Quantitative analysis of blooming artifact caused by calcification based on X-ray energy difference using computed tomography.

Blooming artifacts caused by calcifications appearing on computed tomography (CT) images lead to an underestimation of the coronary artery lumen size, and higher X-ray energy levels are suggested to reduce the blooming artifacts with subjective visual assessment. This study aimed to evaluate the effect of higher X-ray energy levels on the quantitative measurement of adjacent pixels affected by calcification using CT images. In this two-part study, CT images were acquired from dual-energy CT scanners by changing the X-ray energy levels such as kilovoltage peak (kVp) and kilo-electron volts (keV). Adjacent pixels affected by calcification were measured using the brightened length, excluding the actual calcified length, as determined by the full width at third maximum. In a separate clinical study, the adjacent affected pixels associated with 23 calcifications across 10 patients were measured using the same method as that used in the phantom study. Phantom and clinical studies showed that the change in kVp (field of view [FOV] 300 mm: p = 0.167, 0.494, and 0.861 for vendors 1, 2, and 3, respectively) and keV levels (p = 0.178 for vendor 2) failed to reduce the adjacent pixels affected by calcification, respectively. Moreover, the change in keV levels showed different aspects of adjacent pixels affected by calcification in the phantom study (FOV 300 mm: no significant difference [p = 0.191], increase [p < 0.001], and decrease [p < 0.001] for vendors 1, 2, and 3, respectively). Quantitative measurements revealed no significant relationship between higher X-ray energy levels and the adjacent pixels affected by calcification.

[Coronary CT Angiography-Based Assessment of Coronary in-Stent Restenosis: A Journey through Past and Present Trends]. / 관상동맥 CT ì¡°ì˜ìˆ ì„ 활용한 ìŠ¤í íŠ¸ 재협착 평가: 과거와 현재 ìµœì‹ ë™í–¥ìœ¼ë¡œì˜ ì—¬ì •.

Treatment of patients with coronary artery disease commonly involves the use of balloon-expandable stent placements, currently recognized as the most prevalent approach for coronary artery revascularization. Nevertheless, the occurrence of restenosis remains a significant complication following percutaneous coronary interventions. The diagnostic role of coronary CT angiography (CCTA) in detecting stent restenosis has limitations primarily attributable to challenges in accurately discerning the lumen, due to issues such as blooming and motion artifacts. As a result, many cases often necessitate a transition to conventional coronary angiography. However, recent advancements in CT technology have led to notable improvements in both sensitivity and specificity, underscoring the growing significance of CCTA as a diagnostic tool. The consistent reporting of high negative predictive value is particularly noteworthy. This review aims to explore the historical context, current status, and recent trends in diagnosing coronary artery stent restenosis using CCTA.

Computed Tomography Measurement of the Aorta in Midaortic Syndrome in Children and Adolescents and Their Clinical Manifestations and Outcomes.

Midaortic syndrome (MAS) presents challenges in diagnosis due to the absence of well-defined diagnostic criteria in pediatric patients. This retrospective study aimed to aid in the diagnosis of MAS by employing computed tomography (CT) to measure the z-score of the aorta as well as to identify and understand its clinical features. CT images, echocardiography findings, and medical records of 17 patients diagnosed with MAS between 1997 and 2023 were reviewed, and z-scores were calculated. Aortic size on follow-up CT, blood pressure, and left ventricular function and hypertrophy at the last follow-up were analyzed, and possible prognostic factors were examined. Except for one patient, all individuals exhibited a z-score below - 2 at the level corresponding to stenosis. Left ventricular dysfunction occurred more frequently in patients aged < 5 years (p = 0.024). Patients with idiopathic MAS showed a better prognosis in terms of blood pressure and follow-up aortic size (p = 0.051 and 0.048, respectively). CT-measured aortic z-scores may be useful for the diagnosis and follow-up of MAS.

An extreme case of cor triatriatum mimicking hypoplastic left heart syndrome and combined pulmonary vein stenosis.

