JPS59120136A - X-ray diagnostic appartus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention belongs to the field of medical equipment for diagnosis, and more particularly, it relates to the field of medical equipment for diagnosis. The present invention relates to a radiation diagnostic device.

[Departure] Technical background and its problems]

If a contrast agent concentration change curve in a predetermined tissue is determined using an x-fat CR device, and a blood contrast agent concentration change curve in blood vessels at other sites is simultaneously determined, the above group 1. & is regarded as a unique transfer system, and by using the blood contrast agent concentration as input and the tissue contrast agent concentration as output, the transfer function tU of the tissue can be obtained.

By the way, since 6e, the following method has been used to obtain the blood contrast medium concentration change curve.

(1) A means of collecting blood from an artery in synchronization with a CT scan and then analyzing the blood to determine changes in blood contrast agent concentration and glands.

(2) Move the bed each time data is collected, and for example, scan the area of interest on even-numbered scans, and scan areas including large arteries on odd-numbered scans, and select the desired song from the latter. A means of obtaining #.

However, according to the first method described above, blood sampling from the artery causes pain for the patient and requires a considerable amount of time to obtain the results, and according to the second method, the accuracy of movement of the bed is [Objective of the Invention] This invention was made in view of the above-mentioned circumstances. At the same time as obtaining a contrast agent concentration change curve in the tissue of the region of interest,
The purpose of this study is to provide an X-ray diagnosis device that can easily obtain blood contrast agent concentration change curves.

[Soan of invention]

The outline of the present invention for achieving the above object includes a contrast agent injecting means for injecting the entire contrast medium into a subject, and an X-ray beam that rotates and scans the subject at a predetermined angle along a predetermined tomographic plane of the subject. a pair of first X-ray sources for collecting all radiographic data;
a pair of second X-ray sources and a second X-ray detector that collect all fluoroscopic r images of about 111S different from the front self-cut Wt plane of the subject; Based on the output of the first X-ray detector, the tissue contrast agent concentration curve 'fc in the tomographic plane is calculated, and the blood contrast agent concentration curve mk is calculated based on the output of the second X-ray detector. This is an X-ray diagnostic apparatus characterized by having a calculating means for calculating.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to all the drawings. Fig. 1 is a schematic explanatory diagram of an X-ray diagnostic apparatus which is an embodiment of the present invention. This is an Xs gas inhalation device which is a contrast agent injection means, and is used to cause the subject 2 to inhale Xe gas.This Xe gas immediately enters the blood after inhalation.First X-ray source 6 The first X-ray detector 4 constitutes the entire data collection section of the X-ray CT apparatus, and rotates and scans the X-ray beam at a predetermined angle along the tomographic plane S1 of the subject, and scans the X-ray beam in each arrow direction. Collect projection data from.

Then, the tomographic plane S1 is scanned many times intermittently over time to obtain a plurality of tomographic images. collect. second X
ii #l source 5 and second X-ray detector 6 constitute a data collection unit for X-ray fluoroscopic images, and are located at a site different from the tomographic plane SI, including a large artery, 4 f, (including Part X
Collect fluoroscopic images. Note that the second X-ray source 5 and the second
The ray detector 6 is adapted to obtain K X m J visual images for each rotational scan of the first X-ray source 3 and the second X-ray detector 4 . The calculation means 7 includes the first detector 4. Based on the output of the second detector 6, a tissue contrast agent +/a degree curve in the tomographic plane S1 and a blood contrast agent (a degree curve and a 'ff:'lJ- degree curve) for the artery A are detected. The input device 8 is used by the operator to give necessary instructions to the operation means 7, such as specifying a region of interest, which will be described later.The display section 9 displays the calculation result f of the calculation means 7.
r: Displayed/on.

The operation of the apparatus 60 for one treatment and one treatment place configured as shown in FIGS. 2 to 4 will be explained in addition to reference.

First, before the entire contrast medium is injected into the subject 2 from the Xe gas inhaler 1, X149 is irradiated from the second X-ray source 5 to perform fluoroscopic credit imaging of the artery Afa-. This perspective image is provided to the calculation means 7 as a mask image for subtraction, which will be described later.

Next, the Xe gas inhaler 1 is operated, and the subject 2 K
Inhale Xe gas gold. This Xe gas quickly dissolves and flows into the blood of the subject 2. The first X-ray source 6 and the first X-ray detector 4 collect temporal changes in the flow of this Xe gas on the tomographic plane Sl as a plurality of tomographic images. On the other hand, the second X-ray source 5 and @2 X-ray detector 6 detect temporal changes in the flow of the Xe gas through the artery 74.
Each tomographic image obtained from the first X-ray detection H:÷4 is collected simultaneously to obtain each transparent image.

