EP2584957A1

EP2584957A1 - Device and method for combined optical and nuclear image acquisition

Info

Publication number: EP2584957A1
Application number: EP11727447.2A
Authority: EP
Inventors: Thomas Wendler; Nassir Navab
Original assignee: Technische Universitaet Muenchen; SURGICEYE GmbH
Current assignee: Technische Universitaet Muenchen; SURGICEYE GmbH
Priority date: 2010-06-23
Filing date: 2011-06-22
Publication date: 2013-05-01
Also published as: DE102010017543A1; US20130168570A1; US9146198B2; WO2011161197A1

Abstract

A device for combined optical and nuclear image acquisition comprises a nuclear image acquisition module (30) and a reference image acquisition module (60). The reference image acquisition module (60) has: an optical image sensor (70); and an optical imaging system (80) for deflecting the optical radiation from a reference field of view (66) to the image sensor (70), wherein the optical imaging system (80) comprises a mirror (82) for the optical radiation, which mirror (82) is arranged between the reference field of view (66) and the optical image sensor (70). On the image sensor (70), a respective image area (75) is assigned to at least one of nuclear partial fields of view (37). The optical imaging system (80) is arranged such that the optical radiation coming from the at least one nuclear partial field of view (37) is deflected substantially exactly to the respectively assigned of the image areas (75).

Description

description

DEVICE AND METHOD FOR COMBINED OPTICAL AND

NUCLEAR PICTURE CAPTION

The invention is in the field of image acquisition, in particular the combined optical and nuclear image acquisition, and relates to an apparatus for such image acquisition, in particular such a device with a nuclear image acquisition module for detecting an intensity distribution of a nuclear radiation and a

Reference imaging module for detecting an intensity distribution of an optical radiation. The invention further relates to a method for image acquisition.

Nuclear imaging techniques have proven to be extremely useful in various fields, particularly in nuclear medicine applications, as well as in the search for radioactively contaminated material such as nuclear waste. At the nuclear

Imaging technique visualizes the nuclear radiation coming from a space in a two- or three-dimensional image and thus for humans

made perceptible. The space area in which the spatial distribution of

Nuclear radiation can be detected with sufficient reliability is also referred to as a nuclear field of view. Even in cases where the boundaries of this space are fluid, the nuclear field of view can be meaningfully used e.g. by a given

Defining sensitivity thresholds for the radiation intensity and / or for the spatial resolution of the detector: The nuclear field of view is then the spatial area whose radiation passes through the detector with a sensitivity threshold

Sensitivity can be detected.

Despite their significant benefits, the evaluation of the generated nuclear images is difficult. This is also because the structures recognizable in the nuclear image can not easily be assigned to the structures perceptible with the naked eye. For example, hardly any anatomical structures are visible in a typical medical nuclear image.

This problem can be alleviated by placing radioactive markers in known anatomical positions. The markers can then be displayed in the nuclear image be recognized in order to get at least rough indications. Systems for hybrid SPECT / CT or PET / CT imaging are also known for superimposing nuclear images on CT images containing anatomical information. Also, methods are currently being developed to present three-dimensional nuclear images in appropriate perspective and superimpose them with a video image to collect anatomical and nuclear image information collectively.

Also, devices for the combined acquisition of X-ray and optical images are known, for example from DE 10049103, JP 61057804, US 2007/0019787, US 6,447,163 and US 3,679,901. However, the approaches used there are not easily transferable to the visualization of nuclear radiation, since the X-ray and nuclear imaging methods are based on different basic principles. In US 2007/0019787, the X-ray and optical images must also be recorded with a time delay. Moving samples can therefore not be detected optimally.

EP 0 743 538 describes an apparatus for remote localization of radioactive sources in an observation zone. The apparatus has a mirror and an optical camera for providing an image of the observation zone, and means for

Detecting radioactive rays. The means for detecting radioactive rays comprise a collimator with a single collimator aperture (pinhole collimator) which allows the acquisition of a spatially resolved nuclear image. The nuclear image can then be combined with the image of the optical camera. However, the achievable image quality of the nuclear image is limited by the pinhole collimator within a certain time frame.

Against this background, therefore, an apparatus for combined optical and nuclear image acquisition according to claim 1 and a method for image acquisition according to claim 13 is proposed. Further advantages, features, aspects and details of the invention as well as preferred embodiments and particular aspects of the invention will become apparent from the subclaims, the description and the figures.

