• Title/Summary/Keyword: non-testing methods

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Diagnostic Performance of Radial Probe Endobronchial Ultrasound without a Guide-Sheath and the Feasibility of Molecular Analysis

  • Moon, Seong Mi;Choe, Junsu;Jeong, Byeong-Ho;Um, Sang-Won;Kim, Hojoong;Kwon, O Jung;Lee, Kyungjong
    • Tuberculosis and Respiratory Diseases
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    • 제82권4호
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    • pp.319-327
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    • 2019
  • Background: Radial probe endobronchial ultrasound (R-EBUS), is effective for tissue diagnosis of lung lesions. We evaluated the diagnostic performance of R-EBUS both a guide-sheath and fluoroscopy and identified factors associated with accurate diagnosis. The feasibility of molecular and genetic testing, using specimens obtained by R-EBUS, was also investigated. Methods: The study retrospectively reviewed 211 patients undergoing R-EBUS without a guide-sheath and fluoroscopy, June 2016-May 2017. After excluding 27 patients of which the target lesion was not reached, 184 were finally included. Multivariate logistic regression was used, to identify factors associated with accurate diagnosis. Results: Among 184 patients, R-EBUS-guided biopsy diagnosed malignancy in 109 patients (59%). The remaining 75 patients (41%) with non-malignant results underwent additional work-ups, and 34 were diagnosed with malignancy. Based on final diagnosis, diagnostic accuracy was 80% (136/170), and sensitivity and specificity for malignancy were 76% (109/143) and 100% (27/27), respectively. In multivariate analysis, peripheral location (adjusted odds ratio [aOR], 3.925; 95% confidence interval [CI], 1.203-12.811; p=0.023), and central position of the probe (aOR, 2.435; 95% CI, 1.424-7.013; p=0.035), were associated with accurate diagnosis of malignancy. Molecular and genetic analyses were successful, in all but one case, with inadequate specimens. Conclusion: R-EBUS-guided biopsy without equipment, is effective for tissue diagnosis. Peripheral location and central position of the radial probe, were crucial for accurate diagnosis. Performance of molecular and genetic testing, using samples obtained by R-EBUS, was satisfactory.

Automated Detection and Segmentation of Bone Metastases on Spine MRI Using U-Net: A Multicenter Study

  • Dong Hyun Kim;Jiwoon Seo;Ji Hyun Lee;Eun-Tae Jeon;DongYoung Jeong;Hee Dong Chae;Eugene Lee;Ji Hee Kang;Yoon-Hee Choi;Hyo Jin Kim;Jee Won Chai
    • Korean Journal of Radiology
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    • 제25권4호
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    • pp.363-373
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    • 2024
  • Objective: To develop and evaluate a deep learning model for automated segmentation and detection of bone metastasis on spinal MRI. Materials and Methods: We included whole spine MRI scans of adult patients with bone metastasis: 662 MRI series from 302 patients (63.5 ± 11.5 years; male:female, 151:151) from three study centers obtained between January 2015 and August 2021 for training and internal testing (random split into 536 and 126 series, respectively) and 49 MRI series from 20 patients (65.9 ± 11.5 years; male:female, 11:9) from another center obtained between January 2018 and August 2020 for external testing. Three sagittal MRI sequences, including non-contrast T1-weighted image (T1), contrast-enhanced T1-weighted Dixon fat-only image (FO), and contrast-enhanced fat-suppressed T1-weighted image (CE), were used. Seven models trained using the 2D and 3D U-Nets were developed with different combinations (T1, FO, CE, T1 + FO, T1 + CE, FO + CE, and T1 + FO + CE). The segmentation performance was evaluated using Dice coefficient, pixel-wise recall, and pixel-wise precision. The detection performance was analyzed using per-lesion sensitivity and a free-response receiver operating characteristic curve. The performance of the model was compared with that of five radiologists using the external test set. Results: The 2D U-Net T1 + CE model exhibited superior segmentation performance in the external test compared to the other models, with a Dice coefficient of 0.699 and pixel-wise recall of 0.653. The T1 + CE model achieved per-lesion sensitivities of 0.828 (497/600) and 0.857 (150/175) for metastases in the internal and external tests, respectively. The radiologists demonstrated a mean per-lesion sensitivity of 0.746 and a mean per-lesion positive predictive value of 0.701 in the external test. Conclusion: The deep learning models proposed for automated segmentation and detection of bone metastases on spinal MRI demonstrated high diagnostic performance.

