• Korean Journal of Clinical Laboratory Science
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• v.38 no.1
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• pp.16-21
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• 2006

Parallel testing means ordering a number of tests at the same time so abnormalities in any of the tests can be found quickly and used in making the diagnosis. This is a good medical strategy to eliminate diseases and it is relatively inexpensive if all the tests are potential sources of information and performed on the same analyzer. In regression, the equation for the straight line is recast as y = bx + a. This change in terminology leads to confusion. Here a is the y-intercept or constant and b is the coefficient or slope of the line. A few more words of caution about regression - as in all of statistics there are certain assumptions: the x value is a true measure, both X and Y distributions are normal, and homoscedasticity, i.e., the variance of y is the same for each value of x. In this study the linearity classification made by different scientists were always in agreement. Typical examples of curves that were considered linear are presented in Fig. 1-5. Because these automated procedures values were usually within five percent of each other the curvature could be easily detected. The plot of the WBC, RBC, hemoglobin, hematocrit and platelet concentrations from approximately 74.4 to $0{\times}10^3/{\mu}L$ and $80.4-0{\times}10^3/{\mu}L$, $5.6-0{\times}10^6/{\mu}L$ and $6.1-0{\times}1106/{\mu}L$, 18.3-0 g/dL and 19.0-0 g/dL, 54.1-0% and 56.8-0% and 642.0 to $0.03{\times}10^3{\mu}L$ and $754.0-0{\times}10^3/{\mu}L$ on the ADVIA 2120 C Versus and A and B typical of an acceptable linear study as shown in Fig. 1-5. The grand mean of R2, intercept and slope is 0.99898, 0.99459 and 1.54626.

• Journal of Biomedical Engineering Research
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• v.20 no.2
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• pp.173-182
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• 1999

Contrast-enhanced CT has an important role in assessing liver lesions, the optimal protocol to get most effective result is not clear. The mein goal when deciding injention protocol is to optimize lesion detectability with rapid scanning when lesion to liver contrast is maximum. For this purpose, we developed a physiological model of the contrast medium enhancement based on the compartment modeling and pharmacokinetics. Blood supply to liver is achieved in two paths. This dual supply characteristic distinguishes the CT enhancement of liver from that of the other organs. The first path is by hepatic artery and to second, by portal vein. However, it is assumed that only gepatic artery can supply blood to hepatocellular carcinoma(HCC) compartment, thus, the difference of contrast enhancement is resulted between normal liver tissue and hepatic tumor. By solving differential equations for each compartment simultaneously using the computer program Matlab, CT contrast-enhancement curves were simulated. The simulated enhancement curves for aortic, hepatic, portal vein, and HCC compartments were compared with the mean enhancement curves from 24 patients exposed to the same protocols as the simulation. These enhancement curves showed a good agreement. Furthermore, we simulated lesion-to-liver curves for various injection protocols, and the effects were analyzed. The variables to be considered in the injection protocol were injection rate, dose, and concentration of contrast material. These data may help to optimize scanning protocols for better diagnosis.

• Imaging Science in Dentistry
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• v.50 no.3
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• pp.227-236
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• 2020

Purpose: Image artifacts caused by patient motion cause problems in cone-beam computed tomography (CBCT) because they lead to distortion of the 3-dimensional reconstruction. This prospective study was performed to quantify patient movement during CBCT acquisition and its influence on image quality. Materials and Methods: In total, 412 patients receiving CBCT imaging were equipped with a wireless head sensor system that detected inertial, gyroscopic, and magnetometric movements with 6 dimensions of freedom. The type and amplitude of movements during CBCT acquisition were evaluated and image quality was rated in 7 different anatomical regions of interest. For continuous variables, significance was calculated using the Student t-test. A linear regression model was applied to identify associations of the type and extent of motion with image quality scores. Kappa statistics were used to assess intra- and inter-rater agreement. Chi-square testing was used to analyze the impact of age and sex on head movement. Results: All CBCT images were acquired in a 10-month period. In 24% of the investigations, movement was recorded (acceleration: >0.10 [m/s²]; angular velocity: >0.018 [°/s]). In all examined regions of interest, head motion during CBCT acquisition resulted in significant impairment of image quality (P<0.001). Movement in the horizontal and vertical axes was most relevant for image quality (R²>0.7). Conclusion: Relevant head motions during CBCT imaging were frequently detected, leading to image quality loss and potentially impairing diagnosis and therapy planning. The presented data illustrate the need for digital correction algorithms and hardware to minimize motion artefacts in CBCT imaging.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.169-173
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• 2015

