TW391868B - A new style ventilation apparatus of kr-81m gas for lung scintigraphy - Google Patents

Abstract

The invention, herein, concerns the fabrication of a ventilation apparatus of <81m>Kr, obtained from a radionuclide generator, suitable for use in nuclear medicine lung imaging. <81m>Kr is an artificial radioactive gas isotope, with extremely short half-life of 13 seconds, obtained from decay of the parent isotope <81>Rb. The structure of the apparatus mainly consists of a structure of the apparatus mainly consists of a lead-shielded container, containing a millicuries <81m>Kr generator, equipped with the peripheral devices and other fittings, such as a compressed air tank, flowmeter, inspiration mask, tubings, adapters, radiation dosimeter, and a push car. During the performance with this apparatus, high purities of <81m>Kr can be continuously flushed out from the provided millicuries generator at air (or oxygen) gas flow 1Lpm. The patients breathe <81m>Kr into the lung via an inspiration mask for diagnostic imaging with a gamma camera. The results obtained from the operation tests of the millicuries generator indicate that this apparatus is a feasibly useful ventilation equipment with simple and ease of operation for lung scintigraphy.

Description

V. Description of the invention (1) 1. Field of the invention: The present invention relates to a ventilated radon-81m pulmonary angiography device suitable for nuclear medicine pulmonary angiography, especially a radon-81m (81nKr) nuclear species generator, and The radon-81m gas produced by the human body through inhalation through a breathing mask is used in the lungs' for imaging with a Gama camera for nuclear medicine contrast diagnosis. 2. Background of the invention: Thallium is an inert gas in the periodic table of atoms in atomic state. Its physical and chemical properties are stable and its solubility in water is extremely low. Qi-81m is an artificial radioactive isotope with a short half-life of only 13 seconds. Its mother nucleus species 铷 -81 (t1 / 2 = 4. 5 8h) is mainly produced by cyclotron irradiation. At present, nuclear medicine is used in the diagnosis of lung function in China. Although contrast agents such as xenon-133 and 99 &quot; Tc-DTPA Aerosols are used in clinical diagnosis, the contrast resolution is not as good as 氪 -81m, and the half-life period is long. The adverse effect of the gas on the environment is its disadvantage. Specifically, compared with the above-mentioned contrast agents currently used in China, thorium-81m mainly has the following advantages: (1) only emits a single gamma ray and the energy is moderate [E 7 * = 19〇KeV (65%)], in the single Photon emission computed tomography (SPECT) images are clear. On the contrary, Qi-133 also emits gamma rays, but the energy is low, only 81KeV, the contrast resolution and sharpness are not as good as 氪 -81jd; as for the recorded -99m-DTPA Aerosols, the particle shape, the gamma energy is 140KeV, the contrast effect is slightly difference. k (2) Very short physical and physiological half-life ’can tolerate filming with higher activity’ without causing human radiation damage “氪 -81m half-life period is only 13 乂

PT-024.ptd V. Description of the Invention (2)

Second 'is more than two minutes, and conversely, Xenon-133 L is less radioactive. At the time, they all spit out with the breath more than 6.27 days in the air phase and 6 hours in the half-half phase. Xenon-133 is also an inert gas. It will be exhausted indoors and outdoors. The gas must be passed through the adsorbent to avoid filtering, spitting + staining, and inconvenience in use. If not fully, continue to breathe: Either stay in the room and let the patient and the operator go, or spread the environment with the flow of air. 'Increase the radiation value of J. As for nDTPA Aer〇s〇i S is a white fine: Β π β 入Most of the lungs remain inside the body, and the clearance time is longer. In the second pass, the 'operator will inhale some, which has an impact on the health of patients and medical staff. (3): Continuously or intermittently flush out the urns and claws from the generator without worry about loss; Can be used continuously for 12 hours for many patients with imaging. The 之 -133 or 鍀 -99m_DTPA is used in separate packages. Each bottle is used by one or two patients. The relative radiation dose received by the patient is many times higher than that used-81 in. Β (4) Mother and daughter nucleus The half-life is short and there is no problem of radioactive waste disposal. The mother seed -81 had a half-life of 4.58 hours, and after 24 hours (5 half-lifes) of the day decayed, only 1/32 of the original radioactivity remained. Simultaneous nuclear species plutonium-81m has a half-life period of 13 seconds. After 1 minute (4.6 half-life periods), the intensity is only 1/24, and there is no threat of radioactive species remaining in the body.