A 65-day-old girl presented to the emergency room with lethargy, requiring emergency venoarterial extracorporeal membrane oxygenation for refractory cardiogenic shock. Initially, hypoplastic left heart syndrome was suspected. However, cor triatriatum with a pinpoint opening on the membrane was diagnosed based on a detailed echocardiographic examination. After membrane resection, the left heart size was restored. However, follow-up echocardiography performed 4 months later showed occlusion of both upper pulmonary veins and stenosis in both lower pulmonary veins. Hybrid balloon angioplasty was performed in all pulmonary veins, and stents were inserted into the right upper and lower pulmonary veins. Despite repeated balloon angioplasty, all pulmonary vein stenosis progressed over 6 months and the patient expired while waiting for a heart-lung transplant. Even after successful repair of cor triatriatum, short-term close follow-up is required for detecting the development of pulmonary vein stenosis.

Usefulness of two-dimensional shear wave elastography in diagnosing hepatic veno-occlusive disease in pediatric patients undergoing hematopoietic stem cell transplantation.

PURPOSE: This study aimed to evaluate the usefulness of two-dimensional shear wave elastography (2D-SWE) in diagnosing hepatic veno-occlusive disease (VOD) in pediatric patients. METHODS: This study retrospectively included pediatric patients who underwent hematopoietic stem cell transplantation (HSCT) between November 2019 and January 2021. All 34 patients (8.7±5.0 years) were examined using 2D-SWE for an initial diagnosis. A subgroup analysis was performed using the data from follow-up examinations of patients diagnosed with VOD. The characteristics of the initial VOD diagnosis were compared with the longitudinal changes observed in VOD patients who underwent multiple ultrasound examinations. RESULTS: In total, 19 patients were diagnosed with VOD at 17.6±9.4 days after HSCT. All VOD patients showed hepatomegaly, ascites, and gallbladder wall thickening. Liver stiffness was higher in VOD patients than in non-VOD patients (12.4±1.1 vs. 6.3±0.8 kPa, P<0.001). Liver stiffness values above 7.2 kPa showed 84.2% sensitivity and 93.3% specificity in distinguishing VOD from non-VOD (area under the curve, 0.925; 95% confidence interval, 0.780 to 0.987; P<0.001). A subgroup analysis of 11 patients showed a linear decrease in liver stiffness values after VOD diagnosis with treatment (first, second, and third follow-ups; 13.5±1.7, 11.3±1.4, and 9.5±0.8 kPa, respectively), but without statistical significance in the pairwise analysis. CONCLUSION: Liver stiffness measured using 2D-SWE increased in pediatric patients who develop VOD after HSCT. Therefore, liver stiffness can be a predictive and quantitative parameter for diagnosing VOD.

Deep neural network for automatic volumetric segmentation of whole-body CT images for body composition assessment.

BACKGROUND & AIMS: Body composition analysis on CT images is a valuable tool for sarcopenia assessment. We aimed to develop and validate a deep neural network applicable to whole-body CT images of PET-CT scan for the automatic volumetric segmentation of body composition. METHODS: For model development, one hundred whole-body or torso 18F-fluorodeoxyglucose PET-CT scans of 100 patients were retrospectively included. Two radiologists semi-automatically labeled the following seven body components in every CT image slice, providing a total of 46,967 image slices from the 100 scans for training the 3D U-Net (training, 39,268 slices; tuning, 3116 slices; internal validation, 4583 slices): skin, bone, muscle, abdominal visceral fat, subcutaneous fat, internal organs with vessels, and central nervous system. The segmentation accuracy was assessed using reference masks from three external datasets: two Korean centers (4668 and 4796 image slices from 20 CT scans, each) and a French public dataset (3763 image slices from 24 CT scans). The 3D U-Net-driven values were clinically validated using bioelectrical impedance analysis (BIA) and by assessing the model's diagnostic performance for sarcopenia in a community-based elderly cohort (n = 522). RESULTS: The 3D U-Net achieved accurate body composition segmentation with an average dice similarity coefficient of 96.5%-98.9% for all masks and 92.3%-99.3% for muscle, abdominal visceral fat, and subcutaneous fat in the validation datasets. The 3D U-Net-derived torso volume of skeletal muscle and fat tissue and the average area of those tissues in the waist were correlated with BIA-derived appendicular lean mass (correlation coefficients: 0.71 and 0.72, each) and fat mass (correlation coefficients: 0.95 and 0.93, each). The 3D U-Net-derived average areas of skeletal muscle and fat tissue in the waist were independently associated with sarcopenia (P < .001, each) with adjustment for age and sex, providing an area under the curve of 0.858 (95% CI, 0.815 to 0.901). CONCLUSIONS: This deep neural network model enabled the automatic volumetric segmentation of body composition on whole-body CT images, potentially expanding adjunctive sarcopenia assessment on PET-CT scan and volumetric assessment of metabolism in whole-body muscle and fat tissues.

