• Title/Summary/Keyword: False negative rate

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Electrical Detection of Ear Acupuncture Points and Musculoskeletal Pain (경혈탐측기에 반응한 이혈(耳穴)과 신체 동통 부위와의 관계 연구)

  • Kang, Mun-Su;Park, Hyun-Chul;Kim, Lak-Hyung;Yu, Jeong-Suk;Song, Beom-Yong
    • Journal of Acupuncture Research
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    • v.24 no.6
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    • pp.187-193
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    • 2007
  • Objectives : The objectives of this study were to investigate the relationship between electrical detection of ear acupuncture points and musculoskeletal pain. Methods : 18 adults who have musculoskeletal pain without trauma factorsparticipated in this study. They answered the questionnaire and their ear acupuncture points were examined with electrical detectors. We analyzed the relationship between electrical detection of ear acupuncture points and musculoskeletal pain with concordance rate and validity. Results : Total concordance rates of the head region was 68.00%(questionnaire) 32.08%(investigation), that of vertebral region was 67.86%, 59.38%, that of both upper limbs was 86.67%, 39.69%, and that of both lower limbs was 50.00%, 23.46%. The true positive rate was 0.704, the true negative rate was 0.492, the false positive rate was 0.508, and the false negative rate was 0.296 in the validity test. In the head, two concordance rates of the temporal and occipital regions were relatively higher than those of the parietal and frontal regions. In the vertebral region, two concordance rates of the cervical and lumbar regions were relatively higher than those of the thoracic and sacrum regions. In the upper limb, two concordance rates of the shoulder and shoulder joints were relatively higher than those of the others. In the lower limb, concordance rates of investigation were relatively low at all areas. The right lower limb was relatively higher than the left in concordance rates of the questionnaire. Conclusions : The results suggest that electrical detection of ear acupuncture points can be used in the diagnosis and treatment of musculoskeletal pain.

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A Method for Efficient Malicious Code Detection based on the Conceptual Graphs (개념 그래프 기반의 효율적인 악성 코드 탐지 기법)

  • Kim Sung-Suk;Choi Jun-Ho;Bae Young-Geon;Kim Pan-Koo
    • The KIPS Transactions:PartC
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    • v.13C no.1 s.104
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    • pp.45-54
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    • 2006
  • Nowadays, a lot of techniques have been applied for the detection of malicious behavior. However, the current techniques taken into practice are facing with the challenge of much variations of the original malicious behavior, and it is impossible to respond the new forms of behavior appropriately and timely. There are also some limitations can not be solved, such as the error affirmation (positive false) and mistaken obliquity (negative false). With the questions above, we suggest a new method here to improve the current situation. To detect the malicious code, we put forward dealing with the basic source code units through the conceptual graph. Basically, we use conceptual graph to define malicious behavior, and then we are able to compare the similarity relations of the malicious behavior by testing the formalized values which generated by the predefined graphs in the code. In this paper, we show how to make a conceptual graph and propose an efficient method for similarity measure to discern the malicious behavior. As a result of our experiment, we can get more efficient detection rate.

A Study on the Identification Algorithm for Organization's Name of Author of Korean Science & Technology Contents (국내 과학기술콘텐츠 저자의 소속기관명 식별을 위한 소속기관명 자동 식별 알고리즘에 관한 연구)

  • Kim, Jinyoung;Lee, Seok-Hyong;Suh, Dongjun;Kim, Kwang-Young;Yoon, Jungsun
    • Journal of Digital Contents Society
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    • v.18 no.2
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    • pp.373-382
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    • 2017
  • As the number of scientific and technical contents increases, services that support efficient search of scientific and technical contents are required. When an author's affiliation is used as a keyword, not only the contents produced by the affiliation can be searched, but also the identification rate of the search result using the author and the term as keyword can be improved. Because of the ambiguity and vagueness of the data used as a search keyword, the search result may include false negative or false positive. However, the previous research on the control through identification of the search keyword is mainly focused on the author data and terminology data. In this paper, we propose the algorithm to identify affiliations and experiment with show the experiment with scientific and technological contents held by the Korea Institute of Science and Technology Information.