As thorium-81m has the advantages as described above, it has recently been replaced by xenon_133 and chromium_99m_DTpA for lung function diagnosis in Europe and the United States.

PT-024.ptd Page 7 Trend ’However, the European JL system has a complicated structure and is expensive to manufacture. The generator is made of: The applicant is the only one in the country: the right hand movement is insufficient and needs to be improved. In addition, we are trying to produce a mechanism that has a medium-sized cyclotron, and has a mother nucleus capable of ^ * m such as -81 isotope.

If a new and improved nuclear medicine angiography diagnosis of 811 is applied, it is still to be developed; then there is the development of a device for the use of pulmonary angiography. 3. Purpose of the invention: The purpose of the invention is to provide a device for use in nuclear medicine for pulmonary angiography, which is small, light and portable.

Fully reliable and easy to implement. Another purpose of the Umbrella Life is to provide a device for nuclear medicine lung imaging, which can continuously blow out radon-81m to provide multi-directional imaging of the lungs. The month S is providing a device for use in nuclear medicine pulmonary angiography. The physical and biological half-life of the generated gas -81m is short, which will not cause radiation damage to patients and staff. Still another object of the present invention is to provide a device for using nuclear medicine for pulmonary angiography ', which has a simple structure and low cost, and can be made purely in the country. Due to the short physiological half-life of 氪 -81 «! And non-invasiveness, it can provide multi-dimensional imaging of the lungs by inhalation of patients and is a nuclear medicine tool. Differential diagnosis of disease, (2) Follow-up examination after lung tumor resection '(3) Examination of lung tissue lesions affecting ventilation function and (4) Pulmonary function diagnosis after month * J of lung surgery. V. Description of the invention (4) The specific embodiment of a device for use in nuclear medicine pulmonary angiography according to the present invention will be described in detail in accordance with the accompanying drawings: _ The first circle in the drawing is a front view of the device for pulmonary ventilation according to the present invention. One picture is a side view of the device of the present invention shown in the first picture, and the third picture is a plan view thereof. First, please refer to the first to third pictures. The device of the present invention is mainly made of a small four-wheeled mobile cart for easy pushing. Go to the patient's side for the patient to use in the standing or sitting position. This device is mainly composed of: a bottom surface, with movable casters 11 'the back has a door 12 which can be opened to access the seed generator 2 and other attachments, and a two-stage box type 13 for the cart extending backward and upward. Main frame 1; A millicurie H-81m nuclear seed generator 2 which can be placed in the main frame 1; a compressed air bottle or tritium gas bottle which can be placed in the top of the main frame 1; One is installed on the main frame], the upper-stage front flowmeter 4; One is located inside the main frame 1 at an appropriate position inside the sealed small plastic pure water box 5 with pure water;-used to switch and adjust the compressed air ( (Or oxygen) control valve 6 output from the gas cylinder 3; a nasal breathing mask 7;-provided on the top rear side of the main frame 1 for hanging the hanging rod 15 with a hook 14 on the top of the breathing mask 7; An exhaust gas discharge groove 8 provided inside the main frame 1; and the above-mentioned gas cylinder 3, control valve 6, flow meter 4, pure water box 5, nuclear generator 2, breathing mask 7, and discharge groove 8 are mainly composed of hoses The pipeline 9 is formed. The top stage on the front of the main frame 1 is also provided at the corresponding position of the nuclear seed generator 2-a top cover 16 for the nuclear seed generator 2 to access and place the hose from the front. A container 17 is provided for placing a dosimeter (not shown).