Effects of contamination by either blood or a hemostatic agent on the shear bond strength of orthodontic buttons

  • Gungor, Ahmet Yalcin;Alkis, Huseyin;Turkkahraman, Hakan
    • 대한치과교정학회지
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    • 제43권2호
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    • pp.96-100
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    • 2013
  • Objective: To evaluate the effects of contamination by either blood or a hemostatic agent on the shear bond strength (SBS) of orthodontic buttons. Methods: We used 45 freshly extracted, non-carious, impacted third molars that were divided into 3 groups of 15. Each tooth was etched with 37% phosphoric acid gel for 30 s. Human blood or the blood stopper agent was applied to the tooth surface in groups I and II, respectively. Group III teeth were untreated (controls). Orthodontic buttons were bonded to the teeth using light-curing composite resin. After bonding, the SBS of the button was determined using a Universal testing machine. Any adhesive remaining after debonding was assessed and scored according to the modified adhesive remnant index (ARI). ANOVA with post-hoc Tukey's test was used to determine significant differences in SBS and Fisher's exact test, to determine significant differences in ARI scores among groups. Results: ANOVA indicated a significant difference between groups (p < 0.001). The highest SBS values were measured in group III ($10.73{\pm}0.96$ MPa). The SBS values for teeth in groups I and II were significantly lower than that of group III (p < 0.001). The lowest SBS values were observed in group I teeth ($4.17{\pm}1.11$ MPa) (p < 0.001). Conclusions: Contamination of tooth surfaces with either blood or hemostatic agent significantly decreased the SBS of orthodontic buttons. When the contamination risk is high, it is recommended to use the blood stopper agent when bonding orthodontic buttons on impacted teeth.

선구조와 지하 투과 레이더를 이용한 지하공동구 위치 해석 (The Analysis of Underground Utility Tunnel Positions using Lineament and GPR)

  • 장호식;서동주
    • 한국지리정보학회지
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    • 제9권4호
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    • pp.142-150
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    • 2006
  • 최근 토목시공 현장에서는 사면안정 및 보강공사를 하기 위한 앵커 및 굴착작업 도중에 일부 구간에서 지하 공동구가 발견되어 현장애로 사항이 발생되고 있다. 본 연구에서는 이들의 문제점을 사전에 미리 파악하고자 비파괴 물리검사인 지하 투과 레이다 탐사방법을 적용하여 지하공동구의 위치를 파악하는데 목적을 두었으며, 또한 입지적인 환경인 지질상태를 이해하기 위해 선구조 분석을 병행하였다. 먼저 입지분석에 의하여 연구 대상 지역의 지질상태를 파악할 수 있었고, 이를 기초로 하여 지하 투과 레이다 탐사 결과, 소규모 및 대규모의 지하 공동구 및 이상대의 위치와 규모를 파악할 수 있었다. 향후, 이와 같은 방법을 적용하여 시공현장에서 조사 및 설계에 대한 효율적인 시공방법과 유지관리를 수행하기 위한 접근 가능한 방법이라 판단된다.

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Fracture resistances of zirconia, cast Ni-Cr, and fiber-glass composite posts under all-ceramic crowns in endodontically treated premolars

  • Habibzadeh, Sareh;Rajati, Hamid Reza;Hajmiragha, Habib;Esmailzadeh, Shima;Kharazifard, Mohamadjavad
    • The Journal of Advanced Prosthodontics
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    • 제9권3호
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    • pp.170-175
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    • 2017
  • PURPOSE. The aim of the present study was to evaluate the fracture resistances of zirconia, cast nickel-chromium alloy (Ni-Cr), and fiber-composite post systems under all-ceramic crowns in endodontically treated mandibular first premolars. MATERIALS AND METHODS. A total of 36 extracted human mandibular premolars were selected, subjected to standard endodontic treatment, and divided into three groups (n=12) as follows: cast Ni-Cr post-and-core, one-piece custom-milled zirconia post-and-core, and prefabricated fiber-glass post with composite resin core. Each specimen had an all-ceramic crown with zirconia coping and was then loaded to failure using a universal testing machine at a cross-head speed of 0.5 mm/min, at an angle of 45 degrees to the long axis of the roots. Fracture resistance and modes of failure were analyzed. The significance of the results was assessed using analysis of variance (ANOVA) and Tukey honest significance difference (HSD) tests (${\alpha}=.05$). RESULTS. Fiber-glass posts with composite cores showed the highest fracture resistance values ($915.70{\pm}323N$), and the zirconia post system showed the lowest resistance ($435.34{\pm}220N$). The corresponding mean value for the Ni-Cr casting post and cores was reported as $780.59{\pm}270N$. The differences among the groups were statistically significant (P<.05) for the zirconia group, as tested by ANOVA and Tukey HSD tests. CONCLUSION. The fracture resistance of zirconia post-and-core systems was found to be significantly lower than those of fiber-glass and cast Ni-Cr post systems. Moreover, catastrophic and non-restorable fractures were more prevalent in teeth restored by zirconia posts.

