• Title/Summary/Keyword: Radioactive Isotope

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The Usefulness of Scintigraphy for the Detection of Gastroesophageal Reflux and Pulmonary Aspiration (위식도 역류와 폐 흡인 진단 방법으로서 위식도 역류 신티그래피의 유용성)

  • Kang, Sung-Kil;Hyun, In-Young;Lim, Dae-Hyun;Kim, Jeong-Hee;Son, Byong-Kwan
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.11 no.1
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    • pp.12-20
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    • 2008
  • Purpose: Chronic pulmonary disease may be caused by aspiration of gastric contents secondary to gastroesophageal reflux. At present, there is no gold standard for documenting pulmonary aspiration. The purpose of this study was to investigate the usefulness of radionuclide scintigraphy in the detection of gastroesophageal reflux and pulmonary aspiration. Methods: Thirty-five patients with suspected aspiration pneumonia, and five normal control subjects, were included in the study. All subjects underwent gastroesophageal reflux scintigraphy after the ingestion of a $^{99m}Tc$-tin colloid mixture. Dynamic images to detect gastroesophageal reflux were obtained for 1 hour. Additional static images of the chest, to detect lung aspiration, were obtained at 6 and 24 hours after oral ingestion of the tin colloid. In addition to visual analysis, pulmonary aspiration was quantitated by counting the number of pixels labeled with radioactive isotope in the region of interest (ROI) of both lung fields. Aspiration index (AI) was obtained by subtracting the pixel counts of the background from the pixel counts of the ROI. Results: Among 35 patients with suspected aspiration pneumonia, 23 proved to have gastroesophageal reflux by scintigraphy. One patient showed definite pulmonary accumulation of activity by visual analysis of the 6-hour image. Thirty of 35 (85.7%) patients showed higher AI beyond the upper limit of AI in the healthy controls. When we compared the reflux group with the non-reflux group, there was a significantly higher AI at 6 hours in the reflux group (p<0.05). Conclusion: The results suggest that radionuclide scintigraphy is useful in detecting small pulmonary aspiration in patients with suspected aspiration pneumonia secondary to reflux.

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A study on the Hematologic Effects of Radioactive Iodine($^{131}I$) Therapy on Various Thyroid Diseases (방사성동위원소옥소(放射性同位元素沃素)($^{131}I$)의 치료량(治療量)이 갑상선종환자(甲狀腺腫患者)의 혈액상(血液像)에 미치는 영향(影響)에 관(關)한 연구(硏究))

  • Kim, Myung-Jae;Kim, Noe-Kyeong;Lee, Jung-Sang;Choi, Keun-Chul;Lee, Ryong-Woo;Kim, Kee-Won;Kang, Shin-Il
    • The Korean Journal of Nuclear Medicine
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    • v.3 no.1
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    • pp.51-58
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    • 1969
  • To clarify the hematologic effects of the radioiodine ($^{131}I$) in therapeutic doses ($5{\sim}10$ mCi) on the various thyroid patients, authors studied the peripheral blood pictures of 396 goitrous patients before and after radioiodine ($^{131}I$) administrations in the Isotope Clinic of Seoul National University Hospital. Among these 396 cases of goiters, we gave 5 to 10 mCi of radioiodine ($^{131}I$) with single or fractionated administrations. The blood pictures of peripheral blood were repeated after 3 months in 40 cases of 65 cases who had been treated with $^{131}I$. The blood pictures of non-treated thyroid patients were compared with that of normal Korean values to clarify any difference between normal and goiter. The blood pictures of hyperthyroid patients treated with $^{131}I$ therapy were compared with the blood pictures of non-treated thyroid patients. The results were as following: 1) The incidence according to type: Toxic diffuse goiter: 35.4% Nontoxic nodular goiter: 29.7% Euthyroid: 13.8% Nontoxic diffuse goiter: 12.6% Hypothyroidism: 4.3% Thyroiditis($\bar{s}$ subacute form): 1.8% Toxic nodular goiter: 1.4% Malignancy: 1.0% 2) Age incidence: The range of distribution was 11 to 71 years. The peak incidence was found in the 4th decade of life. $80.6{\sim}82.6%$ of those 396 cases were found among the 3rd, 4th and the 5th decades of life. 3) Sex incidence: Sex ratio of male:female was 1:7.8. 4) The most outstanding findings in peripheral blood before treatment were decreased erythrocyte count and hemoglobin value in all types of thyroid diseases, especially in. the cases of hypothyroidism and thyroiditis. Hook worm-infested patients showed no significant difference in erythrocytes and hemoglobin values from those of other hook worm free patients. 5) Total leukocytes count was within normal range. Differential count of W.B.C. showed increased percentile of lymphocyte in diffuse toxic goiter and thyroiditis. 6) 39 cases of diffuse goiter treated with $^{131}I$ toxic showed amelioration in the anemia and restoration to normal range of lymphocyte count in association with increased percentile of neutrophiles 3 months after administration, except a case of toxic nodular goiter. One can observe anemia in slight degree, and increased lymphocytes count in hypothyroidism. Therapeutic dose of radioiodine ($^{131}I$) does not result any residual effect on the hematopoietic function. Radioiodine ($^{131}I$) therapy resulted in improvement of thyroid function in association of amelioration of pevious abnormal blood pictures. 7) Authors did not observe any myxedema resulted from radioiodine therapy during the 3 months period in this study.

