CN1910472A - Event positioning achieved via a lookup table - Google Patents
Event positioning achieved via a lookup table Download PDFInfo
- Publication number
- CN1910472A CN1910472A CN 200580002490 CN200580002490A CN1910472A CN 1910472 A CN1910472 A CN 1910472A CN 200580002490 CN200580002490 CN 200580002490 CN 200580002490 A CN200580002490 A CN 200580002490A CN 1910472 A CN1910472 A CN 1910472A
- Authority
- CN
- China
- Prior art keywords
- component
- max
- sensor
- comp
- value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/16—Measuring radiation intensity
- G01T1/161—Applications in the field of nuclear medicine, e.g. in vivo counting
- G01T1/164—Scintigraphy
- G01T1/1641—Static instruments for imaging the distribution of radioactivity in one or two dimensions using one or several scintillating elements; Radio-isotope cameras
- G01T1/1642—Static instruments for imaging the distribution of radioactivity in one or two dimensions using one or several scintillating elements; Radio-isotope cameras using a scintillation crystal and position sensing photodetector arrays, e.g. ANGER cameras
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/16—Measuring radiation intensity
- G01T1/1603—Measuring radiation intensity with a combination of at least two different types of detector
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/02—Devices for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
- A61B6/03—Computerised tomographs
- A61B6/037—Emission tomography
Abstract
A diagnostic imaging system (10) comprises a matrix of sensors (22) situated to view an event. Each sensor (22) is connected to an analog-to-digital converters (24) for converting output analog values of associated sensors (22) to digital numbers. A sensor (50) in the matrix which, in response to the event, has a highest output value relative to the other sensors (22) is identified. Outer sensors (52) that are closest neighbors to the high sensor (50) are identified. The outputs of the outer sensors (52) are compressed by a use of various non-linear square-root functions to reduce a number of bits of the respective outputs. The outputs of sensors carrying the most information are compressed the least, while those carrying the least information are compressed the most. An address of each event is generated and stored in a lookup table (44). The lookup table (44) is used to perform real-time positioning iterative algorithms off-line.
Description
The present invention relates to diagnostic imaging system and method.The present invention is devoted to the application-specific in conjunction with positron emission tomography (PET) and single photon emission tomographic imaging (SPECT) system, and describes the present invention with particular reference to it.Be to be understood that the present invention also can be applied in other similar application and the diagnosing image pattern.
Nuclear imaging uses radioactive source that patient's anatomical structure is carried out imaging.Usually, radiopharmaceutical is injected in patient's body.Radiopharmaceutical compounds comprises the radioactive isotope that carries out gamma-ray decay according to measurable speed and characteristic energy.Radiation detector is used for monitoring and record radiation emitted near being placed on the patient.Usually, detector is used to monitor the radiation emitted from a plurality of directions around patient's rotation or indexing.According to measured position and the such information of energy, radiopharmaceutical distribution in vivo is determined, and the rebuilt picked-up that is used for studying the circulation system, radiopharmaceutical in selected organ or tissue of distributed image, or the like.
In traditional scintillation detector, detector has the scintillator of being made up of big scintillation crystal or less scintillation crystal matrix.Under any situation in both of these case, scintillator is observed by sensor matrices.Normally used sensor is photomultiplier (" PMT ").The collimating apparatus that comprises the latticed or honey-comb shape array of radiation-absorbing material can be placed on scintillator and just between the person under inspection of receiving check, be used to limit the entering angle of the radiation that bumps with scintillator.All produce corresponding flash of light (flicker) with each radiation event of scintillator collision, and this flash of light (flicker) can be observed by PMT.In the close hexagoinal lattice array of composing and laying out of PMT, incident mainly is to be observed by immediate PMT and 6 PMT on every side thereof.The PMT degree of approach individual and the flash of light source has had influence on the degree of the light that is observed by above-mentioned PMT individuality.Each PMT that observes incident all produces corresponding electric pulse.Each amplitude of electric pulse usually and each PMT be directly proportional to the distance of glistening.Gamma camera is drawn radiation event according to the output of PMT, just, and its energy and position definite and radioactive ray that scintillator collides.
Usually, the traditional Anger method that is used for the incident location is determined event location, and this method the output signal summation and the weighting of back to PMT occur in incident.The Anger method that is used for the incident location is calculated based on simple first moment.Energy is measured as the summation of all PMT signals usually, and the position is measured as " barycenter " or the mass centre (centroid) of all PMT signals usually.
But present real-time positioning algorithm does not have known alternative manner accurate.So far, alternative manner is still intensive on calculating for supporting real-time image to generate and handling.Therefore, need a kind ofly allow to use iterative technique to determine the method and apparatus of incident more accurate location.The present invention proposes a kind of improved novel imaging device and method, is used to overcome the problems referred to above and other problem.
