• 제목/요약/키워드: False-negative results

검색결과 302건 처리시간 0.026초

Discriminatory ability of cervical vertebral maturation stages in predicting attainment of the legal age threshold of 14 years: A pilot study using lateral cephalograms

  • Banda, Thirupathi Reddy;Komuravelli, Anil Kumar;Balla, Sudheer B.;Korrai, Bala Raju;Alluri, Kavya;Kondapaneni, Jayasurya;Abhyankar, Sourab
    • Imaging Science in Dentistry
    • /
    • 제50권3호
    • /
    • pp.209-216
    • /
    • 2020
  • Purpose: In India, the age of 14 years is the legal age threshold for child labour. Therefore, in suspected instances of child labour, age assessment plays a crucial role in determining whether a violation of the law on the employment of children has occurred. The aim of this retrospective cross-sectional study was to assess the discriminatory ability of stages of cervical vertebral maturation (CVM) in predicting the legal age threshold of 14 years. Materials and Methods: Routinely taken lateral cephalograms from 408 subjects aged 10 to 18 years were evaluated retrospectively using the CVM stages described by Baccetti et al. Descriptive statistics, accuracy, sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated for stages 2, 3, and 4 of CVM. Results: Real age increased as the CVM stage gradually increased. The results of 2×2 contingency tables showed that CVM stage 4 produced an accuracy of 71% and 73%, a false positive rate of 7% and 18%, and a post-test probability of 59% and 68% for boys and girls, respectively. Conclusion: Based on these findings, it can be concluded that the stages of CVM are of limited use for predicting the attainment of the legal age threshold of 14 years. Future studies should investigate whether combinations of skeletal and dental methods could achieve better accuracy and post-test probability.

Sentinel Lymph Node Navigation Surgery for Early Gastric Cancer: Is It a Safe Procedure in Countries with Non-Endemic Gastric Cancer Levels? A Preliminary Experience

  • Neto, Guilherme Pinto Bravo;Santos, Elizabeth Gomes Dos;Victer, Felipe Carvalho;Neves, Marcelo Soares;Pinto, Marcia Ferreira;Carvalho, Carlos Eduardo De Souza
    • Journal of Gastric Cancer
    • /
    • 제16권1호
    • /
    • pp.14-20
    • /
    • 2016
  • Purpose: Early diagnosis of gastric cancer is still the exception in Western countries. In the East, as in Japan and Korea, this disease is an endemic disorder. More conservative surgical procedures are frequently performed in early gastric cancer cases in these countries where sentinel lymph node navigation surgery is becoming a safe option for some patients. This study aims to evaluate preliminary outcomes of patients with early gastric cancer who underwent sentinel node navigation surgeries in Brazil, a country with non-endemic gastric cancer levels. Materials and Methods: From September 2008 to March 2014, 14 out of 205 gastric cancer patients underwent sentinel lymph node navigation surgeries, which were performed using intraoperative, endoscopic, and peritumoral injection of patent blue dye. Results: Antrectomies with Billroth I gastroduodenostomies were performed in seven patients with distal tumors. The other seven patients underwent wedge resections. Sentinel basin resections were performed in four patients, and lymphadenectomies were extended to stations 7, 8, and 9 in the other 10. Two patients received false-negative results from sentinel node biopsies, and one of those patients had micrometastasis. There was one postoperative death from liver failure in a cirrhotic patient. Another cirrhotic patient died after two years without recurrence of gastric cancer, also from liver failure. All other patients were followed-up for 13 to 79 months with no evidence of recurrence. Conclusions: Sentinel lymph node navigation surgery appears to be a safe procedure in a country with non-endemic levels of gastric cancer.

촉지 림프절의 세침흡인 세포검사 - 단일 기관의 1,346예 경험 - (Fine Needle Aspiration Cytology of Palpable Lymph Nodes -A Single Institutional Experience of 1,346 Cases-)

  • 신동훈;김지연;강현정;김익두;설미영;최경운
    • 대한세포병리학회지
    • /
    • 제18권2호
    • /
    • pp.126-132
    • /
    • 2007
  • The aim of this study was to evaluate the diagnostic value of fine needle aspiration cytology (FNAC) for the assessment of palpable enlarged lymph nodes. The authors reviewed the results of 1,346 FNACs of palpable enlarged lymph nodes performed at Pusan National University Hospital from 1998 to 2004. Of the 1,346 cases, 1,265 (94.0%) were satisfactory and 81 (6.0%) unsatisfactory. Cytologic diagnoses were judged in 488 cases, based on subsequent histologic diagnoses, clinical follow up, or both. Global results for all malignancies (lymphoid and non-lymphoid neoplasms) based on cases with final diagnoses, showed a sensitivity of 87.4% and a specificity of 98.7%. The overall diagnostic accuracy was 93,2%, and the false negative rate reduced from 12,6% to 7,3% when lymphomatous cases were excluded. The annual data for this period showed that the number of diagnostic lymph node biopsies and the rate of inadequately sampled material markedly decreased. Gene rearrangement studies for IgH and TCR ${\gamma}$ were helful in 30 cases. FNAC is a useful initial diagnostic procedure for the evaluation of palpable enlarged lymph nodes. However, the technique should be assisted by the appropriate ancillary studies and by proper interpretation by a cytopathologist.