According to one aspect of the invention, an apparatus for combined optical and nuclear imaging is proposed. The device comprises a, so at least one, nuclear imaging module; and a reference image acquisition module. The nuclear imaging module is one for detecting an intensity distribution Nuclear field of view, ie information on whether and optionally how many nuclear radiation particles were detected per location. The

A nuclear imaging module includes a nuclear radiation detector, and a collimator having a plurality of collimator apertures disposed between the nuclear field of view and the nuclear radiation detector, the or each of the collimator apertures for transmitting one of a respective nuclear partial field of view of the nuclear field of view coming partial radiation of nuclear radiation are arranged. The

A reference imaging module is configured to detect an intensity distribution of optical radiation from a reference field of view and comprises: an optical image sensor; and an optical imaging system for directing the optical radiation from the reference field of view to the image sensor, the optical imaging system comprising a mirror (with respect to the beam path) between the reference field of view and the optical image sensor for the includes optical radiation. On the image sensor is assigned to at least one, to several, or even to each of the nuclear partial fields of view, a respective image area, namely, the assignment is essentially by the optical imaging system and its arrangement: The optical imaging system is namely arranged to direct the optical radiation coming from a respective one of the at least one nuclear partial field of view or even from each of the nuclear partial visual fields substantially exactly to the respectively assigned one of the image areas. Thus, the imaging system is tuned to the collimator and the majority of the collimator openings.

In particular, thanks to the majority of the collimator openings recording a spatially resolved nuclear image of high quality is possible. In addition, the optical imaging system allows the nuclear image to be easily and effectively assigned an optical image in real time. The assignment may be for different room depths, i. in three dimensions, since the nuclear partial view fields including their image depth are assigned to the respective image areas of the optical image sensor.

The optical camera may comprise a laparoscope, endoscope, one or more general camera (s) or the like. Even cameras that can only record narrow (narrow band) and / or several separate frequency bands, eg multi-spectral cameras, or that emit light themselves for image acquisition, such as fluorescence cameras, interference cameras or time-of-flight cameras, can be used as optical Cameras used become. By optical radiation is meant herein any electromagnetic radiation deflectable by a mirror. This is usually in one

Wavelength range between 100 nm and 10 μιη wavelength possible. The mirror is accordingly suitable for reflecting the optical radiation at least to a considerable extent, but it can be transmissive to nuclear radiation. For example, the nuclear radiation may include neutron, alpha, beta, and / or gamma rays with e.g. more than 15 keV. Accordingly, the nuclear radiation detector may be a gamma, beta, Compton detector. The nuclear radiation detector may also include a

Nuclear field opposite nuclear radiation detector include, for. to detect low-noise PET signals.

According to a further aspect of the invention, the device for medical imaging, in particular for nuclear-guided surgery, nuclear medicine, and cell detection is advantageously used; In addition, the invention is also useful for the detection of radioactive waste.

The invention also relates to an apparatus for carrying out the disclosed methods and also includes apparatus parts for carrying out individual process steps. These method steps may be performed by hardware components, by a computer programmed by appropriate software, by a combination of both, or in some other way. The invention is further directed to methods according to which the devices described in each case operate. It includes steps to perform each function of the devices.

In addition, the invention with reference to shown in FIGS

Embodiments will be explained, from which further advantageous parts and

Variations result. To show:

Figure 1 shows a schematic side view of a device according to a first

Embodiment of the invention;

Figures 2-6 are respective schematic side views of apparatus according to second to sixth embodiments of the invention; FIG. 7a shows schematic diagrams of further embodiments with image calibration and generation modules;

Figure 8a shows a perspective view of a calibration element, and Figure 8b shows an image of this calibration element generated by the device; and

Figures 9a and 9b show different collimator openings in a frontal view.

In the figures, similar or corresponding elements are identified by the same reference numerals. Aspects and characteristics described herein, although described in conjunction with individual embodiments, may be combined as desired with other aspects, features, or embodiments to obtain other embodiments.

Figure 1 serves to illustrate some general aspects of the invention, which will be explained in the following. FIG. 1 shows a device 1 for combined optical and nuclear image acquisition according to an embodiment of the invention. The device 1 has a nuclear image acquisition module 30 and a reference image acquisition module 60. The

Nuclear imaging module 30 has a collimator 50 and a

Nuclear radiation detector 40, e.g. the shown in Fig. 2 in more detail

Nuclear radiation detector can be. The reference imaging module 60 includes an optical image sensor 70 and an optical imaging system 80 having a mirror 82 which reflects the optical radiation but is transmissive to nuclear radiation.