According to an aspect of the present invention, a kind of diagnostic imaging system is disclosed.Sensor matrices is oriented in order to observed events, and these sensors have the output separately of response events.Each sensor all is connected on the independent analog to digital converter, is used for converting the imitated output quantity of related sensor to digital quantity.A kind of device is identified in high sensor in the matrix (high sensor), and this sensor has the highest output valve in response to incident with respect to other sensor.A kind of device is identified in the matrix number of the external sensor that is high sensor arest neighbors.A kind of figure place of installing the output of compression external sensor in order to each output of minimizing.Look-up table is by the output addressing by compression, in order to regain the events corresponding position.
According to another aspect of the present invention, a kind of diagnosing image method is disclosed.Utilize the sensor matrices of gamma camera to detect radiation, these sensors are oriented in order to observed events and have the output of response events separately.The imitated output quantity of related sensor is converted to digital quantity by analog to digital converter, and wherein each sensor all is connected on the independent analog to digital converter.High sensor in the matrix is identified, and described high sensor has the highest output valve in response to incident with respect to other sensor.Be identified in the matrix number of the external sensor that is the high sensor arest neighbors.The output of external sensor is compressed in order to reduce the figure place of each output.Look-up table by by the compression the output addressing in order to regain the events corresponding position.
An advantage of the present invention is by using iterative algorithm can estimate event location more accurately.
Another advantage of the present invention is can be to those incident execution incident discriminating/eliminatings that can not be properly oriented.
Reading and understanding on the basis of following detailed description of preferred embodiment, other advantage of the present invention and benefit are apparent for those of ordinary skills.
The present invention can adopt multiple parts and arrangement of parts, and can adopt plurality of step and step arrangement.Accompanying drawing only is used to illustrate preferred embodiment, is not to be construed as the present invention is construed as limiting.
Fig. 1 is the synoptic diagram of diagnostic imaging system;
Fig. 2 is the synoptic diagram of a part of diagnostic imaging system;
Fig. 3 is according to a part of software program of the present invention;
Fig. 4 is the synoptic diagram according to a kind of encoding scheme of the present invention;
Fig. 5 is to use the synoptic diagram of 4 pipe families of horizontal symmetrical;
Fig. 6 is the synoptic diagram according to another kind of encoding scheme of the present invention;
Fig. 7 is the synoptic diagram of 7 pipe families, and wherein incident occurs near the exterior tube;
Fig. 8 is the synoptic diagram according to another kind of encoding scheme of the present invention; With
Fig. 9 is the synoptic diagram of 7 pipe families, and wherein incident occurs near the center of high sensitivity pipe.
With reference to figure 1, PET scanning machine 10 comprises a plurality of probes or gamma camera or detector 12, they towards and preferably be mounted to 14 motions around (preferably comprise radioactive nuclide distribute) person under inspection, wherein person under inspection 14 is arranged in surveyed area 16.Each detector 12 includes scintillator 20, and scintillator 20 converts radiation event (for example, the radioactive ray that distribute from radioactive nuclide that bump with scintillator 20) to flash of light or flicker.The matrix of the sensor 22 as photomultiplier (PMT) is used to observe or receives flash of light from scintillator 20.In preferred embodiments, the matrix of sensor 22 is close hexagoinal lattice arrangements of composing and laying out of PMT.But other sensor and the mode of composing and laying out have also been considered.Usually, radiation is created in the gamma quantum that occurs in the radioactive isotope transformation.Transformation quantum bump scintillator 20 causes flicker, and wherein above-mentioned scintillator 20 preferably includes doping sodium iodide (NaI).The light that flicker is sent is distributed on a plurality of sensors 22.From the light quantity of 22 observations of given sensor or the specific flicker that receives the trend that reduces gradually to incident distance along with sensor is arranged.As the response to the flash of light that receives, each sensor 22 all produces output signal (for example, the analog electrical pulse) separately, and wherein output signal and the flashing signal that receives are directly proportional.Preferably, each sensor 22 all is electrically connected on modulus (A/D) converter 24, and it converts each simulation output to digital signal.Information is transmitted to processor 28, by processor 28 measure or the position of each scintillation event of determining in addition to take place with respect to each detecting head (x, y) and/or energy (z).For given incident, the output valve of each sensor 22 is determined by following content alternatively: the integration of the sensor output signal of response events (just, determining amplitude or the area under the intensity curve or a part of area that the output pulse of sensor 22 changes at relative time); The peak amplitude of the sensor output signal of response events; Or be directly proportional or some suitably relevant other measurements with the light total amount that observes (thus with the incident energy).Can be nominally in two dimension (2D) Cartesian coordinates of x, y coordinate resolved and/or definite in use at the event location on the scintillator 20.But, also considered other coordinate system.
Continuation is with reference to figure 1, and scanning machine 10 can be operated under SPECT pattern or the PET pattern selectively as required.In the SPECT pattern, camera 12 has the collimating apparatus (not shown) that is attached on it, and collimating apparatus is used for radiation entered and is limited in specific direction, just, and along known rays.Therefore, detecting the definite position of radiation and the angular coordinate of camera 12 on scintillator 20 defines at the ray of each radiation event along its generation.These ray tracings and (for example, from angular coordinate resolver 30 obtain) camera angular coordinate are delivered to reconstruction processor 32, and reconstruction processor 32 is with the ray back projection or be reconstructed into the volume image that stores in the video memory 34 in addition and represent.
