• 제목/요약/키워드: False Positive Incidence Rate

검색결과 9건 처리시간 0.024초

갑상선결절(甲狀腺結節)에서의 흡인세포학적(吸引細胞學的) 소견(所見)과 병리조직학적(病理組織學的) 진단(診斷)에 대한 비교연구(比較硏究) (Histopathologic Comparative Study of Aspiration Biopsy Cytology from 139 Thyroid Nodules)

  • 김광철;왕희정;서연림;장석효;이혁상
    • 대한두경부종양학회지
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    • 제8권2호
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    • pp.97-105
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    • 1992
  • One hundred and thirty-nine thyroid nodules were evaluated by aspiration biopsy cytology (ABC) and were compared with the postoperative histologic diagnosis during the period from May 1, 1986 through Aug. 31, 1992. The correlation betwen the two diagnoses proved to be comparable with a low incidence of false-negative diagnoses, but with a relatively high incidence of false-positive ones. The sensitivity was 93.5%, specificity 89.6%, false-negative rate 6.5%, false-positive rate 10.4%, positive predictability 87.9%, negative predictability 94.5%, and overall diagnostic accuracy 91.4%.

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Statistical Analysis of Count Rate Data for On-line Seawater Radioactivity Monitoring

  • Lee, Dong-Myung;Cong, Binh Do;Lee, Jun-Ho;Yeo, In-Young;Kim, Cheol-Su
    • Journal of Radiation Protection and Research
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    • 제44권2호
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    • pp.64-71
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    • 2019
  • Background: It is very difficult to distinguish between a radioactive contamination source and background radiation from natural radionuclides in the marine environment by means of online monitoring system. The objective of this study was to investigate a statistical process for triggering abnormal level of count rate data measured from our on-line seawater radioactivity monitoring. Materials and Methods: Count rate data sets in time series were collected from 9 monitoring posts. All of the count rate data were measured every 15 minutes from the region of interest (ROI) for $^{137}Cs$ ($E_{\gamma}=661.6keV$) on the gamma-ray energy spectrum. The Shewhart ($3{\sigma}$), CUSUM, and Bayesian S-R control chart methods were evaluated and the comparative analysis of determination methods for count rate data was carried out in terms of the false positive incidence rate. All statistical algorithms were developed using R Programming by the authors. Results and Discussion: The $3{\sigma}$, CUSUM, and S-R analyses resulted in the average false positive incidence rate of $0.164{\pm}0.047%$, $0.064{\pm}0.0367%$, and $0.030{\pm}0.018%$, respectively. The S-R method has a lower value than that of the $3{\sigma}$ and CUSUM method, because the Bayesian S-R method use the information to evaluate a posterior distribution, even though the CUSUM control chart accumulate information from recent data points. As the result of comparison between net count rate and gross count rate measured in time series all the year at a monitoring post using the $3{\sigma}$ control charts, the two methods resulted in the false positive incidence rate of 0.142% and 0.219%, respectively. Conclusion: Bayesian S-R and CUSUM control charts are better suited for on-line seawater radioactivity monitoring with an count rate data in time series than $3{\sigma}$ control chart. However, it requires a continuous increasing trend to differentiate between a false positive and actual radioactive contamination. For the determination of count rate, the net count method is better than the gross count method because of relatively a small variation in the data points.

자궁경부 세포진검사 및 자궁경부 확대촬영술의 비교연구 (A Comparative Study of Cytology & Cervicography for Cervical Cancer Screening)