SVM을 이용한 SNMP MIB에서의 트래픽 폭주 공격 탐지 (Traffic Flooding Attack Detection on SNMP MIB Using SVM)

  • 유재학;박준상;이한성;김명섭;박대희
    • 정보처리학회논문지C
    • /
    • 제15C권5호
    • /
    • pp.351-358
    • /
    • 2008
  • DoS/DDoS로 대표되는 트래픽 폭주 공격은 대상 시스템뿐만 아니라 네트워크 대역폭 및 프로세서 처리능력, 시스템 자원 등을 고갈시킴으로써 네트워크에 심각한 장애를 유발하기 때문에, 신속한 트래픽 폭주 공격의 탐지는 안정적인 서비스의 제공 및 시스템의 운영에 필수요건이다. 전통적인 패킷 수집을 통한 DoS/DDoS의 탐지방법은 공격에 대한 상세한 분석은 가능하나 설치의 확장성 부족, 고가의 고성능 분석시스템의 요구, 신속한 탐지를 보장하지 못하는 문제점을 갖고 있다. 본 논문에서는 MIB 정보 갱신 시점 단위로 수집된 SNMP MIB 객체 정보를 바탕으로 Support Vector Data Description(SVDD)을 이용하여 보다 빠르고 정확한 침입탐지와 쉬운 확장성, 저비용탐지 및 정확한 공격유형별 분류를 가능케 하는 새로운 시스템을 설계 및 구현하였다. 실험을 통하여 만족스러운 침입 탐지율과 안전한 False Negative Rate(FNR), 공격유형별 분류율 수치 등을 확인함으로써 제안된 시스템의 성능을 검증하였다.

Clinical experience with $^{18}F$-fluorodeoxyglucose positron emission tomography and $^{123}I$-metaiodobenzylguanine scintigraphy in pediatric neuroblastoma: complementary roles in follow-up of patients

  • Gil, Tae Young;Lee, Do Kyung;Lee, Jung Min;Yoo, Eun Sun;Ryu, Kyung-Ha
    • Clinical and Experimental Pediatrics
    • /
    • 제57권6호
    • /
    • pp.278-286
    • /
    • 2014
  • Purpose: To evaluate the potential utility of $^{123}I$-metaiodobenzylguanine ($^{123}I$-MIBG) scintigraphy and $^{18}F$-fluorodeoxyglucose ($^{18}F$-FDG) positron emission tomography (PET) for the detection of primary and metastatic lesions in pediatric neuroblastoma (NBL) patients, and to determine whether $^{18}F$-FDG PET is as beneficial as $^{123}I$-MIBG imaging. Methods: We selected 8 NBL patients with significant residual mass after operation and who had paired $^{123}I$-MIBG and $^{18}F$-FDG PET images that were obtained during the follow-up. We retrospectively reviewed the clinical charts and the findings of 45 paired scans. Results: Both scans correlated relatively well with the disease status as determined by standard imaging modalities during follow-up; the overall concordance rates were 32/45 (71.1%) for primary tumor sites and 33/45 (73.3%) for bone-bone marrow (BM) metastatic sites. In detecting primary tumor sites, $^{123}I$-MIBG might be superior to $^{18}F$-FDG PET. The sensitivity of $^{123}I$-MIBG and $^{18}F$-FDG PET were 96.7% and 70.9%, respectively, and their specificity were 85.7% and 92.8%, respectively. $^{18}F$-FDG PET failed to detect 9 true NBL lesions in 45 follow-up scans (false negative rate, 29%) with positive $^{123}I$-MIBG. For bone-BM metastatic sites, the sensitivity of $^{123}I$-MIBG and $^{18}F$-FDG PET were 72.7% and 81.8%, respectively, and the specificity were 79.1% and 100%, respectively. $^{123}I$-MIBG scan showed higher false positivity (20.8%) than $^{18}F$-FDG PET (0%). Conclusion: $^{123}I$-MIBG is superior for delineating primary tumor sites, and $^{18}F$-FDG PET could aid in discriminating inconclusive findings on bony metastatic NBL. Both scans can be complementarily used to clearly determine discrepancies or inconclusive findings on primary or bone-BM metastatic NBL during follow-up.

