CN219777953U - Gamma probe and detection system thereof - Google Patents

Abstract

The utility model provides a gamma probe and a detection system thereof, wherein the gamma probe comprises: the probe comprises a probe body, a probe cover and a probe cover, wherein the probe body is formed by shielding materials and is internally provided with a pinhole; a first gamma detector disposed within the pinhole; a second gamma detector disposed within the probe body and at a rear end of the first gamma detector; and the third gamma detector is arranged in the pinhole and positioned at the front end of the first gamma detector. When the gamma probe provided by the utility model is used for detection, the first gamma detector, the second gamma detector and the third gamma detector can work cooperatively, so that the gamma rays are accurately judged to come from the front of the probe, the direction of a gamma source can be accurately judged, and the angular resolution of the gamma probe is improved; in addition, the thickness requirement on the probe body is lower, so that the diameter of the probe body can be reduced, the probe can be close to the position where the radioactive source is located, and the position sensitivity is improved.

Description

Gamma probe and detection system thereof

Technical Field

The utility model relates to the technical field of radiation measurement, in particular to a gamma probe and a detection system thereof.

Background

The gamma probe is positioned by using the nuclide tracing principle, converts the detected radioactive rays into electric signals, amplifies the signals and completes processing, counting and displaying in a microprocessor. Currently, it is mainly used for radioguided surgery. Including radioimmunoconducting surgery, stealth lesion localization, sentinel lymph node detection, etc. Has the advantages of portability, high sensitivity, good spatial resolution and the like. The gamma probe is mainly used for intraoperative real-time detection (positioning function) and in-vitro monitoring of various tumors such as gastric cancer, breast cancer, thyroid cancer and the like. The gamma probe is a constant integral measuring instrument. When gamma rays enter the detector crystal, a scintillation light is produced whose intensity is proportional to the energy of the incident particles. The flash light is converted into an initial electrical pulse signal by a photomultiplier tube. The electric pulse is further amplified by electronic circuit, and then fed into pulse amplitude analyzer, and the signal falling into the wide range of channel is fed into computer interface, recorded by computer, and undergone the process of calculation treatment, finally the result is output.

Currently, commonly used gamma probes are classified into mechanically-collimated gamma probes and electronically-collimated gamma probes.

As shown in fig. 1, a mechanically collimated gamma probe, specifically a pinhole type gamma probe A1, wherein a pinhole is formed by a sidewall of a high Z shielding material, which suppresses background gamma rays, and a gamma detector A2 is disposed in the pinhole. However, the shielding against the lateral direction (perpendicular to the side wall of the gamma probe shielding material) and gamma ray A4 from behind the detector A2 is insufficient. Meanwhile, due to the strong penetrating power of gamma rays, the side wall thickness formed by the shielding material is required, and particularly for radionuclides with higher energy (such as 131I,18F and the like), thicker shielding material is required, so that the gamma probe is heavy and large in diameter, and the gamma probe is difficult to approach to the position of the radioactive source A3, so that the detection sensitivity of the gamma probe A1 is limited. Typically the gamma probes are all more than 15mm in position resolution.

As shown in fig. 2, an electron-collimated gamma probe, specifically a coincidence probe B1, suppresses background gamma rays by an electron collimator B2. The shielding of gamma rays on the lateral direction (vertical and the side wall of the shielding material of the probe) and the shielding of gamma rays behind the probe are obviously improved, and particularly the shielding of gamma rays above 350Kev is improved. Due to the change of the structure, the detector can be close to the position of the radioactive source, and compared with a mechanically collimated gamma probe, the angle sensitivity and the position sensitivity are improved. However, the position resolution is also greater than 9mm.

Clinical applications often require high angular resolution and high positional sensitivity.

As can be seen from fig. 1, the angular Resolution (RA) and the geometric detection efficiency (epsilong) of a mechanically collimated gamma probe are inversely proportional. The angular resolution is improved at the expense of position sensitivity. The increase in position sensitivity comes at the expense of angular resolution. The final choice is therefore often a compromise in resolution and sensitivity.

As can be seen from fig. 2, the electron collimation and sensitivity are problematic. The occurrence of the photo-electric reaction on the coincidence probe of fig. 2 losing all energy cannot be recorded.