  • 하중규;윤달식;이준기;최창근;우양례;이진수;이윤희;박재영;이영임
    • 한국건강관리협회지
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    • 제2권1호
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    • pp.27-37
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    • 2004
  • Background 'For many years, the Papanicolaou smear has been used to detect pre-malignant and malignant disease of the cervix. Although cervical cytology screening programmes have result in the reduction of cervical cancer incidence and mortality, Pap smear have been subjected to intense scrutiny and criticism in recent years. So cervicography is introduced. Cervicography is an adjunct method of cervical cancer screening intended to complement Papanicolaou smear. Cervicography involve obtaining and evaluating a photographic image of the cervix. The purpose of this investigation was to evaluate the efficacy of Papanicolaou smear and cervicography in cervical cancer screening. Materials & Methods : This study population was of 74 women, who visited department of obstetrics & Gynecology, Korea association of Health Promotion Chung-nam branch from January, 20O2 to October, 2003. All patients were taken Pap smear before cervicography, and then two cervicography was obtained with applying5% acetic acid. Those women in whom abnormalities were detected by either test subsequently obtained histologic specimen. Results : 1. The sensitivity and the specificity of Papanicolaou smear was 92.1% and 72.7%respectively.2. The sensitivity and the specificity of cervicography was 88.9% and 54.5% respectively. The false negative rate, and false positive rate of Papanicolaou smear were 7.9%, 27.2% respectively. The false negative rate, and false positive rate of cervicography were 11.1%,45.5% respectively. Conclusions . Papanicolaou smear is a useful method and an important tool for detecting cervical cancer. However when Papanicolaou smear and Cervicograpy is used together, the sensitivity is higher than for Papanicolaou smear used alone.

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불임 검사시 자궁난관 조영술의 진단 정확도 (The Accuracy of Hysterosalpingography for Evaluating Female Infertility)

  • 박준철;김종인;이정호
    • Clinical and Experimental Reproductive Medicine
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    • 제32권3호
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    • pp.223-230
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    • 2005
  • Objective: This study was performed to evaluate the accuracy of hysterosalpingography (HSG) for evaluating female infertility patients by comparison with hysteroscopic and laparoscopic examination. Methods and Material: Total 219 infertile patients were retrospectively analyzed between January 1, 2002 and December 31, 2003. Ninety seven patients (44.3%) were primary infertility, 122 patients (55.7%) were secondary infertility. We performed hysteroscopic and laparoscopic examination on next cycle when HSG revealed any abnormal finding, and 3~6 cycles later if HSG was normal. Results: The accuracy of HSG was 65.2% compared with hysteroscopic examination (sensitivity 88.4%, specificity 46.4%, false positive rate 53.6%, false negative rate 11.6%). The most common abnormal finding of hysteroscopy was uterine synechia (67.4%) followed by endometrial polyp, uterine anomaly (e.g. uterine septum), endometrial hyperplasia. Compared with laparoscopic examination, the accuracy of HSG was 76.9% (sensitivity 98.9%, specificity 70.6%, +LR 3.36, -LR 0.02). The positive predictive value of normal patent tube was excellent (99.6%) but that of proximal tubal blockage was only 46.7%. The unilateral tubal obstruction of HSG was poor accuracy (+LR 3.85 -LR 0.68) and 70% of those was patent by laparoscopic examination. Laparoscopic examination also revealed that 53% of patients had peritubal adhesion and 37% of patients has additional pelvic findings, especially endometriosis. Among the patients had normal HSG, 53.5% patients with normal ultrasonography was diagnosed endometriosis (25.6% of them had endometriosis stage I-II). Conclusion: Normal HSG shows a high negative predictive value. Nevertheless, the incidence of associated pelvic disease in the normal HSG group is high enough to warrant diagnostic laparoscopy if nonsurgical treatment is unsuccessful. Because HSG has poor accuracy in predicting distal tubal blockage and peritubal adhesion, and poor positive predictive value of proximal tubal blockage, laparoscopic examination could be considered in abnormal HSG group.