In the PET pattern, collimating apparatus is removed.Therefore, the position of single scintillation event can not limit ray.But the radioactive nuclide that uses in PET scanning has experienced annihilation event, and two radiation photons (just, differing 180 spends) on antipodal direction are penetrated simultaneously in annihilation event.Coincidence detector 36 (coincidence detector) detects the time that the flicker on two cameras 12 occurs simultaneously.Two positions of glimmering simultaneously define the end points of the ray of process annihilation event.Ray or track counter 38 are from each corresponding ray to calculating process person under inspection 14 scintillation event that receives simultaneously.The ray tracing that obtains from ray counter 38 is delivered to reconstruction processor 32, is reconstructed into volume image and represents.Composograph is represented to be stored in the volume image storer 34.
In SPECT and PET pattern, the graphical representation data that show on the monitor 42 are handled and/or be formatted in to video processor 40.
Continuation is with reference to figure 1 and further with reference to figure 2, and processor 28 comprises look-up table 44, and look-up table 44 is produced is used to use iterative algorithm to carry out the real-time event location.Usually, before imaging, PMT 22 is calibrated by a kind of known isotope.The same with all PMT, the center of high sensitivity pipe 50 can accurately obtain from prior imformation (for example, physical measurement).The calibration information of each pipe 22 is stored in the look-up table 44.Look-up table 44 is used for the position of identification incident with respect to the high sensitivity tube hub.More specifically, processor 28 comprises the definite device 46 of the PMT value of determining PMT 22 initial values.The highest output determines that 48 identifications of device or algorithm have the high sensitivity pipe 50 of the highest output valve with respect to other all PMT 22 and are positioned near the high sensitivity pipe 50 arest neighbors pipe or the number of exterior tube 52, for example, PMT subclass as shown in Figure 5 or PMT family 54.Preferably, the maximum number of arest neighbors pipe 52 is 6, and this defines a close hexagon family that composes and lay out of 7-PMT, and its master reference is to have the sensor of high output valve.But family 54 can comprise the pipe of different numbers, for example 3 or 5.Component (fraction) determines that device 56 with managing 50,52 the output value divided by high sensitivity pipe 50 in the family 54, correspondingly eliminates a variable, for example the value of high sensitivity pipe 50.This operation forms 3 to 6 10 hytes and divides F1-F6, and this depends on the number of exterior tube 52 in the family 54.The component order is determined the descending of the component F1-F6 of device 58 identification pipes 52, for example the highest component F1, the second high component F2 and low component F3-F6.Component F1-F6 is stored in the PMT value storer 60.Component F1-F6 discerns the position of incident with respect to the high sensitivity tube hub, and can be used in addressing in look-up table 44.
Typically, each analog to digital converter 24 is all exported 10 intensity levels.Like this, under the situation that does not have compression, look-up table 44 will have 10
21Individual storage address.For addressing in look-up table 44, compression set 70 dynamic application compression algorithms are to reduce figure place, and for example 10 hytes divide F1-F6 to be compressed to space available in look-up table 44 according to various standards discussed in more detail below.Particularly, the small component compression degree greater than the dynamic compression of big component compression degree by advantageous applications.In addition, symmetry is used to eliminate the demand of encoding with respect to one or more event spaces position of 50 pairs of next ones of maximum sensitivity pipe or a plurality of maximum sensitivity pipes.Certainly, can consider: when setting up bigger look-up table (for example, 10
21The look-up table of size) when becoming practical, compression step can be left in the basket.
Continuation is with reference to figure 2, and coding selecting arrangement 72 is each incident Dynamic Selection encoding scheme according to managing 50,52 number, amplitude and other standard of the highest component F1 in the number of look-up table 44 available address positions, the family 54.The pipe 52 that beared information is maximum is compressed minimumly, and those minimum pipes of beared information are compressed at most simultaneously.Preferably, the non-linear compression (for example, weighted quadratic radical function) of pipe component F1-F6 is used to reduce to each component required figure place of encoding.For minimum quantization error, according to the scope of pipe component, different non-linear compression algorithms are used.Preferably, use address bit to indicate: (for example to carry out the signal biasing, fixed value can deduct from the highest component) in order to reducing the time of dynamic range, described dynamic range is the dynamic range that must be compressed to these values for minimum quantization error.
Continuation is with reference to figure 2, and address producing device 74 produces the incident address.Resulting incident address visit look-up table 44 is used to regain the event location with respect to the maximum sensitivity tube hub.Position determining means 80 regains 16 bit address that comprise incident x, y position, and is broken down into visibly different 8 x values and y value.The x of high sensitivity pipe place-centric, y position use look-up table output to regulate by apparatus for adjusting position 82, to derive the final position of incident.
In the embodiment depicted in fig. 5, high sensitivity pipe 50 is placed in the 4 pipe families 54, and just high sensitivity pipe 50 has 3 vicinities or exterior tube 52.Use comes incident (case) number is reduced twice along the horizontal symmetrical of transverse axis.4 pipe families 54 are counted as exterior tube 52 and are placed on the detector top.Preferably, sign is set and is used for indicating the highest component F1 always to be positioned at upper quadrant.