This study is to predict the life exponent by measuring, over 7 years, the insulation resistance of high-voltage cables in 22 kV operation for 13 years. We found out the lifetime index in order to determine the time-dependent trend of deteriorating performance of power cables. The insulation resistances decreased according to elapsed time. We found that: the initial measurements of the cable systems were in agreement with the deterioration properties of the Arrhenius Law. By analyzing the life curve of the cable system, we also verified that the value of the life exponent (n) in the v-t characteristics defined by Weibull distribution has values from 10 to 11. When designing the cable system, the initial value of life exponent was chosen as 9 without any grounding. We have verified that the theoretical grounding based on the design safety of n=9 was actually the best one available. In the short term, we apply our research result to the diagnosis and evaluation of the power cables. In the long run, however, we plan to reduce the cost of the installation and management of cable systems in operation at power stations.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.321-331
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• 2011

Mycobacterium bovis, a member of the M. tuberculosis complex (MTC), is the causative agent of bovine tuberculosis. Detection of M. bovis and M. tuberculosis using conventional culture- and biochemical-based assays is time-consuming. Therefore, a simple and sensitive molecular assay for rapid detection would be of great help in specific situations such as faster diagnosis of bovine tuberculosis (bTB) infection in the abattoirs. We developed a novel multiplex real-time PCR assay which was applied directly to biological samples with evidence of bTB and it was allowed to differentiate between M. bovis and M. tuberculosis. The primers and TaqMan probes were designed to target the IS1081 gene, the multi-copy insertion element in the MTC and the 12.7-kb fragment which presents in M. tuberculosis, not in the M. bovis genome. The assay was optimized and validated by testing 10 species of mycobacteria including M. bovis and M. tuberculosis, and 10 other bacterial species such as Escherichia coli, and cattle lymph nodes (n=113). The tests identified 96.4% (27/28) as M. bovis from the MTC-positive bTB samples using conventional PCR for specific insertion elements IS1081. And MTC-negative bTB samples (n=85) were tested using conventional PCR and the real-time PCR. When comparative analyses were conducted on all bovine samples, using conventional PCR as the gold standard, the relative accuracy of real-time PCR was 99.1%, the relative specificity was 100%, and the agreement quotient (kappa) was 0.976. The detection limits of the real-time PCR assays for M. bovis and M. tuberculosis genomic DNA were 10 fg and 0.1 pg per PCR reaction, respectively. Consequently, this multiplex real-time PCR assay is a useful diagnotic tool for the identification of MTC and differentiation of M. bovis and M. tuberculosis, as well as the epidemiologic surveillance of animals slaughtered in abattoir.

• The Korean Society of Law and Medicine
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• v.16 no.2
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• pp.3-26
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• 2015