Surveillance Evaluation of the National Cancer Registry in Sabah, Malaysia

  • Jeffree, Saffree Mohammad;Mihat, Omar;Lukman, Khamisah Awang;Ibrahim, Mohd Yusof;Kamaludin, Fadzilah;Hassan, Mohd Rohaizat;Kaur, Nirmal;Myint, Than
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권7호
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    • pp.3123-3129
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    • 2016
  • Background: Cancer is the fourth leading cause of death in Sabah Malaysia with a reported age-standardized incidence rate was 104.9 per 100,000 in 2007. The incidence rate depends on non-mandatory notification in the registry. Under-reporting will provide the false picture of cancer control program effectiveness. The present study was to evaluate the performance of the cancer registry system in terms of representativeness, data quality, simplicity, acceptability and timeliness and provision of recommendations for improvement. Materials and Methods: The evaluation was conducted among key informants in the National Cancer Registry (NCR) and reporting facilities from Feb-May 2012 and was based on US CDC guidelines. Representativeness was assessed by matching cancer case in the Health Information System (HIS) and state pathology records with those in NCR. Data quality was measured through case finding and re-abstracting of medical records by independent auditors. The re-abstracting portion comprised 15 data items. Self-administered questionnaires were used to assess simplicity and acceptability. Timeliness was measured from date of diagnosis to date of notification received and data dissemination. Results: Of 4613 cancer cases reported in HIS, 83.3% were matched with cancer registry. In the state pathology centre, 99.8% was notified to registry. Duplication of notification was 3%. Data completeness calculated for 104 samples was 63.4%. Registrars perceived simplicity in coding diagnosis as moderate. Notification process was moderately acceptable. Median duration of interval 1 was 5.7 months. Conclusions: The performances of registry's attributes are fairly positive in terms of simplicity, case reporting sensitivity, and predictive value positive. It is moderately acceptable, data completeness and inflexible. The usefulness of registry is the area of concern to achieve registry objectives. Timeliness of reporting is within international standard, whereas timeliness to data dissemination was longer up to 4 years. Integration between existing HIS and national registration department will improve data quality.

수술 동영상에서의 인공지능을 사용한 출혈 검출 연구 (A Study on the Bleeding Detection Using Artificial Intelligence in Surgery Video)

  • 정시연;김영재;김광기
    • 대한의용생체공학회:의공학회지
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    • 제44권3호
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    • pp.211-217
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    • 2023
  • Recently, many studies have introduced artificial intelligence systems in the surgical process to reduce the incidence and mortality of complications in patients. Bleeding is a major cause of operative mortality and complications. However, there have been few studies conducted on detecting bleeding in surgical videos. To advance the development of deep learning models for detecting intraoperative hemorrhage, three models have been trained and compared; such as, YOLOv5, RetinaNet50, and RetinaNet101. We collected 1,016 bleeding images extracted from five surgical videos. The ground truths were labeled based on agreement from two specialists. To train and evaluate models, we divided the datasets into training data, validation data, and test data. For training, 812 images (80%) were selected from the dataset. Another 102 images (10%) were used for evaluation and the remaining 102 images (10%) were used as the evaluation data. The three main metrics used to evaluate performance are precision, recall, and false positive per image (FPPI). Based on the evaluation metrics, RetinaNet101 achieved the best detection results out of the three models (Precision rate of 0.99±0.01, Recall rate of 0.93±0.02, and FPPI of 0.01±0.01). The information on the bleeding detected in surgical videos can be quickly transmitted to the operating room, improving patient outcomes.

디피리다몰 부하 $^{99m}Tc$-MIBI 심근 SPECT 극성결손지도를 이용한 관동맥질환 진단의 남녀 비교 (Comparison of Diagnostic Accuracy for Detecting Coronary Artery Disease of Dipyridamole $^{99m}Tc$-MIBI Myocardial SPECT and It's Defect Map between Men and Women)