Disclosure of Invention

In order to solve the problems in the prior art, the utility model provides a gamma probe and a detection system thereof. The technical scheme of the utility model is as follows:

a gamma probe, comprising:

the probe comprises a probe body, a probe cover and a probe cover, wherein the probe body is formed by shielding materials and is internally provided with a pinhole;

a first gamma detector disposed within the pinhole; further comprises:

a second gamma detector disposed within the probe body and at a rear end of the first gamma detector;

and the third gamma detector is arranged in the pinhole and positioned at the front end of the first gamma detector.

Further, the first gamma detector and the third gamma detector are cesium iodide detector, sodium iodide detector or tellurium zinc cadmium detector respectively.

Further, the second detector is a scintillator detector, preferably a plastic scintillator detector; the gamma probe further includes a photoelectric converter for converting light generated by the scintillator detector into an electrical signal; preferably, the gamma probe further comprises a photomultiplier tube for enhancing the light generated by the scintillator detector.

Further, the gamma probe also comprises a coincidence anti-coincidence processing module; the first gamma detector, the second gamma detector and the third gamma detector respectively input detected gamma signals into the coincidence anti-coincidence processing module respectively, and the coincidence anti-coincidence processing module transmits the detected gamma signals to a control system; only when the coincidence and anti-coincidence processing module receives the gamma signals detected by the first gamma detector and the third gamma detector at the same time and the gamma signal not detected by the second gamma detector, the control system records the gamma signal detected by the first gamma detector.

Further, the coincidence anti-coincidence processing module includes: the amplifying circuit, the delay circuit and the analog-to-digital conversion circuit are sequentially connected, the first gamma detector is electrically connected with the amplifying circuit, and the analog-to-digital conversion circuit is connected with the control system; the circuit is characterized by further comprising a coincidence anti-coincidence circuit, a discrimination circuit, a first amplification discrimination circuit and a second amplification discrimination circuit, wherein the amplification circuit is electrically connected with the coincidence anti-coincidence circuit through the discrimination circuit, the second gamma detector is electrically connected with the coincidence anti-coincidence circuit through the first amplification discrimination circuit, the third gamma detector is electrically connected with the coincidence anti-coincidence circuit through the second amplification discrimination circuit, and the coincidence anti-coincidence circuit is electrically connected with the analog-digital conversion circuit.

Further, the gamma probe also comprises a connecting cable, and the coincidence anti-coincidence processing module is electrically connected with the control system through the connecting cable.

Further, the control system can supply power to the first gamma detector, the second gamma detector, the third gamma detector and the coincidence and anti-coincidence processing module through the connecting cable.

Further, the gamma probe also comprises a power supply, a microprocessor and a wireless communication module; the coincidence anti-coincidence processing module is electrically connected with the microprocessor, and the microprocessor is electrically connected with the wireless communication module; the wireless communication module transmits the detected gamma signal to the control system.

Further, the wireless communication module is a Bluetooth module.

Further, the thickness of the side wall of the pinhole is 1.5 mm-3 mm.

A detection system comprising the gamma probe of any one of the above.

When the gamma probe provided by the utility model detects gamma rays emitted by the body of a patient, the first gamma detector, the second gamma detector and the third gamma detector can work cooperatively to accurately judge that the gamma rays come from the front of the probe, and the direction of a gamma source can be accurately judged, namely the angular resolution of the gamma probe is improved; in addition, the gamma probe of the embodiment mainly detects the radioactive source through the combination of the first gamma detector, the second gamma detector and the third gamma detector, so that the thickness requirement on the probe body is lower, the diameter of the probe body can be reduced, the probe can be close to the position of the radioactive source, and the position sensitivity is improved.

The foregoing description is only an overview of the technical solutions of the present utility model, to the extent that it can be implemented according to the content of the specification by those skilled in the art, and to make the above-mentioned and other objects, features and advantages of the present utility model more obvious, the following description is given by way of example of the present utility model.

Drawings

Fig. 1: the structure of the prior needle hole type gamma probe is schematically shown;

fig. 2: the prior structure diagram of the coincidence probe;

fig. 3: a schematic of the structure of the gamma detector in one embodiment;

fig. 4: a schematic circuit diagram of a gamma detector in one embodiment;

fig. 5: the structure of the wireless gamma detector in one embodiment is schematically shown.