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The Correction Effect of Motion Artifacts in PET/CT Image using System (PET/CT 검사 시 움직임 보정 기법의 유용성 평가)

  • Yeong-Hak Jo;Se-Jong Yoo;Seok-Hwan Bae;Jong-Ryul Seon;Seong-Ho Kim;Won-Jeong Lee
    • Journal of the Korean Society of Radiology
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    • v.18 no.1
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    • pp.45-52
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    • 2024
  • In this study, an AI-based algorithm was developed to prevent image quality deterioration and reading errors due to patient movement in PET/CT examinations that use radioisotopes in medical institutions to test cancer and other diseases. Using the Mothion Free software developed using, we checked the degree of correction of movement due to breathing, evaluated its usefulness, and conducted a study for clinical application. The experimental method was to use an RPM Phantom to inject the radioisotope 18F-FDG into a vacuum vial and a sphere of a NEMA IEC body Phantom of different sizes, and to produce images by directing the movement of the radioisotope into a moving lesion during respiration. The vacuum vial had different degrees of movement at different positions, and the spheres of the NEMA IEC body Phantom of different sizes produced different sizes of lesions. Through the acquired images, the lesion volume, maximum SUV, and average SUV were each measured to quantitatively evaluate the degree of motion correction by Motion Free. The average SUV of vacuum vial A, with a large degree of movement, was reduced by 23.36 %, and the error rate of vacuum vial B, with a small degree of movement, was reduced by 29.3 %. The average SUV error rate at the sphere 37mm and 22mm of the NEMA IEC body Phantom was reduced by 29.3 % and 26.51 %, respectively. The average error rate of the four measurements from which the error rate was calculated decreased by 30.03 %, indicating a more accurate average SUV value. In this study, only two-dimensional movements could be produced, so in order to obtain more accurate data, a Phantom that can embody the actual breathing movement of the human body was used, and if the diversity of the range of movement was configured, a more accurate evaluation of usability could be made.

The difference of image quality using other radioactive isotope in uniformity correction map of myocardial perfusion SPECT (심근 관류 SPECT에서 핵종에 따른 Uniformity correction map 설정을 통한 영상의 질 비교)

