• Journal of Radiation Protection and Research
• /
• v.39 no.4
• /
• pp.206-212
• /
• 2014

We report here on the results of evaluating the radiation doses using chest computed tomography (CT) for patients with pneumoconiosis complication. For the first time, we visited the 17 MIPs to evaluate the dose-length product (DLP, $mGy{\cdot}cm$), CT unit, and protocols of scanning and image reconstruction those is routinely used for treating patients with pneumoconiosis who have complication. All statistical analysis was performed using the Statistical Program for Social Sciences (SPSS ver. 19.0, Chicago, IL, USA). Mean of total DLP was $727.7mGy{\cdot}cm$, ranging from 272.0 to $1228.7mGy{\cdot}cm$. DLP from obtaining parenchymal lung images was significantly reduced than that from obtaining total lung images (555.9 vs. 707.2, p<0.001). Third quartile of total and pre-scanning DLP was 1036.1 and $504.1mGy{\cdot}cm$, respectively. Chest CT radiation doses for patients with pneumoconiosis complication are similar with korean diagnostic reference level as well as international guidelines.

• Journal of radiological science and technology
• /
• v.39 no.1
• /
• pp.13-17
• /
• 2016

In this study, standard model of medical radiation dosage quality control system will be suggested and the useful of this system in clinical field will be reviewed. Radiation dosage information of modalities are gathered from digital imaging and communications in medicine(DICOM) standard data(such as DICOM dose SR and DICOM header) and stored in database. One CT scan, two digital radiography modalities and two mammography modalities in one health promotion center in Seoul are used to derive clinical data for one month. After 1 months research with 703 CT scans, the study shows CT $357.9mGy{\cdot}cm$ in abdomen and pelvic CT, $572.4mGy{\cdot}cm$ in brain without CT, $55.9mGy{\cdot}cm$ in calcium score/heart CT, screening CT at $54mGy{\cdot}cm$ in chest screening CT(low dose screening CT scan), $284.99mGy{\cdot}cm$ in C-spine CT and $341.85mGy{\cdot}cm$ in L-spine CT as health promotion center reference level of each exam. And with 1955 digital radiography cases, it shows $274.0mGy{\cdot}cm2$ and for mammography 6.09 mGy is shown based on 536 cases. The use of medical radiation shall comply with the principles of justification and optimization. This quality management of medical radiation exposure must be performed in order to follow the principle. And the procedure to reduce the radiation exposure of patients and staff can be achieved through this. The results of this study can be applied as a useful tool to perform the quality control of medical radiation exposure.

• Journal of radiological science and technology
• /
• v.28 no.3
• /
• pp.241-248
• /
• 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.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.25 no.2
• /
• pp.25-28
• /
• 2021

Purpose CA 72-4 is a tumor marker that uses two monoclonal antibodies, CC49 and B72.3, to measure tumor-related glycoprotein(TAG72) in the serum. CA 72-4 is used to diagnose stomach, ovarian, and pancreatic cancers, and is known to perform high specificity for stomach cancer. The purpose of this study is to re-evaluate the reference value provided by the manufacturer through revalidation of the reference value in CA 72-4. Furthermore this study was conducted to provide useful help when making a clinical diagnosis at gastric cancer center. Materials and Methods We selected 271 patients who had been to health care center in national cancer center for the month of November 2020. The gender of the subjects was 140 males and 131 females, and the age group was from 30s to 60s. The reagent used in the study was a CA 72-4 IRMA KIT (ISOTOPES, Hungary) and the results were measured using a Dream Gamma-10 gamma counter (Shinjin medics, Korea). Results Statistical analysis of the results of this study used Hoffmann's method and Bayesian's method, which are primarily used in setting reference value. As a result of measuring CA 72-4 of 271 patients, the mean value was 4.54 U/mL and the median value was 3.30 U/mL. 24 people who deviated from 3SD were excluded from the measured value, the mean calculated after that was 3.53 U/mL, median was 3.00 U/mL and SD was 1.89. The reference value calculated based on this results was set to 7.31 U/mL. Conclusion The reference value provided by the manufacturer is less than 4 U/mL. It is slightly different from the value calculated in this study, 7.31 U/mL, so it seems necessary to reset the reference value according to the laboratory environment. Currently, we are receiving inquiries about the reference value from the center for gastric cancer at National Cancer Center. If additional research is carried out along with this study, it will be possible to set more accurate reference value.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.21 no.2
• /
• pp.28-30
• /
• 2017