The collimator 50 has a plurality of collimator openings and is designed as a diverging Holes collimator: The collimator openings are directed away from a common approximately point-like center 32 and to a nuclear field of view 36 out. The center 32 is also referred to as a perspective nuclear radiation center 32. For a sufficiently long collimator 50, this geometry of the collimator 50 allows the detector 40 to obtain a perspective spatially resolved nuclear radiation image of the nuclear radiation in the nuclear field of view 36: Namely, each of the collimator apertures defines a partial field of view of the nuclear field of view 36 towards the center 32; such that the detector 40 detects in a corresponding image area of the nuclear radiation image the radiation coming from the corresponding partial field of view. This becomes a spatially resolved Perspective nuclear image generated with perspective center 32. Accordingly, the nuclear field of view 36 as a whole also has a lateral boundary directed essentially toward the center 32. For a finite collimator length, such a perspective image is generated at least approximately.

The optical imaging system 80 is arranged to direct optical radiation from the reference field of view 66 to the image sensor 70. Also, the optical imaging system 80 is arranged to produce a perspective image, i. the optical radiation is directed from the reference field of view 66 to the image sensor 70 such that optical radiation originating from respective partial volumes converging onto a virtual optical center 62 'is directed onto respective image areas of the image sensor. The position of the center 62 'is defined by the unspecified perspective center 62 and the mirror 82. The mirrored-on perspective center 62 is in turn given by a camera optics (with lenses and aperture) associated with the image sensor 70 and possibly other optical elements. In Fig. 1, the unreflected perspective center 62 is shown lying behind the image sensor 70, but depending on the optical elements, it may also be in front of the image sensor 70. The reference field of view 66 has a lateral boundary directed substantially towards the virtual optical center 62 '. FIG. 1 also shows an arbitrarily selected front boundary of the reference field of vision or of the nuclear field of view. Likewise, there may be a rear boundary. These limits may be determined, for example, by the accessibility of the measurement space, the sensitivity of the nuclear radiation detector 40, and the like. Herein, a limitation is essentially understood to mean the lateral boundary in the region lying in front of the outermost mirror or other optical element.

In Fig. 1, the position and orientation of the image sensor 70, the mirror 82 and optionally other optical elements is selected so that the position of the virtual optical center 62 'substantially coincides with the position of the nuclear image center 32 , In order to achieve a matching position of the two centers 32, 62 ', provision must in particular be made for the (real) center 62 and the center 32 to be at the same distance from a center of the mirror 82. By matching the centers 32, 62 ', the reference image acquisition module 60 is able to capture an optical image with the same perspective as a nuclear image captured by the nuclear imaging module 30. The common perspective allows a good spatial allocation of the nuclear image with the optical Image in the entire spatial area within the reference field of view or the nuclear field of view. In Fig. 1, the nuclear field of view 36 and the reference field of view 66 are even equal. However, this is not a necessary condition. For example, alternatively, the nuclear field of view 36 could be included in the reference field of view 66, or conversely, or the nuclear field of view 36 and reference field of view 66 could overlap in some other way.

Fig. 2 shows a device similar to that shown in Fig. 1 with some further details. The description of Fig. 1 also applies to Fig. 2 accordingly, and in the following only the further details will be described. 2, further details of the nuclear radiation detector 40 are shown including a scintillator 46 and an array of photodiodes 48. The collimator 50 is disposed in front of the scintillator 46 in the beam direction and has a plurality of collimator openings 52. As further details of the

Reference imaging module 60, a lens assembly 86 are shown in addition to the optical image sensor 70. The lens arrangement determines the location of the unsealed perspective center 62. In addition, lateral boundaries 34, 35 of the nuclear field of view 36 and lateral boundaries 64, 65 of the reference optical field of view 66 are shown in FIG.