Refer again to Fig. 2, turning device 84 is searched the event location that gets according to the highest component F1 place quadrant around the axis of symmetry upset.For example, according to the position of the highest component F1 with respect to the y axle, x position adjustments symbol is selected, and according to the position with respect to the x axle, the y correction symbol is conditioned.In described 4 family's examples, position determining means 80 is carried out in the address of having encoded and is searched, and regains x, y position with respect to high sensitivity pipe 50 centers.If upset is not performed, apparatus for adjusting position 82 calculates final x, y position, and it equals high sensitivity pipe 50 centers and adds relevant x, y position.If upset is performed, apparatus for adjusting position 82 calculates final x, y position, and it equals high sensitivity pipe 50 centers and deducts relevant x, y position.Certainly, can consider: suitably also can use vertical symmetry under the situation.
With reference to figure 2 and 3 and further with reference to figure 4, in step 90, encoding scheme selecting arrangement 72 Dynamic Selection encoding schemes 6 are to set up look-up table 44.Preferably, 3 address bits (for example, position 25-27) are used for inditron component F1-F3 and how are encoded and compress.In encoding scheme 6, by using square root equation (A), each component F1, F2, F3 are converted into 8 (256 codings):
(A) F
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied to respective tube component F1-F6;
K is the constant scalar that is used for the compressed pipe component, k=(Code
Max)
2/ F
Max
Code
MaxBe the maximum coding of each component F1-F6, equal 2
Bits-1=255, F
MaxBe the maximal value of each component F1-F6, equal 1023;
k＝(Code
max)
2/F
max＝255
2/1023＝63.56304985。
By using following function, realize decoding or the decompression of each component F1-F6 of use encoding scheme 6 codings:
(A)′ F
uncomp＝((int)((double)(F
comp)
2/k+0.5)
In the embodiment depicted in fig. 7, high sensitivity pipe 50 is placed in the 7 pipe families 54, and just high sensitivity pipe 50 has 6 vicinities or exterior tube 52.Similar with embodiment shown in Figure 5, horizontal symmetrical is used, and so only needs 3 largest component positions.If the highest component F1 is a bottom tube, turning device 84 upset pipe signals.
Refer again to Fig. 3, in step 92, when family 54 has 7 pipes and the highest component F1 greater than 255 the time, for example, incident occurs away from the center of high sensitivity pipe 50, near one or more adjacent tube 52 of indication 2 d of PMT or 3 t, encoding scheme selecting arrangement 72 is selected encoding scheme 0,1 or 2.In step 94, when the highest definite component F1 and the second high component F2 do not have when adjacent one another are, encoding scheme selecting arrangement 72 abandons incident.In step 96, a component (this shows that incident is contaminated) greater than 255 time is arranged in determining low component F3-F6, encoding scheme selecting arrangement 72 abandons incident.
With reference to figure 6, a position 25-27 is used for the inditron component and how is encoded and compresses.Coding ID uses pipe synoptic diagram shown in Figure 7 to be provided with, and the aforementioned tube synoptic diagram is used to indicate and has the position of the pipe of high component F1.When most of signal be comprised in the highest and the second high component F1, F2 in the time, other address bit (for example, position 24) is optimized for the indication second high component F2 to the direction relations of the highest component F1 (clockwise or counterclockwise).This just allows can distribute to more address bit the highest and the second high component F1, F2 with respect to low component F3-F6.Preferably, position 24 is configured to CCW usually, and for example, the second high component F2 is existing to be counterclockwise for the highest component F1.Be clockwise direction if the second high component F2 is existing for the highest component F1,24 of positions are cleared so.
Continuation is with reference to figure 6, and position 17-22 is designated to be used for the highest component F1.By from the highest component F1, deducting 255 (0xFF), and use (input range 0 to 768[0x300] between) square root function (B) is transformed into 6 with the result, carries out compression:
(B) F1
comp＝(int)(sqrt(k*(F1-255))+0.5)，
F1 wherein
CompIt is the weighted quadratic root compression that is applied to respective tube component F1;
K is the constant scalar that is used for the compressed pipe component, k=(Code
Max)
2/ F1
Max
Code
MaxBe the maximum coding of component F1, equal 2
Bits-1=63, F1
MaxBe the maximal value of component F1, equal 768;
k＝63
2/768＝5.16796875。
By using following function, realize using decoding or the decompression of the component F1 of coding function (B) coding:
(B)′ F1
uncomp＝((int)((double)(F1
comp)
2/k+0.5)+255
Continuation is with reference to figure 6, the designated second high component F2 that is used for of position 12-16.Encoding scheme selecting arrangement 72 is selected encoding scheme according to the value of the second high component F2.If the second high component F2 is greater than 200 (0xC8), so by from the second high component F2, deducting 201 (0xC9), and use (input range 0 to 822[0x336] between) square root function (C) is compressed to 5 (32 codings) with the result, carries out compression.Position 23 is set to 1 to be used to representing that subtraction is performed.
