• Radiation Oncology Journal
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• v.32 no.1
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• pp.43-47
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• 2014

Purpose: The degree of radiation-induced lung fibrosis (RILF) can be measured quantitatively by fibrosis volume (VF) on chest computed tomography (CT) scan. The purpose of this study was to investigate the interobserver and intraobserver variability in CT-based measurement of VF. Materials and Methods: We selected 10 non-small cell lung cancer patients developed with RILF after postoperative radiation therapy (PORT) and delineated VF on the follow-up chest CT scanned at more than 6 months after radiotherapy. Three radiation oncologists independently delineated VF to investigate the interobserver variability. Three times of delineation of VF was performed by two radiation oncologists for the analysis of intraobserver variability. We analysed the concordance index (CI) and inter/intra-class correlation coefficient (ICC). Results: The median CI was 0.61 (range, 0.44 to 0.68) for interobserver variability and the median CIs for intraobserver variability were 0.69 (range, 0.65 to 0.79) and 0.61(range, 0.55 to 0.65) by two observers. The ICC for interobserver variability was 0.974 (p < 0.001) and ICCs for intraobserver variability were 0.996 (p < 0.001) and 0.991 (p < 0.001), respectively. Conclusion: CT-based measurement of VF with patients who received PORT was a highly consistent and reproducible quantitative method between and within observers.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.254-258
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• 2001

Objective : The terminology of degenerative disc disease lacks official standardization. Lacks of such standardization may provoke some clinical and litigation problems. The authors investigated interobserver and intraobserver variability in interpretation of lumbar disc abnormality. Methods : Magnetic resonance imaging studies of the lumbar spine performed prospectively in 50 patients, were read blindly by three doctors dealing spinal disorders, using two nomenclature. Nomenclature I was normal, bulging, protrusion, extrusion. Nomenclature II was normal, bulging, herniation without neural compression, with neural compression. Intraobserver and interobserver variation were measured statistically. Results : Interobserver agreement was 70.4-80.8% for nomenclature I, 76.2-80.2% for nomenclature II. Intraobserver agreement was 84.0-88.0% for nomenclature I, 79.2-86.8% for nomenclature II. Interobserver Kappa statistic was 0.53-0.56 for nomenclature I, 0.54-0.57 for nomenclature II. Intraobserver Kappa statistic was 0.60-0.85 for nomenclature I, 0.53-0.72 for nomenclature II. Conclusion : Experienced doctors showed only moderate interobserver agreement when interpreting disc status on lumbar magnetic resonance imaging. Intraobserver agreement was superior to interbserver. The standardization of nomenclatures for lumbar disc extension beyond interspace are needed.

• Clinics in Shoulder and Elbow
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• v.25 no.4
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• pp.304-310
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• 2022

Background: The Boileau classification distinguishes three surgical neck fracture patterns: types A, B, and C. However, the reproducibility of this classification on plain radiographs is unclear. Therefore, we questioned what the interobserver agreement and accuracy of displaced surgical neck fracture patterns is categorized according to the modified Boileau classification. Does the reliability to recognize these fracture patterns differ between orthopedic residents and attending surgeons? Methods: This interobserver study consisted of a randomly retrieved series of 30 plain radiographs representing clinical practice in a level 1 and a level 2 trauma center. Radiographs were included from patients (≥18 years) who sustained an isolated displaced surgical neck fracture if they were taken ≤1 week after initial injury. A ground truth was established by consensus among three senior orthopedic surgeons. All images were assessed by 17 orthopedic residents and 17 attending orthopedic trauma surgeons. Results: Agreement for the modified Boileau classification was fair (κ=0.37; 95% confidence interval [CI], 0.36-0.38) with an accuracy of 62% (95% CI, 57%-66%). Comparison of interobserver variability between residents and attending surgeons revealed a significant but clinically irrelevant difference in favor of attending surgeons (0.34 vs. 0.39, respectively, Δκ=0.05, 95% CI, 0.02-0.07). Conclusions: The modified Boileau classification yields a low interobserver agreement with an unsatisfactory accuracy in a panel of orthopedic residents and attending surgeons. This supports the hypothesis that surgical neck fractures are challenging to categorize and that this classification should not be used to determine prognosis if only plain radiographs are available.

