Background/Aims: While distal radial artery (DRA) access is increasingly being used for diagnostic coronary angiography, limited information is available regarding DRA size. We aimed to determine the DRA reference diameters of Korean patients and identify the predictors of DRA diameter < 2.3 mm. Methods: The outer bilateral DRA diameters were assessed using a linear ultrasound probe in 1,162 consecutive patients who underwent transthoracic echocardiography. The DRA diameter was measured by the perpendicular angle in the dorsum of the hand, and the average values were compared by sex. DRA diameter < 2.3 mm was defined as unsuitable for routine diagnostic coronary angiography using a 5 Fr introducer sheath. Results: The mean DRA diameters were 2.31 ± 0.43 mm (right) and 2.35 ± 0.45 mm (left). The DRA was smaller in women than men (right: 2.15 ± 0.38 mm vs. 2.43 ± 0.44 mm, p < 0.001; left: 2.18 ± 0.39 mm vs. 2.47 ± 0.45 mm, p < 0.001). The DRA diameter was approximately 20% smaller than the radial artery diameter. A total of 630 (54.2%) and 574 (49.4%) patients had DRA diameter < 2.3 mm in the right and left hands, respectively. Female sex, low body mass index (BMI), and low body surface area (BSA) were significant predictors of DRA diameter < 2.3 mm. Conclusions We provided reference DRA diameters for Korean patients. Approximately 50% of the studied patients had DRA diameter < 2.3 mm. Female sex, low BMI, and low BSA remained significant predictors of DRA diameter < 2.3 mm.

Purpose: The study aimed to identify which digital biomarkers are collected and which specific devices are used according to vulnerable and susceptible individual characteristics in a living-lab setting. Materials and Methods: A literature search, screening, and appraisal process was implemented using the Web of Science, Pubmed, and Embase databases. The search query included a combination of terms related to “digital biomarkers,” “devices that collect digital biomarkers,” and “vulnerable and susceptible groups.” After the screening and appraisal process, a total of 37 relevant articles were obtained. Results: In elderly people, the main digital biomarkers measured were values related to physical activity. Most of the studies used sensors. The articles targeting children aimed to predict diseases, and most of them used devices that are simple and can induce some interest, such as wearable device-based smart toys. In those who were disabled, digital biomarkers that measured location-based movement for the purpose of diagnosing disabilities were widely used, and most were measured by easy-to-use devices that did not require detailed explanations. In the disadvantaged, digital biomarkers related to health promotion were measured, and various wearable devices, such as smart bands and headbands were used depending on the purpose and target. Conclusion As the digital biomarkers and devices that collect them vary depending on the characteristics of study subjects, researchers should pay attention not only to the purpose of the study but also the characteristics of study subjects when collecting and analyzing digital biomarkers from living labs.

Polycystic ovarian syndrome (PCOS) is a common endocrine disorder in women of reproductive age and is associated with an increased risk of obesity, compensatory hyperinsulinemia, dyslipidemia, metabolic syndrome, and endometrial cancer. This study analyzed 544619 women using the Korean Informative Classification of Disease, version 10, codes E28.0–E28.9 in the population-based National Health Information Databases from 2010 to 2019. The age-adjusted incidence and prevalence rates of PCOS over 10 years among Korean women were 2.8% and 4.3%, respectively; and they increased in the late teens, peaked in the 20s, and began to decrease at the age of 30. We also found that the body mass index, levels of fasting blood glucose, and high-density lipoprotein values in the recent two years (2018–2019) were higher in women with PCOS compared to the general population. This is the first study to investigate the prevalence of PCOS in a nationwide population of reproductive-aged Korean women. Further research is needed to examine the short- and long-term health risks and psychological problems associated with PCOS.

Purpose: The characteristic topography and climate often affect the occurrence of large-scale wildfires in the Eastern Gangwon-do region of Korea. However, there are no studies on the health effects of these wildfires in Korea. This study aimed to analyze the differences in medical use between a wildfire-affected area and an adjacent non-affected area before and after a wildfire in 2019 in Gangwon-do, Korea. Materials and Methods: We used medical usage data from the Korean National Health Insurance Corporation. Rates of medical use were determined for citizens of a wildfire-affected area in the Eastern Yeongdong region and a non-affected area in the Western Yeongseo region. Logistic regression analysis was performed considering an increase in medical use per individual as a dependent variable; age, sex, income, smoking, drinking, and exercise were included as confounding variables. Results: The odds ratio for medical use in Yeongdong region increased significantly after 3 days, 3 months, and 1 year after a fire occurred, compared with Yeongseo region. Conclusion The results of this study confirmed that the use of medical care increased for residents of a wildfire-affected area, compared with those of an adjacent non-affected area. This is the first study on the relationship between wildfires and inpatient medical use in Korea.