(C) F2
comp＝(int)(sqrt(k*(F2-201))+0.5)，
F2 wherein
CompIt is the weighted quadratic root compression that is applied on the second high component F2;
K is the constant scalar that is used for the compressed pipe component, k=(Code
Max)
2/ F2
Max
Code
MaxBe the maximum coding of component F2, equal 2
Bits-1=31,
F2
MaxBe the maximal value of component F2, equal 822;
k＝31
2/822＝1.169099757。
By using following function, realize using decoding or the decompression of the component F2 of coding function (C) coding:
(C)′ F2
uncomp＝((int)((double)(F2
comp)
2/k+0.5))+201
If the value of the second high component F2 is smaller or equal to 200 (0xC8), so by use (input range 0 to 200[0xC8] between) square root function D is compressed to the second high component value 5 (32 codings) and with position 23 zero clearings, carries out compression:
(D) F2
comp＝(int)(sqrt(k*F)+0.5)，
F2 wherein
CompIt is the weighted quadratic root compression that is applied to pipe component F2;
K is the constant scalar that is used for the compressed pipe component, k=(Code
Max)
2/ F2
Max
Code
MaxBe the maximum coding of component F2, equal 2
Bits-1=31,
F2
MaxBe the maximal value of component F2, equal 200;
k＝31
2/200＝4.805。
By using following function, realize using decoding or the decompression of the component F2 of coding function (D) coding:
(D)′ F2
uncomp＝((int)((double)(F2
comp)
2/k+0.5))
Continuation is with reference to figure 6, and position 0-11 is designated to be used for than low component F3-F6, for example, and the 3rd to the 6th component.By using square root function E, each all is switched to 3 (8 codings) low component F3-F6.The maximal value of supposing component F3-F6 equals 255 (0xFF):
(E) F
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied to respective tube component F3-F6;
K is the constant scalar that is used for the compressed pipe component, k=(Code
Max)
2/ F
Max
Code
MaxBe the maximum coding of low component F3-F6, equal 2
Bits-1=7,
F
MaxBe the maximal value of low component F3-F6, equal 255;
k＝7
2/255＝0.192156863。
By using following function, realize using the decoding or the decompression of hanging down component F3-F6 of coding function (E) coding:
(E)′ F
uncomp＝((int)((double)(F
comp)
2/k+0.5))
Refer again to Fig. 3 and further with reference to figure 9-10, in step 98, when family 54 have 7 manage 50,52 and the highest component F1 greater than 200 and when being less than or equal to 255, encoding scheme selecting arrangement 72 selection encoding schemes 3.By using square root function G, component F1-F6 all is switched to 4 (16 codings).The maximal value of supposing component F1 equals 255 (0xFF):
(G) F
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied to respective tube component F1-F6;
K is the constant scalar that is used for the compressed pipe component, k=(Code
Max)
2/ F
Max
Code
MaxBe the maximum coding of each component F1-F6, equal 2
Bits-1=15,
F
MaxBe the maximal value of each component F1-F6, equal 255;
k＝15
2/255＝0.882352941。
By using following function, realize using decoding or the decompression of the component F1-F6 of coding function (G) coding:
(G)′ F
uncomp＝((int)((double)(F
comp)
2/k+0.5))
Continuation is with reference to figure 4 and 9-10, and in step 100, when family 54 has 7 pipes 50,52 and the highest component F1 greater than 160 and when being less than or equal to 200, for example incident occurs near the high sensitivity pipe 50, and encoding scheme selecting arrangement 72 is selected encoding schemes 4.By using square root function H, component F1-F6 all is converted into 4 (16 codings).The maximal value of supposing component F1 equals 200 (0xC8):
(H) F
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied to respective tube component F1-F6;
K is the constant scalar that is used for the compressed pipe component, k=(Code
Max)
2/ F
Max
Code
MaxBe the maximum coding of each component F1-F6, equal 2
Bits-1=15,
F
MaxBe the maximal value of each component F1-F6, equal 200;
k＝15
2/200＝1.125。
By using following function, realize using decoding or the decompression of the component F1-F6 of coding function (H) coding:
(H)′ F
uncomp＝((int)((double)(F
comp)
2/k+0.5))
Continuation is with reference to figure 4,9 and 10, and in step 102, when family 54 has 7 pipes 50,52 and the highest component F1 when being less than or equal to 160, encoding scheme selecting arrangement 72 is selected encoding schemes 5.By using square root function J, component F1-F6 all is converted into 4 (16 codings).The maximal value of supposing component F1 equals 160 (0xA0):
(J) F
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied on the respective tube component F1-F6;
K is the constant scalar that is used for the compressed pipe component, k=(Code
Max)
2/ F
Max
Code
MaxBe the maximum coding of each component F1-F6, equal 2
Bits-1=15,
F
MaxBe the maximal value of each component F1-F6, equal 160;
k＝(15)
2/160＝1.40625。
By using following function, realize using decoding or the decompression of the component F1-F6 of coding function (J) coding:
(J)′ F
uncomp＝((int)((double)(F
comp)
2/k+0.5))
The present invention is described with reference to preferred embodiment.Obviously, people can expect revising and replacing after the reading comprehension foregoing detailed description.As long as be to be understood that and make various modifications and replacement to the present invention under the situation that falls into claims or its equivalent scope.
