CN100518635C - Single photon emission computed tomography system - Google Patents

Abstract

Collimator assembly (630) is constructed with a plurality of alternating layers of lead and plastic supported between a lower support plate (632) and an upper support plate (634). Threaded adjusted members (636) extend through the lower plate (614) to the lower support member (632) and through the upper plate (612) to the upper support member (634). By adjusting the adjusting members (636) the position of the collimator assembly (630) may be adjusted relative to the remainder of the arc.

Description

Single photon emission computed tomography system

CROSS-REFERENCE TO RELATED APPLICATION

The application on February 5th, 2003 submit to, serial number is No.10/358, the continuation part of 961 U.S. Patent application, this U.S. Patent application is that submission on April 14th, 2000, serial number are No.09/549,435, be U.S. Patent application No.6 now, 525,320 continuation part, that this United States Patent (USP) requires is that on April 14th, 1999 submitted to, serial number is No.60/129,239 and submit on August 30th, 1999, serial number is the priority of 60/151,378 U.S. Provisional Patent Application.The application also requires to submit on June 20th, 2003, serial number is No.60/480, the priority of 381 U.S. Provisional Patent Application, and the full content of this application all is introduced in this as a reference.

Technical field

The present invention relates generally to imaging system, and relate more specifically to single photon emission computed tomography system.

Background technology

Medical radioactive radio nuclide imaging (nuclear medicine) is the key component of modern medicine practice.This methodology relates to the radioactive substance trace quantity administration that the typical case is undertaken by injection, and this radioactive substance is then located in vivo in the mode that depends on examine tissue system physiological function.The radioactive indicator emitting substance, modal is gammaphoton, by the imaging of vitro detection device, generates body radioactivity tracer distribution figure.When the doctor by suitable training understood, these images provided extremely valuable information in disease clinical diagnosis and treatment.The typical case of this technology uses and comprises that coronary artery disease detects (thallium scan) and the cancer stricken skeleton detects (bone scanning).Most clinical radionuclide imagings are to adopt gamma emission radioactive indicator to carry out with the detector that is called " gamma camera ".

The gamma camera typical case is made up of atmospheric shimmer crystal (for example, sodium iodide), and this scintillation crystal has irradiative characteristic when being subjected to the gammaphoton bump.A plurality of photomultiplier tubes and interlock circuit thereof are arranged to detect flash of light and to determine their positions in scintillation crystal in this crystalline back adhesion.In crystalline front is collimator, and its typical case is made up of several millimeters lead, and a plurality of perforates are arranged above the lead.Collimator is used to absorb whole incident photons, except those arrive crystalline photon from suitable direction substantially.Crystal, photomultiplier tube and interlock circuit typical case are contained in the large-scale lead container so that detector and undesired outside alpha ray shield leave.Whole device is installed on the stand with electric device detector is placed near the patient.

Gamma camera provides the two dimensional image of radioactive tracer distribution.Yet body radioactivity tracer distribution typical case is three-dimensional.Single photon emission tomography technology (SPECT) is used for by adopting Computer Processing is similar to " radionuclide CT scan " with establishment three-dimension disclocation photographs with by the three-dimensional tracer distribution of a series of two-dimentional gamma photographic image " reconstruction " that obtains from a plurality of angles around patient.This is almost all by being installed to one or more gamma cameras on the electronic stand and making it rotate and finish around patient.Then thus obtained data are handled to generate 3-D view.

Shown D S PECT image provides higher picture contrast and has reduced the obviously overlapping of body structure.Think that at present the SPECT imaging is the imaging of the prior art of heart radionuclide imaging, and account for the over half of whole heart nuclear imagings of carrying out in the U.S. at present.

Though it has many advantages, SPECT also is still and can not all obtain for the patient that can benefit from it.Present SPECT instrument has the many shortcomings that hinder its extensive use.

Present SPECT system is heavy, needs large-scale andron to hold them usually.The efficient of colimated light system is lower, has hindered the divergent-ray of high percentage ratio.Therefore, most of new clinical systems adopt the two or more photograph detectors that are installed on the stand simultaneously.Several centals because each detector weighs usually, support stand must be large-scale and heavy.Most of SPECT install the room of the special construction that needs the reinforcing of additional floor.Because image reconstruction needs accurate detector location accurately, the SPECT system needs heavy navigation system, and this navigation system is formed by moving with about one millimeter precision with the motor and the gear of location number cental device.These system entails are large-scale, heavy and expensive.

Though need carry out imaging to patient at various environment at the utmost point medically, comprise doctor's office, emergency room and intensive care unit(ICU), the heavy volume of the large-size of SPECT system need be fixed on fixed place with them at present, normally Chemical Examination Material in Hospital department or nuclear medicine department.Carry out the advantage that the cardiac SPECT imaging has significant medical science and patient convenient curing mainly under cardiologist's situation directly on the scene.Many studies show that, the nursing cost of office's occasion of outpatient is lacked than the cost of hospital's occasion.Except these mandatory factors, the size of current system and cost constraint have greatly limited them to the permeability of community and especially limit their availabilities in doctor's office.In addition, current system need be than large space, thereby has bigger pressure cost when providing the SPECT service in hospital.

Current SPECT system also has other limitation.When gamma camera when patient rotates, need a large amount of multiconductor cables to transport electric power and data each detector that comes and goes.These cables bend repeatedly at system's run duration, thereby cause equipment fault through regular meeting.

Large-scale and the heavy characteristic of existing system requires mechanical gantry designs to have high stability, but has cost efficiency.This causes in these systems patient to lie in (back lies low) position of lying on the back stretching on the narrow platform of the stand of vertical direction.For making the detector can as close as possible chest and make large-scale removable detector walk around patient safely, current system needs patient's single armed or two arms to embrace head and keeps uncomfortable posture.This is painful for most patient, and is impossible for some patients.In addition, the position that lies low is uncomfortable for many patients, particularly suffers from the patient of back illness for those.When being arranged in equipment, many patients can suffer from claustrophobia.Need make photographing unit is uncomfortable around the narrow platform that patient rotates for big build is individual, and makes those patients that accept scanning feel dangerous or unstable through regular meeting.And patient is surrounded by environment division during imaging and can limit doctor or nurse near severe-Iy ill patients.

Summary of the invention

The invention provides a plurality of imaging systems and parts thereof.According to an embodiment, a kind of single photon emission computed tomography system comprises the basilar part with the patient support that is used to support patient, thereby patient's a part is positioned at the visual field.Pass the visual field and form longitudinal axis.The contiguous visual field of detector module and comprising can be detected photon and whether strike photo response detector on the detector.This detector module operationally detects patient and is positioned at the inner photon that divides emission in visual field.Photon barrier is arranged between visual field and the detector.This block piece has and passes wherein the perforate slit that forms so that photonic via is aimed at the perforate slit.Pass perforate from detector and form line of response.Collimator assembly comprises a plurality of collimation blades that formed by the photon attenuation material.Supporting component supports collimator assembly.Supporting component comprises first support member and second support member.Second support member and first support member are spaced apart.Collimator assembly is placed between two support members, thereby forms first distance between the collimator assembly and first support member, and forms second distance between the collimator assembly and second support member.Adjust assembly and comprise first adjustor of operationally adjusting first distance and second adjustor of operationally adjusting second distance.

Another aspect of the present invention provide a kind of be used for from the radiophotography system view data is recombinated (rebinning) so that this data corresponding to from the method that is positioned at the data that traditional gamma camera of obtaining the reading types around a plurality of positions of visual field obtains.Can suppose that the visual field has and pass wherein the longitudinal axis that forms.The tradition gamma camera has sensitive surface, and its center line parallel is in longitudinal axis.Between longitudinal axis and centrage, be vertically formed the position line.Induction planes is defined as and comprises the position line and perpendicular to longitudinal axis.Baseline is defined as perpendicular to longitudinal axis and is included in the induction planes.The angle location definition of tradition gamma camera is the angle theta between the baseline and the position line.The tradition gamma camera operationally detects the photon with the induced phase bump, and wherein each bump in the induction planes is positioned at apart from distance between center line r place.Recombination method comprises and comprises the step that the radiophotography system is provided.Imaging system comprises the basilar part with the patient support that is used to support patient, thereby patient's a part is positioned at the visual field.The contiguous visual field of the arciform detector module of cardinal principle and comprising can be detected photon and whether strike photo response detector on the detector.This detector module is also operationally discerned the detector impingement position along arc detector module.Photon barrier is arranged between visual field and the detector.This block piece has and passes wherein the perforate slit that forms so that photonic via is aimed at the perforate slit.Pass perforate from detector and form line of response.Collimator assembly comprises a plurality of parallel collimation blades of cardinal principle that formed by the photon attenuation material.These blades are spaced apart to form a plurality of slits.Displacement actuator operationally makes in detector and the photon barrier one to move with respect to another of detector and photon barrier, thereby perforate is shifted with respect to detector, and at least a portion of the inswept visual field of line of response.Other step is included in and obtains a plurality of detector readings when a plurality of photons strike induction planes substantially.Each reading comprises intensity.Determine that this position comprises apart from the radius R of visual field centrage from the position of each reading of detector module _DetWith position, angle Ψ with respect to baseline.Determine the perforate slit location of each reading, this position comprises apart from the radius R of visual field centrage _AppWith position, angle with respect to baseline

For each r of traditional gamma camera and the combination of θ, below adopting formula calculate Ψ and

Analog value:

With

For the combination of each r and θ, the storage with Ψ, R _AppAnd R _DetThe intensity level that is associated.The present invention also provides the method for various calibration single photon emission computed tomography systems and device thereof.

According to a further aspect in the invention, provide a kind of medical imaging devices that has support base portion and be used for the imaging moiety of view field imaging.This imaging moiety the stiff end that supports by basilar part and and its free end separately between extend.This imaging moiety comprises the supporting component with first support member and second support member.Spaced apart and each support member of two support members have the stiff end that supports by basilar part and with its free end separately.A plurality of tension parts are extending between first and second support members and spaced apart between the stiff end of support member and free end.In certain embodiments, thereby tension part comprises a stiff end near imaging moiety in some angled its ends, and other tension part makes their the close stiff end in other end simultaneously, thereby these tension parts are relative to each other angled.

