• Title/Summary/Keyword: false-negative

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Role of PET in Evaluating Indeterminate Solitary Pulmonary Nodule with CT (CT상 악성여부가 불명확한 단일 폐결절에서의 양전자방출단층촬영술의 유용성)

  • Yoon, Seok-Boo;Choi, Joon-Young;Kim, Sun-Jung;Choi, Yong;Choe, Yearn-Seong;Lee, Kyung-Han;Kim, Sang-Eun;Kwon, O-Jung;Lee, Kyung-Soo;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.31 no.1
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    • pp.83-89
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    • 1997
  • About one-third of radiologically indeterminate solitary pulmonary nodules (SPN) are eventually turned out to be malignant. It is very important to noninvasively determine whether the SPN is malignant or not for the decision of its way of management. PET imaging is highlighted by its unique ability of imaging the function and metabolism of cells. Glucose metabolism is increased in malignant transformed cells. We peformed FDG-PET studies in patients who had radiologically indeterminate SPN and compared the findings with histologic diagnoses to assess the diagnostic accuracy in the detection of malignancy and to decide which parameter is the most suitable for clinical practice among peak SUV (pSUV), average SUV (aSUV), 50/10 ratio, and time-activity curve (TAC), Thirty patients were included in this study and the most useful parameter was pSUV. The sensitivity and specificity in the detection of malignant SPN using 3.5 as a cut off pSUV were both 87%. Interestingly, all 2 false-negative cases were bronch-ioloalveolar carcinoma on histologic examination. If these cases, which could be strongly suspected by CT findings, were excluded, the sensitivity of pSUV was 100%. In conclusion, PET imaging is very helpful for determining malignancy in indeterminate SPN and pSUV is a conveniently measurable parameter which is valuable for interpretation.

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Performance of Gated Myocardial Perfusion SPECT to Diagnose Coronary Artery Disease (게이트 심근 관류 SPECT의 관상 동맥 질환 진단 성능)

  • Kang, Won-Jun;Lee, Myoung-Mook;Chung, June-Key;Lee, Myung-Chul;Koh, Chang-Soon;Lee, Dong-Soo
    • The Korean Journal of Nuclear Medicine
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    • v.31 no.1
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    • pp.50-56
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    • 1997
  • Gated SPECT can evaluate the regional wall motion of the heart. We evaluated the regional wall motion of the perfusion abnormality in conventional perfusion SPECT with gated SPECT. In case of suspicious perfusion abnormalities, we tried to differentiate the artifact from true abnormality in coronary vascular disease using gated SPECT. We thought that artifacts would have normal wall motion, whereas fixed defects with decreased wall motion would probably represent coronary artery disease. A total of 275 patients who were performed coronary angiography and T1-201 rest/Tc-99m MIBI dipyridamole stress gated SPECT within 2 months were enrolled. In coronary angiography, stenosis more than 50% was considered as coronary artery disease. After injection of 111MBq T1-201 rest image was obtained on triple head SPECT system. 370MBg Tc-99m MIBI was used for the stress image. Eight-frame per-cardiac-cycle gated Tc-99m SPECT studies were done. All the images were analyzed visually. Using perfusion SPECT, the overall sensitivity and specificity were 87% and 55% respectively. Regarding artery territory, sensitivity and specificity were 68% and 73% for left anterior descending artery(LAD), 62% and 78% for right coronary artery(RCA), 42% and 90% for left ciramflex artery(LCX). Using gated SPECT, the overall sensitivity and specificity were 87% and 66% respectively. Sensitivity and specificity were 68% and 78% for LAD, 62% and 79% for RCA, 42% and 90% for LCX. Among 21 false positive cases in perfusion SPECT, 5 cases were interpreted as true negative with gated SPECT. We conclude that gated SPECT provides a valuable adjunct to perfusion SPECT in characterizing perfusion abnormalities and to improve specificity.