Recently, Practicing of ghost surgery and duty of informed consent of doctors have become a big issue in the medical dispute and lawsuits. The ground of admitting the informed consent and the agreement(self-determination of patients) can be based on the dignity of man and the right to pursue his happiness guaranteed under Article 10 of the constitution in theory. However there are no explicit legal regulations on the duty of the informed consent and there is no substantive legal enactment on the informed consent, but there is a collision between self-determination of patients and the discretionary power of doctors. If the discretionary power on the duty of the informed consent was extended it may result in the infringement of the right of surgical patients, so called arbitrary medical treatment. Relating to this issue, New Jersey Supreme Court held that a patient has the right to determine not only whether surgery is to be performed on him, but also who shall perform it. Moreover it held that a surgeon who operates without the patient's consent engages in the unauthorized touching of another and, thus, commits a battery'. But there are no ghost surgery cases adopting battery theory in Korea, and professional negligence has been considered rather than the battery, regarding an absence of hostile intent to injure patient. Supreme Court of Korea held that a doctor who operates a medical procedure without the patient's valid prior consent based on wrong diagnosis commits professional negligence resulting in injury, and the patient's invalid consent do not preclude wrongfulness'. However, if a health care provider conducts a completely non-consensual treatment or substitute surgeon without consent, the action should be plead in battery, not negligence, but if a health care provider violate his duty of care in obtaining the consent of the patient by failing to disclosure all relevant information (risks) that a reasonable person would deem significant in making a decision to have the procedure, the action should be plead in negligence, not battery. Therefore, the scope of patients' self-determination can be protected by stating clearly the scope of the duty of the informed consent and the exemption of the informed consent legislatively, it is considered that it is valid to legislate the limitation of the discretionary power.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.3
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• pp.113-128
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• 2019

Objectives To evaluate the pattern identification tool for knee osteoarthritis and to investigate the relationship between pattern identification tool and knee ROM (range of motion), VAS (visual analog scale) and WOMAC (Western Ontario & McMaster Universities osteoarthritis index). Methods We studied 50 patients who are diagnosed as degenerative osteoarthritis. With one patient dropping out, total of 49 patient went through pattern identification tool. Re-test of the pattern identification tool was implemented after about a week. The reliability was analyzed by calculating ICC (intraclass correlation coefficient). Also, reliability of each pattern identification score was calculated along with influence factor and correlation between knee ROM, VAS and WOMAC. Results Reliability of the pattern identification tool was evaluated as 'poor agreement beyond chance' with ICC value of 0.396. Reliablility of each pattern identification score was calculated and four out of five were measured 'good' with one 'moderate' reliability. Two of inter-item consistency were 'good', two were 'acceptable' and one was 'questionable'. Correlation between each pattern identification and knee ROM showed 'clear negative linear relationship' with two patterns. VAS showed 'clear positivie linear relationship' with all five patterns. WOMAC showed 'positivie linear relationship' with all five patterns. Conclusions According to the results, pattern identification tool for knee osteoarthritis seems to have meaningful relationship with other agnedas. Also, further research is needed to develop the tool.

• Journal of Climate Change Research
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• v.2 no.2
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• pp.79-91
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• 2011

In order to study interactions between climate change and air quality, a modeling system including the downscaling scheme has been developed in the integrated manner. This research focuses on the development of a downscaling method to utilize CCSM3 outputs as the initial and boundary conditions for the regional climate model, MM5. Horizontal/vertical interpolation was performed to convert from the latitude/longitude and hybrid-vertical coordinate for the CCSM3 model to the Lambert-Conformal Arakawa-B and sigma-vertical coordinate for the MM5 model. A variable diagnosis was made to link between different variables and their units of CCSM and MM5. To evaluate the dynamic downscaling performance of this study, spatial distributions were compared between outputs of CCSM/MM5 and NRA/MM5 and statistic analysis was conducted. Temperature and precipitation patterns of CCSM/MM5 in summer and winter showed a similar pattern with those of observation data in East Asia and the Korean Peninsula. In addition, statistical analysis presented that the agreement index (AI) is more than 0.9 and correlation coefficient about 0.9. Those results indicate that the dynamic downscaling system built in this study can be used for the research of interaction between climate change and air quality.