Description of drawings

Figure 1A is the perspective view that the best is used for the preferred embodiment of the present invention of cardiac SPECT, and the whole structure of system and patient's location are shown;

Figure 1B is another perspective view of embodiment among Figure 1A;

Fig. 2 is the perspective view that is used for an embodiment of the single detector module of detection photon during the SPECT imaging;

Fig. 3 is the perspective view of the perforate arcuation body of the best embodiment of the invention of being used for SPECT, a radiation detection module is shown with the expression relative localization in this arcuation body back;

Fig. 4 is a fraction of cross-section detail view of perforate arcuation body, and the details of an embodiment of verge of opening processing is shown;

Fig. 5 is the cross-section detail view that is similar to Fig. 4, and the alternative embodiment of edge details is shown;

Fig. 6 is the cross-section detail view that is similar to Figure 4 and 5, and another alternative embodiment of edge details is shown;

Fig. 7 illustrates the cross-section details of a perforate arcuation body part, comprises being used for providing the end part adjusted that can adjust width to perforate;

Fig. 8 is a perforate arcuation body part and the perspective view that can adjust end part;

Fig. 9 A is the diagram top view, and the relative position of the perforate arcuation body, detector arcuation body and the patient visual field that have groove is shown;

Fig. 9 B is the diagram top view, and how the line of response that each detector is shown provides the multi-angle projection that passes human body;

Figure 10 A is in first position of rotation place single detector module of perforate arcuation body and a fraction of schematical top view of perforate arcuation body;

Figure 10 B is the view that is similar to Figure 10 A, but perforate arcuation body is at second position place;

Figure 10 C is the view that is similar to Figure 10 A and 10B, but perforate arcuation body is in the 3rd position;

Figure 11 A-F is a series of diagram top view of the present invention;

Figure 12 is the perspective view of the partially transparent of imaging moiety alternative embodiment of the present invention, comprises perforate arcuation body and angled collimator blade;

Figure 13 is the perspective view of cross section (vertically) collimator assembly, and the relation of itself and detector module is shown;

Figure 14 is the view that is similar to Figure 13, but comprises perforate arcuation body and the line of response of each detector module is shown;

Figure 15 illustrates the curve of spatial resolution in plane, different depth place that adopts the present invention and adopt that traditional " high-resolution " parallel aperture collimator compares;

Figure 16 is the viewgraph of cross-section according to a parallel blade collimator part of the present invention;

Figure 17 is the perspective view according to the supporting component of an embodiment of imaging arcuation body of the present invention;

Figure 18 is the perspective view that is similar to supporting component Figure 17, that have extra tension part;

Figure 19 is the viewgraph of cross-section according to a parallel blade collimator part of the present invention and sensor cluster, and the relative depth of collimation blade is shown;

Figure 20 A is the cross-sectional, top view of an embodiment of removable perforate arcuation body extended blades;

Figure 20 B is the view that is similar to Figure 20 A, wherein is illustrated in the blade at diverse location place;

Figure 21 is the perspective view of the part of the part of lower support according to an embodiment of the invention and perforate arcuation body;

Figure 22 is the rearview that is used for sensor cluster of the present invention;

Figure 23 is the front view of sensor cluster among Figure 22;

Figure 24 is the side view of sensor cluster among Figure 22-23;

Figure 25 is the cross-section detail view of a sensor assembly part;

Figure 26 is the front view of an embodiment of sensor assembly;

Figure 27 is the view that passes the pair of sensors array of collimator assembly observation;

Figure 28 is the perspective view of an embodiment part of scintillator base crystal detector module;

Figure 29 A is the perspective view of another embodiment that adopts the detector module of rectangular strip scintillation material piece;

Figure 29 B is the side view of module among Figure 29 A, and wherein photoelectric detector is in top and bottom;

Figure 29 C is the view that is similar to Figure 29 B, but photoelectric detector is placed on the back of scintillation material;

Figure 30 is the perspective view of detector module, and wherein the scintillation material piece has trapezoidal cross-section;

Figure 31 A is based on the perspective view of the blind detector structure of rectangle scintillation material piece;

Figure 31 B is based on the perspective view of the blind detector structure of cylindrical scintillation material piece;

Figure 31 C is based on the perspective view of the blind detector structure of the scintillation material piece with trapezoidal cross-section;

Figure 32 illustrates the perspective view that is similar to the structure detail of strip blind detector module among Figure 31 A, but photoelectric detector is placed along its back;

Figure 33 is the parallel detection device of expression one embodiment of the invention and the diagram of the perforate arcuation body direction of motion;

Figure 34 has a detector perspective view based on two-dimentional scintillator that covers tape according to of the present invention;

Figure 35 is the perspective view of a perforate arcuation body part, and wherein calibration module is placed on tapping;

Figure 36 is the top pictorial view of another embodiment of the present invention, and this embodiment utilizes two-dimensional detector and linear block piece;

Figure 37 is the perspective view of imaging arcuation body;

Figure 38 is the viewgraph of cross-section according to an embodiment of imaging arcuation body of the present invention;

Figure 39 is the viewgraph of cross-section according to another embodiment of imaging arcuation body of the present invention;

Figure 40 is the viewgraph of cross-section according to another embodiment of imaging arcuation body of the present invention;

Figure 41 is patient visual field and the explanatory view that is shown in traditional gamma camera of two positions;

Figure 42 represents data by the sinogram that traditional gamma camera receives;

Figure 43 is provided with under the condition another sinogram of traditional camera in difference to represent data;

Figure 44 represents data from the sinogram of the imaging system according to the present invention;

Figure 45 is the sketch map that is similar to Figure 41, and the present invention's equivalence perforate arcuation body and detector arcuation body position are shown;

Figure 46 and 47 is sketch maps of necessary geometry that the position conversion of the perforate arcuation body that is used for the conventional two-dimensional date processing and detector arcuation body is shown;

Figure 48 is the top view of a perforate arcuation body part that has an embodiment of radioactive calibration source and keeper;

Figure 49 is the perspective view of calibration source shell or keeper part;

Figure 50 is added with the perspective view that photon stops keeper among Figure 49 of shielding;

Figure 51 is the perspective view that is similar to Figure 49 and 50, wherein has other radiation source container;

Figure 52 is the perspective view that is similar to Figure 49-51, has wherein added cylindric radioactive source;

Figure 53 is the perspective view of calibration source among the Figure 52 that is attached on the perforate arcuation body part;

Figure 54 is a side perspective view of a perforate arcuation body part, and the receptor that is used to receive calibration source is shown;

Figure 55 is the perspective view that is similar to Figure 54, calibration source is shown inserts in the keeper;

Figure 56 is the perspective view of the alternative embodiment of calibration source keeper;

Figure 57 is the cutaway view of keeper among Figure 56;

Figure 58 is the perspective view of the calibration source that keeper uses in Figure 56 and 57;

Figure 59 is the cutaway view of Figure 58 calibration source;

Figure 60 is the perspective view of keeper in Figure 56 and 57, wherein accommodates the calibration source of Figure 58 and 59;

Figure 61 is the perspective view of calibration source and keeper among Figure 60, and its reverse side is shown;

Figure 62 is upper and lower support member and the keeper in Figure 60 and 61 and the perspective view of calibration source that is formed into a picture arcuation body part;

Figure 63 is the perspective view that is similar to Figure 62, has wherein increased another part of perforate arcuation body;

Figure 64 is the perspective view that is similar to Figure 63, has wherein cut the part of upper support element;

Figure 65 is the detailed perspective view of the source keeper of the base section of perforate arcuation body and Figure 64;

Figure 66 is the perspective view of calibration source and keeper, and wherein calibration source partly inserts in the keeper;

Figure 67 is the side view of calibration source and keeper among Figure 66, and wherein calibration source partly inserts in the keeper;

Figure 68 is the side view that is similar to Figure 67, and wherein calibration source all inserts in the keeper;

Figure 69 is another perspective view at the calibration source of the opposition side shown in Figure 66 and keeper, and wherein calibration source partly inserts;

Figure 70 is the perspective view that is similar to Figure 69, and wherein calibration source is depicted as whole insertions;

Figure 71 is the top view of Figure 70 calibration source keeper, and indication has illustrative size on it;

Figure 72 is the top view of calibration source;

Figure 73 is the top view of calibration source storage container, is placed with a plurality of calibration sources in the container;

Figure 74 is the perspective view that is used for the flexure crystal of some embodiments of the invention; With

Figure 75 is a crystalline perspective view among Figure 74, and crystalline behind is a plurality of photocells.

The specific embodiment

In whole description, shown preferred embodiment and example should be regarded as the present invention is played an exemplary role but not restriction.

I. general introduction

One aspect of the present invention comprises the system that carries out single photon emission computed tomography (SPECT).This system comprises the ray detector assembly of being made up of a plurality of radiation detector module, and radiation detector module is preferably placed at 180 degree to the arc of 360 degree around the typical case.By with angular range (being typically the 180-360 degree) the similar angle scope of ray detector assembly on the removable arcuation body or the ring that extend (axially) collimation in the plane is provided.Stride plane (vertically) collimation by remaining on resting position and providing towards a plurality of blades of the photon attenuation material of the direction parallel or thin slice with transverse axis plane (perpendicular to longitudinal axis).Selectively, these blades can be separated by radioparent interval insulant thin slice, as foamed polystyrene

Or other plastics.Some embodiments of the present invention also comprise patient chair or supporting construction.

II. the description of chair, bogen structure and patient location

Figure 1A and 1B illustrate the preferred embodiment of the present invention that the best is used for cardiac SPECT, and it illustrates the whole structure of system 100 and patient 102 location.There is shown the perforate 104 that patients is come in and gone out.The imaging moiety 106 of system extends into arcuation on the patient's chest right side.Imaging moiety is made up of the lead screen shell with internal part as described below.Imaging moiety is supported by the support 108 that is fixed on the basilar part 110.The rear portion of imaging moiety and support form " back " that patient supports together.Patient is sitting on the adjustable bed rearrangement chair 112.The vertical height of this seat can be adjusted so that patient's heart is positioned at the suitable part of imaging device.This adjustment can be undertaken by motor, hydraulic test or miscellaneous equipment.Seat is optionally adjusted horizontally rotating, thereby makes patient be easy to enter to take one's seat the position or come out from the position of taking one's seat.Support and basilar part also can comprise or support handles the needed electronic component of scanning, and the control device of any needs or display device.

As shown in the figure, different with prior art system, patient is seated basically vertically, thereby their trunk is a perpendicular.The reducing of in light weight, more simple design and native system volume collaboratively makes this location become possibility.Be final purpose, will be called as the visual field by imaging moiety 106 area surrounded.Still be final purpose, can suppose to pass the visual field with the aligned vertical axis extension of patient's trunk longitudinal axis substantially.Can suppose longitudinal axis be perpendicular be forced to horizontal location with the location of distinguishing native system and the patient of conventional system.In fact, vertical substantially longitudinal axis can tilt slightly, as shown in the figure, and to increase patient's comfort level.

As those skilled in the clear, it similarly is very important that patient suitably partly is carried out to, to obtain about patient's partial data interested especially.For example, the preferred embodiments of the present invention are designed to heart of patient is carried out imaging.Therefore, it is important comprising heart of patient in by imaging moiety or section.Yet heart of patient always can not determined by visual examination easily in intrathoracic accurate position.In prior art systems, when the operator observed the low resolution be called as twilight sunset oscillograph (p-oscillograph), two dimensional display, patient was positioned at detector the place ahead.Owing to when patient reorientates, need bring in constant renewal in and owing to the two-dimensional characteristics of its image, twilight sunset oscillograph image must be low-quality.Operator error in patient location is very common, and can cause useless scanning when this error occurs.According to a further aspect in the invention, before heart scanning, can carry out " rapid scanning " with correct location heart, thereby imaging so that correctly locating for imaging moiety 106, heart is carried out in the position of adjusting chair to patient's chest.

The present invention's's " rapid scanning " feasibility has several reasons, and these reasons will become apparent after reading whole description.The system of present technique must part rotate to obtain three-dimensional imaging around patient.If obtain the quick three-dimensional positioning image, large-scale heavy (being typically the 450-500 pound) detector must in seconds start or stop.This mechanically is difficult, also can be owing to the fast moving of large-scale heavy detector and patient is produced injury.The present invention only needs mobile perforate arcuation body so that the part of the patient in imaging moiety 106 visual fields is carried out imaging.Perforate arcuation body preferably is hidden in the housing for patient, and can move more fast than the gamma camera of prior art and safety.And whole scanning only needs the arcuation body to move than short distance, is not to resemble those gamma cameras will move very long distance.In addition, the present invention is faster than prior art equipment acquisition of image data.Therefore, just can obtain fast, hang down the counting 3-D view by fast moving perforate arcuation body in housing.Should almost can and be shown as section immediately by the active computer reconstruction immediately by low counting diagram picture, or preferably, be shown as surface of revolution performance (rendered) or maximum intensity projection's image.This volume represent images has clearly been showed inner patient's anatomy and has been used in the daily height of beginning and has been counted as the preceding position of determining heart reliably of picture.

