• 제목/요약/키워드: Diagnostic Tool

검색결과 1,069건 처리시간 0.027초

X선관의 실효초점 측정에 관한 고찰 (Measurement of Focal Spot Size of Heavy Loaded X-ray Tubes)

  • 장광현;임오수;김형기;송창욱;정경모;정환
    • 대한방사선기술학회지:방사선기술과학
    • /
    • 제16권1호
    • /
    • pp.101-106
    • /
    • 1993
  • In order to assure safety of both patient and operator, and to provide uniform quality radiographs, it is necessary to perform periodic calibration of diagnostic X-ray equipment. A basic parameter of diagnostic equipment's and its image sharpness is the size(and shape the energy distribution) of the focal spot as viewed along the central X-ray beam. This size determines the resolution possible with the equipment and also determines the heat characteristics of an anode. A fine focus tube gives high resolution but causes high local heating of target. In past, the pin-hole and star pattern image measurement for evaluation of resolution have been widely used, but it produced blurring and inaccuracy of image. So newly inverted Ug-meter has advantage in more convenient measurement method and less out-put bias than other image measurement. The authors intended to compare measured focal size between Ug-meter and focal spot test tool, changed state from setting to now of units.

  • PDF

진단검사의 특성 평가를 위한 Receiver Operating Characteristic (ROC) 곡선의 활용 (Application of Receiver Operating Characteristic (ROC) Curve for Evaluation of Diagnostic Test Performance)

  • 박선일;오태호
    • 한국임상수의학회지
    • /
    • 제33권2호
    • /
    • pp.97-101
    • /
    • 2016
  • In the field of clinical medicine, diagnostic accuracy studies refer to the degree of agreement between the index test and the reference standard for the discriminatory ability to identify a target disorder of interest in a patient. The receiver operating characteristic (ROC) curve offers a graphical display the trade-off between sensitivity and specificity at each cutoff for a diagnostic test and is useful in assigning the best cutoff for clinical use. In this end, the ROC curve analysis is a useful tool for estimating and comparing the accuracy of competing diagnostic tests. This paper reviews briefly the measures of diagnostic accuracy such as sensitivity, specificity, and area under the ROC curve (AUC) that is a summary measure for diagnostic accuracy across the spectrum of test results. In addition, the methods of creating an ROC curve in single diagnostic test with five-category discrete scale for disease classification from healthy individuals, meaningful interpretation of the AUC, and the applications of ROC methodology in clinical medicine to determine the optimal cutoff values have been discussed using a hypothetical example as an illustration.

변증 설문지 문항을 통해 살펴 본 알레르기 비염 환자의 특성 (Characteristics of Patients with Allergic Rhinitis through the Pattern Questionnaire Items)

  • 손재웅;이규진;장보형;장수빈;고성규;최인화
    • 대한예방한의학회지
    • /
    • 제18권3호
    • /
    • pp.81-90
    • /
    • 2014
  • Objective : We performed a clinical study to investigate pattern characteristics in persistent allergic rhinitis depending on Korean Medicine pattern questionnaire items as a pattern identification diagnostic tool. Method : 32 patients with persistent allergic rhinitis were asked to interview with doctor of Korean Medicine and perform the 4 pattern questionnaires(Cold-Heat Pattern, Phlegm Pattern, Yin Deficiency pattern, bloodstasis pattern). Then, we analyzed the response rate of each pattern questionnaires. Results : After diagnosis of Korean Medicine Doctor's pattern identification, 17 individual items have higher response rate, 7 of 17 items have a common tendency in allergic rhinitis. The other 8 of 10 items belong to Lung qi deficiency cold and Lung-spleen qi deficiency group, these have higher tendency of deficiency. In bloodstasis pattern questionnaires, we don't decide the tendency of patients with allergic rhinitis. Conclusion : The result may provide that we don't use Korean Medicine pattern questionnaires as a major tool in the pattern identification of allergic rhinitis. Continuous studies are needed to develop the standardized pattern identification diagnostic tool.