Claims (21)
1. a diagnostic imaging system (10) comprising:
The matrix of sensor (22) is oriented in order to observed events, and described sensor (22) has the output of response events separately;
Analog to digital converter (24), each sensor (22) are connected to analog to digital converter (24) and are used for converting the imitated output quantity of related sensor (22) to digital quantity;
Be used for the device (48) of the high sensor (50) of recognition matrix, described high sensor has the highest output valve in response to incident with respect to other sensor (22);
Be used for being identified in matrix and be the device (56) of number of the external sensor (52) of high sensitivity pipe (50) arest neighbors;
Be used to compress the output of external sensor (52) to reduce the device (70) of each figure place of exporting; With
Look-up table (44), the output by compression to look-up table (44) addressing in order to regain corresponding event location.
2. system according to claim 1, the event location that wherein regains is relevant with the center of high sensitivity pipe (50), and further comprises:
Apparatus for adjusting position (82) is used for the position at event location and high sensor center is combined.
3. system according to claim 1, wherein sensor (22) is photomultiplier (PMT).
4. system according to claim 1, wherein compression set (70) comprising:
Encoding scheme selecting arrangement (72) is used for being each sensor output dynamic assignment figure place according to possible output area.
5. system according to claim 1 further comprises:
Component is determined device (56), is used for determining divided by the highest output valve by the output of will being correlated with the component (F1-F6) of external sensor (52); With
The component order is determined device (58), is used for determining to minimum component ground from the highest component F1 according to descending the descending order of the component (F1-F6) of sensor (52).
6. system according to claim 5, wherein use symmetry along an axle in transverse axis and the Z-axis, and further comprise:
Turning device (84), the quadrant that is used for basis the highest component (F1) place is around axis of symmetry rollover event position.
7. system according to claim 5, wherein compression set (70) comprising:
Encoding scheme selecting arrangement (72) is used for coming Dynamic Selection encoding scheme (0-6) according to following at least one item:
The available figure place of look-up table (44);
The number of sensor (50,52); Or
The value of the highest component (F1).
8. system according to claim 7, wherein compression scheme selecting arrangement (72) carries out set at least one position and is used in order to show which compression scheme.
9. system according to claim 7, wherein high sensor (50) and external sensor (52) define 7-PMT family (54).
10. system according to claim 9, wherein when one of following situation occurring, encoding scheme selecting arrangement (72) just abandons incident:
The highest component (F1) and the second high component (F2) are not adjacent to each other, or
The value of a component in the low component (F3-F6) is greater than first predetermined value (V1).
11. system according to claim 9, wherein the value of the highest component (F1) is greater than first predetermined value (V1), and is used square root function (B) and is compressed into 6 hyte branch (F1
Comp):
F1
comp＝(int)(sqrt(k*(F1-V1))+0.5)，
F1 wherein
CompIt is the weighted quadratic root compression that is applied to the highest component (F1);
k＝(Code
max)
2/F1
max；
Code
MaxIt is the MAXIMUM SELECTION sign indicating number of the highest component (F1);
F1
MaxIt is the MAXIMUM SELECTION value of the highest component (F1).
12. system according to claim 11, wherein the value of the second high component (F2) is greater than second predetermined value (V2), and is used square root function (C) and is compressed into 5 hyte branch (F2
Comp):
F2
comp＝(int)(sqrt(k*(F1-(V2+1)))+0.5)，
F2 wherein
CompIt is the weighted quadratic root compression that is applied to the second high component (F2);
k＝(Code
max)
2/F2
max；
Code
MaxIt is the MAXIMUM SELECTION sign indicating number of the second high component (F2);
F2
MaxIt is the MAXIMUM SELECTION value of the second high component (F2).
13. system according to claim 11, wherein the value of the second high component (F2) is less than or equal to second predetermined value (V2), and is used square root function (D) and is compressed into 5 hyte branch (F2
Comp):
F2
comp＝(int)(sqrt(k*F2)+0.5)，
F2 wherein
CompIt is the weighted quadratic root compression that is applied to the second high component (F2);
k＝(Code
max)
2/F2
max；
Code
MaxIt is the MAXIMUM SELECTION sign indicating number of the second high component (F2);
F2
MaxIt is the MAXIMUM SELECTION value of the second high component (F2).
14. system according to claim 11, wherein the value of low component (F3-F6) all is used square root function (E) and is compressed into 3 hyte branch (F
Comp):
F
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied to corresponding low component (F3-F6);
k＝(Code
max)
2/F
max；
Code
MaxIt is the MAXIMUM SELECTION sign indicating number of corresponding low component (F3-F6);
F
MaxIt is the MAXIMUM SELECTION value of corresponding low component (F3-F6).
