No abstract available.
Observer Variation*

BACKGROUND: Immunohistochemical staining for p16INK4a and Ki-67 has been used to improve the accuracy in making a diagnosis of the uterine cervix cancer on biopsy. This study was conducted to examine the usefulness of these markers in the pathological diagnosis based on cervical biopsy. METHODS: We selected a consecutive series of 111 colposcopically directed cervical punch biopsies. Using these biopsy samples, we performed an immunohistochemical staining for p16INK4a and Ki-67 to establish a diagnosis. The slides were circulated among four pathologists in a sequential order: the hematoxylin and eosin (H&E) slide, H&E slide and p16INK4a-stained slide, and H&E slide, p16INK4a- and Ki-67-stained slides. RESULTS: The overall rates of the concordance in the first, the second, and the third diagnoses were 77.5%, 82.0%, and 82.0%, respectively. The rate of the concordance in the diagnosis of cervical intraepithelial neoplasm (CIN) 2/3 was increased from 62.2% to 73.0%. But there was a variability in the rate of the revision of the diagnosis between the pathologists. With the application of criteria for interpreting the expressions of p16INK4a and Ki-67, benign and CIN 1 lesions showed a p16INK4a expression score of 0 or 1. But CIN 2 and CIN 3 lesions showed a p16INK4a expression score of 2 and 3, respectively. CONCLUSIONS: The immunostain for p16INK4a and Ki-67 might be useful in reducing an inter-observer variability. But criteria for interpreting both markers should be strictly applied.
Observer Variation ; Biopsy

BACKGROUND: Immunohistochemical staining for p16INK4a and Ki-67 has been used to improve the accuracy in making a diagnosis of the uterine cervix cancer on biopsy. This study was conducted to examine the usefulness of these markers in the pathological diagnosis based on cervical biopsy. METHODS: We selected a consecutive series of 111 colposcopically directed cervical punch biopsies. Using these biopsy samples, we performed an immunohistochemical staining for p16INK4a and Ki-67 to establish a diagnosis. The slides were circulated among four pathologists in a sequential order: the hematoxylin and eosin (H&E) slide, H&E slide and p16INK4a-stained slide, and H&E slide, p16INK4a- and Ki-67-stained slides. RESULTS: The overall rates of the concordance in the first, the second, and the third diagnoses were 77.5%, 82.0%, and 82.0%, respectively. The rate of the concordance in the diagnosis of cervical intraepithelial neoplasm (CIN) 2/3 was increased from 62.2% to 73.0%. But there was a variability in the rate of the revision of the diagnosis between the pathologists. With the application of criteria for interpreting the expressions of p16INK4a and Ki-67, benign and CIN 1 lesions showed a p16INK4a expression score of 0 or 1. But CIN 2 and CIN 3 lesions showed a p16INK4a expression score of 2 and 3, respectively. CONCLUSIONS: The immunostain for p16INK4a and Ki-67 might be useful in reducing an inter-observer variability. But criteria for interpreting both markers should be strictly applied.
Observer Variation ; Biopsy

No abstract available.
Observer Variation ; Humans

BACKGROUND: As measurement of Ki-67 proliferation index is an important part of breast cancer diagnostics, we conducted a multicenter study to examine the degree of concordance in Ki-67 counting and to find factors that lead to its variability. METHODS: Thirty observers from thirty different institutions reviewed Ki-67-stained slides of 20 different breast cancers on whole sections and tissue microarray (TMA) by online system. Ten of the 20 breast cancers had hot spots of Ki-67 expression. Each observer scored Ki-67 in two different ways: direct counting (average vs. hot spot method) and categorical estimation. Intraclass correlation coefficient (ICC) of Ki-67 index was calculated for comparative analysis. RESULTS: For direct counting, ICC of TMA was slightly higher than that of whole sections using average method (0.895 vs 0.858). The ICC of tumors with hot spots was lower than that of tumors without (0.736 vs 0.874). In tumors with hot spots, observers took an additional counting from the hot spot; the ICC of whole sections using hot spot method was still lower than that of TMA (0.737 vs 0.895). In categorical estimation, Ki-67 index showed a wide distribution in some cases. Nevertheless, in tumors with hot spots, the range of distribution in Ki-67 categories was decreased with hot spot method and in TMA platform. CONCLUSIONS: Interobserver variability of Ki-67 index for direct counting and categorical estimation was relatively high. Tumors with hot spots showed greater interobserver variability as opposed to those without, and restricting the measurement area yielded lower interobserver variability.
Breast Neoplasms* ; Breast* ; Observer Variation* ; Online Systems

No abstract available.
Classification* ; Endoscopy* ; Learning* ; Observer Variation* ; Stomach Neoplasms*