Reference numerals:

a1, a pinhole type gamma probe; a2, a gamma detector; a3, a radioactive source; a4, gamma rays;

b1, a coincidence probe; b2, an electron collimator; b3, a radioactive source; b4, gamma rays;

1. a first gamma detector; 2. a second gamma detector; 3. a photoelectric converter; 4. a coincidence anti-coincidence processing module; 4-1, an amplifying circuit; 4-2, a discrimination circuit; 4-3, amplifying and discriminating circuit; 4-5, a delay circuit; 4-6, an analog-to-digital conversion circuit; 4-7, a coincidence road amplifying and discriminating circuit; 4-8, a coincidence anti-coincidence circuit; 5. a cable; 6. a control system; 7. and a third gamma detector.

Detailed Description

The following embodiments of the utility model are merely illustrative of specific embodiments for carrying out the utility model and are not to be construed as limiting the utility model. Any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principles of the utility model are intended to be equivalent arrangements which are within the scope of the utility model.

This embodiment provides a gamma probe, as shown in fig. 3 and 4, comprising:

the probe comprises a probe body, a probe cover and a probe cover, wherein the probe body is formed by shielding materials and is internally provided with a pinhole;

a first gamma detector 1 disposed within the pinhole;

a second gamma detector 2 provided in the probe body and located at a rear end of the first gamma detector 1;

a third gamma detector 7 disposed within the pinhole and located at the front end of the first gamma detector 1.

In the present utility model, when a gamma probe is used, the end close to the radiation source is referred to as "front end", and the end far from the radiation source is referred to as "rear end".

In the existing mechanically collimated gamma probe, particularly as shown in the technical scheme of fig. 1, because the high-energy gamma rays have a strong penetrating effect, the side wall of the pinhole needs to be made thick, so that the peripheral diameter of the pinhole is large, the pinhole and the whole probe are heavy, and the gamma probe is difficult to approach a radioactive source, so that the position detection precision is low. In order to achieve the position detection accuracy, the side wall of the pinhole cannot be too thick, so that gamma rays still pass through the side wall and are projected onto the detector A2, and the angle sensitivity of the gamma probe is insufficient.

The embodiment provides a gamma probe with a new structure, which is an improvement on the existing mechanically collimated gamma probe.

Specifically, in this embodiment, the second gamma detector 2 is disposed at the rear end of the first gamma detector 1, and the third gamma detector 7 is disposed at the front end of the first gamma detector 1, so that the second gamma detector 2 can receive gamma rays passing through the lateral direction of the probe body, and the third gamma detector 7 can detect gamma rays from the front end of the pinhole (and the front end of the first gamma detector 1).

Then, the signals received by the first gamma detector 1, the second gamma detector 2, and the third gamma detector 7 are transmitted to the control system 6 (typically, a main control console, which generally includes functions of a main power supply, acquisition control, acquisition result display, acquisition result recording, and the like). The control system can determine the angle and the position according to the signals of the first gamma detector 1, the second gamma detector 2 and the third gamma detector 7.

Specifically, when gamma rays emitted from the body of the patient are detected, the gamma rays may come from the front of the probe or from other directions (such as the side wall direction of the probe body), when the second gamma detector 2 detects the gamma rays, it is indicated that the gamma rays come from the side wall direction of the probe body, the probe is further moved, and when the first gamma detector 1, the third gamma detector 7 detect the gamma rays and the second gamma detector 2 does not detect the gamma rays, it is indicated that the gamma rays may come from the front of the probe. The third gamma detector 7 is arranged to further determine that the gamma rays detected by the first gamma detector 1 come from the front end of the pinhole, so that the detection accuracy is improved.

Therefore, in the radiation guiding operation, the direction of the gamma source can be accurately judged through the gamma probe provided by the utility model, namely, the angle resolution of the gamma probe is improved.

In addition, since the gamma probe of the present embodiment detects the radiation source mainly through the combination of the first gamma detector 1, the second gamma detector 2, and the third gamma detector 7, the thickness requirement on the probe body is low, so that the diameter of the probe body can be reduced, and the probe can be close to the position of the radiation source, thereby improving the position sensitivity.