15. system according to claim 11, wherein compression set (70) carries out set at least one position, in order to show the direction relations of the second high component (F2) to the highest component (F1).
16. system according to claim 9, wherein the value of the highest component (F1) is less than or equal to first predetermined value (V1) and greater than second predetermined value (V2), the value of component (F1-F6) all is used square root function (G) and is compressed into 4 hyte branch (F
Comp):
F
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied to respective components (F1-F6);
k＝(Code
max)
2/F
max；
Code
MaxIt is the MAXIMUM SELECTION sign indicating number of respective components (F1-F6);
F
MaxIt is the MAXIMUM SELECTION value of respective components (F1-F6).
17. system according to claim 9, wherein the value of the highest component (F1) is less than or equal to second predetermined value (V2) and greater than the 3rd predetermined value (V3), the value of component (F1-F6) all is used square root function (H) and is compressed into 4 hyte branch (F
Comp):
f
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied to respective tube component (F1-F6);
k＝(Code
max)
2/F
max；
Code
MaxIt is the MAXIMUM SELECTION sign indicating number of respective components (F1-F6);
F
MaxIt is the MAXIMUM SELECTION value of respective components (F1-F6).
18. system according to claim 9, wherein the value of the highest component (F1) is less than or equal to the 3rd predetermined value (V3), and the value of component (F1-F6) all is used square root function (J) and is compressed into 4 hyte branch (F
Comp):
F
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied to respective components (F1-F6);
k＝(Code
max)
2/f
max；
Code
MaxIt is the MAXIMUM SELECTION sign indicating number of respective components (F1-F6);
F
MaxIt is the MAXIMUM SELECTION value of respective components (F1-F6).
19. system according to claim 8, wherein high sensor (50) and external sensor (52) define 4-PMT family (54).
20. system according to claim 19, wherein the value of component (F1-F3) all is used square root function (A) and is compressed into 8 hyte branch (F
Comp):
F
comp＝(int)(sqrt(k*F)+0.5)，
F wherein
CompIt is the weighted quadratic root compression that is applied to respective tube component (F1-F3);
k＝(Code
max)
2/F
max；
Code
MaxIt is the MAXIMUM SELECTION sign indicating number of respective components (F1-F3);
F
MaxIt is the MAXIMUM SELECTION value of respective components (F1-F3).
21. a diagnosing image method comprises:
Use the matrix of the sensor (22) of gamma camera (12) to detect radiation, the output that wherein said sensor (22) is oriented to be used for observed events and has response events separately;
Use analog to digital converter (24) to convert the imitated output quantity of related sensor (22) to digital quantity, each sensor is connected on the independent analog to digital converter;
High sensor in the recognition matrix (50), described high sensor has the highest output valve in response to incident with respect to other sensor (22);
Be identified in the matrix number of the external sensor (52) that is high sensitivity pipe (50) arest neighbors;
The output of compression external sensor (52) is to reduce the figure place of each output; With
Output by compression to look-up table (44) addressing in order to regain corresponding event location.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US53675604P | 2004-01-15 | 2004-01-15 | |
| US60/536,756 | 2004-01-15 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1910472A true CN1910472A (en) | 2007-02-07 |
| CN100485410C CN100485410C (en) | 2009-05-06 |
Family
ID=34807041
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200580002490 Expired - Fee Related CN100485410C (en) | 2004-01-15 | 2005-01-05 | Diagnosis imaging system and method for completing event positioning via a lookup table |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP1709462A1 (en) |
| JP (1) | JP2007518096A (en) |
| CN (1) | CN100485410C (en) |
| WO (1) | WO2005071438A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102933983A (en) * | 2010-06-10 | 2013-02-13 | 株式会社岛津制作所 | Two-dimensional position map correction method |
| CN101680953B (en) * | 2007-05-16 | 2014-08-13 | 皇家飞利浦电子股份有限公司 | Virtual pet detector and quasi-pixelated readout scheme for pet |
| WO2015010393A1 (en) * | 2013-07-25 | 2015-01-29 | 苏州瑞派宁科技有限公司 | On-line energy coincidence method and system for all-digital pet system |
| CN105115994A (en) * | 2015-07-22 | 2015-12-02 | 武汉数字派特科技有限公司 | Digital PET energy parameterization calibration method and system |
| CN107110988A (en) * | 2014-10-27 | 2017-08-29 | 皇家飞利浦有限公司 | Pet detector timing alignment |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007019708A1 (en) * | 2005-08-18 | 2007-02-22 | Societe De Commercialisation Des Produits De La Recherche Appliquee - Socpra | Digital identification and vector quantization methods and systems for detector crystal recognition in radiation detection machines |