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Diagnosis of Protein Losing Enteropathy in Connective Tissue Diseases with $^{99m}Tc$-human Serum Albumin(HSA) (교원병에 동반된 단백소실장질환(Protein Losing Enteropathy)에서의 테크네슘표지 인혈청알부민 스캔)

  • Won, Kyoung-Sook;Oh, Yeong-Seok;Bang, Shin-Ho;Park, Won
    • The Korean Journal of Nuclear Medicine
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    • v.27 no.1
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    • pp.88-97
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    • 1993
  • Anterior abdominal scintigraphy after intravenous injection of $^{99m}Tc$-human serum albumin ($^{99m}Tc$-HSA 20 mCi) was done in 16 patients with connective tissue diseases and 15 healthy control patients. Patients with proteinuria or hepatopathy were excluded. 1) 7 (44%) patients among 16 connective tissue disease patients without the apparent evidence of external protein loss showed abnormal intestinal accumulation of albumin. 6 patients with positive albumin scintigraphy showed bypoalbuminemia. 2) There was no false positive scintigraphic finding in control group. 3) The serum albumin level in connective tissue disease patients ($3.1{\pm}0.6 g/dl$, n=16) was lower than control patients ($3.9{\pm}0.3 g/dl$, n=15) (p<0.0001). 4) The serum albumin level was lower in connective tissue disease patients with positive $^{99m}Tc$-HSA scan ($2.8{\pm}0.6 g/dl$, n=7) than the connective tissue disease patients with negative scan ($3.3{\pm}0.3 g/dl$, n=9) (p<0.05). 5) The hemoglobin level in connective tissue disease patients with positive nan ($10.6{\pm}2.91 g/dl$) was lower than that of the control group ($13.6{\pm}1.5 g/dl$) (p<0.05). Mypoalbuminemia is frequently involved in chronic connective tissue diseases. Protein losing enteropathy (PLE) is also responsible for the majority of the bypoalbuminemia in these patients. But it has been ignored because the conventional method for the diagnosis of PLE was difficult to perform. $^{99m}Tc$-HSA scan also must be validated by more extended study and comparison with the quantitative study such as stool ${\alpha}-1$ antitrypsin measurement. There must be a reevaluation of PLE in various diseases especially in connective tissue diseases with easy, fast, economical, and non-invasive method.

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Comparison of Photostimulated Luminescence, Thermoluminescence, and Electron Spin Resonance Spectroscopic Analyses on Dried-spices Irradiated by Gamma Ray and Electron Beam (감마선 및 전자선 조사 처리 건조향신료에 대한 광자극발광, 열발광 및 전자스핀공명의 분광학적 분석 비교)

  • Jeong, Jin-Hwa;Ahn, Jae-Jun;Baek, Ji-Yeong;Kim, Hyo-Young;Kwon, Joong-Ho;Jin, Chang-Hyun;Jeong, Il-Yun
    • Korean Journal of Food Science and Technology
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    • v.46 no.2
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    • pp.256-261
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    • 2014
  • This study was conducted to determine the effect of gamma-ray and electron-beam irradiation on dried spices (black pepper, red pepper, parsley, and basil) using the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods. The spices were irradiated at 0, 1, 5, and 10 kGy. All non-irradiated spices had photon counts (PCs) less than 700 PCs. The PCs of three irradiated spices (red pepper, parsley, and basil) were clearly distinguishable from those of non-irradiated ones, exhibiting PSL signals higher than 5000 PCs. However, negative PSL counts (<700 PCs) were obtained for most irradiated black pepper, except those irradiated with 5 kGy gamma rays and 10 kGy electron-beams. TL glow curves of the irradiated spices showed a higher peak at $150-250^{\circ}C$. TL ratios were found to be less than 0.1 for non-irradiated spices and higher than 0.1 for irradiated ones. No ESR signal was observed for any irradiated spice except red pepper, which displayed cellulose-based ESR spectra. Therefore, the results suggest that the PSL, TL, and ESR methods are effective detection techniques for dried spices irradiated with electron beams as well as gamma rays.

