• Korean Journal of Radiology
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• v.22 no.3
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• pp.344-353
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• 2021

Objective: The mitotic count of gastrointestinal stromal tumors (GIST) is closely associated with the risk of planting and metastasis. The purpose of this study was to develop a predictive model for the mitotic index of local primary GIST, based on deep learning algorithm. Materials and Methods: Abdominal contrast-enhanced CT images of 148 pathologically confirmed GIST cases were retrospectively collected for the development of a deep learning classification algorithm. The areas of GIST masses on the CT images were retrospectively labelled by an experienced radiologist. The postoperative pathological mitotic count was considered as the gold standard (high mitotic count, > 5/50 high-power fields [HPFs]; low mitotic count, ≤ 5/50 HPFs). A binary classification model was trained on the basis of the VGG16 convolutional neural network, using the CT images with the training set (n = 108), validation set (n = 20), and the test set (n = 20). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated at both, the image level and the patient level. The receiver operating characteristic curves were generated on the basis of the model prediction results and the area under curves (AUCs) were calculated. The risk categories of the tumors were predicted according to the Armed Forces Institute of Pathology criteria. Results: At the image level, the classification prediction results of the mitotic counts in the test cohort were as follows: sensitivity 85.7% (95% confidence interval [CI]: 0.834-0.877), specificity 67.5% (95% CI: 0.636-0.712), PPV 82.1% (95% CI: 0.797-0.843), NPV 73.0% (95% CI: 0.691-0.766), and AUC 0.771 (95% CI: 0.750-0.791). At the patient level, the classification prediction results in the test cohort were as follows: sensitivity 90.0% (95% CI: 0.541-0.995), specificity 70.0% (95% CI: 0.354-0.919), PPV 75.0% (95% CI: 0.428-0.933), NPV 87.5% (95% CI: 0.467-0.993), and AUC 0.800 (95% CI: 0.563-0.943). Conclusion: We developed and preliminarily verified the GIST mitotic count binary prediction model, based on the VGG convolutional neural network. The model displayed a good predictive performance.

• Korean Journal of Radiology
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• v.22 no.1
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• pp.106-117
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• 2021

Objective: To explore the value of magnetic resonance imaging (MRI)-based whole tumor texture analysis in differentiating borderline epithelial ovarian tumors (BEOTs) from FIGO stage I/II malignant epithelial ovarian tumors (MEOTs). Materials and Methods: A total of 88 patients with histopathologically confirmed ovarian epithelial tumors after surgical resection, including 30 BEOT and 58 MEOT patients, were divided into a training group (n = 62) and a test group (n = 26). The clinical and conventional MRI features were retrospectively reviewed. The texture features of tumors, based on T2-weighted imaging, diffusion-weighted imaging, and contrast-enhanced T1-weighted imaging, were extracted using MaZda software and the three top weighted texture features were selected by using the Random Forest algorithm. A non-texture logistic regression model in the training group was built to include those clinical and conventional MRI variables with p value < 0.10. Subsequently, a combined model integrating non-texture information and texture features was built for the training group. The model, evaluated using patients in the training group, was then applied to patients in the test group. Finally, receiver operating characteristic (ROC) curves were used to assess the diagnostic performance of the models. Results: The combined model showed superior performance in categorizing BEOTs and MEOTs (sensitivity, 92.5%; specificity, 86.4%; accuracy, 90.3%; area under the ROC curve [AUC], 0.962) than the non-texture model (sensitivity, 78.3%; specificity, 84.6%; accuracy, 82.3%; AUC, 0.818). The AUCs were statistically different (p value = 0.038). In the test group, the AUCs, sensitivity, specificity, and accuracy were 0.840, 73.3%, 90.1%, and 80.8% when the non-texture model was used and 0.896, 75.0%, 94.0%, and 88.5% when the combined model was used. Conclusion: MRI-based texture features combined with clinical and conventional MRI features may assist in differentitating between BEOT and FIGO stage I/II MEOT patients.

• Pediatric Infection and Vaccine
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• v.8 no.1
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• pp.90-93
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• 2001

Purpose : The accurate diagnosis and proper treatment of group A streptococal infection should be emphasized concerning about possible development of late sequelae, such as acute rheumatic fever and acute glomerulonephritis. Inadequate & improperance of antobiotics have resulted in increased number of antibiotic-resistant bacteria. We would like to know the clinical usefulness of rapid strep test compared with conventional throat culture in out-patients with acute pharyngotonsilitis. Methods : From Sep. 2000. to Jan. 2001, rapid strep test(LINK 2 Strep A, USA) & throat culture were taken from 87 patients with clinically suspect pharyngotonsilitis from Masan Fatima hospital & kyunghee university hospital. Results : Of 87 cases with pharyngitis, 39 cases proved to have group A streptococci by throat culture. The positive predictive value of rapid test was 92.3%(36 of 39 cases) and sensitivity test was 81.8%(36 of 44 cases). The specificity of rapid test was 93.0%(40 of 43 cases) and negative predictive value was 83.3%(40 of 48 cases). Conclusion : The positive predictive value & specificity of rapid strep test is high. And so, this test will give the pediatricians practical guidance of antibiotic use in patients with pharyngitis. But more efforts should be made to prevent antibiotics abuse and correct diagnosis of pharyngitis.