  • 배상균;이동수;오병희;정준기;이명묵;박영배;이명철;서정돈;이영우;고창순
    • 대한핵의학회지
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    • 제27권1호
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    • pp.59-64
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    • 1993
  • To evaluate the usefulness and differences in diagnosing coronary artery disease (CAD) between men and women of intravenous dipyridamole $^{99m}Tc$-MIBI myocardial SPECT, we obtained $^{99m}Tc$-MIBI myocardial SPECT and compared with the findings of coronary angiographies. Ninety eight male and 37 female patients who underwent dipyridamole $^{99m}Tc$-MIBI myocardial imaging within one month of cardiac catheterization were studied. Scans were considered abnormal if perfusion defect was detected and the defect size was more than 12% for left anterior descending artery (LAD) and circumflex (LCX) and 8% for right coronary artery (RCA) territories. Lesions${\geqq}$50% luminal diameter narrowing were considered significant CAD. Overall sensitivity for detection of CAD was 94.3% in men and 96.4% in women; specificity was 70% in men and 52.6% in women (P=not significant, ns). Vessel-matched sensitivity was 75.3% in men and 72.7% in women (P=ns): specificity was 84.6% in men and 67.9% in women (P < 0.025). For individual coronary artery, the sensitivity in men and women was 87.7%, 81.8% for LAD; 78%, 83.3% for RCA and 52.2%, 46.7% for LCX (P=ns): the specificity was 80%, 40% for LAD (P<0.01), 82.5%, 68.4% for RCA, 88.9%, 86.4% for LCX (P=ns). The hemodynamic parameter after intravenous dipyridamole in men and women were significantly changed; the heart rate was increased and systolic, diastolic blood pressure was decreased. Adverse effects were reported in 58.8% of men and 72.7% in women (P=ns). The incidence of chest pain and headache were higher in women. There was no significant difference in the incidences of nausea, abdominal pain, dizziness, facial flushing, dyspnea. In conclusion, dipyridamole $^{99m}Tc$-MIBI myocardial SPECT is a safe, noninvasive test for evaluation of CAD. There was no gender difference to detect CAD, but more false-positive rate in women especially in the territory of LAD.

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집단뇨검사(Urinary mass screening) 방법으로 단백뇨와 혈뇨의 동시검사가 가지는 진단적 가치에 대한 연구 (A study of Diagnostic Significance of Simultaneous Examination of Proteinuria and Hematuria in the Urinary Mass Screening)

  • 김영균;이종국
    • Childhood Kidney Diseases
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    • 제3권1호
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    • pp.57-63
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    • 1999
  • 목 적 : 신질환의 조기 진단을 위한 집단뇨검사 방법으로 단백뇨와 혈뇨검사를 동시에 시행하여 그 결과를 분석함으로써 집단뇨검사에서 잠혈검사 추가가 가지는 진단적 의의를 알아 보고자 하였다. 방법 및 대상 : 1차 선별검사는 전국 33개교 26,508명의 고등학교 1년생(16세군)을 대상으로 하였고 정밀검사는 서울시 1개교 875명의 고등학교 1년생(16세군)을 대상으로 실시하였다. 방법은 1997년 8월부터 12월까지 4개월간 한국 건강관리 협회와 공동으로 학교에서 무작위로 채취된 소변을 Combur-10 $N^{(R)}$ M (Boehringer Mannheim, Germany)검사지로 단백뇨, 혈뇨, 농뇨, 아질산염 등을 검사하였다. 양성자의 기준은 단백뇨, 혈뇨, 농뇨가 $1^{+}$ 이상인 경우와 아질산염에 양성반응이 나오는 경우로 정하였다. 실제 신질환의 감별을 위한 정밀검사는 1차 집단뇨검사 양성자를 대상으로 본원에서 실시하였다. 결 과 : 1) 1차 집단검사 결과에서 단백뇨 유병율은 $0.73\%$, 혈뇨 유병율은 $2.69\%$, 농뇨 유병율은 $0.23\%$ 그리고 아질산염 유병율은 $0.03\%$로 조사 되었다. 2)서울지역 1개교(875명)선별 정밀검사 결과: 1차검사 단백뇨 양성자 8명($0.91\%$)중 1명은 기립성 단백뇨, 나머지 7명은 일시적 단백뇨로 확인되었다. 1차검사 혈뇨 양성자는 41명($4.86\%$)이었고 이중 재검이 가능했던 33명중 6명만이 지속적인 혈뇨 양성자였고, 다시 시행한 정밀검사에서 한명만이 무증상 단독 혈뇨증으로 확인되었으며 나머지 5명은 정상이었다. 1차 소변검사 이상자 52명에 대한 혈액검사 및 초음파검사는 모두 정상이었다. 1차검사에서 혈뇨 양성자 33명중 1명(약$3\%$)만이 신질환이 의심되는 경우였고 나머지 32명($91\%$)은 정상이었다. 결 론 : 1) 혈뇨검사는 위양성이 높기 때문에 ($97\%$) 집단뇨검사에 포함시킬 경우 불필요한 시간과 경비의 낭비가 있을수 있다고 생각된다. 2) 집단뇨검사는 검사 기관에 따라 얻어지는 결과의 차이가 심하기 때문에 단일 기관으로 통합 관리해야 할 것이다. 3) 요로감염증의 선별검사에서 농뇨와 아질산염 검사는 양성율이 낮으므로 그 효용성에 대한 연구는 좀더 필요하다고 생각된다.