In one embodiment, the first gamma detector 1 and the third gamma detector 7 are cesium iodide (CsI) detector, sodium iodide (NaI) detector, or cadmium zinc telluride detector, respectively.

The cesium iodide crystal, the sodium iodide crystal and the tellurium-zinc-cadmium crystal are all existing materials, and are convenient to manufacture/use as existing cesium iodide detectors, sodium iodide detectors or tellurium-zinc-cadmium detectors respectively.

In particular, a cadmium zinc telluride detector is preferred. The tellurium-zinc-cadmium crystal material has a relatively large atomic number and a density of 5.85g/cm < 3 >, can enable the crystal to better react with gamma rays, and the tellurium-zinc-cadmium detector manufactured by the tellurium-zinc-cadmium crystal has the advantages of wide forbidden band, high resolution, high detection efficiency, small volume, capability of working at room temperature and the like.

In one embodiment, the second gamma detector 2 is a scintillator detector, preferably a plastic scintillator detector, that converts obliquely incident gamma rays (lost energy) into a number of visible photons. At this time, a photoelectric converter 3 is further provided in cooperation with the second gamma detector 2 to convert an optical signal into an electrical signal. Sometimes a photomultiplier is also provided. The scintillator detector, the photomultiplier and the photoelectric converter are sequentially arranged from the far end to the near end. So that the scintillator detector emits light when receiving the gamma rays, the photomultiplier tube intensifies the light, and the intensified light is converted into an electric signal (gamma signal) by the photoelectric converter.

A scintillator detector is an ionizing radiation detector that detects by means of a flash of ionizing radiation generated in some substances.

A plastic scintillator detector is one type of organic scintillator that can be used for the detection of alpha, beta, gamma, fast neutrons, protons, cosmic rays, fissile fragments, and the like. It is easy to process into various shapes, and has the advantages of no deliquescence, stable performance, radiation resistance, short scintillation decay time, low cost, etc.

The plastic scintillator detector has relatively random appearance structure and size, and can be made into any size and shape; the detection efficiency is high, and the method is suitable for measuring uncharged particles such as gamma rays, X rays, neutrons and the like; and the time characteristic is good, and some detectors (such as plastic scintillators and BaF 2) can realize ns (nanosecond) time resolution.

In one embodiment, as shown in fig. 3 and 4, the gamma probe further comprises a coincidence anti-coincidence processing module 4;

the first gamma detector 1 (as a main gamma detector), the second gamma detector 2 (as an anti-coincidence detector) and the third gamma detector 7 (as a coincidence detector) respectively input detected gamma signals into the coincidence anti-coincidence processing module 4, and the coincidence anti-coincidence processing module 4 transmits the detected gamma signals to a system;

only when the coincidence and anti-coincidence processing module receives the gamma signal detected by the first gamma detector 1 at the same time and the gamma signal not detected by the second gamma detector, the control system records the gamma signal detected by the first gamma detector 1.

In the present utility model, the coincidence-rejection process refers to that in the time-correlation measurement, the time relationship between pulses generated by a plurality of nuclear radiation events is analyzed to select events with time correlation, and some events without time correlation are discarded.

In this embodiment, the coincidence anti-coincidence processing module 4 processes the gamma signals detected by the first gamma detector 1, the second gamma detector 2 and the third gamma detector 7, and when the coincidence anti-coincidence processing module 4 receives the gamma signals from the first gamma detector 1 and the third gamma detector 7 but does not receive the gamma signals of the second gamma detector 2, the coincidence anti-coincidence processing module 4 transmits the gamma signals of the first gamma detector to the control system 6.

In one embodiment, as shown in fig. 4, the coincidence-anti-coincidence processing module 4 is:

the gamma signal from the first gamma detector 1 (main gamma detector) is amplified by the amplifying circuit 4-1, and then the delay of the corresponding signal of the first gamma detector 1 is adjusted by the delay circuit 4-5, and the signal enters the analog-to-digital conversion circuit 4-6. When the analog-to-digital conversion circuit 4-6 receives the door opening signal of the delay circuit 4-5, the analog-to-digital conversion is carried out on the corresponding output of the delayed first gamma detector 1.

The gamma signal amplified by the amplifying circuit 4-1 is screened by the screening circuit 4-2 to meet the requirement of event signals, and the event signals enter the anti-coincidence circuit 4-8 after shielding noise and large-angle scattering signals with low amplitude.

