JP2006026017A - Fluorescent ct apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the distribution of a fluorescence emission amount inside a body to be measured and to generate fluorescent tomographic images based on the distribution of the fluorescence emission amount. <P>SOLUTION: The breast 4 of a subject to which a fluorescent reagent is administered beforehand is irradiated with first extremely-short pulse light L2, the spatial distribution and time change of the light quantity of extremely-short pulse light L4 propagated inside the breast 4 are detected by a photodetection part 32, and the distribution of an optical characteristic value inside the breast 4 is calculated on the basis of the detected result of the photodetection part 32 by an optical characteristic value distribution calculation part 47. Also, second extremely-short pulse light L3 is emitted to the breast 4, the spatial distribution and time change of the light quantity of fluorescence L4 originated from the inside of the breast 4 and propagated inside the breast 4 by irradiation with the second extremely-short pulse light L3 are detected by the photodetection part 32, and the distribution of the fluorescence emission amount inside the breast 4 is calculated on the basis of the detected result and the optical characteristic value distribution in a fluorescence distribution calculation part 48. On the basis of the distribution of the fluorescence emission amount, the fluorescent tomographic image of the breast 4 is generated and displayed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluorescence CT apparatus, that is, a CT (Computed Tomography) apparatus using fluorescence.

  Conventionally, X-ray CT apparatuses using X-rays have been realized in the fields of medicine and the like, and in recent years, research for applying tomography using light (optical CT) to living bodies has been actively conducted. ing. Since the living body is a high scatterer, the light irradiated to the living body is absorbed while repeating multiple scattering and comes out of the living body. By detecting the light emitted to the outside of the living body in this way, an optical characteristic value distribution such as an absorption coefficient distribution or a scattering coefficient distribution of the living body can be obtained. As an example of a method for performing such detection, a system using a picosecond time-resolved measurement method using an extremely short pulsed light with an extremely narrow time width of about picoseconds has been proposed (see Non-Patent Document 1).

In general, the following light diffusion equation is known as an equation describing light propagation in a measurement object such as a living body.

Here, c is the speed of light in the body to be measured, φ (r, t) is the integrated intensity of light, a function of position r and time t, D (r) is a diffusion coefficient, and an equivalent scattering coefficient μ ′ _s (r) is used. D (r) = 1/3 μ ′ _s (r), and μ _a (r) is an absorption coefficient. S (r, t) is a light source in the body to be measured, but is 0 if there is no light emission such as fluorescence.

If the distribution of the equivalent scattering count μ ′ _s (r) and the absorption count μ _a (r) is given in the measurement object that does not emit light, the above equation can be solved using a numerical calculation method such as the finite element method, As a result, the spatial distribution and temporal change of the light quantity measured on the surface of the measurement object can be obtained. The process of obtaining the light quantity to be measured by solving the above light diffusion equation under the given conditions is called forward problem analysis.

Also, in a system using the picosecond time-resolved measurement method, an extremely short pulsed light of about picoseconds is used as the incident light incident on the measurement object, and the light propagated through the measurement object is measured at picosecond times at multiple points. Detect using decomposition measurement method. By this detection, it is possible to acquire the spatial distribution and temporal change of the light quantity at a plurality of positions on the surface of the measurement object. On the other hand, the distribution of optical characteristic values in the measurement object, for example, the absorption count distribution or the scattering count distribution, is estimated, and the amount of light measured on the measurement object surface when the incident light is incident on the measurement object. The spatial distribution and temporal change are calculated based on the light diffusion equation, that is, by performing forward problem calculation. If the calculated result and the actually measured result coincide with each other, the estimated optical characteristic value distribution is considered to be correct. Since the normal calculation result and the measurement result do not match, the optical characteristic value distribution is estimated again based on the error, and the calculation is performed again. If this process is repeated and the error between the calculation result and the measurement result falls below the allowable value, the optical measurement value distribution at that time becomes the solution. Moreover, an optical tomographic image of the measurement object can be generated based on such an optical measurement value distribution. Such a process is called inverse problem analysis. Note that an optical tomographic image can be generated with higher accuracy by detecting the optical path length.
APPLIED OPTICS Vol.41, No.4 P778〜P791 by Fing Gao, et al.