Performance Analysis of Noisy Group Testing for Diagnosis of COVID-19 Infection (코로나19 진단을 위한 잡음 그룹검사의 성능분석)

  • Seong, Jin-Taek
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.15 no.2
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    • pp.117-123
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    • 2022
  • Currently the number of COVID-19 cases is increasing rapidly around the world. One way to restrict the spread of COVID-19 infection is to find confirmed cases using rapid diagnosis. The previously proposed group testing problem assumed without measurement noise, but recently, false positive and false negative cases have occurred during COVID-19 testing. In this paper, we define the noisy group testing problem and analyze how much measurement noise affects the performance. In this paper, we show that the group testing system should be designed to be less susceptible to measurement noise when conducting group testing with a low positive rate of COVID-19 infection. And compared with other developed reconstruction algorithms, our proposed algorithm shows superior performance in noisy group testing.

Assessment of a Deep Learning Algorithm for the Detection of Rib Fractures on Whole-Body Trauma Computed Tomography

  • Thomas Weikert;Luca Andre Noordtzij;Jens Bremerich;Bram Stieltjes;Victor Parmar;Joshy Cyriac;Gregor Sommer;Alexander Walter Sauter
    • Korean Journal of Radiology
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    • v.21 no.7
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    • pp.891-899
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    • 2020
  • Objective: To assess the diagnostic performance of a deep learning-based algorithm for automated detection of acute and chronic rib fractures on whole-body trauma CT. Materials and Methods: We retrospectively identified all whole-body trauma CT scans referred from the emergency department of our hospital from January to December 2018 (n = 511). Scans were categorized as positive (n = 159) or negative (n = 352) for rib fractures according to the clinically approved written CT reports, which served as the index test. The bone kernel series (1.5-mm slice thickness) served as an input for a detection prototype algorithm trained to detect both acute and chronic rib fractures based on a deep convolutional neural network. It had previously been trained on an independent sample from eight other institutions (n = 11455). Results: All CTs except one were successfully processed (510/511). The algorithm achieved a sensitivity of 87.4% and specificity of 91.5% on a per-examination level [per CT scan: rib fracture(s): yes/no]. There were 0.16 false-positives per examination (= 81/510). On a per-finding level, there were 587 true-positive findings (sensitivity: 65.7%) and 307 false-negatives. Furthermore, 97 true rib fractures were detected that were not mentioned in the written CT reports. A major factor associated with correct detection was displacement. Conclusion: We found good performance of a deep learning-based prototype algorithm detecting rib fractures on trauma CT on a per-examination level at a low rate of false-positives per case. A potential area for clinical application is its use as a screening tool to avoid false-negative radiology reports.

Clinical Usefulness of PET-MRI in Lymph Node Metastasis Evaluation of Head and Neck Cancer (두경부암 림프절 전이 평가에서 PET-MRI의 임상적 유용성)