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파주 지역 초등학교 2학년생에게 실시된 집단 뇨검사 분석 (Analysis of Urinary Mass Screening for Second Grade of Elemantary School Children in Paju City)

  • 김성기;김영균;박용원;이종국
    • Childhood Kidney Diseases
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    • 제5권2호
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    • pp.156-163
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    • 2001
  • 목 적 : 본 연구의 목적은 집단뇨검사의 대상으로 8세 전후의 어린이가 포함되는 것이 타당한지 또한 혈뇨 검사를 집단뇨검사에 포함시키는 것이 실효성이 있는지를 알아 보고자 하였다. 대상 및 방법 : 파주 지역 초등학생 2,804명을 대상으로 모두 3차에 걸쳐 단계적 요검사와 정밀 검사를 실시하여 단백뇨와 혈뇨의 유병율을 조사하였다. 요검사 이상자를 대상으로 정밀 검사를 시행하여 실제 신질환의 유병율을 알아보고 집단뇨검사의 유용성을 검증하였다. 결 과 : 파주 지역 초등학생 8세군에서 나타난 무증상 요검사이상 유병율은 $8.3\%$로 각각 단백뇨 $2.3\%$, 혈뇨 $5.8\%$였고 혈뇨와 단백뇨를 동시에 보인 경우는 $0.2\%$로 조사되었다. 1차 선별 검사 이상자 233명중 102명이 2차 검사에 응하여 이들 중 약 1/3인 32명이 다시 양성자로 나타났고 혈뇨가 $41.7\%$, 단백뇨가 $0\%$, 동시에 양성인 경우가 $66.7\%$로 2차 검사에 이상자로 확인되었다. 3차검사에 응한 32명중 30명은 단독 혈뇨증을 보였고 2명은 혈뇨와 단백뇨가 동시 확인되었다. 이들 단독 혈뇨증을 보인 30명 중6명은 정상으로 나타났고, 21명은 특발성 단독 현미경적 혈뇨, 나머지 3명은 요로감염증 1명, 특발성 과칼슘뇨증 1명, 단순 신낭종 1명로 확인되었다. 혈뇨와 단백뇨를 동시에 보인 2명은 만성 사구체 신염을 가지고 있는 것으로 생각되었다. 결 론 : 본 연구의 집단뇨검사에서 단백뇨와 혈뇨의 유병율 $2.3\%,\;5.8\%$로 조사되었고 이들 중 대부분이 정상으로 나타나 집단뇨검사의 특이성이 낮은 것을 알 수 있었다. 검사 대상에 8세군을 포함시키는 문제에 관해서 본 연구에서 비교적 높은 양성율을 보였다는 점을 감안하면 집단뇨검사에 8세군을 포함하는 것이 타당하다고 생각되었다.

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