  However, as described above, when performing forward problem analysis, it is assumed that there is no light source in the body to be measured, that is, there is no light emission such as fluorescence. For this reason, in the inverse problem analysis as described above, when there is a portion that emits fluorescence in the pair to be measured, the optical characteristic value distribution cannot be obtained. There is a problem that a fluorescence tomographic image cannot be generated based on the distribution of the quantity.

  In view of the above circumstances, an object of the present invention is to provide a fluorescence CT apparatus that obtains a fluorescence emission amount distribution in a measured body and generates a fluorescence tomographic image based on the fluorescence emission amount distribution. is there.

A fluorescence CT apparatus according to the present invention includes a first light irradiation means for irradiating a measurement object with a first ultrashort pulse light;
Second light irradiation means for irradiating the object to be measured with second ultrashort pulse light;
A light detection means for detecting a spatial distribution and a temporal change in the amount of light of the first ultrashort pulse light propagated through the measurement object;
Optical characteristic value distribution calculating means for calculating a distribution of optical characteristic values in the measurement object based on a detection result of the light detecting means;
A fluorescence detection means for detecting a spatial distribution and temporal change of the amount of fluorescence emitted from the measured body by being irradiated with the second ultrashort pulse light and propagated through the measured body;
Based on the detection result of the fluorescence detection means and the optical characteristic value distribution calculated by the optical characteristic value distribution calculation means, a fluorescence distribution calculation means for calculating the distribution of the fluorescence emission amount in the measurement object;
Fluorescent tomographic image generation means for generating a fluorescent tomographic image of the measurement object based on the distribution of the fluorescence emission amount calculated by the fluorescent distribution calculating means.

  Here, “ultrashort pulse light” means pulse light having a pulse length of 500 ps or less. The first ultrashort pulse light and the second ultrashort pulse light may be the same pulse light having the same wavelength and the same pulse length, or may be different pulse lights. In addition, the wavelength of the “first ultrashort pulse light” needs to be selected as a wavelength that propagates through the measurement object. Furthermore, the wavelength of the “second ultrashort pulse light” needs to be a wavelength at which fluorescence is emitted from the measurement object when the measurement object is irradiated with the “second ultrashort pulse light”. For example, if the measurement target is a living body to which a fluorescent reagent is administered, the wavelength of the “second ultrashort pulse light” needs to be in a wavelength band for generating fluorescence from the administered fluorescent reagent. In addition, if the object to be measured is a living body to which a fluorescent reagent is not administered, the wavelength of the “second ultrashort pulse light” needs to be a wavelength band that generates autofluorescence from the living body. Moreover, it is preferable that the wavelength of the first ultrashort pulsed light and the fluorescence are close.

  Here, “detecting the spatial distribution and temporal change of the light quantity” means detecting the light quantity of light that has propagated through the measurement object and emitted to the surrounding area at a plurality of positions around the measurement object with high time resolution. Is meant to do. For example, detection is performed at a plurality of positions around the measurement object using a TAC (Time-to-Amplitude-Converter) that is a photodetection device having a very high time resolution. Further, when detecting the spatial distribution and temporal change of the first ultrashort pulse light that has passed through the measurement object, the influence of the fluorescence is measured using a fluorescence cut filter that cuts off the fluorescence emitted from the measurement object. It is necessary not to receive. Similarly, when detecting the spatial distribution and temporal change of the amount of fluorescent light propagated through the measurement object, a second ultrashort pulse is used using a cut filter or the like that cuts the second ultrashort pulse light. It is necessary to avoid the influence of light.

  The “optical characteristic value” is, for example, a scattering coefficient or an absorption coefficient.

A radiation image acquiring means for detecting radiation carrying image information of the measurement object and generating a radiation image of the measurement object;
It may be provided with display means for simultaneously displaying the fluorescence tomographic image and the radiation image.