Purpose Anti-Glutamic acid decarboxylase antibody test (GAD Ab) has been used as a predictor of type 1 diabetes. GAD Ab has also been shown to be highly potent in cerebrospinal fluid (CSF) of patients with suspected diabetic peripheral neuropathy. Recently, it has been known that clinical significance of GAD Ab using CSF is useful for the neurological disorders. However, the reference value of anti-GAD Ab has been provided only for serum. In this experiment, we estimated the reference value of anti-GAD antibody for CSF in neurological patients. Materials and Methods A total of 211 neurological patients were enrolled. Serum and CSF were analyzed by radioimmunoassay (RIA) using commercial RIA anti-GAD Ab kit (RSR, London, United Kingdom). Normal saline was used as the normal CSF control because CSF is most similar to 0.9% normal saline. Results The mean value of normal CSF control was 1.97 U/mL, and two standard deviations (2SD) was 1.44 U/mL. Based on this data, the expected reference range of CSF could be estimated from 0.54 U/mL to 3.40 U/mL Conclusion The reference range of normal CSF control using normal saline obtained with Hoffmann's method. However, there will be a need to validate the CSF reference values using human normal CSF.

• Journal of radiological science and technology
• /
• v.32 no.1
• /
• pp.39-43
• /
• 2009

The medical diagnostic examination using ionizing radiation has improved the patients' life and brought revolution in medical examination along with the mechanical development. However, the development of medical imaging systems has also been the reason to increase the patients' exposure for ionizing radiation. ICRP recommends that each country adopts diagnostic reference levels depending on regional and national situations. The Korea Food & Drug Administration suggested the dosimetry measurement guideline for patients in 2007. Nonetheless, in reality, it is hard to know the skin dose of the patients when applying a x-ray since there is no radiation dosimeter in most of clinical situation. Therefore, this study sets a program based on the bit system to figure out easily the skin dose of a patients using MS Excel program in the PC setting. The results showed 10% better outcome.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.13 no.2
• /
• pp.180-192
• /
• 2010

Purpose: To evaluate the feasibility and usefulness of the waist circumference-to-height ratio (WHTR) in screening for obesity in Korean children and adolescents. Methods: Data, including body mass index (BMI), waist circumference (WC), and height, were obtained from the national growth surveys for children and adolescents in 2005. The WHTR was calculated dividing WC by height in subjects 2~18 years of age. Overweight and obese were defined by BMI percentiles for age and gender. The receiver operating characteristic (ROC) analysis was performed to find out the optimal cutoff values of WHTR that matched BMI-determined overweight and obesity using the STATA program. The area under the curve (AUC), a measure of diagnostic power, of WHTR was compared to WC. The influence of age on WHTR was analyzed by the SAS program. Results: The WHTR significantly decreased with age, and had less correlation with age in the 6~18-year-old age group than the 2~5-year-old age group. Furthermore, the WHTR also had less correlation with age than WC in the 6~18-year-old age group. The AUC of WHTR in identifying overweight and obesity was significantly higher than the AUC of WC in the 6~18-year-old age group. The optimal cutoff values were 0.51 in boys and 0.49 in girls for obesity, and 0.48 in boys and 0.47 in girls for overweight, with all having the AUC>0.9. The optimal cutoff values of WHTR had a higher sensitivity for diagnosing obesity than WC${\geq}$90th percentiles. Conclusion: The WHTR is an easy, accurate, and less age-dependent index with high applicability in screening for obesity in children and adolescents.