Determinants Used to Justify the Strength of Recommendations among Korean Clinical Practice Guidelines.

BACKGROUND: A standardized systematic approach to grade evidence and the strength of recommendations is important for guideline users to minimize bias and help interpret the most suitable decisions at the point of care. The study aims to identify and classify determinants used to make judgement for the strength of recommendations among 56 Korean clinical practice guidelines (CPGs), and explore strong recommendations based on low quality of evidence. METHODS: Determinants used in the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach among 34 CPGs which have reported both strength of recommendations and level of evidence were reviewed. RESULTS: Five of 34 CPGs (14.7%) considered quality of evidence, benefits and harms, patients' values and preferences, and costs. And 24 of 34 CPGs (70.6%) considered both magnitude of effect and feasibility as additional determinants. Judgement table was not widely provided for use to translate evidence into recommendations. Eighty-two of 121 recommendations (67.8%, ranged 20.0% to 100.0%) among 11 CPGs using the same judgement scheme showed 'strong' strength of recommendations based on low or very low quality of evidence. Among 5 paradigmatic situations that justify strong recommendations based on low or very low evidence, situation classified as 'potential equivalence, one option clearly less risky or costly' was 87.8% for 82 strong recommendations. Situation classified as 'uncertain benefit, certain harm' was 4.9%. CONCLUSION: There is a need to introduce and systematize an evidence-based grading system. Using judgement table to justify the strength of recommendations and applying the 5 paradigmatic situations mentioned above is also recommended in the near future.

What Factors Impact Consumer Perception of the Effectiveness of Health Information Sites? An Investigation of the Korean National Health Information Portal.

Lay public's concerns around health and health information are increasing. In response, governments and government agencies are establishing websites to address such concerns and improve health literacy by providing better access to validated health information. Since 2011, the Korean government has constructed the National Health Information Portal (NHIP) website run in collaboration with the Korean Academy of Medical Sciences (KAMS). This study therefore aimed to 1) examine consumer use of NHIP, with respect to the usage patterns, evaluation on health information provided, and perceived effectiveness of the site; and 2) identify factors that may impact perceived effectiveness of the site. An online survey was conducted with 164 NHIP users, recruited through a popup window on the main screen of the portal website from October to November 2015. The significant predicting factors supported by the data include the relevance of health information on the site, the usefulness of information in making health decisions, and the effective visualization of information. These factors can inform future efforts to design more effective health information websites, possibly based on metadata systems, to further advance the lay public's information seeking and health literacy.

Methodological Quality Appraisal of 27 Korean Guidelines Using a Scoring Guide Based on the AGREE II Instrument and a Web-based Evaluation.