A moving means for moving the light detecting means and the light irradiating means and the measured object relatively in a spiral manner;
Based on the spatial distribution of the light quantity of the first ultrashort pulse light propagated through the measurement object and the time change detected by the optical characteristic value calculation means at a plurality of positions, the three-dimensional optical characteristic in the measurement object. Value distribution,
Based on the three-dimensional optical characteristic value distribution and the spatial distribution of the fluorescence propagated through the measurement object and the time change detected by the fluorescence distribution calculation means at a plurality of positions, the fluorescence emission amount of 3 If you want to calculate the dimensional distribution,
The fluorescent tomographic image generation means may generate a three-dimensional fluorescent tomographic image of the measurement object based on the three-dimensional distribution of the fluorescence emission amount.

  The measurement object is a breast, the first ultrashort pulse light and the second ultrashort pulse light are near-infrared light, and the fluorescence tomographic image is a fluorescence tomogram in a cross section parallel to the breast wall of the breast It may be an image. Here, “near infrared light” means light having a wavelength of 700 nm to 1500 nm.

  The breast may be preliminarily administered with a fluorescent reagent having affinity for abnormal tissue, and the fluorescence may be emitted mainly from the fluorescent reagent.

The fluorescent CT apparatus of the present invention includes a first light irradiating means for irradiating a measurement object with a first ultrashort pulse light, and a second light irradiation for irradiating the measurement object with a second ultrashort pulse light. Means, light detection means for detecting a spatial distribution and temporal change of the light quantity of the first ultrashort pulse light propagated inside the measurement object, and based on a detection result of the light detection means in the measurement object Optical characteristic value distribution calculating means for calculating the distribution of optical characteristic values, and a space of the amount of fluorescent light emitted from the measured body by being irradiated with the second ultrashort pulse light and propagated through the measured body Fluorescence detection means for detecting distribution and temporal change, detection result of the fluorescence detection means, and fluorescence emission amount in the measurement object based on the optical characteristic value distribution calculated by the optical characteristic value distribution calculation means Fluorescence distribution calculation to calculate the distribution of And fluorescence tomographic image generation means for generating a fluorescence tomographic image of the measurement object based on the distribution of the fluorescence emission amount calculated by the fluorescence distribution calculation means. A tomographic image can be acquired. That is, first, the optical characteristic value distribution of the measurement object, for example, the distribution of the equivalent scattering coefficient miss number μ ′ _s (r) and the distribution of the absorption coefficient μ _a (r) are calculated using the ultrashort pulse light. Furthermore, the spatial distribution and temporal change of the amount of fluorescent light propagated through the body to be measured are obtained by measurement. Given this calculated optical characteristic value distribution and the spatial distribution and temporal change of the amount of fluorescent light propagated through the measured object, the above-mentioned light diffusion equation can be solved, and as a result, the light source in the measured object A distribution of S (r, t), that is, a fluorescence emission amount distribution can be obtained, and a fluorescence tomographic image can be generated based on the distribution of the fluorescence emission amount.

  In addition, it is preferable to perform detection at a plurality of positions when “detecting spatial distribution of light quantity and temporal change”, and by increasing the number of detection positions, distribution of optical characteristic values or distribution of fluorescence emission amount Can be calculated with high accuracy.

  A radiation image acquisition unit configured to detect radiation carrying image information of the measurement object and generate a radiation image of the measurement object; and a display unit configured to simultaneously display the fluorescence tomographic image and the radiation image. Thus, the observer can easily compare the fluorescence tomographic image and the radiation image.