Diagnosis and Treatment of Papillary Thyroid Microcarcinoma(PMC) (유두 미세 갑상선암의 진단 및 치료에 대한 고찰)

  • Yoon Kyung-Seok;Oh Sung-Soo;Park Sung-Gil;Chung Eul-Sam
    • Korean Journal of Head & Neck Oncology
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    • v.14 no.2
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    • pp.228-235
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    • 1998
  • Objectives: Papillary microcarcinoma of the thyroid was evaluated as to the effectiveness of diagnostic modalities, lymphatic spread pattern, and therapeutic decision according to tumor size. Material and Methods: We retrospectively analyzed a clinicopathologic findings of 72 papillary microcarcinoma patients who were treated at the over 11 years between 1985 and 1995. The authors divided papillary microcarcinoma of the thyroid into two subgroups according to tumor size: $0{\leqq}5mm$ and $5<0{\leqq}10mm$. An analysis including age and gender distribution, diagnostic tools(thyroid sonogram, thyroid scan, thyroid function test, fine needle aspiration cytology, frozen section), pathological examination of lymphnode, and surgical procedures was carried out in each subgroups. Results: The carcinoma of smaller than 5mm were found in 32 patients, and of 6 -10mm were in 40 patients. The average age of patients was 45years and all of them were female. Cold nodules on thyroid scan were noticed in 53 patientss and normal findings were in 15 patients. Suspicious malignant lesions(fine calcification, solid mass, irregular margin) on thyroid sonography were detected in 23 patients and the sonography was more useful in detecting $0{\leqq}5mm$ small sized lesions than other diagnostic methods. FNAC were performed in 17 patients, and 7 patients were diagnosed as having thyroid papillary cancer. But diagnotic rate in $0{\leqq}5mm$ small sized lesions was very low(one of eights).Frozen section were performed in all patients, among these 15 patients were diagnosed as being benign diseases and false negative rates were higher in $0{\leqq}5mm$ small sized lesions than in $5<0{\leqq}10mm$ sized lesions(p-value<0.006). Only thyroidectomies were performed in 24 patients and thyroidectomy with node dissections in 48 patients. The lymphnode metastatic rates were much higher in multifocal lesions(61.5%) than in single lesion. The incidence of cervical lymphnode metastasis was 19.4% in $0{\leqq}5mm$ sized lesions and 47.9% in $5<0{\leqq}10mm$ sized lesions. Postoperative management were performed with TSH suppression therapy(T4, synthroid) in all patients and RI therapy in 29 patients. Conclusion: On the basis of our study, improved preoperative diagnostic tools for papillary microcarcinoma of the thyroid was helpful in the choice of surgical treatment. As a result of techninological progress(ultrasonography, FNAC), the pencentage of the discovery of papillary microcarcinoma has been increased. The thyroid ultrasonography was useful in detecting small sized lesions($0{\leqq}5mm$), but FNAC may not be beneficial in detecting small sized lesions($0{\leqq}5mm$). In the surgical procedure, thyroid lobectomy alone should be avoided because of the high rate of bilaterality and multifocality.

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A Study on Nurses한 and Patients한 Perceptions of Psychotropic Medication (향정신성 약물치료에 대한 간호사와 환자의 지각 비교 연구)

