JP3219280B2 - SPECT tomographic imaging system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a SPECT tomographic imaging apparatus for calculating left ventricular (left ventricular) wall momentum used for cardiac function diagnosis from a cardiac pool SPECT tomographic image.

[0002]

2. Description of the Related Art Conventionally, to calculate left ventricular wall momentum from a cardiac pool SPECT tomographic image, a long-axis horizontal tomographic image (see FIG. 7) and a long-axis vertical tomographic image obtained by oblique tomography based on the central axis of the heart. Image (see FIG. 8) (Borrelo JA, Cli)
nthone NH, Rogers WL, et a
l: Oblique-angle tomograph
y: A restructuring algorithm
hm for transaxial tomograph
phy date. J NuclMed 22:47
1-473, 1981).

In FIG. 7, reference numeral 71 denotes a front wall;
3 is the apex, 74 is the center, 75 is the lower part, 76 is the lower wall,
Reference numeral 77 denotes a left ventricle (left ventricle). 8, 81 is a right side, 82 is a center, 83 is a left side, 84 is a side wall, and 85 is an apex.

[0004]

However, such a long-axis horizontal tomographic image and a long-axis vertical tomographic image are obtained by slices parallel to the central axis of the heart.

For this reason, a cross section distant from the central axis of the heart, that is, an end portion of the heart cannot be evaluated as a tomographic image, and in the prior art using such a tomographic image, a quantified accurate left ventricular wall momentum data is obtained. (The left ventricular wall motion parameter) cannot be obtained.

An object of the present invention is to obtain an accurate tomographic image even at a site distant from the central axis of the heart, and to obtain accurate left ventricular wall momentum data quantified based on the tomographic image. An object of the present invention is to provide a SPECT tomographic imaging apparatus capable of obtaining (left ventricular wall motion parameter).

[0007]

SUMMARY OF THE INVENTION The above object has been achieved by a heart pool tomogram creating means for creating an electrocardiogram synchronized heart pool SPECT tomogram by radial left ventricular long axis tomography, and a heart pool tomogram creating means. The left ventricular contour of a tomographic image corresponding to end diastole (ED) and end systole (ES) is extracted from a large number of cardiac pool tomograms, and the same slice tomogram of end diastole (ED) and end systole (ES) Of the left ventricle by calculating the distance from the central axis of the slice tomographic image to the end-diastolic (ED) and end-systolic (ES) tomographic image contours of each slice tomogram, respectively. This is achieved by providing wall momentum calculation means.

[0008]

The heart pool tomogram creating means creates an electrocardiogram synchronized heart pool SPECT tomogram by radial left ventricular long axis tomography.

The left ventricle wall momentum calculating means is a left ventricle of a tomographic image corresponding to end-diastole (ED) and end-systole (ES) from among a large number of cardiac pool tomographic images obtained by the cardiac pool tomographic image creating means. The contour is extracted, and the contours of the same slice tomogram of end diastole (ED) and end systole (ES) are superimposed. For each slice tomogram, the end diastole (ED) and end systole (ES) are taken from the central axis of the heart. The left ventricle wall momentum is calculated by calculating the distance to each tomographic image contour.

As a result, an accurate tomographic image can be obtained even at a site distant from the central axis of the heart, and accurate left ventricular wall momentum data (left ventricular wall) quantified based on the tomographic image. Motion parameters) are determined.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of a SPECT tomographic imaging apparatus according to the present invention. In FIG. 1, 1 is a scintillation camera, 2 is a camera collection interface, 3 is a memory, 4 is a CPU, and 5 is an input / output device.

In this case, the scintillation camera 1 detects γ-rays generated from the subject (not shown),
Accumulates the γ-ray detection data transmitted through the camera acquisition interface 2. The CPU 4 reads out the stored data in the memory 3, performs image reconstruction and analysis, and displays the results of the calculations on the input / output device 5.

Further, the CPU 4 controls the electrocardiogram synchronized heart pool SP.
The ECT tomogram is sliced by radial left ventricular long-axis tomography so that all sections are radially located at equal angular intervals around the central axis 51 of the heart as shown in FIGS. Equipped with cardiac pool tomographic image creation means for creating pool tomograms (for radial left ventricular long axis tomography, "Nuclear Medicine"
See Vol. 6, No. 10, pages 1267 to 1276. ).