In the embodiment that seat 112 of the present invention can be adjusted up and down, the position of chair is selectively adjusted between two image acquisition to be adjusted to the position of picture section.In certain embodiments, moving can be very little, and with the influence of compensating collimator, this will describe below more specifically.The position of chair can also be adjusted up and down during image acquisition.

As known to those skilled in the art, patient's moving during imaging is serious problems for most imaging systems.Most systems needs patient to lie on the back or prostrate posture lies on the narrow horizontal surface with more uncomfortable.It usually is uncomfortable that there is dyspneic heart patient for the patient who suffers from the back illness is perhaps many in this posture after putting down when lying.This usually causes patient to move in scan period.For adapting to the moving detector of prior art systems, patient must remain on the head at the arm that makes them during the imaging process.This is for many patients, and particularly to suffer from arthritic patient be very uncomfortable to those shoulders.When the following time of large-scale metal detector that lies in existing equipment, many patients can strike fear into or suffer from claustrophobia.Those patients uncomfortable or that fear can adjust their posture usually to attempt becoming more comfortable.When this move out present image acquisition during the time can cause image artifacts, image artifacts may cause incorrect finding and incorrect successive treatment.Aggravated this problem long sweep time.The present invention makes patient keep vertical posture, shown in Fig. 1 a and 1b, has significantly improved patient's comfort level and degree of stability.It is for suffering from the back illness or cardiopathic patient is more comfortable.Arm need not to remain on the head.Open design of the present invention has been eliminated claustrophobia.Thereby, improved patient's comfort level and degree of stability and reduced mobile.And some embodiments of the present invention can significantly reduce scanning times, thereby reduce the influence that patient moves.

III. the general introduction of one dimension solid-state detector module (band)

Fig. 2 illustrates an embodiment of single detector module 150.A plurality of (being typically 64) individual module is arranged on patient's arcuation body.This arcuation body can extend in about 180 to 360 degree scopes.For cardiac SPECT, preferred embodiment is about 180 degree.Shown embodiment is the solid-state detector module that size is suitable for cardiac imaging.Other detector module embodiment is described below.As shown in the figure, detector module 150 is elongated bands.Each solid-state detector element 152 array is represented in rectangular area on the detector surface, and each detector element comprises a pixel of data acquisition.In this embodiment, array of detector elements is unidimensional, i.e. 1 * N is though also can adopt two-dimensional array.Many leads ribbon cable 154 is transported to the electronic circuit of handling these signals with the signal of telecommunication from detector element.Replacedly, some treatment circuits can integrate with detector element or be encapsulated by detector element.

Each detector element 152 operationally detects whether photon strikes is arranged on it.Therefore, all detector 150 operationally detects whether photon strikes is arranged, but also operationally determines along the photon strikes position on its length.Each detector element comprises some semi-conducting materials, as cadmium zinc telluride, and applies electrode on the surface relatively two.Pass electrode and be applied with electromotive force.As those skilled in the clear, when photon interacts by the front electrode and with semi-conducting material, between two electrodes, can flow through little electric current.Measure of the collision of this electric current with induced photon.

Though the present invention is described as adopting above-mentioned detector element at first, other embodiments of the invention can adopt other detector design, and institute more describes in detail as inciting somebody to action below.

IV. perforate arcuation body-general introduction

Fig. 3 illustrates the perforate arcuation body 170 that the best is used for the embodiment of the invention of cardiac SPECT.A radiation detector module 172 is shown in this arcuation body back to show relative localization.As shown in the figure, detector module is parallel to longitudinal axis substantially.Arcuation body 170 is used as photon barrier and can be made by plumbous or similar high attenuating material.Arcuation body 170 has enough height and is positioned at thereafter radiation detection module 172 with covering.The arcuation body has enough thickness (being typically about 3mm), to realize absorbing fully basically the photon by patient's emission.The arcuation body runs through a series of vertical open pores slits 174, arrives detector module so that photon 176 can be aimed at the perforate slit to pass slit from patient.The slit preferred general is parallel to patient's longitudinal axis.

In Fig. 3, arcuation body 170 is shown in the continuous element that wherein is cut with the general rectangular slit.In certain embodiments, slit cuts into straight-through, and the edge is parallel to each other.Replacedly, slit can cut into angled limit.Shown in Fig. 4-6.Each width of cloth of these figure shows and the vertical slit cross section of slit cardinal principle.In the embodiment show in figure 4, arcuation body 170 has tapered ends 171.Arcuation body 170 hypothesis have a pair of apparent surface.Tapered tipped 171 is tapered to a bit that approximately is positioned at arcuation body central plane from each of these apparent surfaces.For simplicity's sake, the part of the arcuation body shown in Fig. 4-6 is linear substantially.Yet as previously mentioned, it is actually arc.

Preferably, arcuation body 170 stops whole photons basically, except those pass the photon of slit 174.Need certain thickness photon barrier material, as lead, suitably to stop these photons.Tapered tipped 171 is thinner than the remainder of arcuation body.Therefore, they are preferably formed by the material with higher photon blocking capability, as tungsten or gold, but also can be plumbous.These tapered tipped 171 are connected on the material that is typically formed arcuation body 170 remainders.Replacedly, comprise that the arcuation body at edge can all be a kind of material, as lead.Fig. 5 and 6 illustrates the alternative embodiment of tapered tipped 173 and 175.In these embodiments, the edge of slit or from front to back or from back to front convergent.For the embodiment of Fig. 4, the tip is preferably formed by the material that has higher photon blocking capability than arcuation body remainder.Slit preferably has sharp-pointed edge, because they provide more uniform obvious slit edge, does not rely on viewing angle.That is to say that when when certain angle is observed, the slit with square limit can present narrower substantially.By making slit edge convergent, when observing with more shallow or darker angle, slit has more uniform effective width.This is particular importance in design of the present invention, so ray can be to enter perforate than wide-angle.Replacedly, " tip " can be rounding.

In some embodiments of the invention, slit preferably has adjustable width.This allows to adjust the sensitivity and the resolution of imaging system.This also can help calibration.Fig. 7 and 8 is depicted as slit a kind of method that can adjust width is provided.Fig. 7 illustrates the cross section of arcuation body 177 parts, is connected with on it to adjust slit formation part 179.Fig. 8 illustrates and has the perspective view that can adjust arcuation body 177 parts of part 179.By adjust the position of part 179 with respect to the remainder of arcuation body 177, just can adjust the relative position and the width of slit 178.For the embodiment of Fig. 4-6, the thin part of end member 179 is preferably formed by the material that has higher photon blocking capability than arcuation body 177 remainders.Convergent before and after end part 179 is depicted as and has but also can have the Any shape shown in Fig. 4-6, or the limit of squarely more or rounded can be provided to slit.And it is symmetric that end part 179 need not.In addition, can provide one can adjust part for each slit, other limit of this slit be formed by not removable edge.As those skilled in the clear, except that shown method, interconnecting between end part 179 and the arcuation body 177 can provide with various forms.The slit width adjustment also can otherwise realize, just as well known to the skilled person.

V. visual field

Fig. 9 A (from top) illustrates the relative position of patient visual field district 180, perforate arcuation body 182 and detector module 184.As can be seen, detector module group and perforate arcuation body are centrally located at around the patient altogether.An embodiment of cardiac imaging comprises about 64 radiation detector module 184, and each module is made up of discrete component or pel array.In this embodiment, perforate arcuation body 182 is placed on the radius a place that is about 30cm, and detector module 184 is placed on the radius b place that is about 40cm.Patient visual field district with about 50cm diameter c is coupled in the arcuation body 182 at an easy rate.Perforate arcuation body 182 and/or detector module group 184 are arranged to real how much arcs at total arc center on longitudinal axis.Replacedly, wherein each or the two can more be partial to oval or be formed the arc of non-shared arc center.For example, longitudinal axis can be arranged to depart to increase radius of the radian in the arc center.It is arc that arcuation body 182 and/or module group 184 also can right and wrong.For example, each all can be arranged to a series of short straight sections, or part is arc and part is non-arc.Another example can be that each has different radius of the radian in the different radii position, thereby bending radius changes along " arc ".

Provide gearshift to move perforate arcuation body 182 with respect to detector 184.As those skilled in the clear, can adopt many diverse ways to move perforate arcuation body.For example, can be provided with by worm gear or other perforate arcuation body 182 is connected on the motor, perforate arcuation body 182 can turn over limited angle around patient's longitudinal axis.As those skilled in the clear, the arcuation body can keep static and only allow detector move.Yet, the more complicated usually and cost height of this method.Be the purpose of the information of handling self-scanning, the device of accurately determining the arcuation body position also is provided.As those skilled in the clear, many methods of this device be can obtain to provide, optical encoding and mechanical pick-up device comprised.Also can adopt induction installation to carry out the feedback control of gearshift.The more detailed description of the method for a mobile perforate arcuation body will provide below.

VI. in the inswept description between moving period of perforate arcuation body

Figure 10 a-c illustrates the top view of the sub-fraction 192 of single detector 190 and perforate arcuation body.These illustrate arcuation body 192 and detector 190 relative position in three different rotary positions of perforate arcuation body 192.In each position, the position of perforate slit 194 is restricted to specific path 196 with the line of response of detector, as shown in the figure.As can be seen, when perforate slit 194 moved to the place ahead of detector 190, the sight line of detector became fan-shaped inswept patient, generates a plurality of line of response or projection.

Shown in Fig. 9 A,, form a plurality of detector response lines at each position of rotation place of perforate arcuation body owing to have a plurality of detector module 184 and a plurality of perforate slits 174 as shown in Figure 3.Fig. 9 B illustrates a smaller subset line of response 200 that obtains from several detectors 202 when 204 rotations of perforate arcuation body.For simplicity's sake, perforate slit self does not illustrate in the drawings.There is shown the diagram " section " 206 of passing patient's chest, show the whole set of projections of heart that obtain to be enough to supply the tomography reconstruction in this mode.

Perforate arcuation body is preferred to be moved continuously, thus line of response " inswept " visual field.Replacedly, perforate arcuation body can move with discontinuous paces, when the arcuation body carries out imaging when each step stops.

VII. each detector is only by single perforate slit irradiation

All detector preferably only " is seen through " slit in all number of times.Determine slit separation so that each detector is only shone by a slit at every turn.The aggregate efficiency of photon detection is directly proportional with slit number in the perforate arcuation body.The maximum slit that is allowed is counted n _SlotsBe the maximum incident angle Φ of expression available rays at perforate slit place _Arc, minimum arc length on detector arcuation body radius and the perforate arcuation body, as the given arc length degree θ on the perforate arcuation body _AFunction, thereby given detector will each only be seen patient visual field (θ by a slit _A):

$n_{\mathrm{slots}}=\frac{\mathrm{\π}\·\frac{{\mathrm{\φ}}_{\mathrm{arc}}}{2\mathrm{\π}}}{{\mathrm{\θ}}_A/2}=\frac{\mathrm{\π}\·\frac{{\mathrm{\φ}}_{\mathrm{arc}}}{2\mathrm{\π}}}{{\sin }^{-1}\left(\frac{R_O}{R_A}\right)-{\sin }^{-1}\left(\frac{R_O}{R_D}\right)}$

R wherein ₀Be patient's radius, R _ABe the radius of perforate arcuation body, and R _DIt is the radius of detector arcuation body.Perforate arcuation body only need rotate the interval Φ between the slit _Arc/ n _Slots, so that whole angle set of projections to be provided.

For one embodiment of the present of invention, patient's radius R ₀Be 22cm, perforate arcuation body RA is 30cm and detector arcuation body radius R _DBe 45cm.Detector arcuation body and perforate arcuation body stride across the angle Φ of 180 degree _Arc, minimum arc length θ _AIt is 36 °.For these values, this equation draws, and five slits are to avoid any detector to see through the maximum slit number that surpasses an above slit at every turn.Therefore, perforate arcuation body only need turn over the angle of 36 degree so that whole angle set of projections to be provided.