  • 이평숙
    • Journal of Korean Academy of Nursing
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    • v.24 no.1
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    • pp.47-57
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    • 1994
  • The purpose of this study was to examine nurses’ perceptions of medication treatment for psychiatric patients and to compare these perceptions with the perceptions held by the patients. The methodology used in this study was a descriptive design with semi-structured and open-ended interviews. This study used a convenience sample of 112 nurses who worked in, and 209 patients who were under psychiatric treatment, in four hospitals attached to a university and one national mental hospital in the city of Seoul. The collected data were analyzed by SAS, using percentages for descriptive purposes, and t-test or x$^2$ for comparing the variables. The results were as follows : 1. There was no significant differences between nurses’ and patients’ perceptions on the extent to which patients complied with their medication treatment. Generally speaking, the mean compliance scores for both nurses and patients was high(nurse : (equation omitted)=3.70, Patient : (equation omitted)=3.76). 2. There was a significant difference in nurses’ and patients’ perceptions on the reasons why patients do not take medication. The nurse group indicated that the patients did not take medication because of the “worry about side effects or habituation(49.53%)”, “boredom from long-term use of medication(26.17%)” and “distrust toward medical staff(12.15% )”, but the patient group indicated that they “did not want to be dependent on medication (25%)”, “forgot to take medication(19.7%) and “worried about side effects or habituation(15.91%). 3. As for the necessity of medication, both groups showed some different responses. Even though both groups were aware of the necessity of taking medication, the patient group(21.53%) showed a more negative response. As (or the effects of medication, both groups (nurses and patients ) showed positive responses. However, the nurse group showed a higher positive response (91.07% ) than the patient group(74.16%), 5. Both the patient and nurse group indicated that the most helpful element for the patient’s life under psychiatric treatment was interviews and conversations with therapists and nurses. However, the nurse group showed a higher response(70.15%) than the patients group(47.15%). According to the patient group, family support for the patient was another important factor for psychiatric treatment and daily struggles. In conclusion, as there were differences between the perception of nurses and patients, the nurse must consider the patients’ subjective perceptions first. They should also revaluate their false belief and prejudice concerning the patients’ perceptions. Such information can provide a base to be applied by the nurses in devloping effective mutual relationships with patients which can in turn help in compliance with medication regimen. As it was confirmed that medication was the most important factor in the patients’ recovery, a thorough education program on the therapeutic effect of medication and the necessity of their continued use after discharge is also needed.

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A Pilot Study on the Usefulness of Tomography and Bone Scan in Diagnosis of Patients with TMJ Osteoarthritis (측두하악관절 골관절염 환자의 진단에서 단층촬영과 골스캔 검사의 유용성에 대한 예비연구)

  • Kim, Cheul;Kim, Young-Jun;Moon, Ji-Hoi;Park, Moon-Soo
    • Journal of Oral Medicine and Pain
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    • v.37 no.2
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    • pp.125-133
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    • 2012
  • TMJ Osteoarthritis is a degenerative disease caused by overload on joint tissue, and often accompany with local tenderness on the joint, crepitus by mandibular movement, restriction of mandibular movement, and anterior openbite. In general, panoramic radiography, TMJ panoramic radiography, and transcranial radiography are conducted to diagnose osteoarthritis after clinical examination, however, these radiographic evaluations are limited in detecting minute bony changes of early pathologic lesion. The aim of this pilot study was to evaluate the limitation and usefulness of several TMJ imaging techniques, so we compare the findings from clinical examination, plain film radiographs, tomograph, and bone scan from 81 patients with temporomandibular joint disorder. The proportion of patients showing same findings in plain film radiographs, TMJ tomograph, and bone scan was high, however, it is desirable that clinician should conduct phased imaging examinations according to the clinical findings due to the possibilities of false negative findings in diagnosis of osteoarthritis.

Fire Detection Approach using Robust Moving-Region Detection and Effective Texture Features of Fire (강인한 움직임 영역 검출과 화재의 효과적인 텍스처 특징을 이용한 화재 감지 방법)

  • Nguyen, Truc Kim Thi;Kang, Myeongsu;Kim, Cheol-Hong;Kim, Jong-Myon
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.6
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    • pp.21-28
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    • 2013
  • This paper proposes an effective fire detection approach that includes the following multiple heterogeneous algorithms: moving region detection using grey level histograms, color segmentation using fuzzy c-means clustering (FCM), feature extraction using a grey level co-occurrence matrix (GLCM), and fire classification using support vector machine (SVM). The proposed approach determines the optimal threshold values based on grey level histograms in order to detect moving regions, and then performs color segmentation in the CIE LAB color space by applying the FCM. These steps help to specify candidate regions of fire. We then extract features of fire using the GLCM and these features are used as inputs of SVM to classify fire or non-fire. We evaluate the proposed approach by comparing it with two state-of-the-art fire detection algorithms in terms of the fire detection rate (or percentages of true positive, PTP) and the false fire detection rate (or percentages of true negative, PTN). Experimental results indicated that the proposed approach outperformed conventional fire detection algorithms by yielding 97.94% for PTP and 4.63% for PTN, respectively.