  • Song, Jae hyuk;Kim, Kyeong Sik;Lee, Dong Hoon;Kim, Sung Hwan;Park, Jang Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.2
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    • pp.87-92
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    • 2015
  • Purpose When the patients takes myocardial perfusion SPECT using $^{201}Tl$, the operator gives the patients an injection of $^{201}Tl$. But the uniformity correction map in SPECT uses $^{99m}Tc$ uniformity correction map. Thus, we want to compare the image quality when it uses $^{99m}Tc$ uniformity correction map and when it uses $^{201}Tl$ uniformity correction map. Materials and Methods Phantom study is performed. We take the data by Asan medical center daily QC condition with flood phantom including $^{201}Tl$ 21.3 kBq/mL. After postprocessing with this data, we analyze CFOV integral uniformity(I.U) and differential uniformity(D.U). And we take the data with Jaszczak ECT Phantom by American college of radiology accreditation program instruction including $^{201}Tl$ 33.4 kBq/mL. After post processing with this data, we analyze spatial Resolution, Integral Uniformity(I.U), coefficient of variation(C.V) and Contrast with Interactive data language program. Results In the flood phantom test, when it uses $^{99m}Tc$ uniformity correction map, Flood I.U is 3.6% and D.U is 3.0%. When it uses $^{201}Tl$ uniformity correction map, Flood I.U is 3.8% and D.U is 2.1%. The flood I.U is worsen about 5%, but the D.U is improved about 30% inversely. In the Jaszczak ECT phantom test, when it uses $^{99m}Tc$ uniformity correction map, SPECT I.U, C.V and contrast is 13.99%, 4.89% and 0.69. When it uses $^{201}Tl$ uniformity correction map, SPECT I.U, C.V and contrast is 11.37%, 4.79% and 0.78. All of data are improved about 18%, 2%, 13% The spatial resolution was no significant changes. Conclusion In the flood phantom test, Flood I.U is worsen but Flood D.U is improved. Therefore, it's uncertain that an image quality is improved with flood phantom test. On the other hand, SPECT I.U, C.V, Contrast are improved about 18%, 2%, 13% in the Jaszczak ECT phantom test. This study has limitations that we can't take all variables into account and study with two phantoms. We need think about things that it has a good effect when doctors decipher the nuclear medicine image and it's possible to improve the image quality using the uniformity correction map of other radionuclides other than $^{99m}Tc$, $^{201}Tl$ when we make other nuclear medicine examinations.

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The Plan of Dose Reduction by Measuring and Evaluating Occupationally Exposed Dose in vivo Tests of Nuclear Medicine (핵의학 체내검사 업무 단계 별 피폭선량 측정 및 분석을 통한 피폭선량 감소 방안)

  • Kil, Sang-Hyeong;Lim, Yeong-Hyeon;Park, Kwang-Youl;Jo, Kyung-Nam;Kim, Jung-Hun;Oh, Ji-Eun;Lee, Sang-Hyup;Lee, Su-Jung;Jun, Ji-Tak;Jung, Eui-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.26-32
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    • 2010
  • Purpose: It is to find the way to minimize occupationally exposed dose for workers in vivo tests in each working stage within the range of the working environment which does not ruin the examination and the performance efficiency. Materials and Methods: The process of the nuclear tests in vivo using a radioactive isotope consists of radioisotope distribution, a radioisotope injection ($^{99m}Tc$, $^{18}F$-FDG), and scanning and guiding patients. Using a measuring instrument of RadEye-G10 gamma survey meter (Thermo SCIENTIFIC), the exposure doses in each working stage are measured and evaluated. Before the radioisotope injection the patients are explained about the examination and educated about matters that require attention. It is to reduce the meeting time with the patients. In addition, workers are also educated about the outside exposure and have to put on the protected devices. When the radioisotope is injected to the patients the exposure doses are measured due to whether they are in the protected devices or not. It is also measured due to whether there are the explanation about the examination and the education about matters that require attention or not. The total exposure dose is visualized into the graph in using Microsoft office excel 2007. The difference of this doses are analyzed by wilcoxon signed ranks test in using SPSS (statistical package for the social science) program 12.0. In this case of p<0.01, this study is reliable in the statistics. Results: It was reliable in the statistics that the exposure dose of injecting $^{99m}Tc$-DPD 20 mCi in wearing the protected devices showed 88% smaller than the dose of injecting it without the protected devices. However, it was not reliable in the statistics that the exposure dose of injecting $^{18}F$-FDG 10 mCi with wearing protected devices had 26% decrease than without them. Training before injecting $^{99m}Tc$-DPD 20 mCi to patient made the exposure dose drop to 63% comparing with training after the injection. The dose of training before injecting $^{18}F$-FDG 10 mCi had 52% less then the training after the injection. Both of them were reliable in the statistics. Conclusion: In the examination of using the radioisotope $^{99m}Tc$, wearing the protected devices are more effective to reduce the exposure dose than without wearing them. In the case of using $^{18}F$-FDG, reducing meeting time with patients is more effective to drop the exposure dose. Therefore if we try to protect workers from radioactivity according to each radioisotope characteristic it could be more effective and active radiation shield from radioactivity.