  • Kim, Jung-Soo;Lee, Hong-Jae;Kim, Jin-Eui
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.1
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    • pp.26-32
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    • 2014
  • Purpose: As PET-MRI which has excellent soft tissue contrast is developed as integration system, many researches about clinical application are being conducted by comparing with existing display equipments. Because PET-MRI is actively used for head and neck cancer diagnosis in our hospital, lymph node metastasis before the patient's surgery was diagnosed and clinical usefulness of head and neck cancer PET-MRI scan was evaluated using pathological opinions and idiopathy surrounding tissue metastasis evaluation method. Materials and Methods: Targeting 100 head and neck cancer patients in SNUH from January to August in 2013. $^{18}F-FDG$ (5.18 MBq/kg) was intravenous injected and after 60 min of rest, torso (body TIM coil, Vibe-Dixon) and dedication (head-neck TIM coil, UTE, Dotarem injection) scans were conducted using $Bio-graph^{TM}$ mMR 3T (SIEMENS, Munich). Data were reorganized using iterative reconstruction and lymph node metastasis was read with Syngo.Via workstation. Subsequently, pathological observations and diagnosis before-and-after surgery were examined with integrated medical information system (EMR, best-care) in SNUH. Patient's diagnostic information was entered in each category of $2{\times}2$ decision matrix and was classified into true positive (TP), true negative (TN), false positive (FP) and false negative (FN). Based on these classified test results, sensitivity, specificity, accuracy, false negative and false positive rate were calculated. Results: In PET-MRI scan results of head and neck cancer patients, positive and negative cases of lymph node metastasis were 49 and 51 cases respectively and positive and negative lymph node metastasis through before-and-after surgery pathological results were 46 and 54 cases respectively. In both tests, TP which received positive lymph node metastasis were analyzed as 34 cases, FP which received positive lymph node metastasis in PET-MRI scan but received negative lymph node metastasis in pathological test were 4 cases, FN which received negative lymph node metastasis but received positive lymph node metastasis in pathological test was 1 case, and TN which received negative lymph node metastasis in both two tests were 50 cases. Based on these data, sensitivity in PET-MRI scan of head and neck cancer patient was identified to be 97.8%, specificity was 92.5%, accuracy was 95%, FN rate was 2.1% and FP rate was 7.00% respectively. Conclusion: PET-MRI which can apply the acquired functional information using high tissue contrast and various sequences was considered to be useful in determining the weapons before-and-after surgery in head and neck cancer diagnosis or in the evaluation of recurrence and remote detection of metastasis and uncertain idiopathy cervical lymph node metastasis. Additionally, clinical usefulness of PET-MRI through pathological test and integrated diagnosis and follow-up scan was considered to be sufficient as a standard diagnosis scan of head and neck cancer, and additional researches about the development of optimum MR sequence and clinical application are required.

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Analysis of Mammography for Patient with Breast Cancer (유방암 환자를 대상으로 한 유방영상검사 분석)

  • Mo, Eun-Hui;Lim, Cheong-Hwan;Lee, Sang-Ho;Jung, Hong-Ryang;Lee, Hye-Nam
    • Journal of radiological science and technology
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    • v.34 no.1
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    • pp.1-7
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    • 2011
  • The purpose of this study is to evaluate the diagnostic accuracy of breast cancer from mammography images and to investigate the characteristics of patients who was diagnosed as a breast cancer. The subjects for this study were 85 patients who underwent breast imaging test with screen-film method and investigated from March 2010 to October 2010. The average age of the subjects is 51.9 years old. The 43.5% of onsets were located at the upper outer quadrant (UOQ). In terms of the age group, group for 40-49 ages were highest 37.6 (32/85)%. As for breast composition, fatty and dense breast were 30.6% (26/85) and 69.4% (59/85) respectively. The average age of the patients with fatty breast is 62.4 years old, whereas those with dense breast was 46.5 years old. The false negative rate of mammography images was 27.1% (23/85) and the sensitivity of mammography was 72.9% (62/85). The false negative rate of the patients with dense breast was 32.2% (19/59). the sensitivity of them was 67.8% (40/59).

Limitations of 99mTc-DMSA scan in diagnosing acute pyelonephritis in children (이해관계 선언)

