• 대한방사선기술학회지:방사선기술과학
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• 제46권2호
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• pp.99-106
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• 2023

The height of the table should be considered important during computed tomography (CT) examination, but according to previous studies, not all radiology technologists set the table at the patient's center at the examination, which affects the exposure dose and image quality received by the patient. Therefore, this study intends to study the image quality exposure dose according to the height of the table to realize the optimal image quality and dose during the brain CT scan. The head phantom images were acquired using Philips Brilliance iCT 256. When the image was acquired, the table height was adjusted to 815, 865, 915, 965, 1015, and 1030 mm, respectively, and each scan was performed 3 times for each height. For the exposure dose measurement, optically stimulated luminescence dosimeter (OSLD) was attached to the front, side, eye, and thyroid gland of the head phantom. In the signal to noise ratio (SNR) measurement result, The SNR values for each table height were all lower than 915 mm. As a result of exposure dose, the exposure dose on each area increased as the table height decreased. The height of the table has a close relationship with the patient's radiation exposure dose in the CT scan.

• 대한핵의학회지
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• 제31권3호
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• pp.339-345
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• 1997

저자들은 1984년부터 1996년까지 서울대학교병원에서 분화성 갑상선암으로 수술을 시행한 후 I-131을 이용하여 수술 후 잔여 갑상선 제거를 받은 350명을 관찰하여 다음과 같은 성적을 얻었다. 1) 분화성 갑상선암 수술 후 30mCi I-131을 평균 $2.6{\pm}1.7$회 투여하며 51%에서, 75mCi 이상 I-131을 평균 $1.6{\pm}1.1$회 투여하여 72%에서 성공적으로 잔여갑상선 조직을 제거하였다. 2) 30mCi 저용량 사용 시 1회 치료의 24%, 2회 치료 22%, 2회 치료 25%, 4회 치료 8%, 5회 치료19%, 6회 이상의 치료로 19%의 환자에서 성공적으로 잔여 갑상선 조직을 제거하였다. 3) 입원 치료가 필요한 75mCi 이상의 고용량 I-131 치료에서는 1회 치료군의 53%, 2회 58%, 3회 0%, 4회 이상 치료군에서 44%의 환자에서 잔여 갑상선을 완전히 제거하였다. 4) 갑상선 전절제 후 78%, 아절제 후 62%, 한엽 및 협부 절제 후 54%, 한엽이하 절제 시 33%에서 수술 후 잔여 갑상선을 제거하여 수술 후 잔여 갑상선 조직이 적을수록 I-131 효과가 있었다. 결론적으로 이 연구에서 수술 후 30mCi I-131을 이용한 경우의 일부에서는 잔여 갑상선의 제거는 충분히 이루어지지 않아, 재발의 위험도가 높은 군에서 분화성 갑상선 암 환자의 치료시 적극적인 수술로 갑상선 전절제 후 고용량의 방사성 옥소 치료가 바람직하리라 여겨진다.

• Journal of Radiation Protection and Research
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• 제40권2호
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• pp.118-123
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• 2015