  The optical detection unit includes a moving unit that relatively spirally moves the light detection unit, the light irradiation unit, and the measurement target, and the optical characteristic value calculation unit propagates through the measurement target detected at a plurality of positions. The three-dimensional optical characteristic value distribution in the measurement object is calculated based on the spatial distribution of the light quantity of the first ultrashort pulsed light and the temporal change, and the fluorescence distribution calculating means is the three-dimensional optical Calculating the three-dimensional distribution of the fluorescence emission amount based on the characteristic value distribution and the spatial distribution and the temporal change of the fluorescence propagated through the measurement object detected at a plurality of positions; If the tomographic image generating means generates a three-dimensional fluorescent tomographic image of the measurement object based on the three-dimensional distribution of the fluorescence emission amount, the three-dimensional fluorescent tomographic image can be acquired with high resolution. it can

  The measurement object is a breast, the first ultrashort pulse light and the second ultrashort pulse light are near-infrared light, and the fluorescence tomographic image is a fluorescence tomogram in a cross section parallel to the breast wall of the breast In the case of an image, near-infrared light is likely to pass through the breast, so that a fluorescence tomographic image can be acquired with high accuracy.

  If a fluorescent reagent having an affinity for abnormal tissue is administered to the breast in advance and the fluorescence is mainly emitted from the fluorescent reagent, the abnormal tissue can be easily visually recognized by observing a fluorescence tomographic image. be able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a fluorescence CT apparatus according to a first embodiment of the present invention. This fluorescence CT apparatus is an apparatus that can simultaneously acquire a fluorescence tomographic image and an X-ray tomographic image of a breast.

  As shown in FIG. 1, the fluorescence CT apparatus includes an X-ray CT unit including an X-ray source 21, an X-ray detection unit 22, and an X-ray tomographic image acquisition unit 23, a light irradiation unit 31 that emits ultrashort pulse light, A fluorescence CT unit including a light detection unit 32 and a fluorescence tomographic image acquisition unit 33 is provided around the rotating ring 10. Further, as shown in FIG. 2, the rotating ring 10 is horizontally disposed in a space 2 provided in the table 1. The subject 3 lies on the table 1 so that the breast 4 from which the fluorescent diagnostic image is acquired is accommodated inside the rotating ring 10. The subject 3 is preliminarily administered with a fluorescent reagent having affinity for an abnormal tissue such as a cancer tissue. This fluorescent reagent emits fluorescence in the vicinity of a wavelength of 800 nm when irradiated with light having a wavelength of 750 nm.

  The X-ray source 21 emits X-rays L1 and is arranged at one end of the rotating ring 10. An X-ray detector 22 is provided at a position substantially opposite to the X-ray source 21 of the rotating ring 10. The X-ray detection unit 22 includes a large number of X-ray detection elements 24a, 24b, 24c..., And each X-ray detection element 24a, 24b, 24c. It consists of a scintillator that emits light and a photodiode that detects the light intensity of visible light emitted from each scintillator.

  The light irradiation unit 31 has a fiber 35 whose one end is opened into the rotary ring 10 and whose other end is connected to the semiconductor laser, and a semiconductor that emits the first ultrashort pulsed light L2 having a wavelength of 800 nm and a pulse width of 100 ps to the fiber 35. It consists of a laser 36 and a semiconductor laser 37 that emits a second ultrashort pulsed light L3 having a wavelength of 750 nm and a pulse width of 100 ps to the fiber 35. One of the semiconductor laser 36 and the semiconductor laser 37 is connected to the fiber 35 by a switching unit (not shown).

  The light detection unit 32 is a light detection device having a time resolution of 100 ps (TAC-Time-Amplitude-Converter) 40a, 40b, 40c... ... 32 fibers 41a, 41b, 41c... Connected to the TACs 40a, 40b, 40c..., And TACs (Time-to-Amplitude-Converters) 40a, 40b. , 40c... And switching filters 42a, 42b, 42c. Each switching filter 42a, 42b, 42c... Is a combination of a filter 43 that cuts light having a wavelength of 850 nm or more and a filter 44 that cuts light having a wavelength of 800 nm or less, as shown in FIG. It is used by appropriately switching by a switching unit (not shown). The fibers 41a, 41b, 41c,... Are arranged at equal intervals around the part of the rotating ring 10 facing the light irradiation part 31.