Diagnostic Value of Ceruloplasmin in the Diagnosis of Pediatric Wilson's Disease

  • Kim, Jung Ah;Kim, Hyun Jin;Cho, Jin Min;Oh, Seak Hee;Lee, Beom Hee;Kim, Gu-Hwan;Choi, Jin-Ho;Kim, Kyung Mo;Yoo, Han-Wook
    • Pediatric Gastroenterology, Hepatology & Nutrition
    • /
    • 제18권3호
    • /
    • pp.187-192
    • /
    • 2015
  • Purpose: Measurement of serum ceruloplasmin level is the first step in screening for Wilson's disease (WD). Despite the rarity of WD in the general population, ceruloplasmin levels are routinely measured through hepatitis screening in both adults and children. Herein, we evaluated the diagnostic value of ceruloplasmin for the diagnosis of WD among children with hepatitis. Methods: We retrospectively reviewed data on serum ceruloplasmin levels measured as a serologic marker for patients with hepatitis at Asan Medical Center (Seoul, Korea) between from January 2004 to November 2013. The diagnosis of WD was confirmed by the identification of pathogenic variants in the ATP7B gene. To determine the diagnostic accuracy of ceruloplasmin, receiver operation characteristic (ROC) curves were constructed and the area under curve (AUC) were calculated. Results: Measurements of serum ceruloplasmin were performed in 2,834 children who had hepatitis. Among these, 181 (6.4%) children were diagnosed with WD. The sensitivity, specificity, and accuracy of a ceruloplasmin level of <20 mg/dL in the discrimination of WD were 93.4%, 84.2%, and 84.8%, respectively. In this study, 418 (14.7%) false-positive cases and 12 (0.4%) false-negative cases were noted. Using a ROC curve, a ceruloplasmin level of ${\leq}16.6mg/dL$ showed the highest AUC value (0.956) with a sensitivity of 91.2%, a specificity of 94.9%, and an accuracy of 94.7%. Conclusion: The measurement of serum ceruloplasmin was frequently used for the screening of WD in children, despite a low positive rate. The diagnostic value of ceruloplasmin may be strengthened by adopting a new lower cut-off level.

Validity of Self-reported Hypertension and Factors Related to Discordance Between Self-reported and Objectively Measured Hypertension: Evidence From a Cohort Study in Iran

  • Najafi, Farid;Pasdar, Yahya;Shakiba, Ebrahim;Hamzeh, Behrooz;Darbandi, Mitra;Moradinazar, Mehdi;Navabi, Jafar;Anvari, Bita;Saidi, Mohammad Reza;Bazargan-Hejazi, Shahrzad
    • Journal of Preventive Medicine and Public Health
    • /
    • 제52권2호
    • /
    • pp.131-139
    • /
    • 2019
  • Objectives: Self-reporting can be used to determine the incidence and prevalence of hypertension (HTN). The present study was conducted to determine the validity of self-reported HTN and to identify factors affecting discordance between self-reported and objectively measured HTN in participants in the Ravansar Non-Communicable Diseases (RaNCD) cohort. Methods: The RaNCD cohort included permanent residents of Ravansar, Iran aged 35-65 years. Self-reported data were collected before clinical examinations were conducted by well-trained staff members. The gold standard for HTN was anti-hypertensive medication use and blood pressure measurements. The sensitivity, specificity, positive and negative predictive values, and overall accuracy of self-reporting were calculated. Univariate and multivariate logistic regression were used to examine the discordance between self-reported HTN and the gold standard. Results: Of the 10 065 participants in the RaNCD, 4755 (47.4%) were male. The prevalence of HTN was 16.8% based on self-reporting and 15.7% based on medical history and HTN measurements. Of the participants with HTN, 297 (18.8%) had no knowledge of their disease, and 313 (19.9%) had not properly controlled their HTN despite receiving treatment. The sensitivity, specificity, and kappa for self-reported HTN were 75.5%, 96.4%, and 73.4%, respectively. False positives became more likely with age, body mass index (BMI), low socioeconomic status, and female sex, whereas false negatives became more likely with age, BMI, high socioeconomic status, smoking, and urban residency. Conclusions: The sensitivity and specificity of self-reported HTN were acceptable, suggesting that this method can be used for public health initiatives in the absence of countrywide HTN control and detection programs.