Above-mentioned equation and solution hypothesis slit are at interval uniformly on the arcuation body, and by 36 angular separation of spending.As those skilled in the clear, crucial problem is actually the angle intervals between the slit, the number of this decision slit.Referring to Fig. 3, shown arcuation body has 5 slits again, because the viewing angle among the figure, one of them slit is ensconced knee.

Though above-mentioned equation and describe the conclusion draw and be needs 5 slits, 36 degree at interval between the slit, it is useful increasing the 6th slit.Figure 11 A diagram illustrates the present invention, and it has a plurality of detectors 195 that are arranged on the arcuation body, has the perforate arcuation body 196 of 5 perforates 197, and visual field 198.Arcuation body 196 is depicted as and is in clockwise extreme position.Suppose that photon interested can be derived from the visual field Anywhere, the projection ray of being drawn the visual field is shown how " projection " to detector arcuation body 196.As shown in the figure, some photons project the clockwise direction position of last detector, thereby image are not produced contribution.Equally, be in perforate arcuation body 196 " beyond the range of observation " of end perforates counterclockwise at the plurality of detection device of holding counterclockwise, thus unexposed at this device place of arcuation body.Unexposed detector shows the optimum efficiency of the system of not reaching.

Figure 11 B illustrates the midpoint that perforate arcuation body is handled its operation.As shown in the figure, in this position, pass the projection of whole perforates 197 and the position consistency of detector 195, thereby do not waste photon and do not have unexposed detector.

Figure 11 C illustrates perforate arcuation body 196 and is in counterclockwise extreme position.In this position, the detector at end place is unexposed clockwise at detector module, and some photons that pass the place's perforate of counterclockwise end are not detected.

A scheme that addresses this problem provides the more detector of big figure.Yet this can increase the size of imaging moiety, and significantly increases equipment cost.Preferred solution is shown in Figure 11 D.Perforate arcuation body 212 has now makes photon project 6 slits 214 on the detector 216 from visual field 218.Yet determining by above-mentioned equation at interval between these slits constant (being 36 degree in the present embodiment).Figure 11 D illustrates arcuation body 212 and is in clockwise extreme position.As shown in the figure, because the 6th slit that is added, all detector all obtains irradiation.Figure 11 E illustrates the intermediate range that arcuation body 212 is in operation, and image 11F illustrates the arcuation body and is in counterclockwise extreme position.Equally, all detector 216 all obtains irradiation in all positions, thereby has increased photon collection efficient." additionally " slit that adds causes the photon introduced and the length Perfect Matchings of detector arcuation body.In this layout, all detector is all obtaining irradiation by the perforate slit in the number of times, thereby makes photon detection efficient optimization.

VIII. oblique line perforate

Referring to Fig. 3, shown slit 174 is cardinal principle vertical slits again.That is to say that they are parallel to the longitudinal axis of visual field.According to other aspects of the invention, these slits can be oblique lines, as shown in figure 12.Assembly shown in Figure 12 comprises having the perforate arcuation body 207 that wherein is formed with oblique line perforate 208.The oblique line perforate is depicted as by adjustable edge spare 209 and forms, but also can replacedly provide by cut out slit in arcuation body 207.And the same with previous slit embodiment, the slit edge is convergent in every way, comprises the disclosed shape in any front.As those skilled in the clear, it is preferred along arcuation body 207 a plurality of perforates being set.For simplicity's sake, in Figure 12, only show two perforates 208.Yet, preferably also have other perforate.Figure 12 illustrates another aspect of the present invention, and it will design be described with reference to collimator below.Can be provided as angle slit or perforate 208 at various angular ranges, angular range can from " vertically " near level.Can be further alternatively, slit can keep " level " with respect to patient's axle fully.Perforate also can form angle as shown in figure 12 round about.

Perforate of the present invention be " vertically " and collimator be among the embodiment of level, or among the opposite embodiment, resolution vertically be different on the horizontal direction.According to one embodiment of present invention, perforate is on a direction that becomes about miter angle, and collimator is on another direction that becomes about miter angle.By making perforate and collimator angled with respect to the transverse axis imaging plane, make the whole resolution that obtains at imaging plane become isotropism basically, promptly similar on all directions.This is ideal in some applications, particularly when recombination data will be along bevel plane reformatting.

IX. collimator

Referring to Fig. 3 and 11A-F, perforate arcuation body and detector set are provided at the data for projection that collimates in the transverse axis plane but do not collimate in the vertical again.Reason for this reason, the present invention preferably provides one group vertically or the crossing plane collimator, as shown in figure 13.As those skilled in the clear, the collimator shown in Figure 13 is designed to use with " vertically " perforate arcuation body for example as shown in Figure 3.Vertically collimator is made up of a series of heap shape arc shaped blades 220, arranges shown in these blades such as the figure and concentrate as shown in FIG. to be positioned on the detector 222 arcs layout.Omitted perforate arcuation body in the figure, navigated on vertical collimation blade but perforate arcuation body is concentrated.Blade preferably is parallel to each other and is vertical with patient's longitudinal axis substantially.Blade is plumbous or the thin slice of similar attenuating material or plate and can separate (not shown) by the dividing plate of radioparent plastic foam or similar material.The quantity of blade, size and thickness can be according to the different application changes.

Figure 14 is similar to Figure 13, but is added with perforate arcuation body 230.As can be seen, each detector element (pixel) of each detector 232 has the unique line of response 234 that is directed to the patient visual field by the combination collimation effect of perforate arcuation body slit 236 and vertical collimation blade 238.

It will be understood to those of skill in the art that blade 220 preferably be arranged on substantially with the vertical plane of the intravital perforate of perforate arcuation in.In the embodiment of Figure 13 and 14, the collimator blade can be thought " level ", because they are perpendicular to " vertical " patient axle.Referring to Figure 12, as can be seen, collimator 210 is angled with vertical angled perforate substantially again.In Figure 12, only show five collimation blades 210, to avoid making the confusion of drawing.Yet, should be appreciated that blade along whole assembly setting, indicated as arrow.If perforate becomes other angle, blade 210 also can be angled to keep vertical with perforate.Replacedly, collimator blade 210 and perforate 208 also can be each other in certain angles except that being perpendicular to one another.

X. resolution and efficient

The plane intrinsic resolution of system according to the invention is respectively by the radius R of detector and perforate arcuation body _DAnd R _A, object is apart from the distance D ist of perforate arcuation body and the width W of slit and detector element _SlotAnd W _DetDetermine:

Figure 15 draws the resolution graphics at the different depth place (distance of point-of-interest in from the collimator to patient) that the present invention compares with traditional parallel aperture collimator.This arcuation system hypothesis with slit have 2.4mm slit width, 4mm the detector width and with reference to described other parameter of Fig. 4.The hole and the thick collimator of 3cm that have the 2.2mm diameter for the parallel aperture collimator of its drawing data.

For the point source in the center, visual field, the detection efficiency with arcuation system of slit is directly proportional with detector solid angle Ω, and can calculate based on Rogers (IEEE TIMI, vol.MI-1, pp63-68,1982):

$\mathrm{\Ω}=n_{\mathrm{slot}}\frac{1}{R_D^2}[\sqrt{r_{\mathrm{obj}}^2-r_D^2}\·\frac{1}{R_A}\sqrt{{\left[r_{\mathrm{obj}}(R_D-R_A)\right]}^2-{\left[R_A{r}_D\right]}^2}]{\mathrm{fp}}_{\det }$

R wherein _ObjAnd r _DBe respectively overall with half maximum (full-width-half-maximum) of object and detector resolution, p _DetBe detector packing fraction (packing fraction), and f vertically collimate the maximum cross-section mark (fraction of frontal area) that blade surrounds.In the present invention should dispose, f=vane thickness/blade at interval.

When perforate arcuation bulk phase moves to diverse location for detector, the apparent widths of perforate slit will change by the sinusoidal function of angle between slit and the detector.Because when when slit is observed, the apparent widths of detector is also according to similar function, and the efficient of whole detector will be according to the function of the sine of detector-slot angles square.Accurate function will depend on the photon cross section (function of detector thickness) of detector element and depend on the photon cross section of slit opening.Be easy to depict the change of sensitivity that detector changes with slit location for given detector, and can calibrate with software by being similar to the mode that the conventional detector that carries out is evenly calibrated in traditional gamma camera.

Should be noted that when having the heterogeneity of detector sensitivity, more insensitive according to the imaging system that method of the present disclosure is constructed for the pseudo-shadow of in rotation gamma camera SPECT system, seeing of structural images.In the described herein system, the count sensitivity that is caused by specific more insensitive detector element reduces crosses the entire image plane and propagates, but not structural " ring-type " or " arcuation " pseudo-shadow of showing as in the legacy system to be seen.These pseudo-shadows usually disturb this pseudo-shadow system.

XI. collimator is constructed

Those skilled in the art will appreciate that there are serious problems in lead collimator.Lead has very high density, but is not hard especially and firm.Therefore, plumbous blade weighs and is easy to the people is produced injury very much.In traditional parallel aperture collimator, blade is done extremely thinly and is formed with a plurality of little parallel holes.The degree of depth of collimator endoporus is limited by the intensity and the hardness of lead material to a certain extent.That is to say that degree is dark if collimator is configured to the bit depthkeeping, thin plumbous blade can subside along with the time, had destroyed collimator effectiveness.The present invention considers similar problem.210 collimation blade in 220 among Figure 13 and Figure 12 is promptly heavy greatly again, thereby has a difficult problem for how suitably supporting each blade.In addition, accurate location of each blade and aligning are very important.

Another creative aspect of the present invention is a kind of design with parallel plumbous blade collimator that provides, and these parallel plumbous blade pass are crossed to form and piled up and place transmissive wire rod tablet and be supported between each plumbous blade.Figure 16 illustrates the part according to the parallel blade collimator of this aspect structure of the present invention.Figure 16 also illustrates the part of supporting component, comprises lower support 240 and upper support element 242.

Figure 17 illustrates whole according to an embodiment of the invention lower support 240 and upper support element 242.Yet the collimator assembly in the not shown supporting component of Figure 17.Referring to Figure 17, lower support 240 and upper support element 242 form the part of supporting component 244.This supporting component 244 is formed into the part of picture arcuation body 106, shown in Figure 1A and 1B.It is enclosed in around the patient visual field, shown in 245 among Figure 17.After assembling, imaging arcuation body comprises supporting component 244, is supported in parallel blade collimator assembly wherein, single or multiple detector and perforate arcuation body.It also preferably is coated with shell to protect inner operation and apparent aesthetic feeling is provided.One end of supporting component 244 interconnects with the chair basilar part 108 that supports to as the arcuation body.This can finish in several ways.Replacedly, can in the middle of the arcuation body, provide other support.

Referring to Figure 16, the part of parallel blade collimator assembly is shown at 246 places again.Collimator assembly comprises lead flake or stereotype 248, and lead flake 248 is separated by transmissive wire rod tablet or plate 250.Collimator assembly can then constantly repeat this process up to forming sufficiently high heap sheet, as shown in the figure by piling up a slice transmissive line sheet above a slice lead flake.The transmissive wire material makes lead flake keep relative localization, and prevent lead flake anyly subside or move.Preferably, at the top of lead flake and transmissive wire rod stockpile and the bottom of upper support element 242 pressure strip or lower support plate 252 are set.Biasing device then is set, as screw element 254, to push down pressure strip 252 downwards.This compresses heap sheet 246 and stablizes.Preferably, thicker lead flake or other photon barrier material 253 are set, enter the top or the bottom of collimator assembly to stop photon in the top and the bottom of heap sheet.