  The fluorescence tomographic image acquisition unit 33 stores a detection result of each TAC 40a, 40b, 40c... For each detection, an optical characteristic value distribution calculation unit 47 that calculates a distribution of optical characteristic values in the breast 4. A fluorescence distribution calculation unit 48 for calculating the distribution of the fluorescence emission amount in the breast 4, and a fluorescence tomography for generating a fluorescence tomographic image of the breast 4 based on the distribution of the fluorescence emission amount calculated by the fluorescence distribution calculation unit 48. The image generating unit 49 includes a three-dimensional fluorescent tomographic image generating unit 50 that generates a three-dimensional fluorescent tomographic image.

  The rotating ring 10 is moved horizontally or vertically by the moving mechanism 11 or vertically moved while rotating in a spiral.

  Hereinafter, an X-ray image acquisition method will be described first. The X-ray L1 is emitted from the X-ray source 21 in a state where the breast 4 of the subject is housed inside the rotating ring 10. In each of the X-ray detection elements 24a, 24b, 24c,... Of the X-ray detection unit 22, when X-rays transmitted through the breast 4 are incident, visible light corresponding to the incident amount is emitted from each scintillator. The light intensity of visible light is detected and output to the X-ray tomographic image generation unit 23. Thereafter, the rotating ring 10 is slightly rotated by the moving mechanism 11, and the X-ray L1 is again emitted from the X-ray source 21, and the next detection is performed. Each time the rotating ring 10 is rotated, the emission and detection of the X-ray L1 from the X-ray source 21 are repeated. After the rotation ring 10 is rotated 360 degrees, the X-ray tomographic image generation unit 23 generates an X-ray tomographic image. Further, if necessary, the vertical position of the rotating ring 10 is slightly lowered to similarly generate an X-ray tomographic image. After the X-ray tomographic image of the entire breast 4 is generated, a three-dimensional X-ray tomographic image of the breast 4 is generated. Further, instead of acquiring a circular slice-like tomographic image on a large number of sheets in this way, a three-dimensional X-ray tomographic image is generated by moving down the rotating ring 10 while spirally rotating, that is, by performing a helical scan. If data is acquired, a three-dimensional X-ray tomographic image can be generated with high resolution.

  Next, a method for acquiring a fluorescence tomographic image will be described. First, the semiconductor laser 36 is connected to the fiber 35, and the first ultrashort pulsed light L 2 having a wavelength of 800 nm and a pulse width of 100 ps is emitted to the breast 4. The switching filters 42a, 42b, 42c,... Provided between the ends of the fibers 41a, 41b, 41c,... Of the light detection unit 32 and the TACs 40a, 40b, 40c,. A filter 43 for cutting the above light is disposed on the front surface of each TAC 40a, 40b, 40c. When light having a wavelength of 800 nm is incident on the breast 4, if the fluorescent reagent is gathered in the abnormal tissue of the breast 4, fluorescence is emitted from the fluorescent reagent. Since the wavelength of the fluorescence emitted normally deviates from the wavelength of the irradiated light to the longer wavelength side, the fluorescence does not enter the TAC by arranging the filter 43 on the front surface of the TAC.

  As shown in FIG. 4, each TAC 40a, 40b, 40c,... Detects a different time-resolved curve at each measurement point, outputs it to the memory 46 of the fluorescence tomographic image acquisition unit 33, and stores it in combination with the detected position data. Is done. The detected position data and the time-resolved curve correspond to “the spatial distribution and temporal change of the light amount of the first ultrashort pulse light propagated through the measurement object” in the present invention.

Thereafter, the rotating ring 10 is slightly rotated by the moving mechanism 11 and the same detection is performed. After the rotation ring 10 is rotated 360 degrees while repeating the detection, the optical characteristic value distribution calculation unit 47 performs the first propagation that propagates in the breast 4 based on the detected position data and the time resolution curve stored in the memory 46. Based on the spatial distribution and temporal change of the light quantity of one ultrashort pulse light, the light diffusion equation is solved by an inverse problem analysis method, and the distribution of optical characteristic values, that is, the equivalent scattering count μ ′ _s (r) and the absorption count μ _a The distribution of (r) is obtained.