학습상황진단도구 개발 사례 연구 : K대학교를 중심으로 (A Study on the Development and Validation of Learning Status Diagnostic Tool)

  • 이성아
    • 기독교교육논총
    • /
    • 제64권
    • /
    • pp.409-444
    • /
    • 2020
  • 본 연구는 대학의 학업 활동에 영향을 미치는 요인들에 대하여 정확하게 진단하기 위한 측정 도구를 개발하여 제안하고자 하는 것이다. 이를 위해 대학생들의 학업 생활에 영향을 미치는 요인들로 평가 영역을 구성하고, 그 도출된 영역들을 진단할 수 있는 도구를 개발하여 학생들의 대학생활 적응에 적절한 도움을 줄 수 있는 근거를 마련하고자 하였다. 이 도구는 선행 연구를 통해 문항을 구성하였고, 델파이 연구를 통해 초안을 개발하였다. 개발된 도구는 K대학의 신입생 182명의 응답값을 분석하여 신뢰도와 타당성을 검증하였다. 분석의 결과 신뢰도는 평가 영역별로 신뢰도 .869~.955로 높은 신뢰도를 보였으며, 문항-총점간 상관분석의 결과 대부분의 문항이 .30~.80사이로 적절하였고, .80이 넘는 문항은 다중공선성값 10 이하로 적절하였다. 탐색적 요인분석의 결과로 도출된 요인과 문항간의 관계를 토대로 확인적 요인분석을 실시 및 검증하여 최종도구 개발 및 제안하였다.

New Diagnostic Tool for Far Lateral Lumbar Disc Herniation : The Clinical Usefulness of 3-Tesla Magnetic Resonance Myelography Comparing with the Discography CT

  • Kim, Duk-Gyu;Eun, Jong-Pil;Park, Jung-Soo
    • Journal of Korean Neurosurgical Society
    • /
    • 제52권2호
    • /
    • pp.103-106
    • /
    • 2012
  • Objective : To prospectively assess the diagnostic and clinical value of a new technique (3-tesla magnetic resonance myelography, 3T MRM) as compared to computed tomographic discography (disco-CT) in patients with far lateral disc herniation. Methods : We evaluated 3T MRM and disco-CT of 25 patients, whom we suspected of suffering from far lateral disc herniation. Using an assessment scale, 4 observers examined independently both 3T MRM and disco-CT images. We analyzed observer agreement and the accentuation of each image. Results : We found complete matching, and observer agreement, between high resolution images of 3T MRM and disco-CT for diagnosing far lateral disc herniation. Conclusion : We think noninvasive 3T MRM is an appropriate diagnostic tool for far lateral disc herniation as compared to disco-CT.

전리수소 영역의 물리량 측정을 위한 방출선 모형연구 (MODELING FOR PROBING THE PHYSICAL STATES OF HII REGIONS)

  • 성현일
    • 천문학논총
    • /
    • 제26권1호
    • /
    • pp.25-35
    • /
    • 2011
  • A diagnostic tool has been proposed to convert the observed surface distribution of hydrogen recombination line intensities into the radial distributions of the electron temperature and the density in HII regions. The observed line intensity is given by an integral of the volume emission coefficient along the line of sight, which comprises the Abel type integral equation for the volume emission coefficient. As the emission coefficient at a position is determined by the temperature and density of electrons at the position, the local emission coefficient resulted from the solution of the Abel equation gives the radial distribution of the temperature and the density. A test has been done on the feasibility of our diagnostic approach to probing of HII regions. From model calculations of an HII region of pure hydrogen, we have theoretically generated the observed surface brightness of hydrogen recombination line intensities and analyzed them by our diagnostic tool. The resulting temperatures and densities are then compared with the model values. For this case of uniform density, errors in the derived density are not large at all the positions. For the electron temperature, however, the largest errors appear at the central part of the HII region. The errors in the derived temperature decrease with the radial distance, and become negligible in the outer part of the model HII region.