The second gamma detector 2 detects gamma rays, the gamma rays are converted into electric signals (gamma signals) after passing through the photoelectric converter 3, the gamma signals are amplified by the amplifying and screening circuit 4-3 (first amplifying and screening circuit) to screen event signals meeting requirements, and the event signals enter the coincidence anti-coincidence circuit 4-8 after shielding large-angle scattering signals with low noise and amplitude.

The third gamma detector 7 detects gamma rays, the gamma signals are amplified and screened by the coincidence amplification screening circuit 4-7 (second amplification screening circuit) to obtain effective signals with the amplitude larger than a threshold value, and the effective signals output logical pulses when the signals are effective and enter the coincidence anti-coincidence circuit 4-8.

When the second gamma detector 2 detects gamma rays and transmits a gamma signal to the coincidence anti-coincidence circuit 4-8.

When the coincidence anti-coincidence circuit 4-8 has output only when the discrimination circuit 4-2 has output, the coincidence amplification discrimination circuit 4-7 has output, and the amplification discrimination circuit 4-3 has no output (the physical description is that there is output on both the third gamma detector 7 and the first gamma detector 1, and no output on the anti-coincidence detector 2), the control system 6 records information from the first gamma detector 1.

When the coincidence anti-coincidence circuit 4-8 has an output at the discrimination circuit 4-2, the amplification discrimination circuit 4-3 has an output, and the coincidence amplification discrimination circuit 4-7 does not output (the physical description is that the side event has an output on both the anti-coincidence detector 2 and the first gamma detector 1, and no output on the third gamma detector 7), the control system 6 does not record information.

Therefore, by the coincidence and anti-coincidence processing module 4, the detection signals can be recorded only when the first gamma detector 1 and the third gamma detector 7 detect the gamma rays, and the purposes of improving the angle sensitivity and the position sensitivity can be achieved.

In one embodiment, as shown in fig. 4, the gamma probe further comprises a connection cable 5, and the coincidence-preventing processing module 4 is electrically connected to the control system 6 through the connection cable 5.

Preferably, the connection cable 5 supplies power to the first gamma detector 1, the second gamma detector 2 and the coincidence anti-coincidence processing module 4.

In this embodiment, the gamma probe communicates with the control system 6 through the connection cable 5, and at the same time, the control system 6 can supply power to the gamma probe through the connection cable 5.

In one embodiment, as shown in fig. 5, the gamma detector further includes a power supply, a microprocessor, and a wireless communication module; the coincidence anti-coincidence processing module is electrically connected with the microprocessor, and the microprocessor is electrically connected with the wireless communication module; the wireless communication module transmits the detected gamma signal to the control system 6. The wireless communication module can be a Bluetooth module, a wifi module and the like, and is preferably a Bluetooth module.

The power supply supplies power to the first gamma detector 1, the second gamma detector 2, the third gamma detector 7, the coincidence anti-coincidence processing module 4, the microprocessor and the wireless communication module.

When the coincidence and anti-coincidence processing module is the coincidence and anti-coincidence processing module shown in fig. 4, specifically, the analog-to-digital conversion circuit 4-6 is electrically connected with the microprocessor.

The embodiment provides a wireless gamma probe scheme. The gamma probe is internally provided with a microprocessor and a wireless communication module, the coincidence anti-coincidence processing module transmits signals to the microprocessor, and the microprocessor controls the wireless communication module to transmit gamma signals to the control system 6, so that data processing and communication with the control system 6 are realized. Meanwhile, the built-in power supply supplies power. The built-in power source may be a rechargeable battery, such as a lithium battery. Therefore, through wireless connection, operators can control the gamma probe more flexibly, and in-vitro monitoring is facilitated.

In one embodiment, the shielding material is a high atomic number material.

The high atomic number material refers to a material with a higher atomic number and a relatively higher atomic mass, and the shielding material used in the embodiment is tungsten, which shields the radiation well.

The thickness of the side wall of the pinhole is 1.5 mm-3 mm.

Compared with the existing mechanically collimated gamma probe, the utility model has the advantages that the thickness of the side wall of the pinhole is small, so that the diameter of the probe is small, and the position sensitivity can be improved.