Further, in Fig. 2 for one of the collimator openings 52 of the collimator 50 by way of example the corresponding partial field of view 37, bounded laterally by the boundaries 34, 34 a, shown. The collimator openings 52 are arranged so that they from the

Nuclear partial field of view 37 transmits incoming nuclear radiation. The collimator opening 52 or the partial field of view 37 is associated with a corresponding image area of the scintillator 46, so that the scintillator 46 and thus the detector 40 in this image area detects the radiation coming from the partial field of view 37. Since the remaining collimator openings are designed in a corresponding manner, a spatially resolved perspective nuclear image with a perspective center 32 and one through the collimator 50 becomes altogether

generated predetermined resolution. In this description blurring of the nuclear image due to the finite length of the collimator is neglected. This neglect is to be maintained below. Especially if certain relations "im

Essentially "fulfilled are described, this should include a neglect of such blurring. By the coincidence of the nuclear radiation center 32 and the virtual optical center 62 ', the reference image acquisition module 60 is capable of capturing an optical image having the same perspective as the nuclear image acquisition module 30. Therefore, there is a partial optical field of view corresponding to the nuclear partial field of view 37, namely the partial field of view bounded by the lateral boundaries 64 and 64a. The optical radiation coming from this partial optical field of view is detected on an image area 75 of the optical image sensor 70. Thus, the image area 75 is associated with the nuclear partial view field 37. This assignment is essentially made by the optical imaging system 80 and its arrangement: The optical imaging system 80 is arranged to direct the optical radiation coming from the nuclear partial field of view 37 substantially exactly to the image area 75.

In order for the centers 32 and 62 'to coincide, it is appropriate that the distance 1 _{Q of} the optical center 62 from a center of the mirror 82 and the distance l _{n of} the nuclear radiation center 32 from the center of the mirror 82 are equal. Furthermore, it is expedient for the aperture a _Q or the angle a _{0 of} the optical image sensor 70 or the associated optical arrangement 86 to be greater than or the same as the aperture a _n predetermined by the collimator 50 (at the same distance from the center 32 referred to as the aperture a _Q ) or the angle a _n . In FIG. 2, the apertures or angles are chosen to be the same, so that the nuclear field of view 36 and the reference field of view 66 coincide.

Further, in Fig. 2, an optional rigid frame 10 is shown schematically. The frame 10 rigidly interconnects the optical image sensor 70 and the nuclear radiation detector 40. The rigid connection does not exclude that the optical image sensor 70 and the nuclear radiation detector 40 are movable relative to each other, for example, by means of calibration, adjustment elements or the like. However, the frame 10 allows a rigid and reliable connection at least during operation. Thus, the association between the image area 75 and the nuclear partial field of view 37 is assured. Also, the mirror 82 and other optical elements may be rigidly connected to the frame 10.

Fig. 3 shows an embodiment similar to Fig. 2. Apart from the differences described below, the description of FIGS. 1 and 2 also applies to FIG. 3. In contrast to FIG. 2, in FIG. 3, the collimator 50 has parallel openings 52. A perspective center 32 as in FIG. 2 therefore does not exist or is infinite postponed. The nuclear partial view fields 37 defined by the respective collimator openings 52 run parallel to one another and do not expand substantially, ie neglecting the finite collimator length. Thus, that has

Nuclear imaging module 30 of FIG. 3 does not have perspective but telecentric imaging properties.

Correspondingly, the reference image acquisition module 60 or the optical imaging system 80 has telecentric imaging properties, so that the optical radiation coming from the nuclear partial field of view 37 is directed substantially exactly to a respectively assigned one of the image regions 75, analogously to Figure 2 described. The telecentric imaging properties of the optical imaging system 80 can be achieved, for example, by means of a telecentric objective lens. Alternatively, an optical radiation collimator with a spatially resolved optical detector 70 disposed behind it may also be used to realize the telecentric imaging properties in an analogous manner as the nuclear imaging module. As a spatially resolved optical detector 70 is about a CCD camera (possibly without further objective optics) or an array of photodiodes low sensitivity into consideration. An array of optical fibers in this case can guide the light from one end of the optical collimator to the optical detector.

FIG. 4 shows a further modification of that shown in FIG

Embodiment. Again, apart from the differences described below, the description of FIGS. 1 and 2 also applies correspondingly to FIG. 4. In FIG. 4, the reference image acquisition module comprises, in addition to the (first) image sensor 70, a second image sensor 74, and the optical imaging system 80 comprises, in addition to the (first) mirror 82, a second mirror 84. The optical field of view of the first image sensor 70 is bounded laterally by the lines 64, 65, and the first mirror 82 is arranged to mirror this field of view 66a so as to cover an (upper) portion of the nuclear field of view 36. The optical field of view of the second image sensor 74 is bounded laterally by the lines 68, 69, and the mirror 84 is arranged to mirror this field of view 66b so as to cover another (lower) part of the nuclear field of view 36. Together they form the

Fields of view 66a and 66b the field of view 66 of the reference image acquisition module. In Figure 4, the field of view 66 of the reference imaging module is substantially equal to the nuclear radiation field of view 36. The field of view 66 may also be the nuclear radiation field of view 36 just overlap. The rigid frame 10 is rigidly connected to the second image sensor 74 and the mirrors 82, 84 in addition to the first image sensor 70 and the nuclear radiation detector 40.