소아 잠복 결핵 감염 진단에 있어서 투베르쿨린 피부반응 검사와 결핵 특이항원 자극 Interferon-γ 분비능 측정의 비교 (Comparison of a whole blood Interferon-γ assay and A tuberculin skin test for detecting latent tuberculosis infection in children)

  • 전진경;김창기;김현숙;정귀영;인요한;김기환;이택진;전지현;김동수
    • Clinical and Experimental Pediatrics
    • /
    • 제51권9호
    • /
    • pp.971-976
    • /
    • 2008
  • 목 적 : 결핵 감염 관리에 있어서 잠복 결핵 감염을 찾아 내어 예방적 화학요법을 시행하는 것은 주요 핵심이다. 결핵에 노출된 소아에서 잠복 결핵 감염 진단을 위해 투베르쿨린 피부반응과 최근 널리 쓰이기 시작한 체외 검사법으로 결핵 특이항원 자극에 의한 T 세포의 $IFN-{\gamma}$ 분비능 측정 (QFT-G IT)이 있다. 잠복 결핵 감염 진단에 있어 두 검사법의 차이를 알아보고자 본 연구를 진행하였다. 방 법 : 2006년 10월 1일부터 2007년 4월 30일까지 6개월 간 총 111명의 소아를 대상으로 투베르쿨린 반응과 QFT-G IT 검사를 시행하였고, 동일 기간 내인 2개월 간 진단 된 성인 결핵 환자 29명에서 동일한 검사 결과를 후향적으로 알아보았다. 결 과 : 결핵 환자와의 가까운 접촉력을 주소로 내원한 무증상의 환자 33명 중 15% (5명)에서 QFT-G IT 검사 양성 소견을 보였고, 투베르쿨린 피부반응은 42% (14명)에서 양성결과를 보여 두 검사 간의 일치율은 낮았다(${\kappa}=0.39$). 성인 결핵 환자에서 QFT-G IT 양성율은 86.2%였고, 결핵균 배양 검사 양성율은 48.2%였다. 배양검사 양성이면서 QFT-G IT 음성이었던 환자는 12.5%였다. 결 론 : 소아에서 잠복 결핵 감염을 진단함에 있어 가족력을 근저에 둔 투베르쿨린 피부반응 검사를 시행하되 접촉력이 불분명하거나 지속적이지 않았을 경우 혹은 BCG 접종 효과로 의심되는 경우 결핵균 특이항원 자극 $IFN-{\gamma}$ 분비능 측정이 보조적 수단으로 사용 될 수 있을 지는 아직 확실하지 않으며 향후 수년 간 다 기관 연구가 필요하다.

갈색세포종의 초기 진단에서 I-123/I-131 Metaiodobenzylguanidine 스캔의 단일 검사로써의 진단 성능: 생화학적 검사, 해부학적 영상과 비교 (Efficacy of I-123/I-131 Metaiodobenzylguanidine Scan as A Single Initial Diagnostic Modality in Pheochromocytoma: Comparison with Biochemical Test and Anatomic Imaging)

  • 문은하;임석태;정영진;김동욱;정환정;손명희
    • Nuclear Medicine and Molecular Imaging
    • /
    • 제43권5호
    • /
    • pp.436-442
    • /
    • 2009
  • 목적: 본 연구는 갈색세포종의 수술 전 초기 진단에서 MIBG 스캔이 생화학적 검사나 해부학적 영상, 각각의 진단방법과 이 두 가지 진단 방법을 함께 이용한 경우와 비교해서 어떠한 진단적 가치를 가질 수 있는지 평가하기 위해 진행되었다. 대상및방법: 환자군은 2004년 4월부터 2008년 4월까지 임상적으로 갈색세포종이 의심되어 본원에 내원한 총 22명의 환자(남:여=13:9, 평균나이: $44.3{\pm}\;19.3$세)를 대상으로 하였고, 환자들은 진단을 위해 생화학적 검사(24 시간 뇨의 VMA, 메타네프린, 뇨와 혈장의 에피네프린, 노르에피네프린)와 해부학적 영상검사(CT 또는 MRI), I-123/I-131 MIBG 스캔을 모두 시행하고 조직학적으로 최종 확진이 이루어졌다. 결과: 각각의 진단방법에 대한 예민도, 특이도, 양성예측율, 음성예측율, 정확도를 구하여 그 수치를 비교하였는데 결과적으로 생화학적 검사는 88.9%, 69.2%, 66.7%, 90.0%, 77.3%, 해부학적 영상은 55.6%, 69.2%, 55.6%, 69.2%, 63.6%로 나타났으며, 위의 두 검사를 함께 사용한 경우에는 88.9%, 61.5%, 50.0%, 83.3%, 59.1% 이었다. 이에 비해 I-123/I-131 MIBG스캔을 단독으로 사용한 경우는 88.9%, 92.3%, 88.9%, 92.3 %, 90.9%로 나와서 생화학적 검사와 해부학적 영상을 각각 이용한 경우의 결과와 비교하여 전반적으로 수치가 높았고, 두 가지 검사를 함께 사용한 경우와 비교해서도 특이도, 양성예측율, 음성예측율, 정확도는 높고 예민도는 같은 결과를 보인 것으로 나타났다. 결론: 따라서 갈색세포종의 수술 전 초기진단에 있어서 생화학적 검사나 해부학적 영상뿐만 아니라 MIBG 스캔도 단일 검사로써 충분히 유용한 진단적 가치를 가질 것으로 기대되며, MIBG의 기능적 영상정보에 CT의 해부학적 영상정보를 함께 융합할 수 있는 SPECT/CT나 교감신경계에 섭취될 수 있는 PET tracer를 이용한 PET/CT를 사용한다면 갈색세포종에 대한 진단 능력을 더욱 높일 수 있을 것이다.