| US9904394B2 (en) | 2013-03-13 | 2018-02-27 | Immerson Corporation | Method and devices for displaying graphical user interfaces based on user contact |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4956796A (en) * | 1986-06-20 | 1990-09-11 | The University Of Michigan | Multiple sensor position locating system |
| DE69528949T2 (en) * | 1994-10-03 | 2003-08-28 | Koninkl Philips Electronics Nv | Improved gamma camera system |
| US5508524A (en) * | 1994-10-03 | 1996-04-16 | Adac Laboratories, Inc. | Spatially variant PMT cluster constitution and spatially variant PMT weights |
| FR2755815B1 (en) * | 1996-11-08 | 1998-12-18 | Commissariat Energie Atomique | DEVICE AND METHOD FOR DETERMINING THE PRESUMED POSITION OF AN EVENT IN RELATION TO A SET OF PHOTODETECTORS, AND APPLICATION TO GAMMA-CAMERAS |
| DE19733338C2 (en) * | 1997-08-01 | 2002-01-17 | Sirona Dental Systems Gmbh | X-ray diagnostic device for creating panoramic slice images of body parts of a patient |
-
2005
- 2005-01-05 EP EP05702589A patent/EP1709462A1/en not_active Withdrawn
- 2005-01-05 JP JP2006548515A patent/JP2007518096A/en active Pending
- 2005-01-05 WO PCT/IB2005/050059 patent/WO2005071438A1/en active Application Filing
- 2005-01-05 CN CN 200580002490 patent/CN100485410C/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101680953B (en) * | 2007-05-16 | 2014-08-13 | 皇家飞利浦电子股份有限公司 | Virtual pet detector and quasi-pixelated readout scheme for pet |
| CN102933983A (en) * | 2010-06-10 | 2013-02-13 | 株式会社岛津制作所 | Two-dimensional position map correction method |
| CN102933983B (en) * | 2010-06-10 | 2015-05-27 | 株式会社岛津制作所 | Two-dimensional position map correction method |
| WO2015010393A1 (en) * | 2013-07-25 | 2015-01-29 | 苏州瑞派宁科技有限公司 | On-line energy coincidence method and system for all-digital pet system |
| CN104337531A (en) * | 2013-07-25 | 2015-02-11 | 苏州瑞派宁科技有限公司 | Online energy conforming method and system for full-digital PET system |
| CN104337531B (en) * | 2013-07-25 | 2016-12-28 | 苏州瑞派宁科技有限公司 | Method and system are met at heat input for digital PET system |
| US10149657B2 (en) | 2013-07-25 | 2018-12-11 | Raycan Technology Co., Ltd. (Suzhou) | On-line energy coincidence method and system for all-digital PET system |
| CN107110988A (en) * | 2014-10-27 | 2017-08-29 | 皇家飞利浦有限公司 | Pet detector timing alignment |
| CN107110988B (en) * | 2014-10-27 | 2019-04-02 | 皇家飞利浦有限公司 | Pet detector timing alignment |
| CN105115994A (en) * | 2015-07-22 | 2015-12-02 | 武汉数字派特科技有限公司 | Digital PET energy parameterization calibration method and system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100485410C (en) | 2009-05-06 |
| JP2007518096A (en) | 2007-07-05 |
| WO2005071438A1 (en) | 2005-08-04 |
| EP1709462A1 (en) | 2006-10-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101902032B1 (en) | Digital detector | |
| CN101379392B (en) | Imaging apparatus using distributed x-ray sources | |
| CN1106579C (en) | Coregistration of multi-modality data in medical imaging system | |
| US8471211B2 (en) | Two-dimensional position map correcting method, and radiation detecting apparatus | |
| JP2011503535A (en) | Indirect radiation detector | |
| JP5459397B2 (en) | Positron CT apparatus and timing correction method | |
| US7470897B2 (en) | Nuclear medical apparatus | |
| US20100046818A1 (en) | Image reconstruction method for tomography scanner, failure diagnosis method, tomography scanner and management program for system matrix | |
| CN1913829A (en) | X-ray CT scanner | |
| CN1768704A (en) | Diagnosis method for detection unit and medical imaging of medical diagnosing equipment | |
| JP4993144B2 (en) | Method for correcting light output of PET detector | |
| US8520797B2 (en) | Medical imaging apparatus, control method, and computer program product | |
| CN1910472A (en) | Event positioning achieved via a lookup table | |
| CN1737549A (en) | Tomography equipment and method therefor | |
| WO2015005481A1 (en) | Nuclear medicine diagnosis device and image processing method | |
| JP4594855B2 (en) | Nuclear medicine diagnostic apparatus, radiation camera, and radiation detection method in nuclear medicine diagnostic apparatus | |
| JP4429915B2 (en) | Gamma camera with dynamic threshold | |
| US7579598B2 (en) | Realtime line of response position confidence measurement | |
| JP2020030097A (en) | Sensitivity correction method and photon counting type detector | |
| US8148694B2 (en) | Realtime line of response position confidence measurement | |
| Tai et al. | MicroPET II: an ultra-high resolution small animal PET system | |
| JP5657925B2 (en) | Nuclear medicine imaging apparatus and control program thereof | |
| EP4312063A1 (en) | Systems and methods for computed tomography | |
| CN114366135A (en) | Monitoring method and device of PET detector, storage medium and electronic equipment | |
| Stolin et al. | Dual-modality scanner for small animal imaging |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090506 Termination date: 20110105 |