• Journal of radiological science and technology
• /
• v.40 no.2
• /
• pp.229-235
• /
• 2017

In abdominal Ultrasonography, the fatty liver is diagnosed through hepatic parenchymal echo increased parenchymal density and unclear blood vessel boundary, and according to many studies, abdominal Ultrasonography has 60~90% of sensitivity and 84~95% of specificity in diagnosis of fatty liver, but the result of Ultrasonography is dependent on operators, so there can be difference among operators, and quantitative measurement of fatty infiltration is impossible. Among examinees who same day received abdominal Ultrasonography and chest computed tomography (CT), patients who were diagnosed with a fatty liver in the Ultrasonography were measured with liver Hounsfield Units (HU) of chest CT imaging to analyze the accuracy of the fatty liver diagnosis. Among 720 subject examinees, those who were diagnosed with a fatty liver through abdominal Ultrasonography by family physicians were 448, which is 62.2%. The result of Liver HU measurement in the chest CT imaging of those who were diagnosed with a fatty liver showed that 175 out of 720 had the measured value of less than 40 HU, which is 24.3%, and 173 were included to the 175 among 448 who were diagnosed through Ultrasonography, so 98.9% corresponded. This indicates that the operators' subjective ability has a great impact on diagnosis of lesion in Ultrasonography diagnosis of a fatty liver, and that in check up chest CT, under 40 HU in the measurement of Liver HU can be used for reference materials in diagnosis of a fatty liver.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.9 no.4
• /
• pp.127-134
• /
• 2005

Design and construction of long-span bridge are recently increasing by development of computer technology. Specially, cable stayed bridge and suspension bridge having cable component are representative of long-span bridge may do. Therefore, this paper a present a methodology for cable tension force monitoring in cable-stayed bridge under construction using acceleration data acquired by the vibration method. To improve accuracy construction, all stay cables are measured, according to 4-step construction stage and change of temperature.

• Laboratory Medicine Online
• /
• v.6 no.1
• /
• pp.25-30
• /
• 2016

Background: The cell cycle-dependent enzyme thymidine kinase 1 (TK1) is known to increase during cancer cell proliferation and has been reported as a prognostic marker for various hematologic malignancies and solid tumors. This study aimed to determine the reference interval in Korean healthy controls and to evaluate the usefulness of TK1 as a biomarker for aggressive clinical behavior in B-cell lymphoma patients. Methods: We enrolled 72 previously untreated patients with B-cell lymphoma and 143 healthy controls. Serum TK1 levels were measured by chemiluminescence immunoassay ($Liaison^{(R)}$, DiaSorin, USA). We established the reference intervals in healthy controls. The diagnostic performance of serum TK1 was studied using receiver operating characteristic (ROC) analysis, and the correlation between the cutoff level for serum TK1 and clinical characteristics of B-cell lymphoma was evaluated. Results: The reference range (95th percentile) of serum TK1 in healthy controls was 5.4-21.8 U/L. There was a clear difference in TK1 levels between patients with B-cell lymphoma and healthy controls ($40.6{\pm}68.5$ vs. $11.8{\pm}4.4U/L$, P <0.001). The area under the curve of serum TK1 for the diagnosis of B-cell lymphoma was 0.73 (cutoff, 15.2 U/L; sensitivity, 59.7%; specificity, 83.2%). An increased TK1 level (${\geq}15.2U/L$) correlated with the advanced clinical stage (P <0.001), bone marrow involvement (P =0.013), international prognostic index score (P =0.001), lactate dehydrogenase level (P =0.001), low Hb level (<12 g/dL) (P =0.028), and lymphocyte count (P =0.023). Conclusions: The serum TK1 level could serve as a useful biomarker for aggressive clinical behavior in B-cell lymphoma patients.