  Next, the semiconductor laser 3 7 is connected to the fiber 35, and the second ultrashort pulsed light L 3 having a wavelength of 750 nm and a pulse width of 100 ps is emitted to the breast 4. In the switching filters 42a, 42b, 42c,..., A filter 44 that cuts light having a wavelength of 800 nm or less is disposed in front of each TAC 40a, 40b, 40c,. When light having a wavelength of 750 nm is incident on the breast 4, if the fluorescent reagent is gathered in the abnormal tissue of the breast 4, fluorescence having a wavelength of about 850 nm is emitted from the fluorescent reagent. By arranging the filter 44 in front of the TAC, the second ultrashort pulsed light L3 does not enter the TAC.

  A time-resolved curve at each measurement point is detected by each TAC 40a, 40b, 40c..., Output to the memory 46 of the fluorescence tomographic image acquisition unit 33, and stored in combination with the detected position data. The detected position data and the time-resolved curve correspond to the “spatial distribution and temporal change in the amount of fluorescent light propagated through the measurement object” in the present invention.

Thereafter, the rotating ring 10 is slightly rotated by the moving mechanism 11 and the same detection is performed. After the rotation ring 10 is rotated 360 degrees while repeating the detection, the fluorescence distribution calculation unit 48 detects the detection result of the fluorescence detection unit 32, that is, the spatial distribution and temporal change of the amount of fluorescence propagated in the breast 4, and the optical Based on the optical characteristic value distribution (distribution of equivalent scattering count μ ′ _s (r) and absorption coefficient μ _a (r)) calculated by the characteristic value distribution calculating unit 47, the light diffusion equation is solved by an inverse problem analysis method. In addition, the fluorescence emission amount distribution in the breast 4 is calculated. Further, the fluorescence tomographic image generation unit 49 generates a fluorescence tomographic image of the breast 4 based on the distribution of the fluorescence emission amount calculated by the fluorescence distribution calculation unit 48. To do. Further, if necessary, the vertical position of the rotating ring 10 is slightly lowered to generate a fluorescence tomographic image in the same manner. After generating the fluorescence tomographic image of the entire breast 4, a three-dimensional fluorescence tomographic image of the breast 4 is generated. Further, instead of acquiring a circular slice-like tomographic image on a large number of sheets in this way, data that generates a three-dimensional fluorescent tomographic image by performing a helical scan while descending while rotating the rotating ring 10 in a spiral shape. Is obtained, a three-dimensional fluorescence tomographic image can be generated with high resolution. In this case, the fluorescence distribution calculation unit 47 calculates a three-dimensional optical characteristic value distribution, and the fluorescence distribution calculation unit 48 determines the fluorescence based on the detection result of the light detection unit 32 and the three-dimensional optical characteristic value distribution. The three-dimensional distribution of the emission amount is calculated, and the fluorescence tomographic image generation unit 49 generates a three-dimensional fluorescence tomographic image based on the three-dimensional distribution of the fluorescence emission amount.

  In order to simplify the description, the X-ray tomographic image and the fluorescence tomographic image acquisition operation have been described separately, but these operations are performed in parallel. For example, a three-dimensional X-ray tomographic image and a three-dimensional fluorescent tomographic image can be acquired by performing only one helical scan.

  After obtaining the X-ray tomographic image and the fluorescent tomographic image, the observer displays each image on a display unit (not shown) as shown in FIG. At this time, the fluorescent tomographic image 62 acquired at the same position is displayed next to the X-ray tomographic image 61. An observer can simultaneously observe an X-ray tomographic image and a fluorescent tomographic image acquired from the same cross section, and can easily compare them. In addition, the fluorescence tomographic image can be interpreted with almost the same feeling as when the X-ray tomographic image is interpreted, and the abnormal tissue 63 that is emitting light can be easily viewed.

  Furthermore, a superimposed image 65 in which an X-ray tomographic image and a fluorescent tomographic image are superimposed may be formed and displayed. By observing the superimposed image 65, the state of the calcification 64 and the state of the abnormal tissue 63 emitting fluorescence can be simultaneously recognized.

    A three-dimensional X-ray tomographic image and a three-dimensional fluorescent tomographic image can be displayed simultaneously or superimposed, and the observer can easily recognize the three-dimensional distribution state of the abnormal tissue.

