• Title/Summary/Keyword: 흉부 CT

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Dose Reduction Method for Chest CT using a Combination of Examination Condition Control and Iterative Reconstruction (검사 조건 제어와 반복 재구성의 조합을 이용한 흉부 CT의 선량 저감화 방안)

  • Sang-Hyun Kim
    • Journal of the Korean Society of Radiology
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    • v.17 no.7
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    • pp.1025-1031
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    • 2023
  • We aimed to evaluate the radiation dose and image quality by changing the Scout view voltage in low-dose chest CT (LDCT) and applying scan parameters such as AEC (auto exposure control) and ASIR (adaptive statistical iterative reconstruction) to find the optimal protocol. Scout view voltage was varied at 80, 100, 120, 140 kV and after measuring the dose 5 times using the existing low-dose chest CT protocol, the appropriate kV was selected for the study using the Dose report provided by the equipment. After taking a basic LDCT shot at 120 kV, 30 mAs, ASIR 50% was applied to this condition. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were assessed by measuring Background noise (B/N). For dose comparison, CTDIvol and DLP provided by the equipment were compared and analyzed using the formulas. The results indicated that the protocol of scout 140 + LDCT + ASIR 50 + AEC reduced radiation exposure and improved image quality compared to traditional LDCT, providing an optimal protocol. As demonstrated in the experiment, LDCT screenings for asymptomatic normal individuals are crucial, as they involve concerns over excessive radiation exposure per examination. Therefore, applying appropriate parameters is important, and it is expected to contribute positively to the public health in future LDCT based health screenings.

Changes in External Radiation Dose Rate for PET-CT Test Patients (PET-CT 검사 환자의 외부 방사선량률 변화)

  • Kim, Su-Jin;Han, Eun-Ok
    • Journal of Radiation Protection and Research
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    • v.37 no.2
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    • pp.103-107
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    • 2012
  • This paper analyzes changes in the external radiation dose rate of PET-CT test patients as a part of providing basic materials for reduction of radiation exposure to PET-CT test patients. In theory the measurement of external radiation dose rate of PET-CT test patients shows that the further the distance from the patient injected with radioactive pharmaceutical and a longer time elapsement from the injection leads to a smaller amount of radiation. Particularly, the amount of radiation marked the highest in the chest was at 4.17 minutes immediately after the intravenous injection and in the head after 77.47 minutes after urination in advance to the PET-CT test. As in the generalized information, it is desired to keep distance between the patient and caretakers or professionals to reduce the amount of radiation exposure from PET-CT test patients and to resume contact the patient after the time when the radiation has reduced. If contact is unavoidable, it is desired to keep at least 200cm from the patient. In addition, the amount of radiation reached the highest in the chest at first and then in the head from 77 minutes after injection. Accordingly, it would be helpful in achieving the optimization if contact is made based on the patient's physical characteristics. This study is significant as it measures changes in radiation the dose rate by; distance from the PET-CT test patient, time elapsed, and specific parts of body. Further studies based on the findings in this paper are required to analyze changes in radiation dose rate in accordance with individual characteristics unique to PET-CT patients and to utilize the results to reduce the amount of radiation patient, caretakers and professions are exposed.

Radiographic Status of the Visited Patients at University Hospital Emergency Room (한 대학병원 응급실 내원환자의 방사선촬영 실태)

  • Ahn, Byeoung-Ju
    • Journal of the Korean Society of Radiology
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    • v.5 no.2
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    • pp.81-92
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    • 2011
  • This study was carried out to improve service efficiency and to cope with a emergency situation in emergency radiography, through analysis of the radiographic distriution and literature cited about emergency care. Data collection of radiographic distribution was surveyed for 1270 emergency outpatients who visit during JAN, 2009at ER of the general hospital in Gwang city. The results is as follows : Emergency radiography rate of simple radiography was 56.6%, special radiography 2. 5%, CT 34.2%, and ultrasonography 6.7%, In simple radiography rate. a high rate was distributed on male(63.6%), thoracicsurgery part(90.0%), admission patient(77.9%), and long stayed patient at ER. In special raiography rate, a high rate was obsurved in urologic part(28.6%), and in CT rate, observed neurosurgerty part(49.2%) and neurologic part(36.7%). Ultrasonography rate was high for female(8.8%) and internal medicine part(15.9%). There are distributed regional radiography rate in radio-graphic type that chest(55.3%) is high in the simple radiography, urinary system(1.2%) in the special study, and brain(40.0%) in the CT. Regional radiography rate according to diagnostic department also was showed highly for head(64.6%) in neuro surgery, chest(90.0%) in thoracic surgery, abdomen(58.0%) in general surgery, spine(40.0%) in neuro surgery, and pelvis(15.9%), upper extrimity(20.5%), and lower extrimity(31.8%) in orthopedic surgery each. Mean radiographic case number per patient of simple radiography was sinificant on sex, age, transfer relation in both total and radiopraphic patients(p<0.05). Mean radiographic case number was highly distributed on male(2.2 case number) in sex, on thirties(2.7) in age, transferred patient(2.7) in patient type, and on nurosurgery(3.4) in diagnostic charged part. Total radiographic case number in regional party was highly distributed on chest(998 case number.) Considering the above results, emergency radiographer should take care of the elder patient in emergency radiography and get hold of injury mechanism to decrease possible secondary injury during radiography. Because of high radiography rate of urinary system in special study, related instrument. All radiographer who take charge emergency patient should cope with a emergency situation during radiography. Because head trauma patients is very important in patient care, especilly in CT at night, charged doctor should be always sitted with CT room and monitoring patient. Radiography was reqested by many diagnostic department in ER. Considering that rate of simple radiography is high, special room for emergency radiopraphy should be established in ER area, and the radioprapher of this room should be stationed radiologic technician who is career and can implement emergency patient care and The disposition of men which is appropriate with emergency patient increase is necessary.