CN103622673B - A kind of autofluorescence tomography molecule image equipment of magnetic resonance compatible - Google Patents

Abstract

The invention discloses a magnetic resonance compatible autofluorescence tomography molecular imaging device, comprising: an optical imaging device, the optical imaging device is provided with a shielding shell and an optical dark box, and an imaging device is arranged in the optical dark box; a guide rail, the The two ends of the guide rail are respectively located in the existing medical magnetic resonance equipment and the optical imaging equipment, and the guide rail is provided with a bearing platform for carrying small animals, and the bearing platform can slide on the guide rail. The shielding shell isolates the mutual interference between the magnetic resonance equipment and the optical imaging equipment; the carrying platform ensures that the small animal does not need to be suspended, and its posture remains unchanged during magnetic resonance imaging and optical imaging. Using two mirrors and a rotating wheel, the optical imaging device can collect multi-angle and multi-spectrum autofluorescence data in one plane. Based on the autofluorescence data, combined with the structural data provided by the magnetic resonance equipment, high-precision three-dimensional imaging is realized.

Description

A Magnetic Resonance Compatible Autofluorescence Tomography Molecular Imaging Device

technical field

The present invention relates to a magnetic resonance-compatible autofluorescence tomography molecular imaging device, more specifically, it relates to a multi-spectral and multi-angle autofluorescence tomography device combined with magnetic resonance, which can realize biological internal Noninvasive real-time dynamic in vivo imaging of physiological or pathological processes.

Background technique

According to the concept of molecular imaging proposed by Weissleder, all biomedical imaging methods that can characterize and measure biological processes in vivo at the cellular and molecular levels belong to the category of molecular imaging. Currently common molecular imaging modalities mainly include nuclide imaging, such as positron emission tomography, single photon emission computed tomography, magnetic resonance imaging, optical imaging, and ultrasound imaging. Each modal imaging technology has its own advantages and disadvantages, and the differences between the modalities are mainly reflected in the temporal or spatial resolution, penetration depth, imaging cost, sensitivity, and damage to the imaging object. Among them, compared with other in vivo imaging techniques, optical molecular imaging has many unique advantages such as simple operation, fast measurement, intuitive results, no radiation, high sensitivity and low equipment cost, and has developed into an ideal living small animal However, the research on bulk optical molecular imaging technology is still in its infancy, and there are key scientific issues in imaging algorithms and imaging systems. The problem has not been resolved.

The imaging review entitled "Animal Imaging-the Whole Picture" published in Nature in February 2010 compared the application occasions and parameters of several major imaging techniques currently in the research and application stages. The paper points out that in view of the respective advantages and limitations of various imaging modalities, the fusion of multiple imaging modalities (such as PET/CT, SPECT/CT, PET/MR, MR/CT, etc.), is the so-called multimodal imaging ( Multimodalities), constructing multi-dimensional, color images is the best choice. In recent years, in the field of biomedical sciences, more and more researches have been carried out in a multimodal way.

In the prior art, Chinese invention patent specification CN101301192B discloses a multi-modal autofluorescence tomographic imaging device. The signal acquisition module of the device adopts small animal suspension and rotation to collect fluorescence and X-ray signals from multiple angles, and performs multi-modal fusion and reconstruction. The position of the light source inside the organism. X-rays are not very effective in soft tissue imaging, and the internal organs of small animals have large deformations in the hanging posture, and the single-spectrum data is insufficient, all of which are unfavorable to the reconstruction effect. A multi-spectral fluorescence tomographic imaging device is also disclosed in the Chinese utility model patent specification CN202568208U, which uses filters to obtain multiple fluorescent images for optical three-dimensional reconstruction, but uses a frontal single-angle optical signal, and does not provide Imaging with other modalities is used to provide tissue structure for 3D reconstruction.

Contents of the invention

In view of the defects existing in the prior art, the object of the present invention is to provide a magnetic resonance compatible autofluorescence tomography molecular imaging device, including:

Optical imaging equipment, the optical imaging equipment is provided with a shielding case and an optical dark box, and the optical dark box is provided with an imaging device;

A guide rail, one end of the guide rail is located in the optical imaging device, and a bearing platform for carrying small animals is arranged on the guide rail, and the bearing platform can slide on the guide rail.

On the basis of the above technical solution, a heating pad is provided in the object stage.

On the basis of the above technical solution, two reflection mirrors are arranged on the object stage.

On the basis of the above technical solution, a lens is arranged above the object stage, and the lens is fixed on the top of the optical dark box.