Thus, the second mirror 82 directs the optical radiation from the reference field of view 66, more specifically from the portion 66a of the reference field of view 66, to the second image sensor 74. Similar to what has already been described with respect to FIGS. 1 and 2 Also in FIG. 4, the virtual centers of the image sensors 70, 74 and the perspective center of the collimator 50 coincide. Due to the coincidence of the centers, the optical images captured by the image sensors 70, 74 have the same perspective as that of the

Nuclear Imaging Module 30 captured nuclear image. This in turn allows a good spatial allocation of the nuclear image with the respective optical images or with a composite optical image of the image sensors 70 and 74th

FIG. 5 also shows a device 1 with two image sensors 70, 74, and the description of FIGS. 1, 2 and 4 also applies to FIG. 5, with the exception of the differences described below. The first image sensor 70 and the first mirror 82 are arranged as shown in FIGS. 1 and 2. The first image sensor 70 is arranged to receive optical radiation of a first type, e.g. a first polarization or a first wavelength range to detect. The first mirror 82 is arranged to mirror the optical radiation of the first kind as described in FIGS. 1 and 2. The second image sensor 74 is arranged to receive optical radiation of a second type, e.g. a second polarization or a second wavelength range to detect. The second mirror 84 is arranged to mirror the second type optical radiation as described in FIGS. 1 and 2, but to transmit the first type optical radiation. Also in Fig. 5, the respective virtual centers of the image sensors 70, 74 and the perspective center of the collimator 50 coincide. Due to the coincidence of the centers, the optical images captured by the image sensors 70, 74 and the nuclear image captured by the nuclear image acquisition module 30 have a single common perspective. This in turn allows a good spatial allocation of the nuclear image and the optical images of the image sensors 70 and 74 with each other. All three images can have the same spatial allocation

be overlaid with each other. By being able to selectively detect optical radiation of various types, additional information can be obtained via the reference field of view 66 and an optical image with improved contrast can be obtained. Fig. 6 shows a device for which in turn the description of Figures 1 and 2 applies mutatis mutandis, apart from the differences described below. In FIG. 6, instead of just a single mirror 82, an arrangement with a plurality of mirrors 82, 84 is shown. The optical radiation coming from the reference field of view 66 is first reflected by the mirror 82 and then by the mirror 84 towards the image sensor 70. The position and orientation of the mirrors 82, 84 and optionally further optical elements is selected so that the position of the virtual optical center 62 'substantially coincides with the position of the nuclear image center 32. Through the further mirror 84, the position of the image sensor 70 can be selected more freely and thus a total of a more compact

Arrangement of the elements of the reference image acquisition module 60 can be achieved.

The devices shown in Fig. 1 to 6 can be further varied. For example, in some of the devices shown, only one collimator with diverging openings is shown. However, a collimator with parallel openings is also possible. In this case, the reference image acquisition module 60 has correspondingly adapted telecentric imaging properties as described with reference to FIG. Furthermore, a still different aperture geometry of the collimator may be chosen, e.g. Multipinhole collimators, converging collimators, Aperture Coded collimators, etc., and also in this case, the imaging characteristics of the reference imaging module 60 are to be adjusted accordingly so that the optical radiation coming from each of the partial nuclear view fields is substantially exactly related to each associated image area of the optical image sensor 70 is directed.

In Figure 7a is another embodiment with a module for

Image calibration and generation shown. A calibration module 90 is connected to the image sensor 70 and the nuclear radiation detector 40. The calibration module 90 allows mapping of spatially coincident image coordinates of one of the

Nuclear radiation detector 40 detected nuclear radiation image and an image captured by the image sensor 70 optical image. In the simplest case, the calibration module can simply include a table or calculation rule generated, for example, during the production of the device, which performs this assignment. However, in other embodiments, it is desired to allow such assignment by the user. For this case, the calibration module may include a user-definable calibration routine. Such a calibration routine is shown below with reference to FIGS. 8a and 8b. Fig. 8a shows a calibration element 2. The calibration element has eight markers 3, which are arranged in a fixed spatial relationship to each other (such as by a rigid connection frame, as indicated in Fig. 8a by lines). The spatial arrangement shown in FIG. 8a is particularly advantageous: four of the markers 3 are arranged planar in a first plane (lower plane) in a first rectangular arrangement, and four further of the markers 3 are planar in a second plane (upper plane) in FIG a second rectangle arrangement, wherein the second rectangle arrangement defines a smaller rectangle area than the first rectangle arrangement. The first and second planes are arranged parallel to each other, and the two rectangle assemblies are arranged around a common central axis perpendicular to the first and second planes.

