• 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.

• Korean Journal of Radiology
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• v.22 no.11
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• pp.1850-1857
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• 2021

Objective: The purpose of this study was to assess whether a deep learning (DL) algorithm could enable simultaneous noise reduction and edge sharpening in low-dose lumbar spine CT. Materials and Methods: This retrospective study included 52 patients (26 male and 26 female; median age, 60.5 years) who had undergone CT-guided lumbar bone biopsy between October 2015 and April 2020. Initial 100-mAs survey images and 50-mAs intraprocedural images were reconstructed by filtered back projection. Denoising was performed using a vendor-agnostic DL model (ClariCT.AI^TM, ClariPI) for the 50-mAS images, and the 50-mAs, denoised 50-mAs, and 100-mAs CT images were compared. Noise, signal-to-noise ratio (SNR), and edge rise distance (ERD) for image sharpness were measured. The data were summarized as the mean ± standard deviation for these parameters. Two musculoskeletal radiologists assessed the visibility of the normal anatomical structures. Results: Noise was lower in the denoised 50-mAs images (36.38 ± 7.03 Hounsfield unit [HU]) than the 50-mAs (93.33 ± 25.36 HU) and 100-mAs (63.33 ± 16.09 HU) images (p < 0.001). The SNRs for the images in descending order were as follows: denoised 50-mAs (1.46 ± 0.54), 100-mAs (0.99 ± 0.34), and 50-mAs (0.58 ± 0.18) images (p < 0.001). The denoised 50-mAs images had better edge sharpness than the 100-mAs images at the vertebral body (ERD; 0.94 ± 0.2 mm vs. 1.05 ± 0.24 mm, p = 0.036) and the psoas (ERD; 0.42 ± 0.09 mm vs. 0.50 ± 0.12 mm, p = 0.002). The denoised 50-mAs images significantly improved the visualization of the normal anatomical structures (p < 0.001). Conclusion: DL-based reconstruction may enable simultaneous noise reduction and improvement in image quality with the preservation of edge sharpness on low-dose lumbar spine CT. Investigations on further radiation dose reduction and the clinical applicability of this technique are warranted.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1054-1065
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• 2021

Objective: We implemented a novel resectable myocardial model for mock myectomy using a hybrid method of three-dimensional (3D) printing and silicone molding for patients with apical hypertrophic cardiomyopathy (ApHCM). Materials and Methods: From January 2019 through May 2020, 3D models from three patients with ApHCM were generated using the end-diastolic cardiac CT phase image. After computer-aided designing of measures to prevent structural deformation during silicone injection into molding, 3D printing was performed to reproduce anatomic details and molds for the left ventricular (LV) myocardial mass. We compared the myocardial thickness of each cardiac segment and the LV myocardial mass and cavity volumes between the myocardial model images and cardiac CT images. The surgeon performed mock surgery, and we compared the volume and weight of the resected silicone and myocardium. Results: During the mock surgery, the surgeon could determine an ideal site for the incision and the optimal extent of myocardial resection. The mean differences in the measured myocardial thickness of the model (0.3, 1.0, 6.9, and 7.3 mm in the basal, midventricular, apical segments, and apex, respectively) and volume of the LV myocardial mass and chamber (36.9 mL and 14.8 mL, 2.9 mL and -9.4 mL, and 6.0 mL and -3.0 mL in basal, mid-ventricular and apical segments, respectively) were consistent with cardiac CT. The volume and weight of the resected silicone were similar to those of the resected myocardium (6 mL [6.2 g] of silicone and 5 mL [5.3 g] of the myocardium in patient 2; 12 mL [12.5 g] of silicone and 11.2 mL [11.8 g] of the myocardium in patient 3). Conclusion: Our 3D model created using hybrid 3D printing and silicone molding may be useful for determining the extent of surgery and planning surgery guided by a rehearsal platform for ApHCM.