최근 의료기관에서의 진단방사선검사 빈도는 2011년 2억 2천만건, 연간 일인당 피폭선량은 1.4 mSv로 2007년 대비 각 51%, 35% 증가하였다. 여기서 흉부촬영건수는 일반촬영 중 가장 높은 빈도인 27.59%로 나타났다. 따라서 본 연구에서는 흉부 방사선 촬영 시 영상판독에 불필요한 신체부위를 차폐하여 피폭선량을 최소화 시키는 차폐기구를 개발하고, 그 유용성 평가를 위해 국제 표준 소아(10세) 팬텀과 유리선량계를 사용하여 기구 사용 전, 후의 입사표면선량(entrance surface dose; ESD)과 장기의 흡수선량 차를 측정하였다. 또한 몬테카를로 시뮬레이션 기반 프로그램(PCXMC 2.0.1)을 이용하여 유효선량을 산출하였고 암발생의 생애귀속위험도(lifetime attributable risk of cancer incidence; LAR)를 비교하여 그 감소율을 간접적으로 평가하였다. 방어기구를 사용할 때, 입사표면선량(감소율)은 비강 $0.55{\mu}Sv$ (74.06%), 갑상선 $1.43{\mu}Sv$ (95.15%), 식도 $6.35{\mu}Sv$ (78.42%)로 평균 86.36% 감소되었고, 심부선량(감소율)은 경추 $1.23{\mu}Sv$ (89.73%), 침샘 $0.5{\mu}Sv$ (92.31%), 식도 $3.85{\mu}Sv$ (59.39%), 갑상선 $2.02{\mu}Sv$ (73.53%) 흉추 $5.68{\mu}Sv$ (54.01%) 로 평균 72.30%로 감소되어 차폐기구의 유용성을 확인할 수 있었다. 또한, 유효선량은 착용 전 $8.33{\mu}Sv$에서 착용 후 $7.35{\mu}Sv$로 11.76% 감소하였고, LAR 평가에서는 갑상선 암은 10세 소아 백만 명당 남아 0.14명(95.12%), 여아 0.77명(95.16%), 모든 암은 남아 0.14명(11.70%), 여아 0.25명(11.70%)의 감소(감소율)를 확인할 수 있었다. 진단방사선검사는 질병과 치료 등 건강을 위해 꼭 필요한 검사이지만, 가능한 진단에 불필요한 부위에 이러한 차폐기구를 적극적으로 사용하여 ALARA 개념에 입각한 의료방사선 최적화를 도모해야 할 것이다.

• Journal of Korean Neurosurgical Society
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• 제49권1호
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• pp.37-42
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• 2011

Objective: The author measured levels of fluoroscopic radiation exposure to the surgeon's body based on the different beam directions during kyphoplasty. Methods: This is an observational study. A series of 84 patients (96 vertebral bodies) were treated with kyphoplasty over one year. The patients were divided into four groups based on the horizontal and vertical directions of the X-Ray beams. We measured radiation exposure with the seven dosimetry badges which were worn by the surgeon in each group (total of 28 badges). Twenty-four procedures were measured in each group. Cumulative dose and dose rates were compared between groups. Results: Fluoroscopic radiation is received by the operator in real-time for approximately 50% (half) of the operation time. Thyroid protectors and lead aprons can block radiation almost completely. The largest dose was received in the chest irrespective of beam directions. The lowest level of radiation were received when X-ray tube was away from the surgeon and beneath the bed (dose rate of head, neck, chest, abdomen and knee: 0.2986, 0.2828, 0.9711, 0.8977, 0.8168 mSv, respectively). The radiation differences between each group were approximately 2.7-10 folds. Conclusion: When fluoroscopic guided-KP is performed, the X-Ray tube should be positioned on the opposite side of the operator and below the table, otherwise the received radiation to the surgeon's body would be 2.7-10 times higher than such condition.

• 대한한방내과학회지
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• 제39권1호
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• pp.84-96
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• 2018

Objective: This is aprospective clinical case study that includes the administration of Ahnjeonbaekho-tang (AJBHT) to patients who have suffered from Graves' disease for the 8 weeks of the clinical research. Methods: Without administration of an antithyroid drug, AJBHT was administered 3 times a day for 8 weeks. In Case 1, AJBHT without modification was administered and in Case 2, in accordance with the patients' symptoms, a dose of Gypsum Fibrosum was increased by 4g from the beginning of week 2, and further increased by 16 g, for a total of 20 g between week 6 and week 8. Body mass index (BMI), thyroid function test (TFT), thyroid autoantibody test, complete blood cell count (CBC), and blood chemistry (BC) tests were conducted at an interval of 4 weeks, for a total of 3 times during the study. The clinical manifestations, a spectrum of symptoms of the patients, was observed by Wayne's Index, Euro-QOL-5 Dimension (EQ-5D), and Perceived Stress Scale (PSS). Results: In both cases, an acceptable significance of reduction of value in T3, fT4, Thyroid stimulating antibody (TSAb) and Thyroid stimulating hormone receptor antibody (TSH-R-Ab) was observed. After treatment, in TFT, T3 decreased by 31.66%, fT4 decreased by 32.82% in Case 1, and T3 decreased by 43.42%, and fT4 decreased by 37.32% in Case 2. In the thyroid autoantibody test, TSAb decreased by 7.59%, and TSH-R-Ab decreased by 53.19% in Case 1, and TSAb decreased by 33.45%, TSH-R-Ab decreased by at least 7.75% in Case 2. Besides this, there was a decreasing trend of Wayne's index, and a loss of typical symptoms of hyperthyroidism also declared the efficacy. Conclusion: From these results, AJBHT is very effective in the regulation of TFT and improving the symptoms of hyperthyroidism, and is also expected to be an effective alternative to antithyroid drugs for patients who have side effects or drug intolerance.

