• Imaging Science in Dentistry
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• v.53 no.4
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• pp.375-381
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• 2023

Purpose: This study assessed the diagnostic performance of stitched and non-stitched cross-sectional cone-beam computed tomography (CBCT) images of non-displaced ovine mandibular fractures. Materials and Methods: In this ex vivo study, non-displaced fractures were artificially created in 10 ovine mandibles (20 hemi-mandibles) using a hammer. The control group comprised 8 hemi-mandibles. The non-displaced fracture lines were oblique or vertical, <0.5 mm wide, 10-20 mm long, and only in the buccal or lingual cortex. Fracture lines in the ramus and posterior mandible were created to be at the interface or borders of the 2 stitched images. CBCT images were obtained from the specimens with an 80 mm×80 mm field of view before and after fracture induction. OnDemand software (Cybermed, Seoul, Korea) was used for stitching the CBCT images. Four observers evaluated 56 (28 stitched and 28 non-stitched) images to detect fracture lines. The diagnostic performance of stitched and non-stitched images was assessed by calculating the area under the receiver operating characteristic curve (AUC). Sensitivity and specificity values were also calculated (alpha=0.05). Results: The AUC was calculated to be 0.862 and 0.825 for the stitched and non-stitched images, respectively (P=0.747). The sensitivity and specificity were 90% and 75% for the non-stitched images and 85% and 87% for the stitched images, respectively. The inter-observer reliability was shown by a Fleiss kappa coefficient of 0.79, indicating good agreement. Conclusion: No significant difference was found in the diagnostic performance of stitched and non-stitched cross-sectional CBCT images of non-displaced fractures of the ovine mandible.

• Korean Journal of Radiology
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• v.21 no.4
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• pp.442-449
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• 2020

Objective: To compare the diagnostic performance of contrast-enhanced spectral mammography (CESM) versus ultrasonography (US) in symptomatic patients with dense breasts, while using histology as the gold standard. Materials and Methods: After obtaining approval from the local ethics board, this prospective study collected data from patients with symptomatic breasts who underwent CESM and US examinations from May 1, 2017 to September 30, 2017. We then selected those with dense breasts and pathological results as our sample population. Both CESM and US results were classified by a radiologist through the Breast Imaging Reporting and Data System, and the results were compared with their corresponding histological results. The chi-square test was conducted to compare the diagnostic performance of CESM and US, and the receiver operating characteristic curves for the two imaging modalities were obtained. Results: A total of 131 lesions from 115 patients with dense breasts were included in this study. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 93.8%, 88.1%, 88.2%, 93.7%, and 90.8% for CESM, and 90.6%, 82.1%, 82.9%, 90.2%, and 86.3% for US, respectively. The p values for sensitivity, specificity, PPV, NPV, and accuracy were 0.687, 0.388, 0.370, 0.702, and 0.238, respectively. The area under the curve of CESM (0.917) was comparable with that of US (0.884); however, the differences between CESM and US were not statistically significant (p = 0.225). Eight false-positive cases and 4 false-negative cases for breast cancer were found in CESM, while 12 false-positive cases and 6 false-negative cases were found in US. Conclusion: The diagnostic performances of CESM and US are comparable in symptomatic women with dense breasts; however, the routine use of additional US imaging is questionable for lesions that can be detected by CESM.

• The Journal of the Korea Contents Association
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• v.12 no.10
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• pp.385-394
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• 2012

The aim of this study was to determine the effectiveness of diagnostic range for BMD measurement tools(DEXA, QUS, and RA) to health examination in transitional ages. In standard T-score -2.5 of DEXA, cutoff value by RA is -1.675(sensitivity: 70.0%, specificity: 63.7%) and cutoff value by QUS is -1.733(sensitivity: 70.4, specificity: 59.5%), also T-score -3.0 of DEXA, cutoff value by RA is -2.325(sensitivity: 70.0%, specificity: 42.9%) and cutoff value by QUS is -2.323(sensitivity: 70.4, specificity: 56.8%). There was, however, no significant difference in standard DEXA(lumbar spine and femur) between RA and QUS by repeat measurement(precision), and correlation were without effect. ROC analysis showed that all methods are qualified for BMD measurement tools to health examination in transitional ages; however, the different sensitivities and specificities of the methods, as well as age and gender, calibration parameters for diagnostic tests have to be considered.