1st. The calculation means 7, which handles the outputs of the second X-ray detectors 4 and 6, operates under μ. First, the first X-ray detector 4
Based on the output, the image sequence ll-In for each time as shown in FIG. 2 is reconstructed, and a contrast agent concentration change curve in the tissue in the region of interest RiC is calculated. Here, the X-ray absorption coefficient a in the region of interest R in image 1i is set to rt, and image 1
Assuming that the time kfi at which the scan corresponding to i was performed, the contrast agent concentration change curve in the tissue r(t) is a smooth curve that satisfies (1). It becomes a curve. This is shown in Figure 6. In the manner described above, a tissue contrast agent d degree curve is obtained.

Next, based on the output of the second X-ray detector 6, the calculation means 7 extracts an extracted image sequence Fl-F of the artery A as shown in FIG.
Get n. These image sequences F and -L' are obtained by performing subtraction between the mask image photographed before contrast medium injection and the image sequence I- photographed at each time after contrast medium injection. Each of the images in the image series F1 to Fn is obtained in synchronization with the acquisition time of each image in the image series Il to In. Next, a common region of interest 1? in a direction perpendicular to the blood direction of blood vessel A in images F1 to Fn? Set oi@ (based on the operation of the input device 7). Here, let fi be the total X-ray absorption value in the region of interest Roi for image Fi, and let ti be the time at which image F2 was taken, then the blood contrast agent concentration change curve f(t)) is f (ti ) = Kf i + C・・・・・・ (
It becomes a smooth curve that satisfies 2). Here, let L be the length of the artery A that crosses the region of interest Roi fc (see Figure 4), and let S be the cross-sectional metal plate of the blood vessel in the region of interest Roi, then the value jj multiplied by equation (2) is given by . still,
The cross-sectional area S is determined from the tomographic image obtained by constructing a tomographic image of S2 in FIG. In addition, it may be calculated from the thickness of the artery A within the region of interest ROt in the image sequences F and -Fn.

The constant C in the equation (2) is defined as C
”--Kf.

○ given by Therefore, the above formula (2) is given as follows.

fCti) = K (jtfo) ・−・(
3) As explained above, the tissue contrast agent concentration change curve r(
t) is determined by equation (1), and blood contrast agent a degree change curve f
(t) is obtained using equation (3). These two curves are
Is this because it can be obtained synchronically for different parts? By displaying the information on the display unit 7, it is possible to grasp the entire state of blood flow accurately.

Also, the two curves γ(t) obtained as described above.

fct), consider the region of interest R as a type of transmission system, input all the blood contrast concentrations, and calculate the tissue contrast agent concentration? By considering it as an output, the entire transfer function of the tissue in the region of interest R can be calculated.

That is, focusing on the cross/glue values of the curves r(t) and fct), Z-transformation is performed on the previous curve "C1)-f(t), and Z-transformation of r(t) 't R <2) and f<t
)) Z transformation Q? 'mu). At this time, the tissue transfer function T (s) is T (J) = P (s)/R
(s). This transmission amount M 7'(, r) k
By calculating this, it is possible to easily know the change in the tissue contrast agent concentration, which is the output, when the blood contrast concentration, which is the input, changes.

This invention is not limited to the above-mentioned embodiments, and includes all various modifications within the scope of the invention.
Not even -5. For example, contrast agents are not limited to Xe gas,
Other contrast agents commonly used for diagnostic X-rays can be used. In addition, the display unit 9 may display the contrast agent C4 degree change curve 1~, or may display the transfer function T(,r), or may print it out as numerical data.

Note that the first X-ray source 6 and the first X-ray detector 4 according to the present invention can also be used for image display of a tomographic image as a data acquisition section of a normal OCT apparatus a, and Line 5 and I
The X-ray detector 6 of 742 can also be used alone for digital radiography.

〔Effect of the invention〕

As described above, the present invention provides an X-ray diagnostic apparatus that can easily obtain a contrast agent concentration change curve in blood at the same time as once a change curve of contrast agent in tissues of a region of interest is obtained. can do.

Therefore, in understanding the entire state of blood flow, it is possible to reduce the burden on the patient, simplify the test and make it more reliable, and
It can also improve inspection accuracy0

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an X-ray diagnostic apparatus that is an embodiment of the present invention, and FIG. 2 is a series of images 1 collected from the first detector.
6 is a characteristic diagram showing the −ψ deviation of the tissue contrast agent concentration change curve based on the image sequence 11 to 1, and FIG. 1Ifii image sequence p'1 to Fn; FIG. 1... Contrast medium injection means, 6... First X-ray source, 4
...first X-ray detector, 5...second X-ray source, 6
...Second X-ray detector, 7...Calculating means. Agent: Patent attorney Kensuke Chika (and 1 other person) Condolences
4 A FI F 2 -'Fo'

Claims (1)

[Claims] A contrast agent injection means for injecting a contrast agent into a subject, and a pair of first X a radiation source and a first X-ray detector; a pair of second X-ray source and a second The contrast agent concentration curve in the tissue in the tomographic plane is calculated based on the output of the first X-ray detector, and the blood contrast agent concentration curve 'ft is calculated based on the output of the second X-ray detector. An X-ray diagnostic device characterized by comprising a calculation means.