• 대한수의학회지
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• 제16권1호
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• pp.77-96
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• 1976

In order to investigate the effects and acting mechanism on ovaries, thyroid glands and hypophyses of rabbits in short term administration of sulfadimethoxine (SDM) as medical dose, a total of 90 virgin albino rabbits (mean body weight, 1,362g) were selected at random and alloted to two groups. Rabbits in one group served as controls and the others were administered SDM of 50 mg/kg/day for 5 weeks, and then reared without medication for 4 weeks. Pathological changes of the three organs were observed each week for 9 weeks and the results obtained were summarized as follows: 1. Mean body weights of both groups manifested slow increasing tendency but mean hypophysis weights fluctuated throughout the experimental term. Mean ovary weights of experiments were decreased significantly from the 3rd to 6th week but mean thyroid weights of experiments were increased significantly from the 1st to 6th week compared with those of controls. 2. Many ovarian follicles of each developing stage showed follicular atresia accompanying atrophy or necrosis of oocytes and of disintegrated follicular cells. Theca interna cells and sudanophilic interstitial cells showed atrophy and diminished sudanophilic granules and also liquor folliculi were diminished. These changes icreased from the 1st week, remaining so for 5 weeks and returned to normal status in the 8th or 9th week. 3. The thyroid gland showed a typical hyperplastic goiter. Hypertrophic and hyperplastic epithelia follicular manifested cuboidal or columnar form showing tiny or small vacuoles in cytoplasm. The follicles showed atrophy and decreasing colloidal materials. Necrotic and regenerative changes were also present. The interfollicular vessels showed congestion and hemorrhage. These changes increased from the 1st week, remaining so for 5 weeks and returned to normal status in the 9th week. 4. The rates of differential cell counts of hypophyses revealed increase of basophils (gonadotrophs and thyrotrophs) and decrease of chromophobes. Basophils which had diminished granules stainable with HE, PAS and AF revealed hypertrophy, hyperplasia, and increasing of tiny or small vacuoles in cytoplasm. These changes increased from the 1st week, remaining so for 5 weeks and returned to normal status in the 8th or 9th week. As summarized above histologically, administration of SDM led thyrotrophs and gonadotrophs of pituitary glands to hyperactivity but revealed retrogressive and compensatory changes with functional disturbance in ovaries and thyroid glands. These changes were transitional and attributed to direct actions of the drugs on the ovaries and thyroid glands.

• 대한수의학회지
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• 제8권2호
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• pp.110-116
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• 1968

The mature guinea pigs were grouped as indicated in the table 1. Radio-active iodine(I-131)in dose of 4.5mci, was administered to the experimental groups. The animals were killed for examination in 1, 7, 14, 28, 42, and 55 days after the administration the radio-active iodine. The thyroid and adrenal glands were observed histologically. The results obtained were as follows; 1. One day after the administration, thyroid epithelial cells were abnormally enlarged. After seven days, specimens taken from the middle of the thyroid showed that the follicles and epithelial cells were changing to fibrous tissue, however, some follicles still remained in the verge of the thyroid. Follicles were not observed after fourteen days. After twenty-eight days, the follicles had all changed to fibrous tissue, and had lost their function. 2. The size of the zonas gromerulosa of adrenal cortex epually, in both male and female, showed slight fluctuation in size with no tendency to be changed. 3. Among the zones of the adrenal glands, zona fasciculata showed marked changes. Zona fasciculata was atrophied in Process of time. In females, it was atrophied significantly(P<0.05) after fourteen days, and highly significant (P<0.01) in twenty-eight and fifty-six days after the administration of radioactive iodine. In males, it also decreased significantly(P<0.05) in seventy-eight days and highly significant(P<0.01) in forty-two and fifty-six days after the administration. 4. The size of the Zona reticularis of adrenal cortex in the females increased significantly (P<0.05) in twenty-eight days after the administration. In males, it showed slight fluctuation until twenty-eight days, but it increased significantly(P<0.05) in forty-two and fifty-six days after the administration. 5. The size of the adrenal medulla increased significantly(P<0.05) in twenty-eight and forty-two days in females. It was increased significantly(P<0.05) in fourth-two days and high significantly(P<0.01) in fifty-six days after the administration.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.725-733
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• 2023

