs analog-to-digital conversion, amplification and various signal processing of the received signal. The processor forms an ultrasound image of the object based on the signal output from the signal processor, and the display unit displays the ultrasound image.

On the other hand, the ultrasound system uses the Doppler Effect to measure the movement speed of the red blood cells in the blood vessel or the movement of the heart. When the sample volume is set in the blood vessel region of the ultrasound image by using an input unit (eg, a control panel) from the user, the ultrasound system forms a Doppler spectrum based on data obtained from the scan line of the sample volume.

Meanwhile, the progression of atherosclerotic plaques in blood vessels is a cause of cerebrovascular disease and heart disease, which is the leading cause of death in major developed countries such as Europe. It is well known that Korea's disease is changing along with major developed countries. Timely detection of cerebrovascular disease and heart disease requires identifying the components of the atherosclerotic plaques of blood vessels.

The presence of atherosclerotic plaques can also be detected by computed tomography (CT) and magnetic resonance images (MRI). It is known to be more accurate.

Intravascular Ultrasound (IVUS) can be performed using high frequency bands in the tens of MHz bands, such as Eagle Eye Gold 2.9F 20 MHz phased-array catheter from Volcano Corporation, Rancho Cordova, USA. Support. The ultrasound of the high frequency band is emitted to the object, and the material component of the object may be grasped according to a pattern in which the ultrasound reflected from the boundary of the object is received at the receiving side. The VH-IVUS console and its operation program from Volcano Therapeutics, Rancho Cordova, USA, process images received from the catheter to analyze material components of the subject.

The received image is obtained by electrocardiogram-gated (ECG-gated) technique. After 200 ug of nitroglycerine is injected into the vessel, an IVUS catheter is inserted and the IVUS catheter is pulled at a rate of 0.5 mm / s. Record the images monitored during catheter traction and analyze them.

Conventional methods for diagnosing cerebrovascular disease, heart disease or atherosclerosis include lumens and luminal lumens based on displayed intravascular ultrasound images when an intravascular ultrasound device displays an intravascular ultrasound image. Visually grasp The wall area of the vessel is set based on the lumen and the outer cavity grasped by the naked eye, and the image processing device analyzes the plaque component appearing on the surface of the wall region of the vessel to measure the proportion of the risk component.

In the prior art, an ultrasound image is visually analyzed by an expert to determine the external and internal lumen of blood vessels. However, it is not easy for an expert to understand the lumen of blood vessels due to the inherent resolution of ultrasound. Therefore, the location of the blood vessels is different from one expert to another, and even the same expert is variable in the position of the blood vessels at each examination, so it is not easy to track the history of the same patient. In addition, the conventional method takes a long time to analyze the component of the plaque, so it is not useful in the clinic that needs to determine the treatment of patients in real time.

Therefore, there is a need for the development of a method and apparatus capable of setting a consistent test area regardless of the inspector operating and diagnosing the device and rapidly measuring atherosclerotic plaque components.

It is an object of the present invention to provide a new method of measuring the components of atherosclerotic plaques that provide clinically similar measurement results. The measurement results of the present invention have a high correlation with the measurement results of the prior art, and thus the measuring device and method of the present invention provide clinically equivalent results with the conventional measurement methods. Furthermore, the measuring apparatus and method of the present invention become a means to replace the conventional measuring method.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for measuring a component of atherosclerotic plaque in a blood vessel, which is fast and accurate and has improved reproducibility. In particular, it is an object of the present invention to provide a measuring method and apparatus capable of providing a consistent diagnosis results regardless of the operator or the diagnostic when examining the same lesion (lesion) for the same patient by increasing the reproducibility. It is an object of the present invention to increase the reliability of the measurement of the component of the atherosclerotic plaque in the blood vessel, and to provide a means for easily monitoring the state of the blood vessel by storing the history for patients who need continuous observation.

In addition, an object of the present invention is to provide a measuring method and apparatus that can significantly shorten the time required to measure the components of the atherosclerotic plaque in the blood vessel from the intravascular ultrasound image to quickly diagnose the condition of the patient. As such, the present invention may be usefully used in real time clinical practice in place of the prior art.