On the basis of the above technical solution, a rotating wheel is arranged between the stage and the lens, and bandpass filters with different central wavelengths are arranged on the rotating wheel.

On the basis of the above technical solution, the optical dark box is arranged in the shielding shell, and the shielding shell is provided with an outer shielding door and an inner shielding door, and a transition space is formed between the outer shielding door and the inner shielding door.

On the basis of the above technical solution, the optical dark box is made of opaque material, and the shielding shell is made of high magnetic permeability material.

On the basis of the above technical solution, the guide rail is provided with a small animal coil.

The magnetic resonance-compatible autofluorescence tomography molecular imaging device provided by the present invention works in cooperation with the magnetic resonance device, one end of the guide rail is located in the optical imaging device, and the other end is located in the magnetic resonance device, and the carrying platform can move along the sliding between the optical imaging device and the magnetic resonance device along the guide rail.

The beneficial effect of the present invention is that: the magnetic shielding design is adopted, the optical imaging equipment is placed in the magnetic resonance room, and the small animal posture is kept unchanged through the guide rail transmission, which is extremely important for optical three-dimensional tomographic reconstruction. The double-layer isolation door design completely isolates the magnetic field of the magnetic resonance equipment from interfering with the optical imaging equipment.

The use of magnetic resonance to provide structural information of small animals has higher soft tissue spatial resolution than the traditional computerized tomography method, which is conducive to more accurate segmentation of small animal internal soft tissues, thereby improving the accuracy of optical three-dimensional tomographic reconstruction.

Using two mirrors and rotating wheels, the optical imaging equipment can capture multi-angle and multi-spectral autofluorescence information in one plane. More data, less morbidity in autofluorescence tomography theory.

In the traditional autofluorescence system combined with computed tomography imaging, small animals are placed in a suspended state, and the internal organs are deformed and difficult to fix, making the experiment inconvenient. The present invention adopts the carrying platform, and the small animals do not need to be suspended, and the experiment is more convenient.

Description of drawings

Fig. 1 is a structural diagram of a magnetic resonance compatible autofluorescence tomography molecular imaging device of the present invention;

Fig. 2 is a schematic structural diagram of the shielding case of the present invention;

Fig. 3 is a schematic structural diagram of the optical imaging device of the present invention;

Fig. 4 is a flow chart of experiments using a magnetic resonance-compatible autofluorescence tomography molecular imaging device of the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

Please refer to Fig. 1. Fig. 1 is a structural diagram of a magnetic resonance-compatible autofluorescence tomography molecular imaging device. The optical dark box 105 is connected to the magnetic resonance device 101 through the guide rail 104, so as to ensure the uniform posture of the small animal 102 and ensure the safety of the small animal in the subsequent steps. The internal organs are not deformed. The optical signal and magnetic resonance are scanned sequentially. The small animal 102 is sent into the optical dark box 105 and the small animal coil 103 through the guide rail 104 .

Please refer to FIG. 2 . FIG. 2 is a schematic diagram of the structure of the shielding shell; it demonstrates how the small animal 102 enters the inner compartment 205 of the optical obscura. The small animal 102 is placed on the guide rail 104 . Both the outer cabin door 202 and the inner cabin door 204 are in a closed state. First, the outer cabin door 202 is opened, and the small animal 102 automatically runs to the transition cabin 203 along the guide rail 104 . The outer cabin door 202 is closed, and the inner cabin door 204 is opened. The small animal 102 runs along the guide rail 104 to the inner cabin 205, and the inner cabin door 204 is closed. The small animal 102 goes out of the cabin and adopts the opposite process. The material of the shielding shell is permalloy, so as to achieve the effect of isolating the magnetic field of the optical equipment and the magnetic resonance equipment.

3 is a schematic diagram of an optical imaging device. It includes a shielding case 301 and an optical dark box 302, and axial flow fans 303 and 315 form a convective air flow for cooling the camera. A high-sensitivity EMCCD camera 304 and a lens 305 are used to capture optical signals. The lens 305 is fixed above the rotating wheel 306 , and the filter 307 is placed at different holes of the rotating wheel 306 . Multispectral optical signals may be acquired. Optical signals of different wavelengths can be photographed by rotating the rotating wheel 306, so as to obtain multi-spectral information. LED white light lamps 308, 314 can provide white light illumination in the dark box 302, which is convenient for photographing the white light surface of the small animal 102. The high-reflectivity thin-film mirrors 309 and 313 provide optical information on two sides, and realize simultaneous collection of optical signals from multiple angles. The stage 311 adopts a movable design up and down to make the optical focusing more flexible. A heating pad 312 is used inside the stage 311 to ensure that the body temperature of the small animal is constant during the experiment.