Association of chairside salivary aMMP-8 findings with periodontal risk assessment parameters in patients receiving supportive periodontal therapy

  • Schmalz, Gerhard;Kummer, Max Kristian;Kottmann, Tanja;Rinke, Sven;Haak, Rainer;Krause, Felix;Schmidt, Jana;Ziebolz, Dirk
    • Journal of Periodontal and Implant Science
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    • 제48권4호
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    • pp.251-260
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    • 2018
  • Purpose: The aim of this retrospective cross-sectional study was to evaluate whether salivary findings of active matrix-metalloproteinase 8 (aMMP-8) chairside (point of care; POC) tests were associated with periodontal risk assessment parameters in patients receiving supportive periodontal therapy (SPT). Methods: A total of 125 patients receiving regular SPT were included, and their records were examined. The following inclusion criteria were used: a diagnosis of chronic periodontitis, at least 1 non-surgical periodontal treatment (scaling and root planning) with following regular SPT (minimum once a year), at least 6 remaining teeth, and clinical and aMMP-8 findings that were obtained at the same appointment. In addition to anamnestic factors (e.g., smoking and diabetes), oral hygiene indices (modified sulcus bleeding index [mSBI] and approximal plaque index), periodontal probing depth simultaneously with bleeding on probing, and dental findings (number of decayed, missing, and filled teeth) were recorded. Salivary aMMP-8 levels were tested using a commercial POC test system (Periomarker, Hager & Werken, Duisburg, Germany). Statistical analysis was performed using the t-test, Mann-Whitney U test, Fisher's exact test, and ${\chi}^2$ test, as appropriate (P<0.05). Results: Only the mSBI was significantly associated with positive salivary aMMP-8 findings (aMMP-8 positive: $27.8%{\pm}20.9%$ vs. aMMP-8 negative: $18.0%{\pm}14.5%$; P=0.017). No significant associations were found between aMMP-8 and smoking, diabetes, periodontal parameters, or parameters related to the maintenance interval (P>0.05). Conclusions: Salivary aMMP-8 chairside findings were not associated with common parameters used for periodontal risk assessment in patients receiving SPT. The diagnostic benefit of POC salivary aMMP-8 testing in risk assessment and maintenance interval adjustment during SPT remains unclear.

복합재료의 파손 감지를 위한 동조형 음향방출 신호분석 기법 (Resonance Type Acoustic Emission Signal Analyzing Method for the failure detection of the composite materials)

  • 이창훈;최진호;권진희
    • 한국항공우주학회지
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    • 제32권3호
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    • pp.30-36
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    • 2004
  • 장섬유 복합재료는 항공우주 구조물, 로봇 팔 등의 구조물에 광범위하게 적용되고 있으며, 복합재료의 비파괴 검사방법에 대한 연구는 구조의 안전성과 신뢰성을 향상시키기 위하여 매우 중요한 연구 분야로 대두되고 있다. 본 논문에서는 AE 선호의 특정주파수 성분을 추출할 수 있는 풍조회로를 가진 AE 신호 분석 장비를 설계, 제작하였다. 제작된 AE 신호 분석 장비에 충격이나 기계적 진동 등과 같은 외란을 가하였을 때 제작된 AE 신호 분석 장비의 잡음레벨은 상용 AE 신호 분석 장비의 잡음레벨보다 매우 낮은 값을 나타내었다. 또한 복합재료 시편의 정, 동적 인장시험 하에서 제작된 AE 분석 장비는 상용 장비와 통일한 수준의 복합재료 파손감지능력을 나타냄을 확인할 수 있었다.