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Evaluation of Radiation Exposure to Nurse on Nuclear Medicine Examination by Use Radioisotope (방사성 동위원소를 이용한 핵의학과 검사에서 병동 간호사의 방사선 피폭선량 평가)

  • Jeong, Jae Hoon;Lee, Chung Wun;You, Yeon Wook;Seo, Yeong Deok;Choi, Ho Yong;Kim, Yun Cheol;Kim, Yong Geun;Won, Woo Jae
    • The Korean Journal of Nuclear Medicine Technology
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    • v.21 no.1
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    • pp.44-49
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    • 2017
  • Purpose Radiation exposure management has been strictly regulated for the radiation workers, but there are only a few studies on potential risk of radiation exposure to non-radiation workers, especially nurses in a general ward. The present study aimed to estimate the exact total exposure of the nurse in a general ward by close contact with the patient undergoing nuclear medicine examinations. Materials and Methods Radiation exposure rate was determined by using thermoluminescent dosimeter (TLD) and optical simulated luminescence (OSL) in 14 nurses in a general ward from October 2015 to June 2016. External radiation rate was measured immediately after injection and examination at skin surface, and 50 cm and 1 m distance from 50 patients (PET/CT 20 pts; Bone scan 20 pts; Myocardial SPECT 10 pts). After measurement, effective half-life, and total radiation exposure expected in nurses were calculated. Then, expected total exposure was compared with total exposures actually measured in nurses by TLD and OSL. Results Mean and maximum amount of radiation exposure of 14 nurses in a general ward were 0.01 and 0.02 mSv, respectively in each measuring period. External radiation rate after injection at skin surface, 0.5 m and 1 m distance from patients was as following; $376.0{\pm}25.2$, $88.1{\pm}8.2$ and $29.0{\pm}5.8{\mu}Sv/hr$, respectively in PET/CT; $206.7{\pm}56.6$, $23.1{\pm}4.4$ and $10.1{\pm}1.4{\mu}Sv/hr$, respectively in bone scan; $22.5{\pm}2.6$, $2.4{\pm}0.7$ and $0.9{\pm}0.2{\mu}Sv/hr$, respectively in myocardial SPECT. After examination, external radiation rate at skin surface, 0.5 m and 1 m distance from patients was decreased as following; $165.3{\pm}22.1$, $38.7{\pm}5.9$ and $12.4{\pm}2.5{\mu}Sv/hr$, respectively in PET/CT; $32.1{\pm}8.7$, $6.2{\pm}1.1$, $2.8{\pm}0.6$, respectively in bone scan; $14.0{\pm}1.2$, $2.1{\pm}0.3$, $0.8{\pm}0.2{\mu}Sv/hr$, respectively in myocardial SPECT. Based upon the results, an effective half-life was calculated, and at 30 minutes after examination the time to reach normal dose limit in 'Nuclear Safety Act' was calculated conservatively without considering a half-life. In oder of distance (at skin surface, 0.5 m and 1 m distance from patients), it was 7.9, 34.1 and 106.8 hr, respectively in PET/CT; 40.4, 199.5 and 451.1 hr, respectively in bone scan, 62.5, 519.3 and 1313.6 hr, respectively in myocardial SPECT. Conclusion Radiation exposure rate may differ slightly depending on the work process and the environment in a general ward. Exposure rate was measured at step in the general examination procedure and it made our results more reliable. Our results clearly showed that total amount of radiation exposure caused by residual radioactive isotope in the patient body was neglectable, even comparing with the natural radiation exposure. In conclusion, nurses in a general ward were much less exposed than the normal dose limit, and the effects of exposure by contacting patients undergoing nuclear medicine examination was ignorable.

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