• Journal of Auto-vehicle Safety Association
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• v.10 no.4
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• pp.7-12
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• 2018

Injury mechanisms of lower extremity injuries in motor vehicle accidents are focused on fractures, sprains, and contusions. The purpose of this study is to evaluate the analysis of lower extremity injury mechanism in occupant motor vehicle accident by using Hospital Information System (HIS) and reconstruction program, based on the materials related to motor vehicle accidents. Among patients who visited the emergency department of Wonju Severance Christian Hospital due to motor vehicle accidents from August 2012 to February 2014, we collected data on patients with agreement for taking the damaged vehicle's photos. After obtaining the verbal consent from the patient, we asked about the cause of the accident, information on vehicle involved in the accident, and the location of car repair shop. The photos of the damaged vehicle were taken on the basis of front, rear, left side and right side. Damage to the vehicle was presented using the CDC code by analytical study of photo-images of the damaged vehicle, and a trauma score was used for medical examination of the severity of the patient's injury. Among the 1,699 patients due to motor vehicle crashes, 88 (5.2%) received a diagnosis of lower extremity fracture and 141 (8.3%) were the severe who had ISS over 15. Nevertheless during 19 months for research, it was difficult to build up in-depth database about motor vehicle crashes. It has a limitation on collecting data because not only the system for constructing database about motor vehicle crash is not organized but also the process for demanding materials is not available due to prevention of personal information. For accurate analysis of the relationship between occupant injury and vehicle damage in motor vehicle crashes, build-up of an in-depth database through carrying out various policies for motor vehicle crashes is necessary for sure.

• Korean Journal of Radiology
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• v.25 no.6
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• pp.575-588
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• 2024

Objective: Differentiating intracranial aneurysms from normal variants using CT angiography (CTA) or MR angiography (MRA) poses significant challenges. This study aimed to evaluate the efficacy of proton-density MRA (PD-MRA) compared to high-resolution time-of-flight MRA (HR-MRA) in diagnosing aneurysms among patients with indeterminate findings on conventional CTA or MRA. Materials and Methods: In this retrospective analysis, we included patients who underwent both PD-MRA and HR-MRA from August 2020 to July 2022 to assess lesions deemed indeterminate on prior conventional CTA or MRA examinations. Three experienced neuroradiologists independently reviewed the lesions using HR-MRA and PD-MRA with reconstructed voxel sizes of 0.25³ mm³ or 0.2³ mm³, respectively. A neurointerventionist established the gold standard with digital subtraction angiography. We compared the performance of HR-MRA, PD-MRA (0.25³-mm³ voxel), and PD-MRA (0.2³-mm³ voxel) in diagnosing aneurysms, both per lesion and per patient. The Fleiss kappa statistic was used to calculate inter-reader agreement. Results: The study involved 109 patients (average age 57.4 ± 11.0 years; male:female ratio, 11:98) with 141 indeterminate lesions. Of these, 78 lesions (55.3%) in 69 patients were confirmed as aneurysms by the reference standard. PD-MRA (0.25³-mm³ voxel) exhibited significantly higher per-lesion diagnostic performance compared to HR-MRA across all three readers: sensitivity ranged from 87.2%-91.0% versus 66.7%-70.5%; specificity from 93.7%-96.8% versus 58.7%-68.3%; and accuracy from 90.8%-92.9% versus 63.8%-69.5% (P ≤ 0.003). Furthermore, PD-MRA (0.25³-mm³ voxel) demonstrated significantly superior per-patient specificity and accuracy compared to HR-MRA across all evaluators (P ≤ 0.013). The diagnostic accuracy of PD-MRA (0.2³-mm³ voxel) surpassed that of HR-MRA and was comparable to PD-MRA (0.25³-mm³ voxel). The kappa values for inter-reader agreements were significantly higher in PD-MRA (0.820-0.938) than in HR-MRA (0.447-0.510). Conclusion: PD-MRA outperformed HR-MRA in diagnostic accuracy and demonstrated almost perfect inter-reader consistency in identifying intracranial aneurysms among patients with lesions initially indeterminate on CTA or MRA.