폐결핵에 있어서 기관지폐포세척액 결핵균검사 및 PCR의 진단적 가치 (The Diagnostic Value of Bronchoalveolar lavage fluid microscopic study and PCR in Pulmonary tuberculosis)

  • 박문환;최춘한;김남진
    • Tuberculosis and Respiratory Diseases
    • /
    • 제43권2호
    • /
    • pp.128-137
    • /
    • 1996
  • 연구배경: 폐결핵은 고전적인 방법인 객담 도말 검사 및 배양검사로 전단할 수 있지만 객담 도말 민감도가 낮고 배양검사는 시일이 오래걸리는 단점이 있고 효과적인 객담배출이 되지 않는 환자에서는 검사가 불가능하기도 하다. 또한 최근에 개발된 PCR법은 신속하기는 하지만 위양성과 위음성이 문제가 되고 있다. 그래서 기관지내시경을 통한 기관지폐포세척액을 이용하여 세균학적 검사 및 PCR을 시행하여 폐결핵진단에 있어서 민감도와 예민도를 높이고 보다 신속한 진단을 할 수 있는지 연구하였다. 방법: 폐결핵 67예와 폐결핵이외의 폐질환을 가진 43예를 대상으로 객담 도말검사 및 배양검사를 시행하고, 기관지내시경을 시행하여 흉부 X-선상 병변이 보이는 엽상기관지에 기관지내시경을 위치하고 생리식염수 5cc로 3-5회에 걸쳐서 세척을 시행하여 세척액을 채취한 후 세균학적검사 및 PCR을 시행하였다. 결과: 1) 폐결핵환자의 기관지폐포세척액 결핵균 도말 검사 및 배양검사의 민감도는 각각 47.8% 및 80.6%로서, 객담 도말검사 및 배양검사의 민감도인 32.8% 및 57.4%보다 유의하게 높았다. 2) 폐결핵환자의 기관지폐포세척액 PCR의 민감도는 80.6%로서 배양검사의 민감도와 같았고, PCR의 배양검사에 대한 양성예측율은 81.5%였다. 3) 객담 도말검사 및 배양검사상 음성을 보인 폐결핵환자에서 시행한 기관지내시경을 통한 기관지폐포세척액 도말검사의 민감도는 23.1%였으며, 배양검사의 민감도는 100%였고, PCR의 민감도는 88.5%였으며, PCR의 배양검사에 대한 양성예측율 82.4%였다. 4) 기관지폐포세척액 PCR의 특이도는 77.0%였다. 5) 폐결핵의 최초 진단 후 치료시작까지의 기간은 객담 도말검사로 최초 진단이 된 경우가 평균 5일로 가장 빨랐고, 기관지폐포세척액 도말검사가 평균 9일, 기관지폐포세척액 PCR이 평균 26일이었으며, 객담배양검사는 평균 32일이었고, 기관지 폐포세척액 배양검사는 평균 56일로 가장 길었다. 결론: 폐결핵환자에서 기관지내시경을 통한 기관지폐포세척액의 결핵균 도말검사 및 배양검사는 객담을 이용한 검사보다 민감도가 높다. 그러므로, 객담을 배출하지 못하는 환자나 객담의 세균학적 검사가 음성인 환자에서 기관지내시경이 고려되어야 하며, 기관지폐포세척액의 PCR법까지 병행할 때에는 보다 신속하고 높은 진단율을 나타내므로, 조기에 적절한 항결핵제 투여에 도움이 될 것으로 기대된다.

  • PDF