• Tuberculosis and Respiratory Diseases
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• v.47 no.6
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• pp.757-767
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• 1999

Background: Diagnosis by smear and/or cultures of the Mycobacterium tuberculosis from body fluid or biopsy specimen is "Gold standard". However the sensitivity of the direct microscopy is relatively low and culture of mycobacteria is time consuming. Despite an explosion in the techniques of rapid identification of mycobacteria by molecular genetic means, it is laborious and expensive and then rapid, inexpensive serodiagnosis is interested in diagnosis of tuberculosis. But sensitivity and specificity of known serologic antigen is not full sufficient level and then new antigen develop and combination cocktails of new developed antigens by ELISA are needed. Method: To compare the efficacy of different mycobacterial specific antigen and to assess the applicability of the combination of several different antigens in the diagnosis of tuberculosis, five ELISA tests derived 14KDa, 16KDa, 19KDa, 23KDa, 38KDa were evaluated in 57 active pulmonary patient and 24 inactive post-therapy follow up patient and 48 normal control. Results: The optical densities of ELISA test with 14KDa, 16KDa, 19KDa, 23KDa, 38KDa were significantly higher in active tuberculosis cases than in normal control(P<0.001, P<0.001, P<0.027, P<0.001, P<0.001) and those with 16KDa, 38KDa were significant higher in active tuberculosis cases than in inactive post-therapy follow up cases(P<0.01. P<0.001) and those of 14KDa, 16KDa, 23KDa, 38KDa were significant higher in inactive post-therapy follow up cases than in normal control(P<0.008. P<0.01. P<0.006. P<0.001). The sensitivity of 14KDa, 16KDa, 19KDa, 23KDa, 38KDa in active pulmonary patient cases was 42.1%, 43.9%, 15.8%, 28.0%, 70.2%, respectively and the specificity of 14KDa, 16KDa, 19KDa, 23KDa, 38KDa in active pulmonary patient cases was 95.8%, 95.8%, 91.7%, 89.6%, 93.8%, respectively. The sensitivity and specificity of combination 38KDa with 16KDa was 87% and 93.7%. Conclusion: The sensitivity and specificity of new antigens for serodiagnosis of the tuberculosis still remains limited at around 70%, which makes its a poor diagnostic tool for disease confirmation. A combination of cocktail antigens provided by cut-off value adjustment for serodiagnosis of tuberculosis some improved diagnostic yield than single antigen serologic test.

• Korean Journal of Radiology
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• v.23 no.12
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• pp.1260-1268
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• 2022