PURPOSE: There are few reports from Asian countries about the long-term results of aromatase inhibitor adjuvant treatment for breast cancer. This observational study aimed to evaluate the long-term effects of letrozole in postmenopausal Korean women with operable breast cancer. METHODS: Self-reported quality of life (QoL) scores were serially assessed for 3 years during adjuvant letrozole treatment using the Korean version of the Functional Assessment of Cancer Therapy-Breast questionnaires (version 3). Changes in bone mineral density (BMD) and serum cholesterol levels were also examined. RESULTS: All 897 patients received the documented informed consent form and completed a baseline questionnaire before treatment. Adjuvant chemotherapy was administered to 684 (76.3%) subjects, and 410 (45.7%) and 396 (44.1%) patients had stage I and II breast cancer, respectively. Each patient completed questionnaires at 3, 6, 12, 18, 24, 30, and 36 months after enrollment. Of 897 patients, 749 (83.5%) completed the study. The dropout rate was 16.5%. The serial trial outcome index, the sum of the physical and functional well-being subscales, increased gradually and significantly from baseline during letrozole treatment (p<0.001). The mean serum cholesterol level increased significantly from 199 to 205 after 36 months (p=0.042). The mean BMD significantly decreased from −0.39 at baseline to −0.87 after 36 months (p<0.001). CONCLUSION: QoL gradually improved during letrozole treatment. BMD and serum cholesterol level changes were similar to those in Western countries, indicating that adjuvant letrozole treatment is well tolerated in Korean women, with minimal ethnic variation.
Aromatase ; Asian Continental Ancestry Group ; Bone Density ; Breast Neoplasms* ; Breast* ; Chemotherapy, Adjuvant ; Cholesterol ; Consent Forms ; Female ; Humans ; Observational Study ; Quality of Life*

PURPOSE: The purpose of this study was to visualize and identify peri-implant bone defects in optical coherence tomography (OCT) images and to obtain quantitative measurements of the defect depth. METHODS: Dehiscence defects were intentionally formed in porcine mandibles and implants were simultaneously placed without flap elevation. Only the threads of the fixture could be seen at the bone defect site in the OCT images, so the depth of the peri-implant bone defect could be measured through the length of the visible threads. To analyze the reliability of the OCT measurements, the flaps were elevated and the depth of the dehiscence defects was measured with a digital caliper. RESULTS: The average defect depth measured by a digital caliper was 4.88±1.28 mm, and the corresponding OCT measurement was 5.11±1.33 mm. Very thin bone areas that were sufficiently transparent in the coronal portion were penetrated by the optical beam in OCT imaging and regarded as bone loss. The intraclass correlation coefficient between the 2 methods was high, with a 95% confidence interval (CI) close to 1. In the Bland-Altman analysis, most measured values were within the threshold of the 95% CI, suggesting close agreement of the OCT measurements with the caliper measurements. CONCLUSIONS: OCT images can be used to visualize the peri-implant bone level and to identify bone defects. The potential of quantitative non-invasive measurements of the amount of bone loss was also confirmed.
Dental Implants ; Diagnosis ; Intention ; Mandible ; Peri-Implantitis ; Tomography, Optical Coherence

PURPOSE: The aims of the present study were to compare the image quality and visibility of tooth cracks between conventional methods and swept-source optical coherence tomography (SS-OCT) and to develop an automatic detection technique for tooth cracks by SS-OCT imaging. METHODS: We evaluated SS-OCT with a near-infrared wavelength centered at 1,310 nm over a spectral bandwidth of 100 nm at a rate of 50 kHz as a new diagnostic tool for the detection of tooth cracks. The reliability of the SS-OCT images was verified by comparing the crack lines with those detected using conventional methods. After performing preprocessing of the obtained SS-OCT images to emphasize cracks, an algorithm was developed and verified to detect tooth cracks automatically. RESULTS: The detection capability of SS-OCT was superior or comparable to that of trans-illumination, which did not discriminate among the cracks according to depth. Other conventional methods for the detection of tooth cracks did not sense initial cracks with a width of less than 100 μm. However, SS-OCT detected cracks of all sizes, ranging from craze lines to split teeth, and the crack lines were automatically detected in images using the Hough transform. CONCLUSIONS: We were able to distinguish structural cracks, craze lines, and split lines in tooth cracks using SS-OCT images, and to automatically detect the position of various cracks in the OCT images. Therefore, the detection capability of SS-OCT images provides a useful diagnostic tool for cracked tooth syndrome.
Cracked Tooth Syndrome ; Image Interpretation, Computer-Assisted ; Tomography, Optical Coherence* ; Tooth Fractures ; Tooth*