고성능 2단 축류송풍기의 공력설계를 위한 수치해석 및 실험에 관한 연구 (A Numerical Method & Experiments for the Aerodynamic Design of High Performance 2-Stage Axial Flow Fans)

  • 조진수;한철희;조이상
    • 대한기계학회논문집B
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    • 제23권8호
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    • pp.1048-1062
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    • 1999
  • A numerical method and experiments for the aerodynamic design of high performance two-stage axial flow fans was carried out. A vortex ring element method used for the aerodynamic analysis of the propellers was extended to the fan-duct system. Fan Performance and velocity profiles at the fan inlet and outlet are compared with experimental data for the validations of numerical method. Performance test was done based on KS B 6311(testing methods for turbo-fans and blowers). The velocity profile was obtained using a 5-hole pitot tube by the non-nulling method. The two stage axial flow fan configurations for the optimal operation conditions were set by using the experimental results for the single rotating axial flow fan and the single stage axial flow fan. The single rotating axial flow fan showed relatively low efficiency due to the swirl velocities behind rotor exit which produced pressure losses. In contrast, the single stage and the two-stage axial flow fans showed performance improvements due to the swirl velocity reduction by the stator. The peak efficiency of the two stage axial flow fan was improved by 21% and 6%, compared to the single rotating axial flow fan and the single stage axial flow fan, respectively.

한글 경추 통증 및 기능장애 측정 도구의 개발과 타당도 및 신뢰도 검사 (Cross-Cultural Adaptation of Korean Language Versions on Neck Pain and Disability Questionnaires and Their Psychometric Testing)

  • 이해정
    • Korean Journal of Acupuncture
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    • 제24권2호
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    • pp.99-112
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    • 2007
  • Objectives : It was to translate three neck and spinal pain disability questionnaires - the Neck Disability Index (NDI), the Neck Pain and Disability Scale (NPDS), and the Functional Rating Index (FRI) - into Korean language, and evaluate the psychometric properties of Korean versions of questionnaires to achieve a good cross-cultural adaptation. Methods : Forty (23 males, 17 females) subjects aged from 15 to 64 years old, participated to examine test-retest reliability. One hundred and eighty (76 males, 104 females) subjects with a primary diagnosis of non-specific neck pain and 81 healthy volunteers were undertaken to examine internal consistemcy, discriminative validity and longitudinal construct validity. Versions of each questionnaire in idiomatic modern Korean were developed using a procedure proposed by Beaton et al. (2000). To assess reliability, the Intraclass Correlation Coefficient (ICC $_{(2,1)}$) was calculated. Internal consistency was evaluated by Cronbach's alpha. Discriminative validity was examined with independent-group t-tests. Responsiveness was tested by calculating the effect size and standardized response mean for each questionnaire and using Pearson' s r and the area under the receiver operating characteristic curve analysis. Results : Test-retest reliability ofthe translated versions of the three disability questionnaires was excellent (ICC $_{(2,1)$ = 0.86-0.90). High internal consistency was found in the three disability questionnaires (Cronbach's alpha ranged from ${\alpha}=0.88$ for the FRI to ${\alpha}=0.96$ for the NPDS and 0.82 for the Short Form McGill Pain Questionnaire(SFMPQ)). the VAS subscale of the SFMPQ was found to be the most responsive of the subscales (ES=1.44, SRM=1.37). The VAS was also the most responsive pain and disability index in internal responsiveness analysis, although disability indices showed marginally better responsiveness when compared with external standards. No floor or ceiling effects were observed. Conclusions : It is concluded that the questionnaires were successfully translated and exhibit acceptable measurement properties, and may suggest that they are suitable for use in clinical and research application.

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Study on a Single-Dose Toxicity Test of D-Amino Acid Oxidase (DAAO) Extracts Injected into the Tail Vein of Rats

  • Kang, Jungue;Lee, Eun-Yong;Song, Bong-Keun;Lee, Seung-Deok;Yook, Tae-Han;Ahn, Seong-Hun;Son, Il-Hong;Kim, Sungchul
    • 대한약침학회지
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    • 제16권2호
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    • pp.28-32
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    • 2013
  • Objective: This study was performed to analyze the single-dose toxicity of D-amino acid oxidase (DAAO) extracts. Methods: All experiments were conducted at the Korea Testing & Research Institute (KTR), an institution authorized to perform non-clinical studies, under the regulations of Good Laboratory Practice (GLP). Sprague-Dawley rats were chosen for the pilot study. Doses of DAAO extracts, 0.1 to 0.3 cc, were administered to the experimental group, and the same doses of normal saline solution were administered to the control group. This study was conducted under the approval of the Institutional Animal Ethics Committee. Results: In all 4 groups, no deaths occurred, and the $LD_{50}$ of DAAO extracts administered by IV was over 0.3 ml/kg. No significant changes in the weight between the control group and the experimental group were observed. To check for abnormalities in organs and tissues, we used microscopy to examine representative histological sections of each specified organ, the results showed no significant differences in any organs or tissues. Conclusion: The above findings suggest that treatment with D-amino acid oxidase extracts is relatively safe. Further studies on this subject should be conducted to yield more concrete evidence.