PTO24, pld $ 9 page 5. Description of the invention (5) As shown in the fourth figure, the 氪 -81m nuclear seed generator 2 is composed of a 枉 -shaped structure with a rectangular groove 23 for the inner lead can in the middle. The outer lead can 21 and an inner lead can 22 which are accommodated in the groove 23 are formed. The inner lead tank 22 is composed of two special lead screens 22a and 22b connected with a connecting pipe 30 and a Tygon hose 24 by screws. The connecting pipe 30 is filled with an appropriate amount of cation exchange resin 25, for example: Dowex 50w X 8 (100 ~ 200 mesh) or equivalent resin is used as the absorbent for j-81 deficiency. The two ends of the connecting tube 30 are plugged with glass fiber 26 and fixed with a stainless steel filter 27 to prevent resin loss during the insufflation. The inlet and outlet of the hose is provided with a joint C1 for the inner lead can 22 to be fitted with 铷 81/7 | § (not shown) to inject ϊ 8 8 1 The water flow is absorbed by the cation exchange resin pipe string to complete 氪- Equipment for 81m nuclear seed generator. The surface of the outer lead tank 21 is lined with stainless steel skin, which can be kept beautiful and durable. A lead cover 28 is added on the top surface to enhance radiation shielding, and a handle 29 ′ is provided on the tank body for easy lifting. The thickness of the lead shield should be 5 cm or more around it to ensure good radiation shielding. The filling activity of Gal-81 can be 1-50 mCi. The connection of the pipeline 9 is shown in the fifth figure, which is connected to the control valve 6 of the gas cylinder 3 by a hose 91-9 5 —flow meter 4 —pure water box 5 —nuclear seed generator 2—> breathing mask 7 ~ The drain tank 8 is connected to form a one-way open flow path. For the necessity and convenience of piping, 'on the generator 2', the top surface of the box of the main frame 1, the pure water box 5 and the flow meter 4 are provided with connectors C1-C4 of appropriate materials, and the breathing mask 7 is provided with Y Connector C5. In addition to the above-mentioned joints C1-C5, in addition to the joints on the table, such as C4, it is best to use stainless steel products. Others such as polyethylene (PE), polypropylene (PP), Teflon (acrylic) and other plastics should be used. Hazy material, but like

PT-024.ptd Page 10 5 'Explanation of the Invention (6) ~~ ---- Mining = No recording of steel is not necessary. As for the hose 9, polymer hoses such as M ?, pE, = on, Si 1 icone, Nylon, Tygon, or their composites can be used: The flow meter 4 can be measured with 0-10 liters / min. The range is better. The cylinder capacity can be 50-100 liters. The structure of the device of the present invention has been described in detail above, and the method of use is explained below: First, the gas cylinder 3 filled with compressed air or oxygen of sufficient pressure and the 氪 -8im nuclear seed generator which has been filled with the mother nuclear seed α-81 2 After being positioned in the box-shaped main frame 1, respectively, connect the hoses 9195 properly to complete the 输送 1 m gas delivery pipeline 9. Then, open the control valve 6 and adjust the reading of the flow meter 4 to, for example, every The flow rate is 1 liter per minute (1 liter / minute), but in actual operation, it can be adjusted to 0.5_3 liters / minute according to the needs of diagnosis, and then the control room 6 is closed and ready for use. When in use, leave the breathing mask 7 on the nose of the patient, open the control valve 6, adjust the flow rate to the predetermined value according to the flow meter 4, and then use the Gama camera to perform the imaging contrast, and then close the control valve 6 to complete. . Because the device is small and mobile, it can be pushed to the patient and used in a sitting, standing or lying position, which is very convenient. There are two applications of H-81m nuclear seed generator: (1) Ventilation mode; (2) Perfusion mode. The former rinses out 氪 81m (8inKr) with air or oxygen for diagnosis of respiratory lung imaging; the latter uses pure water as the eluent, and at the outlet of the generator with 1.8% NaCl saline or 10% glucose water to 1: 1 mixed for intravenous injection to measure blood flow. The use device of the present invention is mainly of a breathing type, but does not exclude irrigation.

Page 11 V. Description of the invention (7) Application of flow pattern, herewith a statement. The experimental example of the device of the present invention is described as follows: Experimental Example 1: Purity analysis of thorium-81m nuclear species. Compressed air from the gas cylinder 3 was passed through the pure water box 5 into the prepared millicurie under a controlled flow rate of one liter per minute. Grade 氪 -81m nuclear seed generator 2, collect the blown out 氪 -81m with a suitable molecular sieve 5A in a 250ml plastic bottle installed in the outlet tube of generator 2, and connect it with a high-purity germanium detector via a Multichannel Analyzer (MCA). The detector's measurement showed that the Gama energy spectrum showed a peak only at 190.3KeV as shown in the sixth figure. After another two minutes of continuous measurement, the Gama peak gradually disappeared. When the measurement time continued to be extended to 20 minutes, there were no other peaks in the analysis chart of the Gama spectroscopy. It showed that the emitted plutonium-81m nucleus had a purity of greater than 99.99%, which met the requirements of the US Pharmacopeia (purity greater than 9 9.9%). Experimental Example 2: Quantitative analysis and time-dependent stability test of thorium-81m nuclear seed generator. This experiment is to prepare a milli-Curie nuclear seed generator with a flow rate of 1 liter of air per minute in a breathing mode. 811lKr) blowing rate 'its calculation formula can know the following mathematical formulas:

Akr = a · b · c · ARb (l_e λι) where Akr = 81 &quot; Kr measures activity, ARb = 81Rb loading activity, a = 81-Kr blow-out rate, b = 81 &quot; Kr blows out of the stream from the generator Activity attenuation correction factor to the isotope corrector 'db generation &quot; Kr activity balance factor [about 0.96],

PT-024.ptd Page 12 V. Description of the invention (8) t = 81mKr, the time from the generator to the detector, and λ = 81mKr decay constant. The length of the hose connecting the generator outlet to the detection position of the isotope calibrator is about 80 cm. Under a 1 Lpm air flush, the gas linear flow rate is 2.4 m / sec, b = 0.8, t = 6.3, λ = 0.0533, and experiments. The results are shown in Table 1. Table 1 氪 -81m blow-out rate and time-dependent stability test analysis time point (unit: hour) Test result -81 activity (mCi) 氪 -81m activity (mCi) blow-out rate (¾) 氪 -81m purity ( %) 0.00 8.99 3.81 93.7 &gt; 99.9 1.10 7.82 3.22 92.4 2.00 7.10 2.80 93.8 2.80 6.30 2.52 92.0 3.60 5.70 2.28 93.1 4.50 5.40 2.12 92.8 &gt; 99.9 6.10 4.39 1.75 92.2 7.10 3.77 1.51 92.1 8.10 3.24 1.30 92.5 9.10 2.79 1.12 92.6 &gt; 99.9 10.10 2.40 0.96 91.7 11.10 2.06 0.83 91.6 12.20 1.77 0.71 90.4 13.20 1.68 0.70 90.3 &gt; 99.9 14.50 1.55 0.65 90.7 15.50 1.45 0.60 90.5 16.40 1.25 0.50 89.9 &gt; 99.9 17.40 1.07 0.43 89.8 18.50 0.92 0.37 89.7 19.60 0.79 0.32 89.1 20.60 0.68 0.27 0.27 88.2 &gt; 99.9 21.60 0.55 0.20 88.2 22.70 0.50 0.18 88.3 &gt; 99.9

PT-024.ptd Page 13

V. Description of the invention (9) Stability test of 氪 _81m gas over time is before entering the clinical test. J test basis ’is to ensure that the device of the present invention can meet the lung failure. This experiment is based on the prepared microcurie ㈣m nuclear seed hair :: grid: pm) The plutonium is flushed out by air, except for the amount = degree and # operator output rate, and the purity of the nuclear seed is analyzed by sampling, as shown in the seventh figure. It is known from Table 1 that the bleaching activity of 氪 8111 shows a reasonable decrease with the eight decays of the parent nucleus species. During the 22-hour operation, the bleaching rate of 氪 -81Π1 &quot; was 93.7 to 88.2%, which was slightly reduced. This phenomenon is mainly due to the reduced sensitivity of measuring lower activities. The seventh figure shows Qi Zhen II: The degree of change in the degree of activity-gamma-81 activity attenuation decreases steadily, which shows that the device of the present invention has good yield stability. Experimental example 3: Radiation safety protection In order to effectively prevent workers from being injured by radiation and improve the safety of use, this experiment uses the 5 cm container around the thickness of the lead screen of the device of the present invention to fill 15 millicuries 81-81, measured by radiation dose measurement The radiation dose rate of the surface around the lead container is less than 200 / zSv / hr 'The radiation dose rate is less than 10 # Sv / hr at a distance of 1 meter, which is far lower than the standard for controlling the transport of radioactive sources (2mSv / hr ·) in China, which meets Requirements for safe transportation. Usually at the time of pulmonary angiography, '氪 不 -81m-the inhalation dose is 1-10 millicuries, taking into account the attenuation loss of the transport time activity when the future supply to the hospital is used, even if the nuclear generator filling activity is 20-30 millicuries The device of the present invention can also meet the standard of safe transportation.