As those skilled in the clear, can adopt the improved form of this assembling process to build collimator assembly, as shown in figure 12.According to a further aspect in the invention, can adopt correlation technique to form parallel aperture collimator.That is to say, can adopt the transmissive wire material to charge into and form parallel aperture collimator in the hole of parallel aperture collimator, thereby support the collimator blade.Because the lead between the hole is every very fragile, parallel aperture collimator usually in use damages.According to the present invention, the hole of collimator can charge into the transmissive wire material when building.This makes parallel aperture collimator become solid slug basically, thereby not fragile more.And this can form and support the blade darker and/or thinner than other feasible blade.

Referring to Figure 17, can strain the replacement that the forms parallel blade collimator assembly method that provides each other again by make upper and lower support member 240 and 242 by for example tension part 256 according to the present invention.That is to say that the alternately heap of stereotype and transmissive line plate can be placed on the lower support 240, covered by upper support element 242, and employing compresses or tension part 256 compresses.Those skilled in the art will appreciate that parallel blade collimator according to the present invention is very heavy, thereby cantilever arcuation supporting component bears bigger load.Figure 18 illustrates this supporting component can comprise a plurality of angled tension parts 258, itself or angled to the left side as shown in the figure, perhaps angled, perhaps angled to the left and right sides to the right.Tension part plays the effect that structure and support are provided as the bicycle spoke.They also make arcuation body formation backside openings basically to cool off with being used near electronic component.

Figure 19 provides a part of viewgraph of cross-section of imaging moiety of the present invention.It illustrates lower support 240, upper support element 242 and therebetween lead flake 248.Not shown transmissive wire material in this diagrammatic sketch.Yet common illustrating at 260 places is used to detect electronic package or the detector array that enters photon.This detector array can be described in more detail below.

Design of the present invention provides the advantage that had not obtained that designs about collimator before this.Traditionally, the collimator designer has limited the depth over width ratio of collimator holes.That is to say the degree of depth and while arriving or head-to-foot width before and after the hole that is formed by collimator can be considered to have.(in parallel aperture collimator, the width while arriving with head-to-foot is normally identical.In the present invention, " limit is to the hem width degree " is the function of bore size in the perforate arcuation body, and head-to-foot width is the function of spacing between the parallel blade).In the prior art, be considered to best less than the depth-to-width ratio of 10:1.In fact, document shows that the ratio of 10:1 almost is equivalent to infinite ratio.In other words, get rid of the theoretical depth-to-width ratio that can not reach that shown above 10:1.In addition, the design of the collimator of prior art makes that it is extremely difficult forming very large depth-to-width ratio.Dark collimator can run into structural integrity problems.In the prior art design, need too thin and too high blade oneself to support oneself for reaching high depth-to-width ratio.Therefore, high depth-to-width ratio also is unpractical.

The present invention is obviously different with the method for prior art.In one embodiment of the invention, lead flake has the thickness of about 2mm, shown in the A among Figure 16.Transmissive line sheet has the thickness of about 4.5mm.Therefore " slit " between the adjacent lead flake is about 4.5mm.In this same embodiment, the front and back degree of depth of plumbous blade 248 is about 150mm, shown in the C among Figure 19.In this embodiment, depth-to-width ratio is greater than 33:1.In more preferred embodiment of the present invention, plumbous blade has the thickness of about 1.25mm.Yet the slit still keeps same about 4.5mm.Therefore, depth-to-width ratio keeps identical.According to the present invention, be preferred greater than the present depth-to-width ratio of the maximum depth-to-width ratio 10:1 of technology.Depth-to-width ratio greater than 20:1 is preferred.Chamber depth-to-width ratio greater than 30:1 is more preferably.

According to the present invention, also the thickness of preferred plumbous blade is greater than .5mm.Thickness greater than .75mm is preferred, and 1mm or bigger thickness are more preferably, and the thickness of 1.25mm is most preferred at least.These thickness are also significantly different with prior art.The high-resolution parallel aperture collimator of prior art has the plumbous blade of .2mm or littler thickness usually, and expends great effort for obtaining more and more thinner plumbous blade.

Employing is than the bigger basically depth-to-width ratio of using in the prior art, and the thicker basically plumbous blade of employing, can provide not recognized in the prior art or unfathomed big advantage.

In the SPECT imaging, accurately determine the energy level of photon spread direction, photon and be important from the number of photons of this direction.These photons have enough energy and penetrate thick inadequately lead.In the parallel aperture collimator of prior art, thin plumbous blade is too thin usually and be not enough to stop many photons therefrom to pass.Therefore, the photon that strikes the specific region can not be assumed to be and directly propagate contiguous this regional hole.On the contrary, this photon may and penetrate this adjacent holes and respond to plumbous blade between the hole of this photon from another hole.Thereby sacrificed accuracy.This can produce smudgy when drawing image.The depth-to-width ratio of collimator mesopore also has influence to the resolution of imaging device.If collimator holes is short and wide, photon can enter this hole with the angle that significantly departs from this axially bored line.If the hole is dark and narrow, then propagated this hole to enter the photon angular range narrower.

In the present invention, the collimator that adopts thicker basically blade and employing to have high depth-to-width ratio, all accuracy that can be increased basically or resolution.Because blade is thicker and very dark, the photon of any arrival collimator back side upper sensor can be supposed and passes the perforate in the perforate arcuation body and pass between the adjacent plumbous blade.In other words, each photon " counting " is good counting.

Prior art also trends towards adopting the slit littler than the present invention.Experiment of the present invention shows, 4 or the 4.5mm order of magnitude on bigger slit, adopt thicker plumbous blade simultaneously, can obtain higher efficient and resolution.As described in another aspect of the present invention, it is preferred adopting the slit greater than 2mm, and it is preferred adopting the slit greater than 3mm, and 4mm or bigger slit are most preferred.

Referring to Figure 19, sensor array 260 is placed on the back side of contiguous collimator assembly again.In certain embodiments, each pick off is placed on the rearmost end of next-door neighbour's blade, and in further embodiments, pick off and vacuum side of blade be a bit of distance at interval.The effective dark space that is produced by the photon that is subjected to leaf baffle can be reduced in the slit that increases between blade 248 back sides and the pick off.In a preferred embodiment, pick off and vacuum side of blade interval 2 is to 3mm.

XII. extension flap

As shown in figs. 1 and 4, be used for the embodiment of cardiac imaging, adopt the arc imaging device to make patient can be easy to enter and leave imaging system for the best.Yet when perforate arcuation body rotates, it will extend into the open area of arcuation body slightly.Therefore the present invention selectively is provided with pivotable extension flap at the place, one or both ends of perforate arcuation body, shown in Figure 20 A and 20B.One end of the arcuation of perforate shown in figure body 300, it comprises the extended blade 302 that extends its length.Figure 20 A is illustrated in the perforate arcuation body 300 and the blade 302 of an extreme position of arcuation body motion, and Figure 20 B illustrates them in another extreme position.Extended blade 302 is movably attached on the perforate arcuation body by hinge 304.Pivoting lever 306 is arranged in the path of blade, thereby when the motion by perforate arcuation body is pushed against extended blade on the pivoting lever, extended blade can be pivoted move apart patient, shown in Figure 20 B.This part that makes arcuation body or blade put in opening minimizes, and detector and undesired outside alpha ray shield are left.

Now referring to Figure 21, it illustrates a preferable configuration of perforate arcuation body.Perforate arcuation body is depicted as 310, and it is supported on the support member 240, and support member 240 is formed into the bottom of picture arcuation support structure.In this embodiment, perforate arcuation body 310 is formed by each cambered plate 312 placed adjacent one another, thereby perforate 314 is provided betwixt.The width of perforate 314 can be determined by the relative position of plate 312.Also can be driven by drive motors 316 on the track that perforate arcuation body 310 is supported in the support member 240, motor 316 drives a series of belts and pulleys.

XIII. detector modification

At detector or sensor design, the present invention can adopt the whole bag of tricks now.Fig. 2 and 3 illustrates the banded detector that can regard the one-dimensional linear array as.Also can provide two-dimensional array in the present invention.These arrays can provide maybe and can be similar to formation together by two or more one-dimensional arraies are closely placed with integrated unit.The total sensitivity of imaging system and the linear ratio of available detector surface area.

Referring to Figure 22-24, three views that are used for the preferred embodiment of sensor cluster of the present invention are depicted as 320.Be clear that as Figure 23 assembly 320 comprises three dimension sensor arrays 322,324 and 326.Each sensor array is formed by a series of sensor assemblies successively, for example 328 among Figure 24.Sensor assembly is solid-state CZT (cadmium zinc telluride), perhaps replacedly, also can adopt cadmium telluride.Figure 25 illustrates the cross-sectional view of a sensor assembly 328.This module has CZT centrosome 330, has a plurality of Xiao Bao square-shaped electrode 332 on the front surface of centrosome 330.On the rear surface, be provided with bigger electrode, and 336 places are provided with the chip that is used to handle from sensor data signal at the rear portion.Photon strikes is to the front surface of sensor assembly 328 and by this module induction.Figure 26 illustrates another embodiment, and 338 of its chips cover half by inductive material 340.Figure 26 also is illustrated in lip-deep electrode 342 structures of this module.

Figure 22 and 24 illustrates the cooling manifold 346 of inductive component.

As well known to those skilled in the art, very difficult manufacturing does not have the solid-state photon sensor of internal flaw.Referring to Figure 25, the body of CZT material 330 is the crystal that may form flaw during producing or making.If body 330 does not have flaw, pass the photon that front surface enters CZT body 330 and make electrode 332 and 334 existence that can sense this photon.As shown in figure 26, electrode 342 forms two-dimensional grid.Thereby, can sense the existence of photon and determine the photon strikes position by determining which electrode.If there is flaw in CZT, it just has the Null Spot that can not sense photon strikes.Usually, the size of the electrode on this body front surface of CZT and interval are arranged to an electrode and are responsible for responding to " pixel " information.Usually, Pixel Dimensions is chosen to and equals the desired resolution of induction system.In the heart induction, preferably has about 4 to 4.5mm resolution.Therefore, electrode should be arranged on the 4-5mm center usually, thereby an electrode is responsible for each " pixel ".If CZT has flaw, this flaw can cause inactive pixels, and it can have a strong impact on picture quality.

According to another aspect of the present invention, the desired resolution that is 4 to 4.5mm in this case is subdivided into more fraction and the littler electrode of employing.In Figure 26, wide and high 4 to 5mm the zone that is about of square frame 350 expressions.Yet, be not to have single electrode, but should " grand pixel " be subdivided into four pixels that each has its oneself electrode 352 in this zone.If the CZT below grand pixel 350 has flaw, this flaw usually only can cause the single bad pixel relevant with an electrode 352.For example, in four electrodes can with do not have sensitivity, have the sensitivity of minimizing or under few situation, have the CZT part of sensitivity of increase relevant.This sensor assembly of adjustable then, and handle data from four electrodes 352, thus the meaningful data from grand pixel 350 are provided.For example, if an electrode is relevant with inactive pixels, then can merges from the output of its excess-three pixel and multiply by 3/4 to obtain the output of grand pixel 350.By this way, the sensor assembly that has a CZT body that contains some flaws is still available.In the module of Figure 26, electrode 352 preferably have about 2.46mm while arriving and head-to-foot size, and the interval between the adjacent electrode is about .04mm.At another best especially preferred embodiment that is used for the heart application, electrode is about 2.25mm to the pitch of electrode.Referring to Figure 19, sensor cluster 260 is depicted as the rear portion of contiguous plumbous blade 248 again.Figure 27 illustrates as passing that blade 362 is observed and the view of the sensor array 360 that obtains.In certain embodiments, the pitch between the blade 362 can not be divided equally by the pitch between the electrode 364.For example, in one embodiment, the pitch between the blade 362 is about 6.5mm, and the pitch between the electrode 364 is about 2.5mm.For avoiding, need make the number of pixels in each slit between the blade roughly the same owing to the aligning between blade and the pixel has caused wave pattern.Because in this embodiment, vanepiston is not the multiple of pixel or electrode pitch, and it is the center that sensor array 360 is arranged to intermediate blade 366.As shown in figure 27, this layout prevents that electrode and pixel just in time are positioned at blade 362 back.