Objective: To propose standardized MRI-proton density fat fraction (PDFF) cutoff values for diagnosing hepatic steatosis, evaluated using contemporary PDFF measuring methods in a large population of healthy adults, using histologic fat fraction (HFF) as the reference standard. Materials and Methods: A retrospective search of electronic medical records between 2015 and 2018 identified 1063 adult donor candidates for liver transplantation who had undergone liver MRI and liver biopsy within a 7-day interval. Patients with a history of liver disease or significant alcohol consumption were excluded. Chemical shift imaging-based MRI (CS-MRI) PDFF and high-speed T2-corrected multi-echo MR spectroscopy (HISTO-MRS) PDFF data were obtained. By temporal splitting, the total population was divided into development and validation sets. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance of the MRI-PDFF method. Two cutoff values with sensitivity > 90% and specificity > 90% were selected to rule-out and rule-in, respectively, hepatic steatosis with reference to HFF ≥ 5% in the development set. The diagnostic performance was assessed using the validation set. Results: Of 921 final participants (624 male; mean age ± standard deviation, 31.5 ± 9.0 years), the development and validation sets comprised 497 and 424 patients, respectively. In the development set, the areas under the ROC curve for diagnosing hepatic steatosis were 0.920 for CS-MRI-PDFF and 0.915 for HISTO-MRS-PDFF. For ruling-out hepatic steatosis, the CS-MRI-PDFF cutoff was 2.3% (sensitivity, 92.4%; specificity, 63.0%) and the HISTO-MRI-PDFF cutoff was 2.6% (sensitivity, 88.8%; specificity, 70.1%). For ruling-in hepatic steatosis, the CS-MRI-PDFF cutoff was 3.5% (sensitivity, 73.5%; specificity, 88.6%) and the HISTO-MRI-PDFF cutoff was 4.0% (sensitivity, 74.7%; specificity, 90.6%). Conclusion: In a large population of healthy adults, our study suggests diagnostic thresholds for ruling-out and ruling-in hepatic steatosis defined as HFF ≥ 5% by contemporary PDFF measurement methods.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2341-2344
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• 2014

Background: p53 protein expression has been detected immunohistochemically in papillary thyroid carcinoma(PTC). We investigated the relations between its expression and clinicopathologic features and its significance as a diagnostic marker. Materials and Methods: We compared and evaluated 93 patients in whom thyroidectomy with lymph node dissection had been performed to treat PTC for clinicopathologic significance and 102 patients with 23 papillary thyroid overt carcinomas (POC), 57 papillary thyroid microcarcinomas(PMC), 5 follicular adenomas (FA), 5 Hashimoto's thyroiditis (HT) and 12 nodular hyperplasias (NH) for significance as a diagnostic marker. Expression of p53 protein was evaluated immunohistochemically in sections of paraffinembedded tissue. Results: Statistical analysis showed significantly different expression of p53 in PTC versus other benign thyroid lesions (BTL).The diagnostic sensitivity and specificity were 85.0% and 72.7%, respectively. Overexpression of p53 protein was observed in 44 of the 93 PTC cases (47.3%), but no significant correlation between p53 protein overexpression and clinicopathologic features (age, size, multiplicity, lymph node metastasis, extrathyroidal extension and vascular invasion) was noted. Conclusions: p53 is valuable to distinguish PTC from other BTL, but there is no correlation between p53 protein overexpression and clinicopathologic features.

• Clinical Endoscopy
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• v.57 no.1
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• pp.11-17
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• 2024

Although magnifying endoscopy with narrow-band imaging is the standard diagnostic test for gastric cancer, diagnosing gastric cancer using this technology requires considerable skill. Artificial intelligence has superior image recognition, and its usefulness in endoscopic image diagnosis has been reported in many cases. The diagnostic performance (accuracy, sensitivity, and specificity) of artificial intelligence using magnifying endoscopy with narrow band still images and videos for gastric cancer was higher than that of expert endoscopists, suggesting the usefulness of artificial intelligence in diagnosing gastric cancer. Histological diagnosis of gastric cancer using artificial intelligence is also promising. However, previous studies on the use of artificial intelligence to diagnose gastric cancer were small-scale; thus, large-scale studies are necessary to examine whether a high diagnostic performance can be achieved. In addition, the diagnosis of gastric cancer using artificial intelligence has not yet become widespread in clinical practice, and further research is necessary. Therefore, in the future, artificial intelligence must be further developed as an instrument, and its diagnostic performance is expected to improve with the accumulation of numerous cases nationwide.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.529-536
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• 1994