• Korean Journal of Radiology
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• v.21 no.4
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• pp.431-441
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• 2020

Objective: To compare the diagnostic performance and interobserver variability of strain ratio obtained from one or two regions of interest (ROI) on breast elastography. Materials and Methods: From April to May 2016, 140 breast masses in 140 patients who underwent conventional ultrasonography (US) with strain elastography followed by US-guided biopsy were evaluated. Three experienced breast radiologists reviewed recorded US and elastography images, measured strain ratios, and categorized them according to the American College of Radiology breast imaging reporting and data system lexicon. Strain ratio was obtained using the 1-ROI method (one ROI drawn on the target mass), and the 2-ROI method (one ROI in the target mass and another in reference fat tissue). The diagnostic performance of the three radiologists among datasets and optimal cut-off values for strain ratios were evaluated. Interobserver variability of strain ratio for each ROI method was assessed using intraclass correlation coefficient values, Bland-Altman plots, and coefficients of variation. Results: Compared to US alone, US combined with the strain ratio measured using either ROI method significantly improved specificity, positive predictive value, accuracy, and area under the receiver operating characteristic curve (AUC) (all p values < 0.05). Strain ratio obtained using the 1-ROI method showed higher interobserver agreement between the three radiologists without a significant difference in AUC for differentiating breast cancer when the optimal strain ratio cut-off value was used, compared with the 2-ROI method (AUC: 0.788 vs. 0.783, 0.693 vs. 0.715, and 0.691 vs. 0.686, respectively, all p values > 0.05). Conclusion: Strain ratios obtained using the 1-ROI method showed higher interobserver agreement without a significant difference in AUC, compared to those obtained using the 2-ROI method. Considering that the 1-ROI method can reduce performers' efforts, it could have an important role in improving the diagnostic performance of breast US by enabling consistent management of breast lesions.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.3
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• pp.225-232
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• 2019

Purpose: To evaluate intra- and inter-observer variability and guideline adherence amongst pediatricians in treating children aged between 4 and 18 years referred with recurrent abdominal pain (RAP) without red flags. Methods: The first part of the study is a retrospective single-center cohort study. The diagnostic work-ups of eight pediatricians were compared to the national guidelines. Intra- and inter-observer variability were examined by Cramer's V test. Intra-observer variability was defined as the amount of variation within a pediatrician and inter-observer variability as the amount of variation between pediatricians in the application of diagnostic work-up in children with RAP. Prospectively, the same pediatricians were requested to provide a report on their management strategy with a fictitious case to prove similarities in retrospective diagnostic work-up. Results: A total of 10 patients per pediatrician were analyzed. Retrospectively, a (very) weak association between pediatricians' diagnostic work-ups was found (0.22), which implies high inter-observer variability. The association between intra-observer diagnostic was moderate (range, 0.35-0.46). The Cramer's V of 0.60 in diagnostic work-up between pediatricians in the fictitious case implied the presence of a moderately strong association and lower inter-observer variability than in the retrospective study. Adherence to the guideline was 66.8%. Conclusion: We found a high intra- and inter-observer variability and moderate guideline adherence in daily clinical practice amongst pediatricians in treating children with RAP in a teaching hospital.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.15 no.2
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• pp.81-86
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• 2004

Background and Objectives : In general, ambulatory 24-hour pH monitoring is considered the current gold standard for larynogopharyngeal reflux(LPR). There is no validated instrument whose purpose is to document the physical finding and severity of laryngopharyngeal reflux. The purposes of this study are to revaluate the validity and reliability of the reflux finding score(RFS) and to quantify laryngoscopic findings using reflux finding score. Material and Methods : Thirty-three LPR patients confirmed by dual-probe pH monitoring and thirty patients of control were selected. The RFS was documented for each patient with telescopic laryngoscopy before treatment. For test-retest intraobserver reliability assessment, a blinded laryngologists determined the RFS on two separate occasions. To evaluate interobserver reliability assessment, the RFS was determined by t재 different blinded laryngologists. Results : The mean age of the cohort with pH-documented LPR was 45.8 years and the mean RFS was 11.4. The mean age of cotrol subjects was 52 years and the mean RFS was 5.4. The mean RFS for laryngologist no. 1 was 10.8 at the initial screening and 10.9 at the repeat evaluation. The mean FRS for laryngologist no.2 was 11.1 at the intial test and 10.9 at the repeat evaluation. The correlation coefficient for interobserver variability was 0.93 and intraobserver variability was 0.94. Conclusion : The RFS demonstrates excellent inter-and introaobserver reproducibility and is helpful for quantifying laryngeal finding in LPR. We can be 95% certain that an individual with a RFS greater than 7 has LPR.