Further, the CPU 4 extracts a left ventricular contour of a tomographic image corresponding to the end diastole (ED) and the end systole (ES) from among a large number of cardiac pool tomograms obtained by the above-mentioned cardiac pool tomogram creating means. And end-diastole (ED) and end-systole (ES)
The left ventricular wall momentum is obtained by superimposing the contours of the same slice tomographic image on each slice tomogram, and obtaining the distance from the central axis of the slice tomographic image to the end diastolic (ED) and end systolic (ES) tomographic image contours. Is calculated.

As a method of capturing an ECG-gated image in an ECG-gated cardiac pool SPECT tomographic image, a multi-gate acquisition method ("Recent Medical Diagnostic Apparatus" supervised by Hirokazu Kimura, June 25, 1988, Inc. Asakura Shoten, page 195).

Next, the operation will be described with reference to FIG.

That is, the CPU 4 fetches the ^99m T _C SPECT heart pool data collected by the multi-gate collection method into the memory 3 (step 401), and creates and analyzes a reconstructed image.

Here, the CPU 3 first creates an electrocardiogram-synchronized cardiac pool SPECT tomographic image from the stored data in the memory 3 by the radial left ventricular long-axis tomography method as a cardiac pool tomographic image creating means (radially converting the created tomographic image). (Referred to as left ventricle long axis tomographic image) (step 402).

Next, the CPU 3 calculates the left ventricle wall momentum as the left ventricle wall momentum calculation means as follows. First, only tomographic images corresponding to the end-diastolic (ED) and end-systolic (ES) are extracted from the multiple cardiac tomographic images obtained as described above, and the left ventricular contours ED5 and ES5 of each tomographic image are obtained. Extract (step 403). Next, end-expansion (ED)
ED of the same slice tomogram at the end of systole (ES)
5 and ES5 are superimposed (step 404). For each slice tomographic image, as shown in FIG. 5, from the heart central axis (left ventricular central axis) 21 to the end-diastolic (ED) tomographic image contours ED5 and ES5. Of the tomographic image of the end systole (ES) from the distance (d) of the heart and the heart axis 21 of the same as above.
The distance (s) up to 5 is obtained (step 405).

At this time, as shown in FIG. 5, the heart is divided into three parts on the center axis 21 thereof, and a two-thirds area (area of the heart base part 51 and the center part 52) E1 near the heart base part 51 has a center. Axis 2
1 is drawn at regular intervals at a predetermined pitch p1, and a straight line (vertical straight line) l
The distances (d) and (s) on the upper and lower sides of the center axis 21 on 11 to 11n are obtained. 1/3 of the apex 53
In the area E2, the center axis 21 and the apex 53 are 1/3
At a predetermined angle, for example, at an interval of 6 ° from an intersection 54 with a straight line ln perpendicular to the central axis 21 at the point (1).
Then, the distances (d) and (s) above and below the central axis 21 on the straight lines l21 to l2n are obtained (step 405).

Radial straight lines l21 to l2n are drawn in a 1/3 region E2 near the apex 53, and the straight lines l21 to l2 are drawn.
The distances (d) and (s) are calculated on n in such a manner that all the straight lines (radial straight lines) 121
This is because distances (d) and (s) are obtained for ~ l2n, and an accurate apex wall momentum can be calculated. (Apex 5
Even if the distances (d) and (s) are determined on the straight line 11 similar to the region E1 closer to the base 51 in the region E2 closer to the center 3, only a few lines 11 out of the straight line 11 drawn to the apex 55 In the example of FIG. 5, the distance (d),
(S) is simply obtained, and an accurate apex wall momentum cannot be calculated. ) Based on the distances (d) and (s) obtained as described above, the left ventricular (local) wall motion parameter f (θ, i) is calculated by the following equation (1).