This study evaluated the methodological quality of CPGs using the Korean AGREE II scoring guide and a web-based appraisal system and was conducted by qualified appraisers. A total of 27 Korean CPGs were assessed under 6 domains and 23 items on the AGREE II instrument using the Korean scoring guide. The domain scores of the 27 guidelines were as following: the mean domain score was 82.7% (median 84.7%, ranging from 55.6% to 97.2%) for domain 1 (scope and purpose); 53.4% (median 56.9%, ranging from 11.1% to 95.8%) for domain 2 (stakeholder involvement); 63.0% (median 71.4%, ranging from 13.5% to 90.6%) for domain 3 (rigor of development); 88.9% (median 91.7%, ranging from 58.3% to 100.0%) for domain 4 (clarity of presentation); 30.1% (median 27.1%, ranging from 3.1% to 67.7%) for domain 5 (applicability); and 50.2% (median 58.3%, ranging from 0.0% to 93.8%) for domain 6 (editorial independence). Three domains including scope and purpose, rigor of development, and clarity of presentation were rated at more than 60% of the scaled domain score. Three domains including stakeholder involvement, applicability, and editorial independence were rated at less than 60% of the scaled domain score. Finally, of the 27 guidelines, 18 (66.7%) were rated at more than 60% of the scaled domain score for rigor of development and were categorized as high-quality guidelines.

Does Objective Structured Clinical Examinations Score Reflect the Clinical Reasoning Ability of Medical Students?

BACKGROUND: Clinical reasoning ability is an important factor in a physician's competence and thus should be taught and tested in medical schools. Medical schools generally use objective structured clinical examinations (OSCE) to measure the clinical competency of medical students. However, it is unknown whether OSCE can also evaluate clinical reasoning ability. In this study, the authors investigated whether OSCE scores reflected students' clinical reasoning abilities. METHODS: Sixty-five fourth-year medical students participated in this study. Medical students completed the OSCE with 4 cases using standardized patients. For assessment of clinical reasoning, students were asked to list differential diagnoses and the findings that were compatible or not compatible with each diagnosis. The OSCE score (score of patient encounter), diagnostic accuracy score, clinical reasoning score, clinical knowledge score and grade point average (GPA) were obtained for each student, and correlation analysis was performed. RESULTS: Clinical reasoning score was significantly correlated with diagnostic accuracy and GPA (correlation coefficient = 0.258 and 0.380; P = 0.038 and 0.002, respectively) but not with OSCE score or clinical knowledge score (correlation coefficient = 0.137 and 0.242; P = 0.276 and 0.052, respectively). Total OSCE score was not significantly correlated with clinical knowledge test score, clinical reasoning score, diagnostic accuracy score or GPA. CONCLUSIONS: OSCE score from patient encounters did not reflect the clinical reasoning abilities of the medical students in this study. The evaluation of medical students' clinical reasoning abilities through OSCE should be strengthened.

Correlations of Communication and Interpersonal Skills between Medical Students and Residents.

PURPOSE: Medical students' communication and interpersonal skills can be evaluated by standardized patients in a clinical performance examination (CPX). The purpose of this study is to investigate which communication and interpersonal skills are more closely correlated between medical students and residents. METHODS: This study included 2nd-year residents in 2009 who took the eight-station CPX as 4th-year medical students in 2006. In-patients who were cared for by the residents were asked the seven items related to interpersonal and communication skills. The correlation between the scores of these seven items in the 2006 CPX and the scores in the 2009 patient survey was evaluated. RESULTS: Twenty-six residents, 11 in medical wards and 15 in surgical wards, participated in the study. The medical students' total scores tended to be correlated with the residents' scores (r=0.381, p=0.055). There was significant correlation between the scores for students and residents for 'Explaining more explicably' (r=0.470, p=0.015), and marginally significant correlation (r=0.385, p=0.052) for 'Listening attentively.' There was no significant correlation for the other five items. CONCLUSION: 'Explaining more explicably' and 'Listening attentively', these skills were more closely correlated between medical students and residents. These basic communication skills should be included in graduate or licensing evaluations.

Effect of patient safety education in surgical clerkship to develop competencies for managing and preventing medical errors.

