• 제목/요약/키워드: 방사선검사

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An Estimate of Image Quality and Radiation Doses of Coronary Artery in MDCT Using Prospective and Retrospective ECG Gating Scan Mode (MDCT 관상동맥 조영 검사에서 전향적 동조화 및 후향적 동조화 기법의 화질과 선량 관계)

  • Oh, Jong-Kap
    • Journal of radiological science and technology
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    • v.34 no.4
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    • pp.315-321
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    • 2011
  • The goal of this study is to reduce patient exposure dose by providing image quality and radiation dose according to inspection methods. Volume Computed Tomography Dose Index(CTDIvol) and Dose Length Product(DLP) of prospective and retrospective ECG gating snapshot segment of Coronary CT angiography(CTA) were measured each snapshot segment methods. CT number, noise, uniformity, and resolution were also measured using phantom under the same condition of coronary CTA. The results showed that CT number, noise, uniformity and resolution are similar to each other. In terms of CTDIvol and DLP, however, measurement dose of prospective ECG gating snapshot segment was lower than the retrospective case by 37.5% and 40.3%. Therefore, it is highly recommended that in the coronary CTA, prospective ECG gating scan mode should be chosen to reduce patient dose.

Study on the Image Quality Comparison between in Digital RT and Film RT (용접부에 대한 디지털 방사선투과영상과 필름 방사선투과영상의 상질 비교에 관한 연구)

  • Park, Sang-Ki;Ahn, Yean-Shik;Gil, Doo-Song
    • Journal of the Korean Society for Nondestructive Testing
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    • v.31 no.4
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    • pp.391-397
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    • 2011
  • Conventional film radiographic test has been generally and widely used in the inspection on the weldment for quality assurance. On the other hand, since the analog RT is well known for typical time and cost consuming method with complex process of inspection, the industry has researched various ways how to improve radiographic test technology. In this study, we verified the fact that digital RT provides a lot more benefit in effectively detecting defects, ever film details, through digital processing of image enhancement, compared to film RT. As a result, we reached conclusion that digital RT is positively able to replace the film RT in industry in part or in whole.

Patient exposure doses from medical x-ray examinations in Korea (진단방사선검사에서 환자피폭선량에 관한 연구)

  • Kim, You-Hyun;Choi, Jong-Hak;Kim, Sung-Soo;Oh, Yuw-Han;Lee, Chan-Hyeup;Cho, Pyong-Kon;Kang, Dae-Hyun;Lee, Young-Bae;Kim, Hyung-Chul;Kim, Chel-Min
    • Journal of radiological science and technology
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    • v.28 no.3
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    • pp.241-248
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    • 2005
  • X-ray examinations represent the largest man-made source of radiation exposure for the population. The need for standardization of radiation exposures has been suggested and the guidance levels for various radiographic and radioisotope examinations has been proposed by the International Atomic Energy Aency(IAEA) as a safety standard. In many countries, the situation of medical radiographic exposures in each country should be researched before the appropriate guidance level is established. In this study, measurements of entrance surface dose, dose-area product(DAP), computed tomograghic dose index(CTDI) and mean glandular dose(MGD) were carried out in patients who underwent routine x-ray examinations, fluoroscopy, computed tomograghy and mamography in Korea. These measured quantities were compared with the results from the calculation method in previous study. And we suggested diagnostic reference levels in medical imaging in Korea.

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Development of Acanthial Parieto Projection for Maxillary Diagnosis in X-ray Paranasal Sinuses (X-ray 코곁굴 검사에서 위턱굴 진단을 위한 비극-두정방향 촬영법 개발)

  • Byung-Ju Ahn;Yong-Wan Kim;In-Soo Kim
    • Journal of the Korean Society of Radiology
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    • v.17 no.3
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    • pp.327-333
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    • 2023
  • In Order to Diagnose Maxillary Bone and Maxillary Sinus in the X-Ray Paranasal Sinus Projection test, this Study used Skull Rando Phantom to Change the Posture and X-ray tube Angle to 5° of the Head or 5° of ROC Who worked for more than 10 years. The Significance of the Evaluated score was Verified through SPSS Ver. 3.0, and the Cronbach value was Significantly higher at 0.712. In addition, as a Result of Calculating SNR by Setting the ROI(Receiver Operation Characteristic) of the Maxillary bone and Maxillary sinus images, it was the Highest at 6,449 in the Examination by tilting 5° toward the Head or Leg of the X-ray tube. In the study, it is believed that among the X-Ray simple Paranasal Sinus projection tests, a sharp Image can be Obtained during the Examination by Tilting the X-ray tube 5° toward the Head or Leg.

The Survey for Awareness of Radiation Dose of CT and General X-ray Examination (전산화단층촬영검사와 일반촬영검사의 방사선 선량에 대한 인식도 조사)

  • Joo, Young-Cheol;Lim, Cheong-Hwan;Jung, Hong-Ryang;You, In-Gyu;Cho, Han-Byul;Yang, Oh-Nam;Kim, Min-Cheol;Yoon, Joon
    • Journal of radiological science and technology
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    • v.35 no.1
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    • pp.35-44
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    • 2012
  • The goal of this study is to awaken about risk occurred by CT examination. For radio-technologists working at 'S medical center' located in Seoul, we investigated a recognition about dose and risk CT and normal X-ray examination according by working experience in hospital, experience about CT examination and radiation source. For subjects of investigation, radio-technologists working at 'S medical center' located in Seoul helped us. We collected 131 questionnaires for a test of hypothesis. Cronbach @ coefficients of questionnaires were 0.825988 and 0.767161 and a rejection rate of p-value was below 0.05. SAS 9.1(SAS Institute Inc., Cary, NC, USA.) statistic package was used for hypothesis test. We used Mann-Whitney test, Kruskai-Wallis test, Two sample T-test, Two sample T-test with Bonferroni's Correction and One-way ANOVA methods. P-values of hypothesis about dose of CT and normal X-ray examination were 0.2291 ~ 0.9663. p-values of hypothesis about risk were 0.1924 ~ 1.0000. All of hypothesis is over rejection rate(<0.05). This study shows that radio-technologists of S medical center recognized that CT has higher dose and risk than general X-ray examination.