F (θ, i) = (ds) / ED contour length Here, θ is the slice angle in the radial left ventricular long-axis tomography method (see FIGS. 2 and 3), and i is the same as in the above-mentioned tomography method. The straight lines l1 and l2 in each slice (vertical straight lines l11 to l2)
1n and radial straight lines l21 to l2n) (see FIG. 5)
Represents

In the above equation (1), (ds) is each slice angle, each straight line (vertical straight line and radial straight line) l
It represents the absolute value of the left ventricular (local) wall momentum at the 1,12 positions. Further, the ED contour length represents the total contour length of the end-diastolic (ED) tomographic image at each slice angle and each straight line (vertical straight line and radial straight line) 11 and 12 positions, in other words, the size of the left ventricle of the heart.

Also, the size of the left ventricle varies from subject to subject, and if the left ventricle wall momentum is treated as the absolute value, comparison between subjects cannot be made. Therefore, in the above equation (1), (ds) was divided by the size of the left ventricle (ED contour length).

The CPU 4 calculates left ventricular (local) wall motion parameters f for all straight lines (vertical straight lines and radial straight lines) 11 and 12 for all slices (tomographic images) according to the above equation (1). Step 407), displaying two-dimensional polar coordinates on the display of the input / output device 5 (Bull's eye)
e) and a three-dimensional model display (Bullet display) is performed (step 408).

Two-dimensional polar coordinate display (Bull's eye)
Indicate), the apex 53 to the base 51 are represented by concentric circles from the center outward (see FIG. 6), and the value of f is arranged at a corresponding position on the concentric circle by shading or color and displayed. It is.

In the display of the three-dimensional model, from the apex 53 to the base 51, the two-dimensional polar coordinate display is two-dimensional, whereas the two-dimensional polar coordinate display is three-dimensionally displayed in the vertical direction. The values of the above f are arranged and displayed for different shades or colors.

[0028]

As described above, according to the present invention, an accurate tomographic image can be obtained even for a portion distant from the central axis of the heart, and further, it is possible to contribute to the diagnosis of cardiac function based on the tomographic image. Thus, there is an effect that quantified and accurate left ventricular wall momentum data (left ventricular wall motion parameter) can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the device of the present invention.

FIG. 2 is a perspective view showing a slice position by radial left ventricular long axis tomography.

FIG. 3 is a polar coordinate display diagram showing slice positions by radial left ventricular long axis tomography.

FIG. 4 is a flowchart for explaining the operation of the device of the present invention.

FIG. 5 is a diagram for explaining a method of calculating a left ventricle wall momentum in the apparatus of the present invention.

FIG. 6 is an explanatory diagram of an example of a display of a calculated left ventricle wall momentum.

FIG. 7 is an explanatory diagram of a conventional technique.

FIG. 8 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Scintillation camera 2 Camera collection interface 3 Memory 4 CPU (cardiac pool tomogram creation means, left ventricle wall momentum calculation means) 5 Input / output device 21 Heart (left ventricle) central axis 51 Heart base 52 Central part 53 Apex ED5 End-diastolic tomographic outline ES5 End-systolic tomographic outline

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-200248 (JP, A) JP-A-2-134148 (JP, A) JP-A-4-231890 (JP, A) JP-A-61- 159181 (JP, A) JP-A-61-251782 (JP, A) JP-A-60-113174 (JP, A) JP-A-58-208683 (JP, A) Japanese Translation of PCT Application No. 55-500563 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01T 1/161 A61B 5/0402

Claims (1)

(57) [Claims] 1. A cardiac pool tomographic image creating means for creating an electrocardiogram synchronized cardiac pool SPECT tomographic image by radial left ventricular long axis tomography, and a plurality of cardiac pool tomographic images obtained by the cardiac pool tomographic image creating means. , The left ventricular contour of the tomographic image corresponding to the end diastole (ED) and the end systole (ES) is extracted, and the outline of the same slice tomographic image of the end diastole (ED) and the end systole (ES) is overlapped, and each slice is overlapped. End-diastolic (ED) and end-systolic (ES) from the center axis of the tomogram
SPECT tomographic imaging apparatus comprising: a left ventricle wall momentum calculating means for calculating a left ventricle wall momentum by calculating a distance to each tomographic image contour.