The Korea Institute of Radiological and Medical Sciences has started a radiation epidemiological study, titled "Korean Radiation Worker Study," to evaluate the health effects of occupational exposure to radiation. As a part of this study, we investigated the methodologies and results of reconstructing organ-specific absorbed doses based on personal dose equivalent, H_p(10), reported from 1984 to 2019 for 20,605 Korean radiation workers. For the organ dose reconstruction, representative exposure scenarios (i.e., radiation energy and exposure geometry) were first determined according to occupational groups, and dose coefficients for converting H_p(10) to organ absorbed doses were then appropriately taken based on the exposure scenarios. Individual annual doses and individual cumulative doses were reconstructed for 27 organs, and the highest values were observed in the thyroid doses (on average 0.77 mGy/y and 10.47 mGy, respectively). Mean values of individual cumulative absorbed doses for the red bone marrow, colon, and lungs were 7.83, 8.78, and 8.43 mSv, respectively. Most of the organ doses were maximum for industrial radiographers, followed by nuclear power plant workers, medical workers, and other facility workers. The organ dose database established in this study will be utilized for organ-specific risk estimation in the Korean Radiation Worker Study.

• 한국방사선학회논문지
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• 제8권7호
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• pp.409-415
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• 2014

하지전신계측검사(low extremity teleography)에서 자세 변화에 따른 중요장기의 방사선량을 측정하고 영상을 비교 분석하여 검사방법에 따른 유용성을 알아보고자 하였다. 대상은 하지전신계측검사를 시행한 성인남자 10명을 대상하였고 촬영조건은 관전압 73 kVp, 관전류량 32 mAs, SID 180 cm로 설정하였다. 방사선량 측정은 란도 팬텀을 이용하여 수정체, 갑상선, 생식선 부위에 유리선량계(glass dosimeter)를 부착한 후 전후방향자세와 후전방향자세를 각각 5번씩 시행하여 부위별로 방사선량을 측정한 후 Paired T-test로 비교 분석 하였다. 영상평가는 전후방향자세와 후전방향자세를 시행한 영상을 blind test를 실시하여 5점 척도로 평가하였다. 결과적으로 전후방향자세검사에 비해 후전방향자세검사가 수정체 약 6%, 갑상선 약 6%, 생식선에 미치는 방사선량을 약 27% 감소시킬 수 있으며 영상평가에서도 두 그룹 간에 큰 차이가 없어, 하지전신계측검사에서 전후방향자세검사보다 후전방향자세검사가 유용할 것으로 사료된다.

• Imaging Science in Dentistry
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• 제43권2호
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• pp.63-69
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• 2013

After over one decade development, cone beam computed tomography (CBCT) has been widely accepted for clinical application in almost every field of dentistry. Meanwhile, the radiation dose of CBCT to patient has also caused broad concern. According to the literature, the effective radiation doses of CBCTs in nowadays market fall into a considerably wide range that is from $19{\mu}Sv$ to $1073{\mu}Sv$ and closely related to the imaging detector, field of view, and voxel sizes used for scanning. To deeply understand the potential risk from CBCT, this report also reviewed the effective doses from literatures on intra-oral radiograph, panoramic radiograph, lateral and posteroanterior cephalometric radiograph, multi-slice CT, and so on. The protection effect of thyroid collar and leaded glasses were also reviewed.