• Imaging Science in Dentistry
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• v.45 no.4
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• pp.213-220
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• 2015

Purpose: The aim this study was to compare the accuracy of orthodontists and dentomaxillofacial radiologists in identifying 17 commonly used cephalometric landmarks, and to determine the extent of variability associated with each of those landmarks. Materials and Methods: Twenty digital lateral cephalometric radiographs were evaluated by two groups of dental specialists, and 17 cephalometric landmarks were identified. The x and y coordinates of each landmark were recorded. The mean value for each landmark was considered the best estimate and used as the standard. Variation in measurements of the distance between landmarks and measurements of the angles associated with certain landmarks was also assessed by a subset of two observers, and intraobserver and interobserver agreement were evaluated. Results: Intraclass correlation coefficients were excellent for intraobserver agreement, but only good for interobserver agreement. The least reliable landmark for orthodontists was the gnathion (Gn) point (standard deviation [SD], 5.92 mm), while the orbitale (Or) was the least reliable landmark (SD, 4.41 mm) for dentomaxillofacial radiologists. Furthermore, the condylion (Co)-Gn plane was the least consistent (SD, 4.43 mm). Conclusion: We established that some landmarks were not as reproducible as others, both horizontally and vertically. The most consistently identified landmark in both groups was the lower incisor border, while the least reliable points were Co, Gn, Or, and the anterior nasal spine. Overall, a lower level of reproducibility in the identification of cephalometric landmarks was observed among orthodontists.

• Radiation Oncology Journal
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• v.36 no.1
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• pp.11-16
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• 2018

Purpose: To investigate interobserver variation in target volume delineations for prostate cancer salvage radiotherapy using planning computed tomography (CT) versus combined planning CT and magnetic resonance imaging (MRI). Materials and Methods: Ten radiation oncologists independently delineated a target volume on the planning CT scans of five cases with different pathological status after radical prostatectomy. Two weeks later, this was repeated with the addition of planning MRI. The volumes obtained with CT only and combined CT and MRI were compared, and the effect of the addition of planning MRI on interobserver variability was assessed. Results: There were large differences in clinical target volume (CTV) delineated by each observer, regardless of the addition of planning MRI ($9.44-139.27cm^3$ in CT only and $7.77-122.83cm^3$ in CT plus MRI) and no significant differences in the mean and standard deviation of CTV. However, there were decreases in mean volume and standard deviation as a result of using the planning MRI. Conclusion: This study showed substantial interobserver variation in target volume delineation for salvage radiotherapy. The combination of planning MRI with CT tended to decrease the target volume and the variation.

• Archives of Plastic Surgery
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• v.50 no.3
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• pp.254-263
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• 2023

Background The three-dimensional (3D) evaluation of skeletal stability after orthognathic surgery is a time-consuming and complex procedure. The complexity increases further when evaluating the surgery-first orthognathic approach (SFOA). Herein, we propose and validate a simple time-saving method of 3D analysis using a single software, demonstrating high accuracy and repeatability. Methods This retrospective cohort study included 12 patients with skeletal class 3 malocclusion who underwent bimaxillary surgery without any presurgical orthodontics. Computed tomography (CT)/cone-beam CT images of each patient were obtained at three different time points (preoperation [T0], immediately postoperation [T1], and 1 year after surgery [T2]) and reconstructed into 3D images. After automatic surface-based alignment of the three models based on the anterior cranial base, five easily located anatomical landmarks were defined to each model. A set of angular and linear measurements were automatically calculated and used to define the amount of movement (T1-T0) and the amount of relapse (T2-T1). To evaluate the reproducibility, two independent observers processed all the cases, One of them repeated the steps after 2 weeks to assess intraobserver variability. Intraclass correlation coefficients (ICCs) were calculated at a 95% confidence interval. Time required for evaluating each case was recorded. Results Both the intra- and interobserver variability showed high ICC values (more than 0.95) with low measurement variations (mean linear variations: 0.18 mm; mean angular variations: 0.25 degree). Time needed for the evaluation process ranged from 3 to 5 minutes. Conclusion This approach is time-saving, semiautomatic, and easy to learn and can be used to effectively evaluate stability after SFOA.

• Clinical Endoscopy
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• v.55 no.2
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• pp.197-207
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• 2022

Background/Aims: Endoscopic visualization of the microscopic anatomy can facilitate the real-time diagnosis of pancreatobiliary disorders and provide guidance for treatment. This study aimed to review the technique, image classification, and diagnostic performance of confocal laser endomicroscopy (CLE). Methods: We conducted a systematic review of CLE in pancreatic and biliary ducts of humans, and have provided a narrative of the technique, image classification, diagnostic performance, ongoing research, and limitations. Results: Probe-based CLE differentiates malignant from benign biliary strictures (sensitivity, ≥89%; specificity, ≥61%). Needle-based CLE differentiates mucinous from non-mucinous pancreatic cysts (sensitivity, 59%; specificity, ≥94%) and identifies dysplasia. Pancreatitis may develop in 2-7% of pancreatic cyst cases. Needle-based CLE has potential applications in adenocarcinoma, neuroendocrine tumors, and pancreatitis (chronic or autoimmune). Costs, catheter lifespan, endoscopist training, and interobserver variability are challenges for routine utilization. Conclusions: CLE reveals microscopic pancreatobiliary system anatomy with adequate specificity and sensitivity. Reducing costs and simplifying image interpretation will promote utilization by advanced endoscopists.