In the method of measuring the component of the vascular atherosclerotic plaque according to an embodiment of the present invention, obtaining an intravascular ultrasound image including a peripheral region of a blood vessel using an apparatus for photographing an intravascular ultrasound image, within the ultrasound image, Setting an outer circumferential boundary of a catheter inserted into a blood vessel as a first boundary, and setting an outer circumferential boundary (outer cavity) of an outer wall region of the blood vessel as a second boundary in the ultrasound image, the first boundary And setting an area between the second boundary lines as a test area or a region of interest (ROI), and measuring a ratio of a risk component area in the test area.

In this case, the step of measuring the proportion of the hazardous component region may include the inspection region as a fibrous region, a fibrofatty region, a necrotic core (NC) region, and a calcium density (DC) region. And dividing the dangerous component region into the NC region and the DC region.

In this case, the measuring of the ratio of the dangerous component may be divided into the dangerous component region and the remaining region based on the brightness intensity and the pattern of each pixel image or the sample volume of the ultrasound image.

The atherosclerotic plaque component measuring method of the present invention may further comprise the step of storing the measured risk component area ratio in a database and comparing it with a previous measurement ratio stored in the database of the patient of the blood vessel.

An apparatus for measuring a component of an atherosclerotic plaque in a blood vessel according to an embodiment of the present invention includes a display apparatus for displaying an intravascular blood vessel image including a peripheral region of a blood vessel generated by the intravascular ultrasonic imaging apparatus.

In addition, the apparatus of the present invention sets the outer boundary of the catheter to be inserted into the blood vessel as the first boundary within the ultrasound image (in this case, the outer boundary should be avoided by the catheter artefact, so that the size (radius) of the catheter outer boundary) Inspection apparatus setting logic for setting a peripheral boundary of the outer wall region of the blood vessel as a second boundary, and setting an area between the first boundary and the second boundary as an inspection region It includes.

The apparatus of the present invention also includes measurement logic to measure the proportion of hazardous component areas within the test area.

In this case, the measurement logic divides the inspection area into a fibrous, fibrofatty, necrotic core (NC) region, and calcium dense (DC) region, and divides the NC region and the DC region. It can be set as dangerous component area.

The intravascular ultrasound imaging apparatus may insert the catheter into the vessel to radiate ultrasound in a 20 MHz band, and image the intensity and pattern received by reflecting the emitted ultrasound.

The measurement logic may distinguish the dangerous component area from the remaining area based on the light intensity and pattern of each pixel displayed in the ultrasound image, and calculate a ratio of the area occupied by the dangerous component area to the inspection area.

The measuring device of the present invention may further include a database for storing the measured ratio of the dangerous component regions. The measuring device may diagnose whether the patient is at risk of atherosclerosis by comparing the patient's previous measurement ratio and the current measurement ratio of the blood vessel stored in the database.

The measurement results according to the invention are clinically similar to the prior art and have a high statistical relevance. Therefore, the new method for measuring the components of the atherosclerotic plaque of the present invention provides a clinically equivalent result to the conventional measuring method, and can replace the conventional measuring method.

According to the present invention, it is possible to quickly measure the component of the atherosclerotic plaque in the blood vessel from the intravascular ultrasound image, so that it can be applied to the treatment of the patient in clinical practice. In addition, high accuracy and excellent reproducibility can replace traditional measuring methods. In the past, since the examination area was set by the expert who participates in the diagnosis, the diagnosis results are different for each expert even for the same lesion of the same patient, and even the same expert presents different diagnosis results for each test. It was a cause for greatly lowering the reliability of.

According to the present invention, since the diagnosis of the same lesion of the same patient provides a consistent diagnosis result regardless of the operator or the diagnoser, it is possible to increase the reliability of the diagnosis result. In addition, by storing the history of the patient it is possible to easily monitor the condition inside the blood vessels of the patient when the periodic examination. Since follow-up studies are required for patients with vascular disease, changes in atherosclerotic plaques over time are measured. At this time, high reproducibility and reliability are most important, and the present invention can be solved by suggesting a new measuring method.

In addition, the present invention can shorten the time required to measure the components of the atherosclerotic plaque in the blood vessels from the endovascular ultrasound image to quickly diagnose the condition of the patient. This enables rapid response to changes in the patient's condition.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or limited by the embodiments. Like reference numerals in the drawings denote like elements.