Figure 4 is a complete experimental flow chart of the small animal experiment. Combined with real animal experiments, the working process of the device is explained in detail. The small animal 102 is pretreated and anesthetized accordingly, injected with the substrate, and fixed on the guide rail 104 . The fans 303 and 315 are turned on, the camera 304 is powered on, semiconductors are used to cool down to the working temperature, the heating pad 312 is turned on, the focal length of the lens 305 and the height of the stage 311 are adjusted for optical focusing. The small animal 102 is sent into the small animal coil 103, and together with the small animal coil 103 enters the scanning chamber of the magnetic resonance equipment 101 for scanning. Next, on the one hand, the acquired magnetic resonance volume data is segmented using a semi-automatic method, and the contours of the body surface and organs of the small animal are obtained and subdivided. On the other hand, optical photography is performed in an optical darkroom 302 . The small animal 102 is transported to the entrance of the optical equipment through the guide rail 104, and enters the interior of the optical dark box according to the cabin entry steps shown in FIG. 2 . The rotation of the rotating wheel 306 is controlled to switch filters 307 of different wavelengths to shoot the fluorescence signal, and the exposure time is adjusted according to the intensity of the fluorescence light, which is between 10s and 180s. After photographing the fluorescent signal, white light photography is required. The rotating wheel 306 is switched to the position without filter, the LED white light lamps 308, 314 are turned on, and the white light signal is photographed with an exposure time of 0.1s. After the optical signal is taken, the registration and surface mapping of the optical signal and the magnetic resonance data are carried out. The magnetic resonance data registration is carried out automatically based on the contour of the small animal 102, and the surface light is carried out based on the free-space light propagation model of the Lambertian source. strong mapping. Based on the diffusion model, the finite element method is used to perform accurate reconstruction of the position and size of the light source.

The invention adopts the magnetic shielding design, places the optical equipment in the magnetic resonance room, and transmits it through the guide rail to keep the posture of the small animal unchanged, which is extremely important for optical three-dimensional tomographic reconstruction. The double-layer isolation door design completely isolates the mutual interference between the magnetic field and the equipment.

The use of magnetic resonance to provide biological structure information has better soft tissue resolution characteristics than the traditional method of computer tomography. In optical reconstruction, the accurate imaging of soft tissue has a great impact on tissue segmentation.

The rotating wheel is used to control the multi-spectral acquisition, and the multi-mirror design enables multi-angle and multi-spectral autofluorescence information to be captured on one plane. More data, less morbidity in autofluorescence tomography theory.

Compared with the traditional autofluorescence system combined with computed tomography imaging, small animals are placed in a suspended state, which causes large deformation of internal organs, and small animals are not easy to fix in a suspended state, which often brings inconvenience. The invention adopts the mirror surface to shoot the optical signal and collects the structure information through the magnetic resonance, the small animal does not need to be suspended, and the experiment is more convenient.

The present invention is not limited to the above-mentioned embodiments. For those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also considered protection of the present invention. within range. The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (5)

1. A magnetic resonance compatible autofluorescence tomography molecular imaging device, characterized in that it comprises: Optical imaging equipment, the optical imaging equipment is provided with a shielding case and an optical dark box, and the optical dark box is provided with an imaging device; A guide rail, one end of the guide rail is located in the optical imaging device, and a stage for carrying small animals is provided on the guide rail, and the stage can slide on the guide rail; at the same time, A heating pad is provided in the stage, two mirrors are arranged on the stage, and a small animal coil is also arranged on the guide rail; One end of the guide rail is located in the optical imaging device, and the other end is located in the magnetic resonance device, and the object stage can slide along the guide rail between the optical imaging device and the magnetic resonance device. 2 . The magnetic resonance compatible autofluorescence tomography molecular imaging device according to claim 1 , wherein a lens is arranged above the stage, and the lens is fixed on the top of the optical dark box. 3 . 3. A magnetic resonance compatible autofluorescence tomography molecular imaging device according to claim 2, characterized in that: a rotating wheel is arranged between the stage and the lens, and different A bandpass filter for the center wavelength. 4. A magnetic resonance compatible autofluorescence tomography molecular imaging device according to claim 1, wherein the optical dark box is arranged in the shielding shell, and the shielding shell is provided with an outer shielding door and an inner shielding door. A shield door, a transition space is formed between the outer shield door and the inner shield door. 5 . The magnetic resonance compatible autofluorescence tomography molecular imaging device according to claim 1 , wherein the optical dark box is made of opaque material, and the shielding shell is made of high magnetic permeability material. 6 .