Evaluation of Respiration Reproducibility of Chest General X-ray Examination using Self-made Respiratory Synchronization Device (자체 제작한 호흡 동기화 장치를 통한 흉부 일반촬영 검사의 호흡 재현성 평가)

  • Kwon, Oh-Young;Lee, Chang-Hun;Yong, Keum-Ju;Jin, Seon-Hui;Jung, Da-Bin;Heo, Yeong-Cheol
    • Journal of the Korean Society of Radiology
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    • v.15 no.7
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    • pp.1049-1056
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    • 2021
  • The purpose of this study was to develop a respiratory synchronization device for X-ray (X-RSD) to increase the reproducibility of inspiration when examining the Chest X-ray of a patient who difficulty in breathing coordination. The X-RSD was self-made using an air pressure sensor and air was injected by connecting a ventilator to the mannequin for CPR. At this time, the amount of injected air was quantified using the SkillReporting device. After placing the X-RSD on the chest of the mannequin, the amount of air was tested in 6 steps from 200 to 700 cc by 100 cc increased. For the accuracy evaluation, the sensitivity of X-RSD was measured by repeating a total of 80 measurements, and the sensitivity was 100%, and very precise results were obtained. After that, the images examined while viewing the X-RSD of the chest lateral examination and the images obtained by the blind examination were compared and evaluated. The lung volume of X-RSD was larger than that of the blind test, and the deviation was smaller. Overall, the use of X-RSD can help with chest X-ray examination of patients who have difficulty in cooperating, and it is thought that it will be possible to contribute to the reduction of exposure dose by reducing the repeat rate of general X-ray examinations.

Measurement of the Spatial Dose Rates During PET/CT Studies (전신 PET/CT 검사에서 공간선량률 측정)

  • Park, Myeong-Hwan
    • Journal of radiological science and technology
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    • v.29 no.4
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    • pp.257-260
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    • 2006
  • In order to evaluate the exposure to the radiologic technologists from patients who had been administrated with radiopharmaceuticals, we measured the spatial dose rates at $5{\sim}300\;cm$ from skin surface of patients using an proportional digital surveymeter, 1.5(PET scan) and 4hr(bone scan) after injection. In results, the exposure to the technologists in each procedure was small, compared with the dose limits of the medical workers. However, the dose-response relationships in cancer and hereditary effects, referred to as the stochastic effects, have been assumed linear and no threshold models ; therefore, the exposure should be minimized. For this purpose, the measurements of spatial dose rate distributions were thought to be useful.

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Diagnosis with Ultrasound for Rib Fractures in the Golf (골프 운동중 발생한 늑골 골절의 초음파 진단)

  • Lim, Che-Joon;Youn, Te-Hyun;An, Ki-Yong
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.7 no.1
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    • pp.50-54
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    • 2008
  • Purpose: In most cases, the main cause of chest or back pain during playing golf is rib fractures. This kind of rib fractures can be easily overlooked in plain radiographs. The purpose of this article is to clarify the value of the ultrasound in detecting rib fractures. Materials and Methods: We compared the findings of chest-X rays (anteroposterior, left or right lateral, both oblique view) with those of the ultrasound in 56 patients between the ages of 20th & 60th who were diagnosed rib fractures. Their chief complaints were chest or back pain which developed during playing golf. The results were analyzed statistically. Results: Among 56 cases of rib fractures, 34 cases were diagnosed with initial X-rays. 51 cases were diagnosed with ultrasound. The sensitivity of radiograph and ultrasound were 60.71% & 91.07%, respectively. Dignosis was ultrasound with statical significance whereas radiography did not(p=0.0004). Conclusion: It was concluded that ultrasound is a valuable tool in the diagnosis of the rib fractures which were undetected with X-rays during playing golf.

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A Study of Radiation Dose Reduction using Bolus in Medical Radiation Exam (볼루스를 이용한 방사선영상검사 피폭선량저감 연구)

  • Jeong-Min Seo
    • Journal of the Korean Society of Radiology
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    • v.17 no.6
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    • pp.1001-1007
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    • 2023
  • Dose limits are not applied to medical radiation exposure therefore justification and optimization should be essential for protecting radiation. This study explores methods to reduce exposure dose undergoing general radiation exam by bolus(tissue equivalent material) with keeping image quality. Hand PA projection with 50 kVp, 5 mAs, SID 100 cm, and 8×10 inch is referred by covered bolus of thickness 0, 3, 5, 8, and 10 mm for evaluation entrance dose and SNR. The entrance dose (μGy) to the hand by bolus thickness was 125.41±0.288, 106.85±0.255, 104.97±0.221, 91.68±0.299, and 90.94±0.106 showing a significant reduction in radiation exposure depending on if the bolus was used and bolus thickness. The SNR of the image was 13.997, 13.906, 12.240, 12.538, and 12.548 at each bolus thickness, showing no significant difference. It was confirmed that if appropriate thickness and size of bolus is used depending on the type of radiological imaging exam and the body site, a significant radiation dose reduction effect can be achieved without deteriorating image quality.