1 is a view illustrating a measurement process of atherosclerotic plaques of blood vessels according to an embodiment of the present invention, and comparing them with the related art.

Intravascular Ultrasound (IVUS) can be performed using high frequency bands in the tens of MHz bands, such as Eagle Eye Gold 2.9F 20 MHz phased-array catheter from Volcano Corporation, Rancho Cordova, USA. Support. The ultrasound of the high frequency band is emitted to the object, and the material component of the object may be grasped according to a pattern in which the ultrasound reflected from the boundary of the object is received at the receiving side. The VH-IVUS console and its operation program from Volcano Therapeutics, Rancho Cordova, USA, process images received from the catheter to analyze material components of the subject.

The received image is obtained by electrocardiogram-gated (ECG-gated) technique. After 200 ug of nitroglycerine is injected into the vessel, an IVUS catheter is inserted and the IVUS catheter is pulled at a rate of 0.5 mm / s. Record the images monitored during catheter traction and analyze them.

Conventional methods for diagnosing cerebrovascular disease, heart disease, or atherosclerosis include the lumen 120 of the blood vessel based on the displayed intravascular ultrasound image when the intravascular ultrasound apparatus displays the intravascular ultrasound image. Grasp the outer cavity 110 with the naked eye. Based on the lumen and the outer cavity grasped by the naked eye, the wall area 130 of the blood vessel is set, and the image processing device analyzes the plaque component appearing on the surface of the wall region 130 of the blood vessel, and the area of the dangerous component occupies. Measure

The prior art analyzes the ultrasound image visually by an expert to determine the outer lumen 110 and lumen 120 of the vessel, wherein the outer lumen 110 of the vessel is relatively clear and easy to understand. However, identifying the lumen of blood vessels 120 is not easy even for professionals. Therefore, the location of the blood vessels is different from one expert to another, and even the same expert is variable in the position of the blood vessels at each examination, so it is not easy to track the history of the same patient.

In contrast, the measurement method of the present invention does not attempt to accurately grasp the lumen of the vessel, but analyzes the atherosclerotic plaque of the vessel based on the outer periphery 220 of the catheter. The present invention sets the area between the outer circumference 220 of the catheter and the outer diameter 210 of the vessel as the test area 230. An inspection area is also called a Region of Interest (ROI). By the measuring method of the present invention, the expert has conventionally solved the inconvenience of having to draw a boundary along the inner diameter 120 of the blood vessel while viewing the displayed image, and the measuring device easily checks the inspection area 230 according to the user's input. This can greatly reduce the time required for the measurement process.

Figure 2 is a view showing the measurement results of atherosclerotic plaques of blood vessels according to an embodiment of the present invention, compared with the prior art.

The image 310 is an original ultrasound image that has been analyzed in the prior art. The image 320 is an image showing an inspection area separated after being set by an expert according to the related art. The image 330 is a result of analyzing the components of the plaque in the inspection area by the prior art. The proportion of the area occupied by the components in the plaque is shown in color.

The image 410 is an original ultrasound image that is measured by the measuring device of the present invention. The image 420 is a diagram image showing an inspection area set by the measuring apparatus of the present invention. Image 430 shows the proportion of the area occupied by each component of the plaque in the test area by the measuring device of the present invention.

Green areas represent fibrous (FI) and yellow areas represent fibrofatty (FF). The white area represents dense calcium (DC), and the red area represents necrotic core (NC).

Generally, DC and NC are cited as factors causing vascular disease. Therefore, the measuring device of the present invention diagnoses the degree of risk by measuring the proportion of NC and DC in the inspection area.

3 is a view showing a measurement result of the atherosclerotic plaque of blood vessels according to an embodiment of the present invention, and compared with the prior art.

Referring to FIG. 3, the measurement rate of the present invention and the measurement ratio of the conventional NC and the measurement ratio of DC were compared for two sample sets. This is a view showing that the measurement method of the present invention is similar to the prior art (diagnosis of the expert), which is a statistically meaningful diagnosis result.

The correlation coefficient (R) was 0.994 and 0.998 for the NC ratio, very close to 1, and the probability (P) of significant difference between the two measurement results was less than 0.001.

4 is a view showing the reproducibility of the measurement results of atherosclerotic plaques of blood vessels according to an embodiment of the present invention.