The markers 3 emit radiation which can be recognized both by the optical image sensor 70 and by the nuclear radiation detector 40. The markers 3 may also reflect optical radiation in a further embodiment. In embodiments, this radiation can be approximated approximately by a point radiation source. The signals of the eight markers 3 are thus detected by the nuclear radiation detector 40 and by the image sensor 70 and transmitted to the calibration module 90. FIG. 8 b shows an image of the calibration element 2 with the markers 3 taken by the nuclear radiation detector 40 or by the image sensor 70. The markers 3 may, but need not be, point radiation sources. Thus, the markers 3 may be formed in a further embodiment, but also as lines, patterns, or surfaces, etc ..

The calibration module 90 has an image evaluation function, which is the respective image coordinates of the eight markers 3 (see Fig. 8b) in the of the

Nuclear radiation detector 40 detected nuclear radiation image and in the detected by the image sensor 70 optical image. As a result, an assignment of at least these image coordinates is possible. Because of these image coordinates can also the rest

Image coordinates of the nuclear radiation image and the optical image are assigned by interpolation. Already sufficient for the assignment, the positions of three markers. Due to the total of eight markers the problem of assignment is overdetermined. This additional overdetermined information can be used by a suitable interpolation algorithm for error correction and to achieve a more reliable association. Also, multiple exposures of the calibration element 2, such as in various orientations, may similarly be used to provide an even more robust and more reliable association of spatially coincident image coordinates of the

Nuclear radiation image and the optical image. This calibration is possible due to the particular imaging properties of the reference imaging module described above. Only thanks to the particular imaging properties described above-namely, that the optical radiation coming from a respective one of the nuclear partial fields of view is directed substantially exactly to the respective assigned image areas-are the three-dimensionally arranged markers 3 calibrated without any contradiction. Formally, this manifests itself in the fact that the overdetermined system of equations for the assignment of the

Image coordinates is solved (or that still existing insoluble equations of the equation system must be based on inaccuracies and thus can be compensated).

The calibration module also allows manual operation. Here the two images, the optical image and the nuclear radiation image, are overlaid as partial images and can be manually moved against each other and distorted until all marker positions overlap with sufficient accuracy.

In another embodiment, the calibration element 2 may also be used to position the reference imaging module 60 or elements thereof relative to elements of the nuclear imaging module 30 (see, e.g., Fig. 2). For example, the image sensor 70 or the mirror 82 may be positioned until all the markers 3 overlap with sufficient accuracy. This calibration may be manual or included in a calibration module position calibration routine that issues corresponding instructions for positioning elements of the reference imaging module 60 relative to elements of the nuclear imaging module 30.

Next, an overlay module 92 is shown in Fig. 7a. The overlay module 92 receives the image information from the nuclear radiation detector 40 and the image sensor 70 and receives association information from the calibration module 90. Using this information, the overlay module 92 overlays the nuclear radiation image (first field) with the optical Picture (second picture) to a common

superposed image in which spatially mutually associated image areas of the respective sub-images are superimposed. The overlay module 92 then outputs the overlaid image to an image display 98. The respective image portion of the partial images can be replaced by a Controller adjustable or fixed. Also, the overlay module 92 may be switchable between the output of both fields to output either one or the other field or possibly a superimposed image. An advantage of the embodiment is that calibration is required only when changes are made to the nuclear imaging module and / or to the reference imaging module

be made. In the absence of such changes, the device can be used immediately and without further calibration.

Various shapes of the collimator openings of the collimator 50 are shown by way of example in FIGS. 9a and 9b in a frontal view (viewed from the direction of the nuclear field of view 36 in FIG. 1, ie from the left). These collimator openings can

be divergent or arranged in parallel. In Fig. 9a, an arrangement is shown as a regular square matrix of picture elements resulting in a pixel-like picture. In Fig. 9b, the collimator openings 50 are each elongate in shape and extend in different directions. As a result, in particular anisotropic structures can be easily recognized. The collimator 50 of Figure 9b may be rotatable. Also another e.g.

honeycomb arrangement of hexagonal collimator openings is possible.

