Image and Exposure Dose in Accordance with Radiation Quality on Plain Chest Radiography (흉부촬영(胸部撮影)에서 증감지(增感紙)-필름계의 선질변화(線質變化)에 따른 감도(感度)와 화질에 관(關)한 연구(硏究))
-
- Journal of radiological science and technology
- /
- v.15 no.1
- /
- pp.65-78
- /
- 1992
Routine chest radiography is generally imaged by high voltage technique but some radiological technologists use low voltage for imaging. High voltage is usually said between
Background: Diagnosis by direct microscopy and/or by culture of the Mycobacterium tuberculosis from body fluids or biopsy specimens is "Gold standard". However, the sensitivity of direct microscopy after Ziehl-Neelsen staining is relatively low and culture of mycobacteria is time consuming. Detection of mycobacterial DNA in clinical samples by the polymerase chain reaction is highly sensitive but laborious and expensive. Therefore, rapid, sensitive and readily applicable new tests need to be developed. So we had evaluated the clinical significance of serologic detection of antibody to 38 kDa antigen, which is known as the most specific to the M. tuberculosis complex, and culture filtrate antigen by ELISA in sputum AFB smear negative patients. Method: In this study, culture tests for acid fast bacilli with sputa or bronchial washing fluids of 183 consecutive patients who were negative of sputum AFB smear were performed. Simultaneously serum antibodies to 38 kDa antigen and unheated culture filtrate of M. tuberculosis were detected by an ELISA method. Results: The optical densities of ELISA test with 38 kDa and culture filtrate antigen were significantly higher in active pulmonary tuberculosis cases than in non tuberculous pulmonary diseases (p<0.05), but in patients with active pulmonary tuberculosis, those of the sputum culture positive patients for M. tuberculosis were not significantly different from those of the sputum culture negative cases(p>0.05). In the smear-negative active pulmonary tuberculosis patients, the sensitivity of the ELISA using 38 kDa antigen and culture filtrate was 20.0% and 31.4%. respectively. The specificity was 95.3% and 93.9%. respectively. Conclusion : In active pulmonary tuberculosis but smear negative, the serologic detection of antibody to 38 kDa antigen and culture filtrate by ELISA cannot substitute traditional diagnostic tests and does not have clinically significant role to differenciate the patient with active pulmonary tuberculosis from other with non-tuberculous pulmonary diseases.
Swine whipworm(Trichuris suis) is cosmopolitan nematode which can cause serious pathology in immature stage(larva2~larva5) of infected pigs, such as anorexia, diarrhea, anemia, and death in heavy infections. In this larval stages, it is very difficult to diagnose the infection of whipworm and to differentiate from other common swine gastrointestinal disorders such as 21 day scours which are associated with TGE virus, rota virus, coccidium, and the stress of weaning. In this experiment, the isolated antigens of Trichuris spp. were carried out to examine the structure and specificity of antigens and to select the reasonable antigens which would be used in serological diagnosis by electrophoresis, Western blotting, ELISA. The results of this experiment were as follows; 1. The common fractions of each Trichuris suis antigen were identified 28,32,45, 80kDa by SDS-PAGE with silver stain and four major fractions could be detected in positive swine sera by Western blot analysis. 2. The OD(optical density) values of somatic and excretory-secretory antigens which were reacted against positive(negative) sera from pigs infected with Trichuris suis by ELISA reader were; 1) OD values(
The first neutral beam injector (NBI-1) has been developed for the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. A first long pulse ion source (LPIS-1) has been installed on the NBI-1 for an auxiliary heating and current drive of KSTAR core plasmas. Performance of ion and neutral beam extractions in the LPIS-1 was investigated initially on the KSTAR NBI-1 system, prior to the neutral beam injection into the main plasmas. The ion source consists of a JAEA magnetic bucket plasma generator with multi-pole cusp fields and a set of KAERI prototype-III tetrode accelerators with circular apertures. The inner volume of plasma generator and accelerator column in the LPIS-1 is approximately 123 liters. Final design requirements for the ion source were a 120 kV/ 65 A deuterium beam and a 300 s pulse length. The extraction of ion beams was initiated by the formation of arc plasmas in the LPIS-1, called as an arc-beam extraction method. A stable ion beam extraction of LPIS-1 has been achieved up to an 100 kV/42 A for a 4 s pulse length and an 80 kV/25 A for a 14 s pulse length. Optimum beam perveance of 1.21 microperv has been found at an accelerating voltage of 80 kV. Neutralization efficiency has been measured by using a water flow calorimetry (WFC) method of calorimeter and an operation of bending magnet. The full-energy species of ion beams have been detected by using the diagnostic method of optical multichannel analyzer (OMA). An arc efficiency of the LPIS was 0.6~1.1 A/kW depending on the operating conditions of arc discharge.