The present invention also provides by as the scintillator material of sodium iodide or cesium iodide and so on and relevant photomultiplier tube or the ray detector that constitutes as other photoelectric detector of solid state photodiode and so on.Figure 28 illustrates the detector module 400 based on scintillation.This embodiment comprises the transmissive line that is coated on as aluminum and so on, the column scintillation material crystal 4 02 in the reflection shield 404.Cover 404 both ends opens at cylinder.Each end is by optical coupling material set photodetector, as photomultiplier tube, photodiode or other photoelectric detector (not shown).The position that scintillation event occurs in scintillation material is definite by the output ratio of two photoelectric detectors, thereby the lengthwise position of detector internal induction is provided.This embodiment manufacturing cost is extremely low, but shortcoming is can change owing to scintillator varied in thickness on its circular plane of structure causes its photon detector efficient across horizontal direction.This causes the receptance function of detector to depart from pure rect function, thereby spatial resolution is reduced slightly.

Figure 29 A-C illustrates more effective embodiment of scintillator base detector, and it is made up of the scintillator material sq.rd 420 that is coated in aluminum and so on transmissive line, the light reflecting material 422.In Figure 29 B, coating has opening at top and bottom, can put into photoelectric detector 424.In the alternative embodiment shown in Figure 29 C, coating is in the rear aperture of module, thus but the two or more photoelectric detectors 426 of set.Which kind of situation no matter is all considered photoelectric detector is placed near the scintillation material end, thereby is made photoelectric detector can determine the position of scintillation event.

Figure 30 illustrates and is similar to being coated on of earlier figures has trapezoidal cross-section in the reflecting material 432 scintillator material 430.Identical with the embodiment of Figure 29 A-C, photoelectric detector can anchor at the top or the bottom of module, perhaps anchors at the rear surface.The advantage of the embodiment of band trapezoidal cross-section is that the incident ray is had more uniform cross-sectional area, but its manufacturing cost is higher.That is to say whole degree of depth that the ray of coming at a certain angle from front surface still can pass scintillator material.

The axial resolution of tomograph system directly depends on the width of detector, as mentioned above.Particularly, the axial resolution of narrower detector increase system.Yet, along with the detector narrowed width, may before they deposit its whole energy, just scatter to outside the detector material, thereby photon detector efficient is reduced owing to strike the photon of narrower detector front surface.According to the present invention, have high-resolution elongated strip shaped scintillation material and can improve its efficient by a part of covering its front surface.Figure 31 A illustrates the detector configurations 440 based on rectangle scintillation material piece.Figure 31 B illustrates the detector configurations 442 based on cylindrical scintillation material piece.Figure 31 C illustrates based on the detector configurations 44 with trapezoidal cross-section scintillation material piece.In above-mentioned each embodiment, except that reflection coating 446, scintillator also is coated in the shielding layer 448 of other lead, tungsten or similar high attenuating material.Cover this outside or screen layer is constructed with the narrow vertical openings 450 that size is suitable for the detector cross section.In case photon passes this opening and strikes on the scintillator, further scattering is easier to appear at the larger volume scintillator that is positioned at shielding layer 448 split sheds 450 back, but not scatters to beyond the scintillation material.If desired, can between coating and screen layer, insert other low-Z material layer (not shown), to absorb secondary lead X line by shielding layer 448 emissions.As those skilled in the clear, the detector shown in Figure 31 D has the greater efficiency of wide detector and has the high-resolution of narrow detector.Similarly cover on the solid-state detector that can be applied to as shown in Figure 2, thereby obtain confers similar advantages.

Referring to Figure 34, similarly masking methods can be applicable to two-dimentional scintillator blocks has above-mentioned advantage with formation detector 452.Particularly, a scintillation material 454 has the lead that is applied to its surface and covers bar 456.The photon inlet stays narrow vertical openings 458 so that can be aimed at this opening.The same with the embodiment shown in Figure 14 a-14c, this has increased accuracy.Photoelectric detector 459 is positioned at scintillation material 454 back and can detects the position that light pulse occurs by for example " Anger logic ".Because the part on surface is covered, electronic circuit " knows " that photon does not strike shaded areas, thereby can find out impingement position more accurately.The detector surface of covering definite part has reduced the position uncertainty of given light pulse effectively, thereby can determine its position more accurate and more accurately.

Figure 32 illustrates the detailed construction of scheming described bar shaped blind detector module 460 as described above, but wherein detector 462 is attached to the rear surface by adopting optical coupled material 464.Similarly shielding structure can be used for the solid-state detector module.

As those skilled in the clear, some costliness of the cost of various types of photoelectric detectors.Therefore, need to reduce the quantity of required photoelectric detector.According to another embodiment of the invention, a pair of or more optical fiber can be attached to each detector, make an optical fiber be connected to each end of detector based on flicker.Optical fiber can be connected to top and bottom and/or with the back side of top and bottom contiguous.Then can be with fiber guides to photomultiplier tube with position sensing degree type.The multichannel photoelectricity multiplier tube that these are easy to obtain can provide the difference output of a plurality of positions of crossing each multiplier tube surface.Then this class photomultiplier tube can be responded to the light pulse of transmitting from various detectors from a large amount of optical fiber.By this way, just can reduce the sum of photoelectric detector.Similarly method can be used for the detector based on the two dimension flicker.Not to adopt to be installed to the photoelectric detector at material rear portion, but can adopt a plurality of optical fiber that light is directed to multichannel detector.

As previously mentioned, the scintillation material piece that forms the basic detector core of flicker is coated in transmissive line as aluminum and so on, the light reflecting material.This has increased the light pulse brightness by the photodetector perception.Yet in some cases, but this reflexive stray light detector is determined the ability of the lengthwise position of photon strikes scintillation material.Therefore, the reflexive on the one or more surfaces of minimizing scintillation material is useful.For this purpose, before coating, can make surperficial roughening, can make the certain regional roughening of coating, perhaps on scintillation material or coating, apply low reflectance coating.Replacedly, the length change reflexive along reflector is ideal.For example, the width of a lip-deep coarse tape of scintillation material can change along the length of detector.This tape can be narrower in central authorities, thereby keep than highly reflective, and at the end broad to reduce reflexive.This has increased the probability that detects close central part incident in the end.

XIV. detector and arcuation body all move

If the interval of detector module is more sparse, can in the one-tenth dihedral sample pattern that native system provides, see the slit.The importance in this class slit depends on dihedral " tank " number of the data that obtain when perforate arcuation body moves.In addition, the significance of any pseudo-shadow that is caused by the sampling of imperfect dihedral depends on clinical setting.If this pseudo-shadow will be removed, then the present invention selectively provides the device that makes detector module 500 rotate through limited angular range 502 (Figure 33), thisly moves or produces in a continuous manner or with limited discrete step number.The moving range of detector arcuation body equals the interval between the detector.In each step that detector moves, perforate arcuation body 504 moved its moving range 506.By this way, even adopt sparse detector set also can obtain whole angle set of projections.

As another replaceable mode, a kind ofly can be provided with fewer purpose detector to reduce the cost of system according to tomograph system of the present invention.This system or have the resolution of reduction or need to increase sweep time.Afterwards, system can upgrade by the other detector of interpolation of the position between existing detector.

XV. calibration

As well known to those skilled in the art, nuclear medical imaging device needs periodic calibration.For typical parallel hole gamma camera, the material piece that has radioactive substance on its one side is placed to form calibration near collimator surface.The present invention forms different challenges.The tubulose radioactive source can be placed by the place at patient's axle.Yet owing to need the long time in time in several locational each arcuation body positions, calibration is very consuming time.This also can cause, and there is unacceptable radiation levels in the room in calibration process.Figure 35 demonstrates a kind of preferred calibration steps.Perforate arcuation body is depicted as 510, and perforate is depicted as 512.Calibrating device 514 is depicted as and is positioned near the perforate 512.It is arcuation and can has than littler radius and curvature are shown.Have active material on the inner surface 516, and be placed to and make active material can cause photon spread to cross perforate 512.This causes active material to cover the visual field that can " see " all sensors of perforate.Obviously, adopt a plurality of calibrating devices 514, place one at each tapping.This can realize the quickly calibrated of equipment, and can realize the compact storage of calibrator (-ter) unit, and the x ray exposure x amount is minimized.

XVI. replaceable structure

Previous embodiment of the present invention regulation detector sensor array, collimator and block piece each all be arcual.It will be apparent to those skilled in the art that other shape also is possible.For example, detector can be arranged in rectangle or square arrangement.Block piece and collimator also can be analogous shapes.In another embodiment, band shape or the two-dimensional detector group position around can be in the visual field is arranged to keep straight on.Adopt this method of two-dimensional detector 520 shown in Figure 36.Every capable detector 520 has the block piece 522 of the straight plate shape formula that is placed on its place ahead.Block piece 522 has the perforate that forms passing wherein, as slit 524, and moves to the shown direction of arrow D, thus line or respond inswept visual field.As described in, also collimator can be set at this other embodiment.As further replaceable form, band shape or two-dimensional detector can be arranged to as shown in figure 36, and can adopt arc or annular block piece.Radian between but the layout among this layout Figure 36 can cover 180 to 360.In these embodiments, if adopt two-dimensional detector, the conventional large-scale two-dimensional detector that is adopted in the gamma camera can be divided into several, preferred four, thinking provides these embodiment needed less two-dimensional detector.This has reduced the totle drilling cost of parts.

According to application, system of the present invention can comprise other adnexa.For example, in cardiac function is checked, may need to make patient to perform physical exercise to increase the weight of the heart burden.For this purpose, system can comprise fixing or removable cycle ergometer.In addition, system can comprise electrocardiograph and/or built-in cardiac defibrillator.In addition, also can comprise maybe and can connect amedrop.

XVII. structure is considered

Figure 37 illustrates the supporting component of the imaging arcuation body 610 that is similar to shown in Figure 18.Yet Figure 37 illustrates the tension part that this arcuation body has the diagonal spoke between upper supporting piece 612 and lower support element 614 or tends to other direction.This wheel shaft can consider to comprise the orthogonal sets and the first and second diagonal groups.Represent the horizontal spoke of orthogonal sets spoke to be labeled as 616.Represent the spoke of spoke in the first diagonal group to be labeled as 618, and represent the spoke of spoke in the second diagonal group to be labeled as 620.As shown in the figure, every group comprises a plurality of similar location spokes of arranging and extending along the arcuation body between upper and lower support member 612 and 614.Though arcuation body 610 can be constructed with whole three groups of spokes, it also can be configured to have only one group or two groups of spokes.In a preferred embodiment, two groups of diagonal spokes representing by 620 only are set.As previously mentioned, supporting component 610 has basilar part or the stiff end 622 that is connected to imaging device remainder of the present invention, and the remainder of arcuation body extend out to free end from basilar part 622.In certain embodiments, the remainder of arcuation body 610 is not supported, thereby must self-supporting.Because arcuation body 610 may be very heavy, it need be built into along its length anti-sagging or anti-twist.By the spoke by 620 representatives is set, can provides certain arcuation body to sink and compensate.As those skilled in the clear, by tension spoke 620, the cantilever free end of arcuation body 610 can promote the present position when spoke is lax to some extent with respect to it.In some cases, spokes by 616 and 618 representatives also can be set with structure that attached middle school is provided or other compensation is provided.