PURPOSE: To examine whether the ACR phantom could be used in quality standards for magnetic resonance imaging (MRI) instruments in Korea. MATERIALS AND METHODS: We conducted the phantom test using the ACR MRI phantom in 20 MRI instruments currently used in Korea. According to ACR criteria, we acquired the phantom images which were then assessed by the following seven tests: geometric accuracy, high spatial resolution, slice thickness accuracy, slice position accuracy, image intensity uniformity, percent signal ghosting, and low contrast object detectability. The phantom images were interpreted by three experienced radiologists according to ACR criteria. Then, we examined the failure rate of each test and evaluated the inter-observer variation in the measurements and test failure. RESULTS: The failure rate of each test could be broken into the following components: geometric accuracy (11-21%), high contrast spatial resolution (10-15%), slice thickness accuracy (6-22%), slice position accuracy (5-17%), image intensity uniformity (6%), percent signal ghosting (16%), and low contrast object detectability (8-10%). In this series, all the failure rates were less than 30%. In addition, no inter-observer variation was seen in the measurements and test failure. CONCLUSION: ACR MRI phantom promises to be established as the standard phantom for MRI instruments in Korea because of its objectivity in assessing the phantom images.
Korea ; Magnetic Resonance Imaging* ; Observer Variation

PURPOSE: To evaluate the inter- and intra-observer variability of ocular response analyzer (ORA) measurements, and to evaluate the relationships among the intraocular pressures (IOPs) obtained by ORA, Goldmann applanation tonometer (GAT) and non-contact tonometer (NCT). METHODS: The present study included 45 normal eyes from 45 volunteers. Three masked observers performed ORA measurements. NCT and GAT measurements were performed by one independent observer. The reproducibility of ORA was assessed by ANOVA-based intraclass correlation coefficient (ICC) and coefficient of variation (CV). Comparison among the tonometers was performed using the Bland-Altman plot and paired t-test. RESULTS: The ICC for inter-observer reproducibility of ORA parameters was 0.90 to 0.97. The corresponding CV values were 13.2% to 19.1%. The intra-observer ICC values for IOP cc were 0.78 to 0.88. CV was 11.2% to 16.8%. For CRF, ICC values were 0.80 to 0.84 with CV values as 11.6% to 15.9%. For CH, ICC values were 0.74 to 0.82 and CV values were 13.0% to 15.9%. The difference in mean IOP values between IOP cc and IOP g was statistically significant (p = 0.04). However, no difference was found among other tonometers, and only IOP cc did not result in significant correlation with central corneal thickness (CCT) (p = 0.38). CONCLUSIONS: The intra- and inter-observer reproducibility was substantial for IOP cc, IOP g, CH and CRF, for all observers. Additionally, IOP measured with ORA did not result in significant differences from GAT and NCT.
Eye ; Intraocular Pressure ; Masks ; Observer Variation ; Peptides

OBJECTIVE: Computed tomography (CT)-based method of three dimensional (3D) analysis (MIMICS®, Materialise, Leuven, Belgium) is reported as very useful software for evaluation of OPLL, but its reliability and reproducibility are obscure. This study was conducted to evaluate the accuracy of MIMICS® system, and inter- and intra-observer reliability in the measurement of OPLL. METHODS: Three neurosurgeons independently analyzed the randomly selected 10 OPLL cases with medical image processing software (MIMICS®) which create 3D model with Digital Imaging and Communication in Medicine (DICOM) data from CT images after brief explanation was given to examiners before the image construction steps. To assess the reliability of inter- and intra-examiner intraclass correlation coefficient (ICC), 3 examiners measured 4 parameters (volume, length, width, and length) in 10 cases 2 times with 1-week interval. RESULTS: The inter-examiner ICCs among 3 examiners were 0.996 (95% confidence interval [CI], 0.987–0.999) for volume measurement, 0.973 (95% CI, 0.907–0.978) for thickness, 0.969 (95% CI, 0.895–0.993) for width, and 0.995 (95% CI, 0.983–0.999) for length. The intra-examiner ICCs were 0.994 (range, 0.991–0.996) for volume, 0.996 (range, 0.944–0.998) for length, 0.930 (range, 0.873–0.947) for width, and 0.987 (range, 0.985–0.995) for length. CONCLUSION: The medical image processing software (MIMICS®) provided detailed quantification OPLL volume with minimal error of inter- and intra-observer reliability in the measurement of OPLL.
Longitudinal Ligaments* ; Methods ; Neurosurgeons ; Observer Variation*

PURPOSE: To investigate and compare inter-observer variability and diagnostic performance of thyroid ultrasound (US) between a faculty member and observing residents. MATERIALS AND METHODS: From October 2007 to June 2009, 18 residents underwent training in thyroid US section. Group 1 included 8 residents that were trained for the first time and group 2 included 10 residents that were trained for the second time. US features of nodules were recoded according to the composition, echogenicity, margin, calcifications, shape, and final assessment by a faculty member and residents, respectively. Following a discussion, a faculty member performed fine needle aspiration. Then, the inter-observer variability and diagnostic performance between a faculty member and residents were investigated and compared for US. RESULTS: In group 1, agreement for composition in resident 1, calcification for residents 5 and 6, and shape for resident 4 were slight, moderate, moderate, and moderate, respectively. In group 2, agreement for composition in residents 1 and 10 were moderate. Substantial or greater agreement was observed more frequently in group 2 than 1. The diagnostic performances for both the faculty and residents were high and not statistically different. CONCLUSION: Agreement for US features between a faculty and residents as well as diagnostic performance were high. Moreover, diagnostic performance of residents that underwent training a second time of training was higher than residents that underwent training only once.
Biopsy, Fine-Needle ; Observer Variation ; Thyroid Gland