The reference image acquisition module is adapted in a corresponding manner to the shape of the collimator openings, so that corresponding image areas are defined on the image sensor, on which the optical radiation coming from the respective nuclear partial field of view is directed. In the case that the image sensor is a pixel sensor, only the affiliation of the individual pixels of the pixel sensor to the respective image areas associated with the collimator openings differs. Alternatively, the reference image acquisition module may also be e.g. be equipped with an optical collimator. In this case, the optical collimator may be designed according to the collimator 50.

In the following some other general aspects of embodiments are described, which can be combined with any of the embodiments described herein. In one aspect, the optical image sensor is a pixel sensor and the image area is a pixel area. In another aspect, the reference field of view substantially completely includes the nuclear field of view. According to a further aspect, a respective image area is assigned to a plurality of the nuclear partial view fields or even to each of the nuclear partial view fields on the image sensor. In another aspect, the nuclear radiation detector is eg a gamma, beta, Compton camera, and / or a PET detector. According to a further aspect, the nuclear radiation detector comprises a collimator, a scintillator and a photodiode array, or equivalent nuclear radiation detector arrangements, such as semiconductor detectors for direct detection of radiation, scintiators with connected photomultiplier tubes (PMT), scintiators with connected silicon photomultipliers (SiPM), etc. In another aspect, the nuclear imaging module has two opposing nuclear radiation detectors for detecting positron emitters.

In another aspect, the collimator is a diverging-holes collimator, and the optical imaging system is focusing. In another aspect, the collimator is a parallel-hole collimator, and the optical imaging system is substantially telecentric, e.g. a telecentric

Lens arrangement or parallel hole collimator with telecentric

Imaging properties. Also, an approximate telecentric lens is considered to be telecentric: Telecentric may also mean that a perspective center of the lens array is not at infinity, but is more than five times, but more preferably, more than ten times farther from the mirror than the optical image sensor. In another aspect, the collimator is a multipinhole collimator, a cover-go holed collimator, a slanted-hole collimator, or a

Aperture-coded collimator, and the optical system is designed to have corresponding imaging characteristics (e.g., also using a corresponding collimator).

In a further aspect, the nuclear image acquisition module defines a nuclear radiation center for the nuclear radiation and the nuclear radiation center

The reference imaging module defines a virtual perspective optical center for the optical radiation, wherein the nuclear radiation center and the virtual optical center are connected to substantially, i. are arranged in the usual position, the same position.

In another aspect, the image sensor is a first image sensor and the mirror is a first mirror, and the reference image capture module has a second optical one Image sensor and a second mirror for directing the optical radiation of the

Reference field of view to the second image sensor. In another aspect, the mirrors are arranged to direct first portion of the optical radiation from the first mirror to the first image sensor, and direct a second portion of the optical radiation from the second mirror to the second image sensor. In another aspect, the

Nuclear radiation detector and the image sensor arranged on the same side of the reference field of view.

In another aspect, the device has a rigid frame which rigidly interconnects the optical image sensor and nuclear radiation detector (in use), but e.g. Calibration screws or other outside the actual use may contain movable elements. In another aspect, the apparatus is equipped to output superimposed images as real-time images and / or moving images.

According to another aspect, the apparatus further comprises a calibration module for assigning spatially coincident image coordinates of one of

Nuclear radiation detector detected nuclear radiation image and an image captured by the image sensor optical image. In another aspect, the apparatus further includes an overlay module for overlaying the nuclear radiation image and the optical image into a common overlaid image. In another aspect, the apparatus further includes a spatial imaging imaging system for reconstructing a three-dimensional reconstruction image from nuclear image data, such as by known methods for 3d image reconstruction, and placing the three-dimensional reconstruction image in an image memory , In particular, the nuclear image data may include data generated by the nuclear sensor. In another aspect, the apparatus includes a virtual image generation system for generating a virtual perspective image from data stored in the image memory such that the virtual perspective image has the same perspective as the optical image. In another aspect, the virtual image generation system is programmed to associate the virtual image and the optical image, such as by associating optical markers contained within the optical image. In another aspect, the virtual image is a nuclear image. In another aspect, the device includes an image display. According to a further aspect, the device is a medical imaging device for determining a tracer concentration in the body of a living being, for example a human.