Arcuation body 610 preferably includes collimator, and this collimator is configured with a plurality of plastic sheets or lead flake.Experiment shows, is not in the same place if upper support element 612 is strained with lower support 614, and the end of arcuation body is carried on just may be slightly, and it can cause each sheet in the collimator assembly relative to each other extremely slightly to slide.If two support members 612 and 614 are forced together again each other, then each sheet of collimator assembly is locked to each other and has greatly increased the hardness of whole arcuation body 610.Therefore, the arcuation body can be for example by adopting fixture to move to optimum position, and then various spokes can be tightened up so that upper board 612 and lower panel 614 clamp each other tightly.

Referring to Figure 38, it shows the cross section of arcuation body.In this embodiment, collimator assembly 630 is configured with a plurality of lead and the plastics alternating layer that is supported between lower support plate 632 and the upper support board 634.Threaded adjustment part 636 passes lower support plate 614 and extends to lower support 632 and pass upper support board 612 and extend to upper support element 634.Each several part can be a not to scale (NTS).By adjusting adjustment part 636, can adjust the position of collimator assembly 630 with respect to the remainder of arcuation body.It will be apparent to one skilled in the art that adjustment part is arranged on along a plurality of positions on the arcuation body length, thereby the position of collimator assembly can be adjusted on the whole length of arcuation body.By adjusting each adjustment part 636, but compensating collimator is along sinking on its length.In addition, can adjust the interior any distortion of collimator assembly.Preferably, adjust collimator assembly so that each blade is smooth substantially.

Figure 38 illustrates the perforate arcuation body 638 between collimator assembly and arcuation body patient-side.Arcuation body patient-side has the transmissive wire material thin slice as aluminum and so on, shown in 640.This material sheet 640 is tied on the lower support 614 upper support element 612 so that arc firm on the structure to be provided.Away from patient-side a spoke 642 is shown at the arcuation body, its representative is depicted as in the spoke of 616-620.

Figure 39 illustrates another embodiment, and wherein thin material tablet 640 other spokes 644 replace.Material piece 640 is preferred in Figure 38, reduces because it provides in photon transmission more uniformly, and adopts spoke can cause the part in the photonic via to be reduced.Yet, it will be apparent to one skilled in the art that and can calibrate existing this machine with compensation spoke wheel 644.

Figure 40 illustrates another embodiment, wherein is labeled as sheet on 646 the arcuation body patient-side around the top of upper support element 612 and the bottom bend of lower support 614.This makes securing member easier to be fixing, from but preferred structure.

XVIII. data recombination

It will be apparent to one skilled in the art that imaging system according to the present invention provides and the current multi-form data of imaging camera that have the rectangular planar surface usually.These traditional cameras are from a plurality of angle acquisition images, and each image provides patient's two dimension " photo " from this angle.In the present invention, a plurality of detectors receive photons from a plurality of angles, when perforate arcuation body and detector are relative to each other mobile, and the line of response of each detector is inswept patient zone.Because imaging finishes by different way,, thereby this data transaction is become to be used for the form of current machine therefore preferably at first to handling from data of the present invention.Then, can adopt tradition to rebuild the resulting data of software processes.This intermediate steps that data format is turned to by the current form that provides of imaging device is referred to herein as " reorganization ".

For understanding, how preferably at first to be described in traditional imaging device deal with data according to data recombination of the present invention.Figure 41 illustrates patient 650 cross section.The part of arcuation body 652 that forms the part of some embodiments of the invention is depicted as and is enclosed in around the transversal part of patient 650.The conventional two-dimensional imaging camera schematically is shown 654 at the primary importance place, is shown 656 again in the position that becomes 90 degree with primary importance.A plurality of parallel imaging lines are represented from the projection of each photographing unit 654 and 656.In the data of handle free 654 and 656 indicated photographing units, the position of incident photon adopts r and θ to represent usually.These argument tables be shown into penetrate photon apart from detector centre apart from r, and position, the angle θ of photographing unit.One of incident photon path is labeled as 658 in Figure 41.This photon path is denoted as r in the drawings apart from the distance of the camera center at 654 places in the position.These data are plotted in the chart that is called as sinogram figure (sinogram).Figure 42 illustrates exemplary sinogram figure.Sinogram figure draws out apart from the relation between position, the angle θ of the position r at imager center and photographing unit, and wherein the center is zero.If being positioned at the point 660 at imaging region middle place is unique point of ballistic phonon, then sinogram figure will be a vertical line as shown in figure 42.This is because will all strike the center (r=0) of photographing unit in the position, whole angle of photographing unit (θ=0 is to 360 degree) from the photon of a single point 660 emissions.Figure 43 illustrates the sinogram figure of single eccentric point.When the rotation of imaging photographing unit coiled picture zone, eccentric point appears to respect to the camera center shifted laterally, thereby obtains sine curve on sinogram figure.

Again referring to Figure 41, if the patient handling vertical position then is depicted as 650 cross-sectional slices and can be regarded as single dropping cut slice.Obviously, the sinogram figure that obtains in the actual patient imaging time will be more more complicated than the sinogram figure shown in Figure 42 and 43.In addition, sinogram figure is set up in each " section " that can be patient.As previously mentioned, the patient visual field that is positioned at it can form and have longitudinal axis.Patient " section " will be usually perpendicular to this longitudinal axis.This also can be called as induction planes.As those skilled in the clear, can form a plurality of induction planes to obtain patient's difference " section ".Again referring to Figure 41, should be appreciated that apart from r to may be defined as distance between the position of in induction planes camera center point or centrage and reception photon.For defining the position, angle of traditional gamma camera, the position line may be defined in induction planes and vertically extends between longitudinal axis and camera center.Then angle θ can be defined as the position line and be also contained in the induction planes and perpendicular to the angle between any baseline of longitudinal axis.

Refer back to Fig. 9 B again, as can be seen when perforate arcuation body and detector are relative to each other mobile, the line of response of each detector inswept visual field how in this equipment.

Figure 44 illustrates and can regard the sinogram figure that has the imaging system of the perforate arcuation body that comprises six perforates according to of the present invention as.If single-point is carried out imaging, and data are plotted in perforate arcuation body position and detector array and list concerning on the chart of the position of sensing photon, then will generate a plurality of angled parallel lines.This is because when move the position of perforate arcuation body, and the photon that can arrive detector from point source also moves with the generally linear relation in the position that detector array lists.Should be noted that Figure 44 is not pro rata, and just attempt to express the notion of a cardinal principle.For being adopted as the algorithm that the data that present with the form in Figure 42 and 43 design the data shown in Figure 44 are handled, must be classified again or recombinate these data.

Referring to Figure 45, section 650 is depicted as has launch point 662.Perforate arcuation body 663 with perforate 664 is around imaging region, and the detector arcuation body or the assembly 665 that have detector 666 center on perforate arcuation body.To pass perforate 664 and receive from the photons of putting 662 emissions by being positioned at 666 detector or pick off.Because the position and the detector location 666 of perforate 664 are known, can calculate the equivalent position data r and the θ of two D cameras.Figure 45 illustrates the equivalent r and the θ of two D cameras.

Referring now to signal Figure 46,, photon path is depicted as 670, and perforate arcuation body is depicted as 672, and detector module or arcuation body are depicted as 674.As shown in the figure, photon path 670 passes perforate 676 and strikes on the detector at 678 places.The center of perforate arcuation body is depicted as C, and the equivalent r of two-dimensional imaging photographing unit and θ indication are on figure.C also represents the center of visual field, and can be positioned on the longitudinal axis.The angle of perforate 676 is expressed as Φ, and the radius of perforate arcuation body is expressed as Rapp.Between these variablees relation by under establish an equation and provide:

Figure 47 illustrates the similarity relation of the position of detector arcuation body 678.In this case, the radius of detector arcuation body is given as R _Det, and the position angle on the detector arcuation body is given as ψ.Relation between these variablees is provided by following:

$\mathrm{\Ψ}=\arcsin \left(\frac{r}{R_{\det }}\right)-\mathrm{\θ}$

As those skilled in the clear, can be by will just generating the sinogram figure of each section of patient in the equation shown in the θ of each position on the sinogram figure and r value substitution Figure 46 and 47.In each case, this will provide position of opening With detector location Ψ.Then the intensity that writes down for this combination of position of opening and detector location can be input among the sinogram figure of this combination of θ and r.Constantly repeat this process up to generating complete hole chamber photographic view.As those skilled in the clear, can adopt computer equipment to finish this reorganization.

XIX. additional calibration is constructed

Figure 35 is described as reference, and the calibration source that need provide certain type is to calibrate according to imaging system of the present invention.In traditional two-dimensional imaging photographing unit, the flat sheet-like radioactive source is placed on the upwards top of the collimator of aiming usually.This calibration source is exposed under the radioactive emission of same level all surfaces of photographing unit, thus the adjustable photographing unit.That is to say,, then can carry out the software adjustment, thereby after calibration, resulting reading is uniform if certain part of photographing unit reading is higher or on the low side with respect to the other parts of photographing unit.These conventional calibration method have several shortcomings.At first, radioactive calibration source weighs greatly, and makes the technical staff usually be difficult to handle.Usually it is stored in the large-scale plumbous box to avoid excessive radioactivity exposure.Yet because the size and the weight of box body, the technical staff usually is forced to box body is stayed a place, then radioactive source is brought into actual will carrying out in the room of imaging with oneself.This is inconvenient and can causes extra radioactivity exposure to the technical staff.In addition, the collimator that is placed between calibration source and the photographing unit sensitive surface only allows a photon in each ten thousand middle photon to arrive sensitive surface.Therefore this calibration process usually is consuming time.

Figure 35 illustrates a calibration method of the present invention.Other method will be described below.In each case, radioactive source be arranged in the perforate of perforate arcuation body or near, thereby the ray projection is passed perforate arcuation body, passes collimator and is arrived detector.Because design of the present invention, more a high proportion of ballistic phonon arrives each detector, thereby has reduced the alignment time.Behind radioactive calibration source location, mobile perforate arcuation body also can adopt the software calibration imaging system adjusting the sensitive variation of detector based on detector with respect to the position of perforate arcuation body, and adjust the different angles and crossing this fact of detector of photon.

Referring now to Figure 48,, it will describe another calibration source.The slit fringeware 702 that has a pair of formation slit 704 in the part of the perforate arcuation body shown in 700 places.Calibration source comprises piped radioactive source 706 substantially, and this radioactive source is attached on the carrier that comprises lead screen body 708 and plastic carrier 710.Figure 49-55 illustrates the assembling and the use of calibration source.Figure 49 illustrates plastic carrier 710, and as shown in the figure, this carrier is the arcuation body with recessed inner surface.Figure 50 illustrates the lead vector shield 708 that is nested in the analogous shape in the plastic carrier 710.In certain embodiments, the lead screen body is about 2 1/2 to 3mm thick.Replacedly, this shield can be formed by tungsten, and this makes it just can stop the lonizing radiation of same amount under thinner situation.Radioactive source can be connected on the carrier in every way.Figure 51 illustrates the clip 712 that employing can be supported radioactive source.Replacedly, can be by bonding or it is adhered to so that radioactive source is remained on the certain position by whole fronts coating plastic layer to carrier.Figure 52 illustrates the radioactive source of being supported by carrier self 706.This radioactive source can be the pipe that is filled with active material, and active material can be as being embedded in the cobalt granule in epoxy resin or other resin.Figure 53 illustrates and is placed on the intravital calibration source of perforate arcuation, has wherein removed fringeware for observability.Figure 54 illustrates the perforate arcuation body that fringeware is installed.Figure 55 illustrate radioactive source slip in a pair of guide so that its location be used for the calibration.Perforate arcuation body can carry out moving while arriving in calibration process.Have than the higher height of perforate arcuation body though calibration source is depicted as, it also can have the height that is equal to or less than perforate arcuation height degree.