• Therapeutic Science for Rehabilitation
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• v.9 no.4
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• pp.69-81
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• 2020

Objective : The purpose of this study was to develop a Yonsei dual task cognitive screening test (Y-DuCog) for the elderly. Methods : The reliability and validity test of Y-DuCog (Yonsei Dual Task Cognitive Screening Test) was developed by 229 elderly people aged over 60 years from community organizations at Gyeonggi-do and Chungcheong-do from May 2019 to August 2019. In addition, the criteria for classifying elderly with cognitive impairment were presented. Results : The correlation analysis between MMSE-K, MoCA-K and Y-DuCog were a correlation between the DTE and CRR of Y-DuCog. As a result of internal consistency, Cronbach's-α values of DTE and CRR showed .848 (p<.01) and .916 (p<.01), respectively. The test-retest reliability was high. The screening point showed 88.7% sensitivity and 83.5% specificity at 31.76 seconds in total DTE, and 84.5% sensitivity and 76.6% specificity at 0.38 in total dual-task CRR. Conclusion : This study verified the reliability and validity of Y-DuCog. It was found that the level of education was not a barrier to the undertaking of this test. Furthermore, the test could be performed easily and quickly. It is also expected to be used to evaluate the effectiveness of cognitive function assessment and intervention methods in the elderly.

• The Journal of Korean Physical Therapy
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• v.22 no.4
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• pp.1-6
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• 2010

Purpose: This study was designed to evaluate the clinical utility of the Four square step test (FSST) for predicting falls in stroke patients, to compare the ability of the FSST test to discriminate between subgroups of fallers, and to determine if the test has any predictive value in identifying stroke patients who will fall. Methods: Stroke patients (N=37) who could walk at least 50 m with minimal assistance were recruited consecutively when attending a physical therapy session during their rehabilitation. Dynamic standing balance was measured using the FSST. The main outcome measures were FSST time and fall number. Numbers of falls were compared with FSST scores. Differences between the groups in FSST scores were examined using a t-test and 1-way analysis of variance. Post hoc analysis using the Tukey B procedure was used to identify specific group differences. Alpha was set at 0.05. Results: A total of 15 participants (40.5%) reported falls 6 had recurrent falls (2 falls) and 9 fell once. The mean FSST time differed significantly between groups with zero and multiple falls. A cutoff score of greater than 17 seconds on the FSST was associated with a sensitivity of 83% and a specificity of 84% for the identification of subjects with multiple risk factors for falls. Conclusion: The FSST is a feasible and valid clinical test of dynamic standing balance and can predict falls in post-stroke patients.

• Korean Journal of Veterinary Research
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• v.58 no.1
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• pp.27-31
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• 2018

Canine coronavirus is a single-stranded RNA virus that causes enteritis in dogs of any age. Coronaviral enteritis is seldom definitively diagnosed, since it is usually much less severe than many other types of enteritis and is self-limiting. Conventional diagnostics for the canine coronaviral enteritis such as polymerase chain reaction (PCR), virus isolation, and electron microscopic examination are inappropriate for small animal clinics due to the complicated experimental processes involved. Therefore, a commercially available lateral flow test kit based on chromatographic immunoassay techniques was tested to evaluate its performance as a first-line diagnostic test kit that could be used in clinics. The coronavirus antigen test kit detected canine coronavirus-infected dogs with 93.1% sensitivity and 97.5% specificity. The detection limit of the test kit was between $1.97{\times}10^4/mL$ and $9.85{\times}10^3/mL$ for samples with a 2-fold serial dilution from $1.25{\times}10^6\;TCID_{50}$ ($TCID_{50}$, 50% tissue culture infectious dose). Additionally, the test kit had no cross-reactivity with canine parvovirus, distemper virus, or Escherichia coli. Overall, the commercially available test kit showed good diagnostic performance in a clinical setting, with results similar to those from PCR, confirming their potential for convenient and accurate use in small animal clinics.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.263-270
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• 2003

The objective of the present study was to investigate the use of fluid released from muscle samples as an alternative to serum for ELISA to detect classical swine fever(CSF) virus antibodies in slaughter pigs. The optimal correspondence between serum 1:20 OD values and muscle fluid OD values was achieved at a muscle fluid dilution of 1:2. Significant correlation was found between serum and neck muscle ELISA ($r_s=0.880$, p<0.0001, ${\kappa}=0.82$; specificity of 97.0% and sensitivity 90.6%). The semimembranous muscle showed similar correlation in CSF ELISA($r_s=0.877$, p<0.0001, ${\kappa}=0.75$; specificity of 94.1% and sensitivity 89.1%). High correlation was obtained between serum and mesenteric lymph node in the CSF ELISA ($r_s=0.937$, p<0.0001, ${\kappa}=0.87$; specificity of 97.1% and sensitivity 93.0%). Measmement agreement between serum ELISA and muscle fluid ELISA was calculated and expressed as limits of agreement. The correspondence of ELISA of serum and muscle fluid indicated limits of agreement. Above 95% of all muscle fluid values were distributed within this limits of agreement. Among the samples used for ELISA for detecting CSFV antibodies, mesenteric lymph node had the most correlation and agreement with serum ELISA. F-test for comparison of variances showed no significant difference between the serum and muscle fluid. In conclusion, muscle fluid is a useful postmortem alternative to serum to detect CSFV antibodies.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7085-7088
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• 2015