Claims

Claims:

A combined optical and nuclear imaging apparatus comprising a nuclear imaging module (30); and a reference imaging module (60), wherein the nuclear imaging module (30) is for detecting an intensity distribution of nuclear radiation from a nuclear field of view (36) and comprises:

a nuclear radiation detector (40); and a collimator (50) disposed between the nuclear field of view (36) and the nuclear radiation detector (40) having a plurality of collimator apertures (52), the collimator apertures (52) permitting passage of one and wherein the reference image acquisition module (60) is for detecting an intensity distribution of an optical radiation coming from a reference field of view (66) :

an optical image sensor (70); and an optical imaging system (80) for directing the optical radiation from the reference field of view (66) to the image sensor (70), the optical imaging system (80) interposing between the reference field of view (66) and the optical radiation mirror (82) arranged in the optical image sensor (70), wherein a respective image area (75) is associated with at least one of the partial nuclear view fields (37) on the image sensor (70), and wherein optical imaging system (80) is arranged in order to direct the optical radiation coming from the at least one of the respective one of the partial nuclear view fields (37) substantially exactly to the respectively assigned one of the image areas (75).

The apparatus of claim 1, wherein the optical image sensor (70) is a pixel sensor, and wherein the image area (75) is a pixel area.

The apparatus of any one of the preceding claims, wherein the reference field of view (66) fully includes the nuclear field of view (36), and wherein each of the nuclear sub-fields (37) on the image sensor (70) has a respective image area (75) is assigned.

4. Device according to any one of the preceding claims, wherein the

Nuclear radiation detector (40) is selected from the set consisting of gamma, beta, Compton camera, PET detector.

The apparatus of any one of the preceding claims, wherein the collimator (50) is a diverging-holes collimator and the optical imaging system (80) is focusing, or wherein the collimator is a parallel-hole collimator and the optical imaging System is essentially telecentric.

6. Device according to any one of the preceding claims, wherein the

A nuclear imaging module (30) defines a nuclear radiation nuclear radiation center (32) for nuclear radiation, and the reference imaging module (60) defines a virtual optical radiation perspective optical center (62 '), and wherein the nuclear radiation center (32) and the virtual optical center (62 ') are arranged at substantially the same position.

A device according to any one of the preceding claims, further comprising a rigid frame (10) rigidly interconnecting the optical image sensor (70) and nuclear radiation detector (40).

Apparatus according to any one of the preceding claims, further comprising a calibration module (90) for allocating spatially coincident image coordinates of a nuclear radiation image captured by the nuclear radiation detector (40) and an optical image captured by the image sensor (70) further comprising a comprehensive Overlay module (92) for overlaying the nuclear radiation image and the optical image into a common overlaid image.

A device according to any one of the preceding claims, wherein the optical camera is selected from the list comprising CCD digital camera, CMOS digital camera, multi-spectral camera, narrow-band camera, fluorescence camera, interference camera and time-of-flight camera ,

10. A method of image capture, comprising

(a) detecting an intensity distribution of nuclear radiation coming from a nuclear field of view (36) by a nuclear image acquisition module (30)

Nuclear imaging module (30) includes a nuclear radiation detector (40) and a

Having collimator (50) with a plurality of collimator openings (52), wherein partial radiation of nuclear radiation coming from a respective nuclear partial field of view (37) of the nuclear field of view (36) is transmitted through a respective one of the collimator openings (52), and then detected by a nuclear radiation detector (40);

(b) directing, by an optical imaging system (80), an optical radiation coming from a reference field of view (66), to an optical image sensor (70) on which image sensor (70) at least one, preferably to each of the nuclear partial field of view (37) is associated with a respective image area (75), wherein a mirror (82) of the optical imaging system (80) redirects the optical radiation so that the radiation from each of the partial nuclear viewing fields (37 ) coming optical radiation is directed substantially exactly to the respectively associated with the image areas (75); and

(c) detecting an intensity distribution of the optical radiation directed to the image sensor (70) by an optical image sensor (70) of the reference image acquisition module (60).

11. The method of claim 10, further comprising associating spatially coincident image coordinates of a nuclear radiation image acquired by the nuclear radiation detector (40) and an optical image captured by the image sensor (70) using a calibration Module (90), and preferably further comprising superimposing the nuclear radiation image as the first field and the optical image as a second field to a common superposed image, in the spatially mutually associated image areas of the respective

Sub-images are superposed with each other, by means of a superposition module (92).