As those skilled in the clear, perforate arcuation body is contained in the imaging arcuation body, thereby when placing calibration source, is very difficult near this perforate arcuation body.Keeper and carrier that a series of accompanying drawings that begin from Figure 56 show assembling, location and the use of calibration source and are used for this calibration source.Figure 56 illustrates the keeper 732 that has assembled.It comprises a pair of siding track 720 with bent upper ends portion, and described upper end is arranged to parallel to each other.Siding track 720 links together by interconnecting part 722 and 724 in their top and bottom.The bottom interconnects part 724 and also plays the effect of distance piece and can suppose the inside that is positioned at siding track.A pair of internal guide rail 726 is connected on the bottom interval spare 724 and is parallel substantially with siding track 720 and extend upward at intervals.Between internal guide rail 726 and siding track 720, form a pair of slit.The open limit of slit is by closure member 728 sealings.Support lugn 730 is adjacent to the bottom of this mounting equipment.Preceding cross member illustrates at 734 places.In one embodiment, cross member 734 comprises the magnetic lock pin that is used in use locating carrier or keeper 732.Figure 57 illustrates the decomposition view of carrier 732.

Figure 58 and 59 illustrates the unit of plastic 736 that forms calibration source 746 parts.As shown in the figure, in the front surface of unit of plastic 736, has recess.In this recess of unit of plastic 736, place lead screen part 738.Stretch out guide finger 740 from the side of unit of plastic 736.Inner surface near the lead screen part is placed radioactivity bar 742.Then the container 744 of plastics or aluminum is covered on radioactive source so that it keeps near lead screen part and unit of plastic.So just obtain the calibration source 746 that assembles.

Figure 60 illustrates the calibration source 746 that is placed in the keeper 732, and keeper is supported by hinge 748.Figure 61 illustrates keeper 736 and the source 746 after the rotation, thereby can see the back side of unit of plastic 736.Figure 62 illustrates at the upper support element 750 of imaging arcuation body and the keeper 732 between the lower support 752, passes upper-part 750 and forms opening 754.Figure 63 has increased perforate arcuation body 755, and it has upper and lower guide rail 758 and 760.Figure 64 illustrates the part of upper support element 750 has been excised.

Figure 65 illustrates the detailed view of the hinge 748 at place, source keeper 746 bottoms.In alternative embodiment, be provided with spring, as at hinge 748 places, to be used for that the upper end of keeper is resiliently biased to perforate arcuation body 755.

During the details of building some embodiments of the invention, it is enough near so that the source can directly fall into the appropriate location that the opening in the upper support element can not be arranged to leave hole arcuation body.On the contrary, it need be placed on the part away from this supports support perforate arcuation body.Figure 66 illustrates source 746 and passes the opening 754 of upper support element 750 and fall into keeper 732.The part of this support member is cut to provide visual.Figure 67 illustrates the side view of Figure 66, and opening 754 is shown how is placed to and retreats enough far, thereby when carrier 746 extended through opening 754, carrier 746 can not enter the position of next-door neighbour's perforate arcuation body.On the contrary, it can bump against on the inclined rear face of keeper 732.This causes the source to tilt slightly, its cause again conversely keeper 732 on hinge to back rotation to aim at the source.Figure 68 illustrates source 746 and inserts in the keeper 732 fully and keeper reverses forward, perhaps causes it to move by the operator or by the intrachain spring of hinge.Then keeper can perhaps be remained on the certain position by other device by the magnetic lock pin or by spring.Figure 69 and 70 illustrates other view of this insertion process.Figure 71 illustrates some exemplary sizes of 732 1 embodiment of keeper.

Figure 72 illustrates the alternative embodiment of calibration source, and it can be used for being similar to the keeper shown in the aforementioned figures.The shape of this calibration source is similar to the source among Figure 48 and has lead or tungsten arcuation spare 798.Calibration source 800 has the lead 798 that is wrapped in the plastics 802 to protect this lead and to make hardening.Active material pipe 804 is fixed to the concave surface of plumbous and plastic assembly.The special advantage that is used for calibrator (-ter) unit of the present invention is that they are littler, lighter than former calibrator (-ter) unit, and is easier to carrying.Figure 73 illustrates the calibration fixed bin 810 that wherein is placed with six calibration sources.Each source can be nested into and be assembled to compactly in the box 810.The gross weight of box and calibration source can be low to moderate 6 or 10 pounds, makes the technical staff be easy to carrying under the situation that need not to be exposed.

XX. Wan Qu crystal detector

As previously mentioned, the present invention can use solid-state detector, as CZT, or makes with attached photocell behind the scintillation material.In the embodiment of front more, each scintillation material piece fits together concurrently.According to preferred distortion, can provide single large-scale crooked scintillator crystal materials, shown in 820 among Figure 74.This single flexure crystal piece can prolong its surperficial groove, and groove is partly cut crystal, thereby crystal is divided into different photon receiving areas.Figure 75 illustrates the crystal 820 of the attached a plurality of photocells 822 in back.

Other modification of disclosed preferred embodiment will be readily apparent to persons skilled in the art.Scope of the present invention comprises that by following claims its whole equivalents limit.

Claims (28)

1, a kind of single photon emission computed tomography system that is used to generate the multi-fault imaging of representing the radioisotopic distributed in three dimensions type of photo emissions, this system comprises:

Basilar part, it comprises and is used to support patient so that patient's a part is positioned at the patient support of visual field, passes the longitudinal axis that this visual field forms;

The detector module of contiguous this visual field, this detector module comprise whether operationally detect photon strikes photo response detector on this detector, and this detector module operationally detects the photon that a part that patient is positioned at the visual field is launched;

Be arranged in the photon barrier between this visual field and this detector, this block piece has the perforate slit that passes wherein formation so that photonic via is aimed at this perforate slit, passes the line of response that this perforate forms from this detector;

Collimator assembly, it comprises a plurality of collimation blades that formed by the photon attenuation material;

Be used to support the supporting component of this collimator assembly, this supporting component comprises first support member and second support member, this second support member and this first support member are spaced apart, this collimator assembly is arranged between two support members, thereby between this collimator assembly and first support member, form first distance, and between this collimator assembly and this second support member, form second distance; With

Adjust assembly, it comprises first adjustor of operationally adjusting this first distance and second adjustor of operationally adjusting this second distance.

2, the system as claimed in claim 1, wherein, this collimator assembly has the front surface that points to the visual field and the rear surface of visual field dorsad, first adjustor comprises first pair of adjustment part, each adjustment part extends between this first support member and this collimator assembly, a front surface than more close this collimator assembly of another adjustment part in this adjustment part.

3, system according to claim 2, wherein, this second adjustor comprises second pair of adjustment part, each adjustment part extends between this first support member and this collimator assembly, this front surface than more close this collimator assembly of another adjustment part in this adjustment part, these first and second pairs of adjustment part cooperations are operationally to adjust this first distance and this second distance and this collimator assembly angle with respect to this supporting component.

4, system according to claim 1, wherein, this support member is co-extension substantially, each support member has stiff end that is supported by basilar part and the free end that is spaced from, this collimator assembly has first end and free-ended second end of contiguous this support member of contiguous this basilar part, this first adjustor is included in more than first adjustment part that extends between this first support member and this collimator assembly, this second adjustor is included in more than second adjustment part that extends between this second support member and this collimator assembly, and these adjustment part cooperations are to adjust the position of this collimator assembly with respect to this support member.

5, system according to claim 4, wherein, more than first adjustment part is spaced apart between the stiff end of this first support member and free end, and more than second adjustment part is spaced apart between the stiff end of this second support member and free end.

6, system according to claim 5, wherein, this collimator assembly has the front surface that points to the visual field and the rear surface of visual field dorsad, and this more than first adjustment part comprises the place ahead group and rear group, and this place ahead group is than the front surface of more close this collimator assembly of this rear group.

7, system according to claim 6, wherein, this more than second adjustment part comprises the place ahead group and rear group, this place ahead group is than the front surface of more close this collimator assembly of this rear group.

8, system according to claim 4, wherein, this support member is substantially arc, and is arranged in substantially in the plane perpendicular to this longitudinal axis, this support member extends substantially around the visual field at least in part arcly.

9, system according to claim 1, wherein, each support member is flat pieces substantially.

10, system according to claim 1, wherein, this support member is the cardinal principle co-extension.

11, system according to claim 1, wherein, this supporting component has stiff end that is supported by basilar part and the free end that is spaced from.

12, system according to claim 1, wherein, this supporting component also comprises a plurality of tension parts that extend between this first and second support member, each tension part have with interconnective first end of this first support member and with interconnective second end of this second support member, can adjust these tension parts to adjust the distance between this first and second end.

13, system according to claim 12, wherein, each support member has by the stiff end of this basilar part support and free end spaced away.

14, system according to claim 13, wherein, these tension parts are spaced apart between this stiff end of this support member and second end.

15, system according to claim 14, wherein, at least some tension parts are angled, so that the distance of this this support member stiff end of first end distance is more farther than the distance of this this support member stiff end of second end distance, and other tension part is angled, so that the distance of this this support member stiff end of second end distance is more farther than the distance of this this support member stiff end of first end distance.

16, system according to claim 1, wherein, this longitudinal axis is substantially vertical, and this supporting component is arranged in the plane perpendicular to this longitudinal axis substantially, thus this first support member is that upper support element and this second support member are lower support.

17, system according to claim 1, wherein, this collimator assembly comprises the heap layer of alternative photon barrier material sheet and transmissive wire rod tablet, this photon barrier material sheet forms the collimation blade.

18, system according to claim 1, also comprise displacement actuator, this actuator operationally makes in this detector and the photon barrier one to move with respect in this detector and the photon barrier another, thereby this perforate is with respect at least a portion of this detector displacement and the inswept visual field of line of response.

19, system according to claim 1, wherein, this part that patient is arranged in the visual field is patient's a trunk, and longitudinal axis is substantially vertical, extends thereby patient's trunk is vertical substantially, and patient's head is basically than patient's buttocks height.

20, system according to claim 19, wherein, basilar part comprises chair shape structure, the vertical back portion of cardinal principle of patients back is divided and supported in the bottom that this chair shape structure has a cardinal principle level that is used to support patient posterior.

21, system according to claim 1, wherein, this supporting component is arc substantially and surrounds the visual field at least in part.

22, system according to claim 1, wherein, this collimator assembly is arranged between this photon barrier and the detector.

23, system according to claim 1, wherein, the transmissive wire material is arranged between the blade of this collimator assembly.

24, system according to claim 1, wherein, this collimation blade is substantially perpendicular to longitudinal axis.

25, system according to claim 1, wherein, this collimation blade is angled with respect to longitudinal axis.

26, system according to claim 1, wherein, this perforate slit is in substantially parallel relationship to longitudinal axis.

27, system according to claim 1, wherein, this perforate slit is substantially perpendicular at least some blades.

28, a kind of imaging system comprises:

Basilar part;

Be used for the visual field is carried out the detector module of imaging, this detector module comprises whether strike photo response detector this detector on, this detector module operationally detects from the photon of visual field emission if operationally detecting photon;

Collimator assembly, it comprises a plurality of collimation blades that formed by the photon attenuation material;

Be used to support the supporting component of this collimator assembly, this supporting component comprises first support member and second support member, this second support member and this first support member are spaced apart, this collimator assembly is arranged between two support members, thereby between this collimator assembly and this first support member, form first distance, and between this collimator assembly and this second support member, form second distance; With

Adjust assembly, it comprises first adjustor of operationally adjusting this first distance and second adjustor of operationally adjusting this second distance.

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