PURPOSE: The aims of this study were to define the necessity and effectiveness of patient safety education during surgical clerkship to develop competency for managing and preventing medical errors. METHODS: Fifty 3rd-year students participated in the patient safety education program during a 4-week surgical clerkship. The students were divided into 4 groups: control group, pretest-only group, education-only group, and pretest and education group. Students were assessed using short essays and an oral exam for reasoning skills, clinical performance exams for patient education and communication skills, and multisource feedback and direct observation of error reporting for real-world problem-solving skills. The results were analyzed with SPSS 14.0K. The reliability (Cronbach alpha) of the entire assessment was 0.893. RESULTS: There was no difference in scores between early and late clerkship groups. Reasoning skills were improved by the pretest. Reasoning, patient education, and error reporting skills were much more developed by patient safety education. Real-world error identification, reporting, and communication did not change after the 4-week course. CONCLUSIONS: Patient safety education during surgical clerkship is necessary and effective. Error prevention and competency management in the real world should developed.

Exploration of a leadership competency model for medical school faculties in Korea.

PURPOSE: To adapt to rapid and turbulent changes in the field of medicine, education, and society, medical school faculties need appropriate leadership. To develop leadership competencies through education, coaching, and mentoring, we need a leadership competency model. The purpose of this study was to develop a new leadership competency model that is suitable for medical school faculties in Korea. METHODS: To collect behavioral episodes with regard to leadership, we interviewed 54 subjects (faculties, residents, nurses) and surveyed 41 faculties with open-ended questionnaires. We classified the behavioral episodes based on Quinn and Cameron's leadership competency model and developed a Likert scale questionnaire to perform a confirmatory factor analysis. Two hundred seven medical school faculties responded to the questionnaire. RESULTS: The competency clusters that were identified by factor analysis were professionalism, citizenship, leadership, and membership to an organization. Accordingly, each cluster was linked with a dimension: self, society, team (that he/she is leading), and organization (to which he/she belongs). The clusters of competencies were: professional ability, ethics/morality, self-management, self-development, and passion; public interest, networking, social participation, and active service; motivating, caring, promoting teamwork, nurturing, conflict management, directing, performance management, and systems thinking; organizational orientation, collaboration, voluntary participation, and cost-benefit orientation. CONCLUSION: This competency model that fits medical school faculties in Korea can be used to design and develop selection plans, education programs, feedback tools, diagnostic evaluation tools, and career plan support programs.

Development of the Korean Academy of Medical Sciences Guideline for rating physical impairment.

Systematic and effective welfare for the disabled is possible when there are scientific and objective criteria demonstrating either presence or severity of the impairment. We need our own scientific criteria suitable for our culture and society, since the impairment is influenced by them. In 2007, we established the Developing Committee of Korean Academy of Medical Sciences (KAMS) Guideline for Impairment Rating under KAMS supervision. We included all fixed and permanent physical impairments after a sufficient medical treatment. The impairment should be stable and medically measurable. If not, it should be reevaluated later. We benchmarked the American Medical Association Guides. The KAMS Guideline should be scientific, objective, valid, reasonable and practical. In particular, we tried to secure objectivity. We developed the KAMS Guideline for Impairment Rating.

OSCE for the Medical Licensing Examination in Korea.

Objective structured clinical examinations (OSCEs) will be introduced in the Medical Licensing Examination in Korea next year. To evaluate the competency of new medical graduates, a written examination is not sufficient to test the clinical skills and attitudes of medical school graduates. The Korean Society of Medical Education and National Health Personnel Licensing Examination Board have been preparing for OSCEs to be included in the licensing examination for a number of years, following the declaration by the Minister of Health and Welfare, of the Korean Government. One center in Seoul will provide two identical sets of stations. The OSCE will have 12 stations. Six short stations will test procedural techniques and skills, and six long stations will feature standardized patients. The test items for the short stations and the clinical presentations of the long stations will be made available to applicants. However, the checklists will not be made available. It is hoped that the OSCE will raise the standard of competencies of new medical doctors and change clinical education in the medical schools.