Sentinel Lymph Node Identification Using $^{99m}Tc$-Neomannosyl Human Serum Albumin in Esophageal Cancer; Comparison with $^{99m}Tc$-Phytate (식도암 환자에서 $^{99m}Tc$-Neomannosyl Human Serum Albumin과 $^{99m}Tc$-Phytate를 이용한 감시림프절 탐색의 비교)

  • Kim, Hyun-Koo;Kang, Du-Young;Kim, Seung-Eun;Park, Jong-Jae;Jeong, Jae-Min;Mok, Young-Jae;Choi, Young-Ho
    • Korean Journal of Bronchoesophagology
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    • v.16 no.2
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    • pp.109-114
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    • 2010
  • Background: The aim of this study was to compare a novel mannose receptor-binding agent(Technetium-99m human serum albumin, $^{99m}Tc$-MSA) with $^{99m}Tc$-phytate for sentinel node mapping in patients with esophageal cancer. Material and Method: Twenty patients with clinical stage T1N0m0 or T2N0M0 esophageal cancer that were candidates for esophagectomy were enrolled. Endoscopic injection of $^{99m}Tc$-MSA or $^{99m}Tc$-phytate was administered at the peri-tumor region before surgery in 10 patients. The radioactive lymph nodes were identified with a handheld gamma probe after lymph node dissection. Results: The patient's age and the sex ratio of both groups were similar. The clinical stage, tumor location, and operative technique did not differ. The total number of dissected lymph nodes did not differ ($28.5{\pm}9.12$ in MSA group, $32.2{\pm}11.24$ in phytate group, p=0.430). The sentinel node was identified in all cases in both groups. The number of sentinel nodes per patient was $2.7{\pm}1.57$ in the MSA group, which was significantly greater than the $1.7{\pm}0.88$ in the phytate group (p=0.036). Five out of 20 patients whose sentinel nodes could be identified had metastases; however, neither group had any false-negative results for sentinel node identification. Conclusion: Sentinel nodes were detected more frequently with MSA than with phytate.

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Analysis of the reasons why single women in their thirties or forties choose not to marry: - implications for population education - (30-40대 싱글여성이 '결혼을 하지 않는 이유'분석 - 인구교육의 시사점 도출을 위하여 -)

  • Wang, Seok Soon;Jun, Joo Ram;Ryu, Kyung Hee
    • Journal of Korean Home Economics Education Association
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    • v.27 no.2
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    • pp.35-51
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    • 2015
  • The purpose of the present study is to investigate the various reasons that might lead single women to choose not to marry. Semi-structured in-depth interviews were arranged with 18 single women who met the criteria for the present research purpose. We considered only those responses of the interviewees that are directly related to their reasons why they choose not to marry, where the collected data were analyzed in three steps by methods of thematic analysis. As a result of the analysis, the reasons for which they chose not to marry could be grouped into three main clusters of themes which may be labeled as (1) themes centered on 'Myself', (2) themes centered on 'Family' and (3) themes centered on 'Surrounding Environments and Friends'. Among the first category of themes of 'Myself', we have found five sub-themes such as "Lack of emotional communication", "Not-found spouse meeting my criteria", "My personality", "Self-narcissism or self-centeredness", "False beliefs in marriage". As for the second category of themes 'Family', three sub-themes have been found including "Family of origin conflict", "Closeness to family of origin", "Comfortable daily lives". And for the final category of themes 'Surrounding Environments and Friends', there were found three sub-themes which include "Negative effects of married friends", "Emotional support system", "Changing social atmosphere". In all there are eleven sub-themes to consider. On the basis of these results, we presented some conclusions on the reasons why single women in their thirties or forties choose not to marry. We also presented some implications of these results on population education and future research.

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