For the sample set, the correlation between the first NC measurement ratio and the second NC measurement ratio is 0.999, and the correlation between the first DC measurement ratio and the second DC measurement ratio is 1.0. In both cases the probability of significant difference is less than 0.001.

It can also be seen that the difference between the two measurement ratios is very small compared to the size of the NC or DC region evaluated.

5 is a view comparing the measurement results of the atherosclerotic plaque of blood vessels according to an embodiment of the present invention and the results of the prior art.

Figure 5 shows the result of the measurement result of the measurement method of the present invention minus the result of the prior art for each sample.

Referring to Figure 5, it can be seen that the NC measuring ratio due to the measuring method of the present invention may be larger or smaller than the conventional NC measuring ratio. However, it can be seen that the average value of the NC measurement ratio due to the measuring method of the present invention is larger than the average value of the NC measurement ratio of the prior art.

In contrast, the DC measurement rate due to the measurement method of the present invention appears consistently smaller than the prior art DC measurement rate for all samples.

This is due to an error in which calcium is higher in the atherosclerotic component due to the contact artifact of the catheter in the prior art, and the measurement method of the present invention can improve the error in the measurement process.

The problem of the prior art in which the ratio of the calcium component is measured by the contact artifact is described with reference to FIG. 6.

6 is a view illustrating a measurement process of atherosclerotic plaques of blood vessels according to an embodiment of the present invention, and comparing them with the related art.

From the original ultrasound image 510, the inspection area 520 set by the prior art and the inspection area 530 set by the measuring method of the present invention are shown.

Looking at the inspection area 520, it can be seen that the white area appears very large, which may be referred to as noise on an image caused by contact artifacts. Since the inspection area 530 includes the area around the catheter, it is possible to reduce the influence of noise caused by such contact artifacts and prevent misdiagnosis.

From the original ultrasound image 610, the inspection area 620 set by the prior art and the inspection area 630 set by the measuring method of the present invention are shown.

Similarly, the test area 620 of the prior art displays more white areas than there is a risk of diagnosing the patient's condition differently from the real world.

7 is an operation flowchart illustrating a measurement process of atherosclerotic plaques of blood vessels according to an embodiment of the present invention.

In the measuring process of the present invention, an ultrasound image including a peripheral region of a blood vessel is obtained (S710).

In the measuring process of the present invention, the outer circumference of the catheter is set as the first boundary (S720).

In the measuring process of the present invention, the outer circumference boundary line (outer cavity) of the outer wall region of the blood vessel is set as the second boundary line (S730).

In the measuring process of the present invention, an area between the first boundary line and the second boundary line is set as an inspection area (S740).

The measurement process of the present invention measures the ratio of the necrotic core NC and the calcium dense region DC in the inspection region (S750).

The present invention is not limited by the specific means for measuring the proportion of the danger zone performed in step S750. Extracting a region of a specific component from an ultrasound image is sufficient if it is a technical configuration known to those skilled in the art, and if necessary, those skilled in the art can determine the phased-array IVUS catheter of Volcano Corporation (Eagle Eye Gold 2.9F 20 MHz). It is possible to complete the required technical configuration by purchasing such a device. The VH-IVUS console provided by Volcano Therapeutics will also help to complete the necessary technical configuration. However, it is apparent to those skilled in the art that the spirit of the present invention is not limited by the specific equipment and programs of Volcano.

Since the measuring apparatus according to an embodiment of the present invention knows the diameter of the outer circumference of the catheter in advance, in operation S720, the user may set the catheter circumference in the ultrasound image by using a predetermined function key. . In this case, when the outer periphery of the catheter is set, the catheter region may be partially distorted or deformed by the artefact around the catheter. To adjust this, one can use another function key to fine tune the catheter perimeter when setting the catheter perimeter. Alternatively, the user may use only one function key and automatically adjust the catheter circumference to exclude the effects of artefacts by the drive software of the measurement device.

The method for measuring an atherosclerotic plaque component of a blood vessel based on an intravascular ultrasound image according to an embodiment of the present invention may be implemented in a program instruction form that can be executed by various computer means and recorded in a computer readable medium. For example, raw data for a vascular ultrasound image may be obtained by a hardware device, and processing of the obtained ultrasound image may be performed on an off-line program. The processing program for the ultrasound image may be recorded and used on the computer readable medium. In addition, both software for driving a hardware device for acquiring raw data of a vascular ultrasound image and software for performing ultrasound image processing may be recorded on a computer readable medium as an embodiment of the present invention.