Novel Heptaplex PCR-Based Diagnostics for Enteric Fever Caused by Typhoidal Salmonella Serovars and Its Applicability in Clinical Blood Culture

  • Hyun-Joong Kim;Younsik Jung;Mi-Ju Kim;Hae-Yeong Kim
    • Journal of Microbiology and Biotechnology
    • /
    • 제33권11호
    • /
    • pp.1457-1466
    • /
    • 2023
  • Enteric fever is caused by typhoidal Salmonella serovars (Typhi, Paratyphi A, Paratyphi B, and Paratyphi C). Owing to the importance of Salmonella serovars in clinics and public hygiene, reliable diagnostics for typhoidal serovars are crucial. This study aimed to develop a novel diagnostic tool for typhoidal Salmonella serovars and evaluate the use of human blood for clinically diagnosing enteric fever. Five genes were selected to produce specific PCR results against typhoidal Salmonella serovars based on the genes of Salmonella Typhi. Heptaplex PCR, including genetic markers of generic Salmonella, Salmonella enterica subsp. enterica, and typhoidal Salmonella serovars, was developed. Typhoidal Salmonella heptaplex PCR using genomic DNAs from 200 Salmonella strains (112 serovars) provided specifically amplified PCR products for each typhoidal Salmonella serovar. These results suggest that heptaplex PCR can sufficiently discriminate between typhoidal and non-typhoidal Salmonella serovars. Heptaplex PCR was applied to Salmonella-spiked blood cultures directly and provided diagnostic results after 12- or 13.5-h blood culture. Additionally, it demonstrated diagnostic performance with colonies recovered from a 6-h blood culture. This study provides a reliable DNA-based tool for diagnosing typhoidal Salmonella serovars that may be useful in clinical microbiology and epidemiology.

A Bayesian Diagnostic for Influential Observations in LDA

  • Lim, Jae-Hak;Lee, Chong-Hyung;Cho, Byung-Yup
    • 품질경영학회지
    • /
    • 제28권1호
    • /
    • pp.119-131
    • /
    • 2000
  • This paper suggests a new diagnostic measure for detecting influential observations in linear discriminant analysis (LDA). It is developed from a Bayesian point of view using a default Bayes factor obtained from the imaginary training sample methodology. The Bayes factor is taken as a criterion for testing homogeneity of covariance matrices in LDA model. It is noted that the effect of an observation over the criterion is fully explained by the diagnostic measure. We suggest a graphical method that can be taken as a tool for interpreting the diagnostic measure and detecting influential observations. Performance of the measure is examined through an illustrative example.

  • PDF

A Bayesian Diagnostic Measure and Stopping Rule for Detecting Influential Observations in Discriminant Analysis

  • Kim, Myung-Cheol;Kim, Hea-Jung
    • Journal of the Korean Statistical Society
    • /
    • 제29권3호
    • /
    • pp.337-350
    • /
    • 2000
  • This paper suggests a new diagnostic measure and a stopping rule for detecting influential observations in multiple discriminant analysis (MDA). It is developed from a Bayesian point of view using a default Bayes factor obtained from the fractional Bayes factor methodology. The Bayes factor is taken as a discriminatory information in MDA. It is shown that the effect of an observation over the discriminatory information is fully explained by the diagnostic measure. Based on the measure, we suggest a stopping rule for detecting influential observations in a given training sample. As a tool for interpreting the measure a graphical method is sued. Performance of the method is used. Performance of the method is examined through two illustrative examples.

  • PDF

Chromosomal Microarray Testing in 42 Korean Patients with Unexplained Developmental Delay, Intellectual Disability, Autism Spectrum Disorders, and Multiple Congenital Anomalies

  • Lee, Sun Ho;Song, Wung Joo
    • Genomics & Informatics
    • /
    • 제15권3호
    • /
    • pp.82-86
    • /
    • 2017
  • Chromosomal microarray (CMA) is a high-resolution, high-throughput method of identifying submicroscopic genomic copy number variations (CNVs). CMA has been established as the first-line diagnostic test for individuals with developmental delay (DD), intellectual disability (ID), autism spectrum disorders (ASDs), and multiple congenital anomalies (MCAs). CMA analysis was performed in 42 Korean patients who had been diagnosed with unexplained DD, ID, ASDs, and MCAs. Clinically relevant CNVs were discovered in 28 patients. Variants of unknown significance were detected in 13 patients. The diagnostic yield was high (66.7%). CMA is a superior diagnostic tool compared with conventional karyotyping and fluorescent in situ hybridization.