Background: The high incidence of prostate cancer as the most common malignancy in males in many countries raises the question of developing reliable detection tests. The prostate specific antigen (PSA) test is the most widely used for screening for prostate cancer; however, its low specificity elevates the number of unnecessarily biopsies. Serum human kallikrein-2 (hK2) is considered as a promising marker, and especially its ratio to fPSA, for predicting the presence of malignancy to select the best choice referring to biopsy or surveillance. In this study, we investigated the role of hK2 and its combinations with other markers to discriminate prostate cancer from benign diseases in Syrian patients. Materials and Methods: In this prospective oriented cross-sectional cohort study, serum samples were collected from patients referred to many Hospitals in Damascus, Syria, between May 2011 and March 2012, and diagnosed with biopsy proven benign prostate hyperplasia (BPH) or prostate cancer (PCa). Serum was analyzed for hK2, PSA and fPSA, and the ratios of fPSA/PSA and hK2/fPSA were calculated. Results: We found that mean hK2/fPSA ratios were significantly higher (P=0.01) in prostate cancer patients than in the BPH or control groups. Also the ratio hk2/fPSA gave the largest area under the curve (AUC:0.96) which was significantly larger than for fPSA/PSA (AUC:0.41) indicative of higher specificity. Conclusions: Our results demonstrate that the ratio of hK2/fPSA might be superior to the use of fPSA/PSA alone. The hK2 could be shown to enhance the early detection of prostate cancer; especially the ratio hK2/fPSA improves specificity and hence may reduce the number of negative biopsies.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5517-5523
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• 2012

Purpose: To evaluate the diagnostic accuracy of ultrasonograph and fine-needle aspiration cytologic examination (USG-FNAC) in the staging of axillary lymph node metastasis in breast cancer patients.Methods: We conducted an electronic search of the literature addressing the performance of USG-FNAC in diagnosis of axillary lymph node metastasis in databases such as Pubmed, Medline, Embase, Ovid and Cochrane library. We introduced a series of diagnostic test indices to evaluate the performance of USG-FNAC by the random effect model (REM), including sensitivity, specificity, likelihood ratios, and diagnostic odds ratios and area under the curve (AUC). Results: A total of 20 studies including 1371 cases and 1289 controls were identified. The pooled sensitivity was determined to be 0.66 (95% CI 0.64-0.69), specificity 0.98 (95% CI 0.98-0.99), positive likelihood ratio 22.7 (95% CI 15.0-34.49), negative likelihood ratio 0.32 (95% CI 0.25-0.41), diagnostic OR 84.2 (95% CI 53.3-133.0). Due to the marginal threshold effect found in some indices of diagnostic validity, we used a summary SROC curve to aggregate data, and obtained a symmetrical curve with an AUC of 0.942. Conclusion: The results of this meta-analysis indicated that the USG-FNAC techniques have acceptable diagnostic validity indices and can be used for early staging of axillary lymph node in breast cancer patients.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.237-241
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• 2012

Objective: Screening for colorectal cancer using guaiac-based fecal occult blood tests (gFOBT) is well established in Western populations, but is hampered by poor patient compliance due to the imposed dietary restrictions. Fecal immunochemical tests (FIT) do not require dietary restriction, but are more expensive than gFOBT and therefore restrict its use in developing countries in Asia. However, Asian diets being low in meat content may not require diet restriction for gFOBT to achieve equivalent results. The objective of this study was to evaluate and compare the validity and suitability of gFOBT and FIT or a combination of the two in screening for colorectal neoplasias without prior dietary restriction in an Asian population. Methods: Patients referred to the Endoscopic Unit for colonoscopy were recruited for the study. Stool samples were collected prior to bowel preparation, and tested for occult blood with both gFOBT and FIT. Dietary restriction was not imposed. To assess the validity of either tests or in combination to detect a neoplasm or cancer in the colon, their false positive rates, their sensitivity (true positive rate) and the specificity (true negative rate) were analyzed and compared. Results: One hundred and three patients were analysed. The sensitivity for picking up any neoplasia was 53% for FIT, 40% for gFOBT and 23.3% for the combination. The sensitivities for picking up only carcinoma were 77.8%, 66.7% and 55.5%, respectively. The specificity for excluding any neoplasia was 91.7% for FIT, 74% for gFOBT and 94.5% for a combination, whereas for excluding only carcinomas they were 84%, 73.4% and 93.6%. Of the 69 with normal colonoscopic findings, FOBT was positive in 4.3%, 23.2 %and 2.9% for FIT, gFOBT, or combination of tests respectively. Conclusion: FIT is the recommended method if we are to dispense with dietary restriction in our patients because of its relatively low-false positivity and better sensitivity and specificity rates.