  • Kim, Byung Gee;Kwak, Jae Ryoung;Park, Ji Min;Pai, Ki Soo
    • Clinical and Experimental Pediatrics
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    • v.53 no.3
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    • pp.408-413
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    • 2010
  • Purpose : We aimed to prove the relative limitation of $^{99m}Tc-DMSA$ scintigraphy (DMSA) compared to computed tomography (CT) in diagnosing acute pyelonephritis (APN) in children. Methods : Since September 2006, after a 64-channel CT was imported, 10 DMSA false-negative patients have been identified: these patients underwent a CT scan for acute abdomen or acute febrile symptoms and were diagnosed as having APN; however, their DMSA scans were clear. We focused on these 10 DMSA false-negative patients and analyzed their clinical findings and CT results. We used Philips Brilliance Power 64-channel CT scanner for the CT scan and Siemens Orbitor Nuclear Camera 60 Hz for the DMSA scan. Results : The 10 DMSA false-negative patients were mostly males (80%) and infants (80%). They had fever for a mean of 1.1-day duration before admission and showed increase in acute reactants: leukocyte, erythrocyte sedimentation rate, and C-reactive protein. The CT findings of renal lesions were focal in 6 (60%) cases and diffuse in 4 (40%) cases, and most of the lesions were unilateral in 80% of patients. CT proved that 22 renal lesions were neglected by DMSA. Differential renal function test by DMSA was also of no use in the evaluation of renal lesions. Conclusion : In this study, DMSA scan showed limitation in finding renal cortical lesions of CT-proven APN patients. DMSA false-negative results seem to occur at early-phase disease of infantile age, but more prospective studies are needed to determine the reasons and their prevalence.

Diagnostic Pitfalls in Breast Fine Needle Aspiration Cytology: False Positive and False Negative (유방 세침흡인 세포검사의 진단적 함정: 위양성과 위음성)

  • Park, Kyeong-Mee
    • The Korean Journal of Cytopathology
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    • v.18 no.2
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    • pp.112-118
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    • 2007
  • Fine needle aspiration cytology (FNAC) has become a highly preferred, minimally invasive diagnostic tool of choice in the diagnosis of a palpable breast mass owing to its sensitivity, specificity, cost-effectiveness, and expediency. Although breast needle biopsies have been widely employed recently due to the increased detection rate of non-palpable early lesions, the importance of the use of FNAC cannot be underestimated. It comprises part of the diagnostic triad for the breast along with a physical examination and mammography, which together contribute to an increasing diagnostic accuracy. The differential diagnosis of a benign and malignant lesion is of the utmost importance in the diagnosis of breast lesions, and therefore the understanding of the possible diagnostic pitfalls is of great importance.

Sentinel Node Biopsy Examination for Breast Cancer in a Routine Laboratory Practice: Results of a Pilot Study

  • Khoo, Joon-Joon;Ng, Chen-Siew;Sabaratnam, Subathra;Arulanantham, Sarojah
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1149-1155
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    • 2016
  • Background: Examination of sentinel lymph node (SLN) biopsies provides accurate nodal staging for breast cancer and plays a key role in patient management. Procurement of SLNs and the methods used to process specimens are equally important. Increasing the level of detail in histopathological examination of SLNs increases detection of metastatic tumours but will also increase the burden of busy laboratories and thus may not be carried out routinely. Recommendation of a reasonable standard in SLN examination is required to ensure high sensitivity of results while maintaining a manageable practice workload. Materials and Methods: Twenty-four patients with clinically node-negative breast cancer were recruited. Combined radiotracer and blue dye methods were used for identification of SLNs. The nodes were thinly sliced and embedded. Serial sectioning and immunohistochemical (IHC) staining against AE1/AE3 were performed if initial H&E sections of the blocks were negative. Results: SLNs were successfully identified in all patients. Ten cases had nodal metastases with 7 detected in SLNs and 3 detected only in axillary nodes (false negative rate, FNR=30%). Some 5 out of 7 metastatic lesions in the SLNs (71.4%) were detected in initial sections of the thinly sliced tissue. Serial sectioning detected the remaining two cases with either micrometastases or isolated tumour cells (ITC). Conclusions: Thin slicing of tissue to 3-5mm thickness and serial sectioning improved the detection of micro and macro-metastases but the additional burden of serial sectioning gave low yield of micrometastases or ITC and may not be cost effective. IHC validation did not further increase sensitivity of detection. Therefore its use should only be limited to confirmation of suspicious lesions. False negative cases where SLNs were not involved could be due to skipped metastases to non-sentinel nodes or poor technique during procurement, resulting in missed detection of actual SLNs.