To establish more specific and simple diagnostic methods for detection of the antibodies and antigens of Aujeszky's disease virus(ADV), we designed indirect dot-immunoassay(IDI) and double sandwich dotimmunoassay(DSDI) using the solid phases of nitrocellolose paper and polystyrene plate. The diagnostic efficacy of these methods was investigated. As the sensitivity of IDI was tested by various virus concentration, the specimens with the virus titer above $10^{4.0}TCID_{50}/0.2ml$ showed positive reaction, but that below $10^{1.0}TCID_{50}/ml$ revealed negative. Tonsil emulsion at the virus titer of $10^{4.5}TCID_{50}/0.2ml$ showed the highest sensitivity as diluted by 1/100. In detection of ADV antigens from the various tissues of the rats and pigs infected with ADV, IDI using monoclonal antibody showed the higher specificity as compared with IDI using polyclonal antibody and virus isolation method. The efficacy of the DSDI for detection of ADV antibody was compared with other tests. The sensitivity of DSDI was higher than virus neutralization(VN) and agar gel immunodiffusion test(AGID). Meanwhile, specificity of DSDI was lower than AGID, but similar to IDEA. In comparison with VN test, DSDI showed 96.9% agreement to VN test that is the highest of three tests. In general, application of polyclonal antibody in both tests caused the higher sensitivity but the lower specificty.

• Investigative Magnetic Resonance Imaging
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• v.19 no.1
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• pp.37-46
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• 2015

Purpose: This report compared the diagnostic effectiveness between ultrasmall superparamagnetic iron oxide (USPIO) and gadolinium (Gd) based magnetic resonance imaging (MRI) for differentiation of axillary status in breast cancer patients. Materials and Methods: The present authors performed a meta-analysis of previous studies that compared USPIO or Gd based MRI with histological diagnosis after surgery or biopsy. We searched PubMed, EMBASE, Cochrane Library, ScienceDirect, SpringerLink, Ovid databases and references of articles to identify studies reporting data until December 2013. Pooled sensitivity and specificity were calculated for every study; summary receiver operating characteristic and subgroup analysis was done. Analyses of study quality and heterogeneity were also assessed. Results: There were 14 publications that met the criteria for inclusion in our meta-analysis. USPIO based MRI showed 0.83 (95% CI: 0.75-0.89) and 0.97 (95% CI: 0.94-0.98) for pooled sensitivity and specificity, respectively. Gd based MRI represented pooled sensitivity and specificity of 0.61 (95% CI: 0.55-0.67) and 0.90 (95% CI: 0.87-0.92) for each. Overall weighted area under the curve for USPIO and Gd based MRI were 0.9563 and 0.9051, respectively. Conclusion: USPIO based MRI had a tendency toward high pooled sensitivity and specificity in detection of axillary metastases for breast cancer. This result may mean that USPIO based MRI could be used as complementary modality to differentiate axillary status more precisely, and assist in the decision-making process regarding possible invasive procedures, such as sentinel node biopsy.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.19 no.1
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• pp.29-37
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• 2016

Purpose: The aim of our study was to establish a safe and convenient diagnostic method for acute gastrointestinal (GI) graft-versus-host disease (GVHD) in children by determining the sensitivity and negative predictive values of upper and lower endoscopic biopsies for children suspected of GI GVHD. Methods: Patients suspected of GI GVHD who received endoscopic evaluation within 100 days after stem cell transplantation and endoscopies between January 2012 and March 2014 in Seoul National University Children's Hospital were included in our study. Results: Fifteen patients with a total of 20 endoscopic procedures were included in our study. Sensitivity at the esophagus, stomach, and duodenum were 22.2%, 30.0%, and 80.0%, respectively. Negative predictive values at the esophagus, stomach, and duodenum were 22.2%, 30.0%, and 60.0%, respectively. Overall sensitivity and negative predictive values of upper endoscopic biopsy for GVHD were 77.8% and 50.0%, respectively. Overall sensitivity and negative predictive values of lower endoscopic biopsy for GVHD were 88.9% and 66.7%, respectively. Conclusion: We recommend flexible sigmoidoscopy as a safe and accurate diagnostic tool for GVHD, similar to other studies reported previously. However, if there is no evidence of GVHD on sigmoidoscopy with high index of suspicion of GI bleeding, full colonoscopy and upper endoscopy should be considered.