The role of radiology department has been greatly increased in the past few years as the technology in the medical imaging devices improved and the introduction of PACS (Picture Archiving and Communications System) to the conventional film-based diagnostic structure is a truly remarkable factor to the medical history. In addition, the value of using digital information in medical imaging is highly expected to grow as the technology over the computer and the network improves. However, the current medical practice, using PACS is somewhat limited compared to the film-based conventional one due to a poor image quality. The image quality is the most important and inevitable factor in the PACS environment and it is one of the most necessary steps to more wide practice of digital imaging. The existing image quality control tools are limited in controlling images produced from the medical modalities, because they cannot display the real image changing status. Thus, the image quality is distorted and the ability to diagnosis becomes hindered compared to the one of the film-based practice. In addition, the workflow of the radiologist greatly increases; as every doctor has to perform his or her own image quality control every time they view images produced from the medical modalities. To resolve these kinds of problems and enhance current medical practice under the PACS environment, we have developed a program to display a better image quality by using the ROI optical density of the existing gray level values. When the LUT is used properly, small detailed regions, which cannot be seen by using the existing image quality controls are easily displayed and thus, greatly improves digital medical practice. The purpose of this study is to provide an easier medical practice to physicians, by applying the technology of converting the H-D curves of the analog film screen to the digital imaging technology and to preset image quality control values to each exposed body part, modality and group of physicians for a better and easier medical practice. We have asked to 5 well known professional physicians to compare image quality of the same set of exam by using the two different methods: existing image quality control and the LUT technology. As the result, the LUT technology was enormously favored over the existing image quality control method. All the physicians have pointed out the far more superiority of the LUT over the existing image quality control method and highly praised its ability to display small detailed regions, which cannot be displayed by existing image quality control tools. Two physicians expressed the necessity of presetting the LUT values for each exposed body part. Overall, the LUT technology yielded a great interest among the physicians and highly praised for its ability to overcome currently embedded problems of PACS. We strongly believe that the LUT technology can enhance the current medical practice and open a new beginning in the future medical imaging.
In Korea, bovine tuberculosis (bTB) is a representative zoonotic disease that causes considerable economic loss. In determining the positive bTB, the ELISA method for examining the amount of interferon-gamma (IFN-γ) is included in Korea's diagnostic standard method. Recently, commercially available BIONOTE TB-Feron ELISA Plus (TB-Feron Plus) that detects IFN-γ has been introduced. However, since the scientific basis for the performance is limited, we evaluated performance by comparing it with the results of another IFN-γ ELISA assay kit (BOVIGAM®) certified by Office International des Epizooties. In our research, 42 positive blood samples preliminarily tested with a tuberculin skin test and/or BOVIGAM® and 54 negative blood samples collected from three bTB free farms were subjected to IFN-γ assay using the TB-Feron Plus and the BOVIGAM®, respectively. The result shows that the sensitivity, specificity and accuracy were 81.0% (34/42), 100% (54/54), 91.7% (88/96) in TB-Feron Plus kit and 78.6% (33/42), 100% (54/54), 90.6% (87/96) in BOVIGAM® kit, respectively. Moreover, the overall accordance percentage of the two kits was 99.0% (95/96) and there was almost perfect agreement between two assays (Kappa=0.977, P<0.0001). Furthermore, additional studies confirmed that elevated lymphocyte numbers in blood did not interfere with the results of the TB-Feron Plus kit. And, delayed time from sampling to culture decreased the optical density (OD) value. Therefore, we concluded that the TB-Feron Plus kit was not inferior to BOVIGAM® in performance. High lymphocyte numbers in blood did not impact on TB-Feron Plus results, while delayed time before culture interfered with OD value.
We aimed to evaluate the dosimetric characteristics of reproducibility, linearity and dose dependence of optical stimulated luminance dosimeter (OSLD) in the Co-60 Gamma-rays and to analyze with a precedent study in field of the diagnostic radiography and radiotherapy. The reproducibility was 0.76% of the coefficient of variation, the homogeneity was within 1.5% of the coefficient of variation and OSLD had supra-linear response more than 3 Gy. So the correlation between dose and count was fitted by quadratic function. The count depletion by repeated reading was 0.04% per reading regardless of the irradiated dose. And the half time of decay curve according to the irradiated dose was 0.68 min. with 1 Gy, 1.04 min. with 5 Gy, and 1.10 min. with 10 Gy, respectively. In case of annealing for 30 min, the removal rate was 88% with 1 Gy, 90% with 5 Gy, and 92% with 10 Gy, respectively and 99% in case of annealing time for 4 hour. It is feasible to use OSLDs for dose evaluation in Co-60 Gamma-rays when considering the uncertainty on the procedure according to the irradiated dose.
Purpose: The serologic diagnosis of rotaviral infections is not commonly used in clinical practice, but is used in seroepidemiologic studies. In this study, the usefulness of Escherichia coli-expressed recombinant VP6 proteins of group A rotavirus in the serodiagnosis of rotavirus infections by ELISA was evaluated. Methods: The recombinant VP6 proteins of group A rotavirus expressed in E. coli Rosetta II strain were purified and identified. One hundred sera from 22 children (4 healthy neonates, 13 healthy children, and 5 immunocompromised children) who had serial sera samples prior to and after rotavirus infections were provided by the Gyeongsang National University Hospital, a member of the National Biobank of Korea. IgG, IgA, and IgM antibodies against rVP6 were analyzed by ELISA in all of the patients and Western blot analysis in 4 neonates. Results: ELISA tests using rVP6 proteins of group A rotavirus as antigen revealed that IgG, IgA, and IgM antibodies increased after rotaviral infections in most neonates and healthy children. IgG antibodies also increased after rotaviral infections in most immunocompromised children without an adequate increase in IgM or IgA antibodies. Western blot analysis in four neonates revealed very early IgM antibody responses, even in the sera with low optical densities in ELISA tests. Conclusion: Our study showed that ELISA using rVP6 as an antigen is a valid diagnostic tool for seroepidemiologic studies of rotavirus infections and Western blot analysis is a sensitive test in detecting IgG, IgA, and and IgM antibodies in patients with rotavirus infections.
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70