V. Description of the invention (10) Experimental example 4: Static angiography of animal experiments This experiment was entrusted by the applicant to Kaohsiung Medical College to use the device of the invention for animal experiments. The rabbit was used as a test animal. The rubber sleeve was used to cover its mouth and nose, and 氪 -81m was continuously inhaled through the aforementioned ventilation operation steps. Static imaging was performed by using a Gamma camera. The image, like the eighth frame, shows that the contrast is extremely clear and evenly distributed. Ten minutes later, the rabbit's lungs were checked for residual radioactivity, and no rotation reaction was found. The diet, excretion, and other activities were observed for two weeks, showing that everything is normal. It proves that the device of the present invention is convenient and safe to operate. From the above description, it can be seen that the present invention provides a lightweight, flexible, safe, reliable and convenient 'low-cost nuclear medicine pulmonary angiography device, which contributes to our nuclear medicine diagnosis. ^ The above is only a specific example of the present invention. The examples are provided to illustrate the present invention, but not to limit the present invention. Those skilled in the art can still make various modifications and changes or substitutions to the present invention without departing from the spirit and principles of the present invention. Such modifications shall be deemed to be included in the following. Within the scope of the invention patent. Illustration: The first picture is the front view of the device of the invention; the second picture is the side view of the device of the invention; the second picture is the top view of the device of the invention; The figure shows the structure of lead cans in the device of the present invention. The fifth figure is the pipe circumference of the device of the present invention. The sixth figure is the analysis spectrum of the 氪 -81m sample with horsepower spectrum.

V. Description of the invention (11) ‘The seventh picture is the change trend curve of the stability test of the 氪 -81m nuclear seed generator over time; the eighth picture is the static radiograph of the lung of the 氪 -8 1 m in rabbit breathing experiment. Explanation of symbols: 1. Box-type mainframe 2. Nuclear seed generator 3. Compressed air (or oxygen) bottle 4. Flow meter 5. Pure water tank 6. Control valve 7. Breathing mask 8. Drain tank 9. Pipe

PT-024.ptd Page 16

Claims (1)

6. Application scope of patent ~~ '--one-by-one type of air-81m lung ventilation imaging using device, which includes: box-type main frame' has space for accommodating various components such as nuclear generator, casters on the bottom, and attached Pushing handle ;, The nuclear seed generator can be placed inside the mainframe to generate plutonium-8U, and it has a lead shield; it can be used as a compressed air (or oxygen) bottle, and it can be replaced in the Γ Department for blowing. To the nuclear seed generator 'leads to a gas meter with a control room exposed on the top surface, which is set at a prominent position 1 on the front of the main frame to display a pure water blowing box, and is arranged inside the main frame to wet the above-mentioned blow. Outside I suction surface [by the hose can be placed in the main box in a predetermined range, the hose will be compressed air bottles, flow meters, pure water :. The nuclear seed generator and the beer suction mask are connected in series to form a unidirectional tracheal = lung ventilation imaging device, where the nuclear species occurs | § uses the parent nuclear species 铷 _81 loaded with Dan τ milli Curie 氪 -81m nuclear type generator. The filling activity is 5G millicuries, such as the lung ventilation angiography of the first patent application scope, so that the nuclear seed generator has a shield thickness of 5 cm ^ and an internal filling is provided as a 铷 _81 cylindrical outer lead can Resin-connected tube and hose rectangular branch attachment cationic cross-linking PT-〇24.ptd $ 17 The two ends of the tube are connected to the outside of the tank by a square: the connecting knife is connected to the pure water box with a hose. 6. The outlet plug for the patent scope and 4. · If the patent is applied for Inside the main frame of the scope 5. If the patent scope beer suction mask is the main branch of the medical head, the outlet tube of the other generator 6. If the scope of the patent scope is suitable for use 7. If the scope of the patent scope radiation dosimeter ， It's up to 100 mSv / min 8 · If the scope of patent application is milli-curie gas -81m, and the device can be used with the inlet plug of the pure β breathing mask, the lung ventilation of the first item Caicai I has a drain slot. The device is used by Αmai, in which the lung ventilation imaging item of the first item is an oronasal mask with a vent hole in the middle to connect the Y-branch to the intake pipe and the exhaust pipe, which are respectively connected to the nuclear joint and the exhaust groove. 5 ~ 3 长 分。 The pulmonary ventilation angiography of item 1 makes the device, wherein the appropriate flow rate is controlled at 0.5 to 3 long minutes. Item 1 of the pulmonary ventilation angiography was performed with a measurement range of 0.1 microsievert 1¾] (in Sv / hr) (mSv / hr). The device for the use of pulmonary ventilation angiography in item 1, in which == a kind of generator, except that it can be used as a respiratory angiography. The water is 氪 -8lm eluent, and it is used as perfusion angiography.