The above embodiments provide a gamma probe, which one skilled in the art would know to use in conjunction with the control system 6 to construct a detection system.

Although the embodiments of the present utility model have been described above, the present utility model is not limited to the above-described specific embodiments and application fields, and the above-described specific embodiments are merely illustrative, and not restrictive. Those skilled in the art, having the benefit of this disclosure, may effect numerous forms of the utility model as described herein without departing from the scope of the utility model as claimed.

Claims (13)

1. A gamma probe, comprising:

the probe comprises a probe body, a probe cover and a probe cover, wherein the probe body is formed by shielding materials and is internally provided with a pinhole;

a first gamma detector disposed within the pinhole;

characterized by further comprising:

a second gamma detector disposed within the probe body and at a rear end of the first gamma detector;

and the third gamma detector is arranged in the pinhole and positioned at the front end of the first gamma detector.

2. The gamma probe of claim 1, wherein the gamma probe comprises a gamma-emitting probe,

the first gamma detector and the third gamma detector are cesium iodide detector, sodium iodide detector or tellurium zinc cadmium detector respectively.

3. The gamma probe of claim 1, wherein the gamma probe comprises a gamma-emitting probe,

the second gamma detector is a scintillator detector;

the gamma probe further includes a photoelectric converter for converting light generated by the scintillator detector into an electrical signal.

4. The gamma probe according to claim 3, wherein,

the second gamma detector is a plastic scintillator detector.

5. The gamma probe according to claim 3, wherein,

the gamma probe further includes a photomultiplier tube for enhancing the light generated by the scintillator detector.

6. The gamma probe of claim 1, wherein the gamma probe comprises a gamma-emitting probe,

the gamma probe further comprises a coincidence anti-coincidence processing module;

the first gamma detector, the second gamma detector and the third gamma detector respectively input detected gamma signals into the coincidence anti-coincidence processing module respectively, and the coincidence anti-coincidence processing module transmits the detected gamma signals to a control system;

only when the coincidence and anti-coincidence processing module receives the gamma signals detected by the first gamma detector and the third gamma detector at the same time and the gamma signal not detected by the second gamma detector, the control system records the gamma signal detected by the first gamma detector.

7. The gamma probe of claim 6, wherein the gamma probe comprises a probe body,

the coincidence and anti-coincidence processing module comprises:

the amplifying circuit, the delay circuit and the analog-to-digital conversion circuit are sequentially connected, the first gamma detector is electrically connected with the amplifying circuit, and the analog-to-digital conversion circuit is connected with the control system;

the circuit is characterized by further comprising a coincidence anti-coincidence circuit, a discrimination circuit, a first amplification discrimination circuit and a second amplification discrimination circuit, wherein the amplification circuit is electrically connected with the coincidence anti-coincidence circuit through the discrimination circuit, the second gamma detector is electrically connected with the coincidence anti-coincidence circuit through the first amplification discrimination circuit, the third gamma detector is electrically connected with the coincidence anti-coincidence circuit through the second amplification discrimination circuit, and the coincidence anti-coincidence circuit is electrically connected with the analog-digital conversion circuit.

8. The gamma probe of claim 6, wherein the gamma probe comprises a probe body,

the gamma probe further comprises a connecting cable, and the coincidence anti-coincidence processing module is electrically connected with the control system through the connecting cable.

9. The gamma probe of claim 8, wherein the gamma probe comprises a gamma-emitting probe,

the control system can supply power to the first gamma detector, the second gamma detector, the third gamma detector and the coincidence anti-coincidence processing module through the connecting cable.

10. The gamma probe of claim 6, wherein the gamma probe comprises a probe body,

the gamma probe also comprises a power supply, a microprocessor and a wireless communication module;

the coincidence anti-coincidence processing module is electrically connected with the microprocessor, and the microprocessor is electrically connected with the wireless communication module;

the wireless communication module transmits the detected gamma signal to the control system.

11. The gamma probe of claim 10, wherein the gamma probe comprises a probe body,

the wireless communication module is a Bluetooth module.

12. The gamma probe of claim 1, wherein the gamma probe comprises a gamma-emitting probe,

the thickness of the side wall of the pinhole is 1.5 mm-3 mm.

13. A detection system, characterized in that,

the detection system comprising the gamma probe of any one of claims 1-12.