• Korean Journal of Radiology
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• v.22 no.2
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• pp.263-280
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• 2021

Percutaneous transthoracic needle biopsy (PTNB) is one of the essential diagnostic procedures for pulmonary lesions. Its role is increasing in the era of CT screening for lung cancer and precision medicine. The Korean Society of Thoracic Radiology developed the first evidence-based clinical guideline for PTNB in Korea by adapting pre-existing guidelines. The guideline provides 39 recommendations for the following four main domains of 12 key questions: the indications for PTNB, pre-procedural evaluation, procedural technique of PTNB and its accuracy, and management of post-biopsy complications. We hope that these recommendations can improve the diagnostic accuracy and safety of PTNB in clinical practice and promote standardization of the procedure nationwide.

• Journal of The Korean Association For Science Education
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• v.27 no.5
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• pp.432-446
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• 2007

The purpose of the study is to explore the science teaching orientations of secondary science teachers, and how they influence the planning and execution of reform-based lessons. Professional development workshop for constructivist teaching consisted of three different phases; five lectures, small group discussion, and preparing lesson plans. Four teachers who participated also executed their lesson plans in their own classroom. All workshops were videotape recorded. Classroom observations and interviews were conducted and recorded. Instructional materials were also collected for each science class. All data recorded were transcribed and analyzed. Based on the data collected from multiple sources, we identified each teacher's teaching orientations, and through this lens, we also tried to understand their classroom practices. We expected teacher-participants to implement constructivist science teaching. However, the differences among teachers in the course of actual planning and implementing activities for constructivist science was wider than we expected and even some teachers were unsuccessful. Teaching orientations can act as a filter for teachers when they decide whether to accept and apply new knowledge about teaching and learning to actual lessons or not. Even if a teacher plans a guided-inquiry lesson, her/his didactic teaching orientation could be revealed in actual classroom, and lead her/his class to other direction which is quite different from her/his original intention. Although the teachers participated in the same workshops in our study, they planned and executed differently and their own teaching orientations contribute substantially to their practice. Understanding the role of science teaching orientations could be an important step in addressing issues of diverse difficulties in supporting reform efforts in science.

• Journal of The Korean Association For Science Education
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• v.28 no.2
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• pp.180-185
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• 2008

The purpose of this study is to inquire the properties and relationship of attitudes toward science and process skills of preservice elementary teachers. Two instruments were used to collect the data, SAS(Science Attitude Scales) for checking up attitude toward science and TIPS II(Test of Integrated Process Skill II) for inspecting science process skills. Three main results were revealed. First, preservice elementary teachers' the attitude toward science and science process skills could not show the significant differences by gender. This result is differ from the results of preceding researches which had set up the students of elementary, middle and high school as objects. Second, the properties of preservice elementary teachers' the attitude toward science and science process skills according to the course in high school were also differ from those of preceding researches having students as objects. The preservice elementary teachers who got the literary courses in high school were more confident in science learning and perform that those who have the academic background of science courses in high school. In addition, although they showed better abilities in two sub-scales of science process skills, the preservice teachers with science course didn't show the better science process skills than those who had taken the literary course in total score of science process skill test. Third, there was a significant relationship between attitude toward science and science process skills of preservice elementary teachers but just one sub-scale was related with science process skills. According to these results, it can be said that the preceding results with students as objects can not be applied to and preservice elementary teachers should be guided by the methods which are considering their special properties.

• Journal of The Korean Association For Science Education
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• v.28 no.4
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• pp.282-290
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• 2008

The Research and Education (R&E) program was a year-long, apprenticeship and research-based program that was guided by mentors who are scientists or science teachers. The objective of the R&E program was to help scientifically gifted students in Korea Science Academy (KSA) and Science High Schools (SHS) to enhance abilities in creative thinking, scientific inquiry, problem solving, positive attitude towards scientists, and promoting cooperative research and interests in science and technology. In this study, the impact of the R&E program on the goals of 182 gifted college students in KAIST was evaluated using Likert-type items and multiple-choice method approach that provided a more comprehensive evaluation of the program's impact on science attitudes, creative thinking, scientific inquiry, and interests in science and technology. The results indicated a positive impact on cooperative research, gaining knowledge on the research topic, attitude towards scientists, interest in science and technology, scientific inquiry, and creative thinking in that order. There were rather remarkable and meaningful differences in science inquiry (p<.05), and scientific knowledge (p<.01), between the two groups of KAIST freshmen who came from SHS and KSA in 2006. Implications for science apprenticeship or a research-based mentorship program and their respective evaluations are also discussed.

• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.818-831
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• 2007

Recognizing the importance of abductive inquiry in Earth science, some theoretical approaches that deploy abduction have been researched. And, it is necessary that the abductive inquiry in a geological field excursion as a vivid locale of Earth science inquiry should be researched. We developed a geological field trip based on the abductive learning model, and investigated students' abductive inference, thinking strategies used in those inferences, and the impact of a teacher's pedagogical intervention on students' abductive inference. Results showed that students, during the field excursion, could accomplish abductive inference about rock identification, process of different rock generation, joints generation in metamorpa?ic rocks, and terrains at the field trip area. They also used various thinking strategies in finding appropriate rules to construe the facts observed at outcrops. This means that it is significant for the enhancement of abductive reasoning skills that students experience such inquiries as scientists do. In addition, a teacher's pedagogical interventions didn't ensure the content of students' inference while they helped students perform abductive reasoning and guided their use of specific thinking strategies. Students had found reasoning rules to explain the 01: served facts from their wrong prior knowledge. Therefore, during a geological field excursion, teachers need to provide students with proper background knowledge and information in order that students can reason rues for persuasive abductive inference, and construe the geological features of the field trip area by the establishment of appropriate hypotheses.

• Therapeutic Science for Rehabilitation
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• v.13 no.1
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• pp.87-97
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• 2024

Objective : This study aimed to acquire activities of daily living (ADL) skills through activity analysis and forward chaining in children with developmental disabilities. Methods : In this study, the performance of children with developmental disabilities was guided stepwise using a changing criterion design. The intervention was conducted in forward chaining after the therapist analyzed the activities of three tasks (shoes, shorts, and short-sleeved T-shirts) set as the Canadian Occupational Performance Measure (COPM). The performance rate at each stage of the three tasks was used as an independent variable, and COPM performance and satisfaction scores before and after the intervention were set as dependent variables. Results : The task performance rates of children wearing shoes, shorts, and short-sleeved T-shirts improved over time. Even at home, the scores for performance and satisfaction of all three tasks increased. Conclusion : Hopefully, activity analysis and behavioral chaining methods will be used not only for ADL but also for various tasks in children with developmental disabilities who have difficulty acquiring tasks.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.1
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• pp.64-71
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• 2024

The most critical aspect of full-arch prosthodontic treatment is evaluating whether the patient's vertical occlusal dimension is appropriate, and if necessary, restoring it through increasing vertical dimension. If the vertical occlusal dimension is too low, it can lead to reduced chewing efficiency, as well as not only aesthetic concerns but also potential issues like hyperactivity of muscles and posterior displacement of the mandible. This report is about the patient dissatisfied with pronunciation and aesthetics due to an inappropriate vertical occlusal dimension resulting from prior prosthetic interventions, underwent full-arch prosthodontic restoration treatment. Through the utilization of digital diagnostic apparatus, a comprehensive evaluation was undertaken for patient's vertical occlusal dimension, occlusal plane orientation, and the condition of prosthetic restorations. Through 3D facial scanning, the facial landmarks were discerned, and subsequently, the new occlusal plane was established. This provided the foundation for a digitally guided diagnostic wax-up. An elevation of 5 mm from the incisor was determined. Comprehensive dental rehabilitation was then executed for all remaining teeth, excluding the maxillary four incisors. The treatment protocol followed a systematic approach by initially creating implant-supported restorations on both sides of the dental arch to establish a stable occlusal contact. Subsequently, prosthetic restorations for the natural dentition were generated. Diagnostic and treatment planning were established through the utilization of facial scanning. This subsequently led to a reduction in treatment complexity and an expedited treatment timeline.