PURPOSE: The purpose of this study was to examine whether periodontal pocket could be satisfactorily visualized by optical coherence tomography (OCT) and to suggest quantitative methods for measuring periodontal pocket depth. METHODS: We acquired OCT images of periodontal pockets in a porcine model and determined the actual axial resolution for measuring the exact periodontal pocket depth using a calibration method. Quantitative measurements of periodontal pockets were performed by real axial resolution and compared with the results from manual periodontal probing. RESULTS: The average periodontal pocket depth measured by OCT was 3.10±0.15 mm, 4.11±0.17 mm, 5.09±0.17 mm, and 6.05±0.21 mm for each periodontal pocket model, respectively. These values were similar to those obtained by manual periodontal probing. CONCLUSIONS: OCT was able to visualize periodontal pockets and show attachment loss. By calculating the calibration factor to determine the accurate axial resolution, quantitative standards for measuring periodontal pocket depth can be established regardless of the position of periodontal pocket in the OCT image.
Calibration ; Gingiva ; Image Interpretation, Computer-Assisted ; Methods ; Periodontal Pocket* ; Tomography, Optical Coherence*

PURPOSE: The objective of this study was to investigate the relationships between primary implant stability as measured by impact response frequency and the structural parameters of trabecular bone using cone-beam computed tomography(CBCT), excluding the effect of cortical bone thickness. METHODS: We measured the impact response of a dental implant placed into swine bone specimens composed of only trabecular bone without the cortical bone layer using an inductive sensor. The peak frequency of the impact response spectrum was determined as an implant stability criterion (SPF). The 3D microstructural parameters were calculated from CT images of the bone specimens obtained using both micro-CT and CBCT. RESULTS: SPF had significant positive correlations with trabecular bone structural parameters (BV/TV, BV, BS, BSD, Tb.Th, Tb.N, FD, and BS/BV) (P<0.01) while SPF demonstrated significant negative correlations with other microstructural parameters (Tb.Sp, Tb.Pf, and SMI) using micro-CT and CBCT (P<0.01). CONCLUSIONS: There was an increase in implant stability prediction by combining BV/TV and SMI in the stepwise forward regression analysis. Bone with high volume density and low surface density shows high implant stability. Well-connected thick bone with small marrow spaces also shows high implant stability. The combination of bone density and architectural parameters measured using CBCT can predict the implant stability more accurately than the density alone in clinical diagnoses.
Bone and Bones ; Bone Density ; Bone Marrow ; Cone-Beam Computed Tomography* ; Dental Implants* ; Diagnosis ; Swine ; X-Ray Microtomography

PURPOSE: Colorectal obstruction develops most frequently by carcinoma, and 7%–30% of these colorectal carcinomas are acute cases. The oncologic safety of self-expanding metal stent (SEMS) insertion as a bridge to surgery has not yet been established. Thus, we investigated the oncologic safety of SEMS insertion as a bridge to surgery in patients with obstructive colorectal cancer.METHODS: This retrospective had 56 patients enrolled requiring emergency management for obstructive colorectal cancer at stage II or III, who had undergone curative surgery between July 2008 and June 2011. These subjects were divided into two groups: patients who had undergone emergency surgery without SEMS insertion (non-stent group) and those who had undergone elective surgery after preoperative decompression with SEMS insertion (stent group). The two groups were compared for clinicopathologic characteristics, postoperative complications, and survival rate.RESULTS: Enterostomy was performed in 25 patients (100.0%) in the non-stent group and 1 patient (3.2%) in the stent group; laparoscopic surgery was carried out in 7 patients (28.0%) in the non-stent group and 19 patients (61.29%) in the stent group, each showing statistically significant differences. There was no statistically significant difference in postoperative complications and 5-year disease-free survival rate (72% vs. 74.19%, P=0.87, respectively).CONCLUSION: In treatment of malignant colorectal obstruction, elective operation after stent insertion had similar oncologic outcomes compared with emergency operation. Preoperative stent insertion not only lowers the incidence of enterostomy but also makes laparoscopic surgery possible, thereby enhancing patients' quality of life. Therefore, preoperative stent insertion is a useful method that may replace emergency surgery in treatment of malignant colorectal obstruction.
Colorectal Neoplasms ; Decompression ; Disease-Free Survival ; Emergencies ; Enterostomy ; Humans ; Incidence ; Intestinal Obstruction ; Laparoscopy ; Methods ; Postoperative Complications ; Quality of Life ; Retrospective Studies ; Stents ; Survival Rate