  In this embodiment, the fluorescent reagent is administered in advance, but the present invention is not limited to this. Certain types of abnormal tissues, such as cancer, tend to emit slightly more intense fluorescence (autofluorescence) than normal tissues. By appropriately selecting the intensity and wavelength of the second ultrashort pulsed light and increasing the detection sensitivity of the light detection unit, a fluorescent image can be acquired without administering a fluorescent reagent.

Fluorescence CT apparatus according to an embodiment of the present invention Explanatory drawing of acquisition state of fluorescence tomographic image Illustration of switching filter Illustration of time-resolved curve Illustration of fluorescence tomographic image and X-ray tomographic image

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Subject 4 Breast 10 Rotating ring 11 Moving mechanism 21 X-ray source 22 X-ray detection part 23 X-ray tomographic image acquisition part 31 Light irradiation part 32 Light detection part
33 Fluorescence tomography image acquisition unit 35 Fiber 36, 37 Semiconductor laser 40a, 40b, 40c ... TAC
41a, 41b, 41c... Fiber 42a, 42b, 42c... Switching filter 46 Memory 47 Optical characteristic value distribution calculating unit 48 Fluorescence distribution calculating unit 49 Fluorescent tomographic image generating unit 50 Three-dimensional fluorescent tomographic image generating unit

Claims (5)

First light irradiating means for irradiating the measurement object with the first ultrashort pulse light;
Second light irradiation means for irradiating the object to be measured with second ultrashort pulse light;
A light detection means for detecting a spatial distribution and a temporal change in the amount of light of the first ultrashort pulse light propagated through the measurement object;
Optical characteristic value distribution calculating means for calculating a distribution of optical characteristic values in the measurement object based on a detection result of the light detecting means;
A fluorescence detection means for detecting a spatial distribution and temporal change of the amount of fluorescence emitted from the measured body by being irradiated with the second ultrashort pulse light and propagated through the measured body;
Based on the detection result of the fluorescence detection means and the optical characteristic value distribution calculated by the optical characteristic value distribution calculation means, a fluorescence distribution calculation means for calculating the distribution of the fluorescence emission amount in the measurement object;
A fluorescence CT apparatus comprising: a fluorescence tomographic image generation unit configured to generate a fluorescence tomographic image of the measurement object based on the distribution of the fluorescence emission amount calculated by the fluorescence distribution calculation unit. Radiation image acquisition means for detecting radiation carrying image information of the measurement object and generating a radiation image of the measurement object;
The fluorescence CT apparatus according to claim 1, further comprising display means for simultaneously displaying the fluorescence tomographic image and the radiation image. A moving means for moving the light detecting means and the light irradiating means and the measured object relatively in a spiral manner;
Based on the spatial distribution of the light quantity of the first ultrashort pulse light propagated through the measurement object and the time change detected by the optical characteristic value calculation means at a plurality of positions, the three-dimensional optical of the measurement object Calculating the characteristic value distribution,
Based on the three-dimensional optical characteristic value distribution and the spatial distribution of the fluorescence propagated through the measurement object and the time change detected by the fluorescence distribution calculation means at a plurality of positions, the fluorescence emission amount of 3 To calculate the dimensional distribution,
3. The fluorescence according to claim 1, wherein the fluorescence tomographic image generation unit generates a three-dimensional fluorescence tomographic image of the measurement object based on the three-dimensional distribution of the fluorescence emission amount. CT device. The measurement object is a breast, the first ultrashort pulse light and the second ultrashort pulse light are near-infrared light, and the fluorescence tomographic image is a fluorescence tomogram in a cross section parallel to the breast wall of the breast The fluorescence CT apparatus according to any one of claims 1 to 3, wherein the fluorescence CT apparatus is an image. The fluorescence according to any one of claims 1 to 4, wherein the breast is preliminarily administered with a fluorescent reagent having an affinity for an abnormal tissue, and the fluorescence is mainly emitted from the fluorescent reagent. CT device.

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