The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

1 is a view illustrating a measurement process of atherosclerotic plaques of blood vessels according to an embodiment of the present invention, and comparing them with the related art.

Figure 2 is a view showing the measurement results of atherosclerotic plaques of blood vessels according to an embodiment of the present invention, compared with the prior art.

3 is a view showing a measurement result of the atherosclerotic plaque of blood vessels according to an embodiment of the present invention, and compared with the prior art.

4 is a view showing the reproducibility of the measurement results of atherosclerotic plaques of blood vessels according to an embodiment of the present invention.

5 is a view comparing the measurement results of the atherosclerotic plaque of blood vessels according to an embodiment of the present invention and the results of the prior art.

6 is a view illustrating a measurement process of atherosclerotic plaques of blood vessels according to an embodiment of the present invention, and comparing them with the related art.

7 is an operation flowchart illustrating a measurement process of atherosclerotic plaques of blood vessels according to an embodiment of the present invention.

Claims (10)

Acquiring an intravascular ultrasound image including a peripheral region of the blood vessel using the intravascular ultrasound imaging apparatus; Setting an outer circumference of a catheter inserted into the blood vessel as a first boundary within the ultrasound image; Setting an outer circumference boundary of the outer wall region of the blood vessel as a second boundary within the ultrasound image; Setting an area between the first boundary line and the second boundary line as an inspection area; And Measuring atherosclerotic plaque component of blood vessels comprising the step of measuring the proportion of the dangerous component area in the test area. The method of claim 1, Measuring the proportion of the dangerous component area Dividing the test zone into a fibrin zone, fiber fat zone, necrotic core zone and calcium dense zone, The dangerous component region is the atherosclerotic plaque component measuring method of the blood vessel comprising the necrotic core region and the calcium dense region. The method of claim 1, Storing, by the measured risk component region, a ratio in a database; And And comparing the previous measurement rate stored in the database of the patient of the blood vessel with the atherosclerotic plaque component measurement method of the blood vessel. The method of claim 1, Measuring the proportion of the dangerous ingredient Atherosclerotic plaque component measuring method of dividing the inspection area into a risk component region and the remaining region based on the intensity and pattern of each pixel image of the ultrasound image. A computer-readable recording medium in which a program for executing the method of any one of claims 1 to 4 is recorded. A display device for displaying an intravascular blood vessel ultrasound image including a peripheral region of a blood vessel generated by the intravascular blood vessel imaging apparatus; Within the ultrasound image, an outer circumference boundary of the catheter inserted into the blood vessel is set as a first boundary line, an outer circumference boundary line of the outer wall region of the blood vessel is set as a second boundary line, and between the first boundary line and the second boundary line. Inspection region setting logic for setting the region as an inspection region; And Atherosclerotic plaque component measuring apparatus of blood vessels including measurement logic for measuring the proportion of the dangerous component region in the inspection region. The method of claim 6, The measurement logic The test area is divided into a fibrin area, a fiber fat area, a necrotic core area and a calcium dense area, An atherosclerotic plaque component measuring apparatus for blood vessels that sets the necrotic core region and the calcium dense region as the dangerous component region. The method of claim 6, The intravascular ultrasound imaging device Atherosclerotic plaque component measuring apparatus for inserting the catheter into the vessel to radiate ultrasound in the 20MHz ~ 40MHz band, and to image the intensity and pattern of the reflected ultrasound reflected. The method of claim 6, The measurement logic The dangerous component area and the remaining area are classified based on the light intensity and pattern of each pixel shown in the ultrasound image. The atherosclerotic plaque component measuring apparatus of blood vessel which calculates the ratio with respect to the said test | inspection area | region of the area which the said dangerous component area occupies. The method of claim 6, Further comprising a database for storing the proportion of the dangerous component region measured; Atherosclerotic plaque component measuring apparatus for diagnosing the risk of arteriosclerosis in the patient by comparing the patient's previous measurement ratio and the current measurement ratio of the blood vessel stored in the database.

Images