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Purpose@#To compare volumetric optical coherence tomography (OCT) biomarkers in bevacizumab responsive and bevacizumab refractory diabetic macular edema (DME) patients switched to the dexamethasone implant to ultimately identify possible prognostic indicators. @*Methods@#Retrospective analysis of DME patients treated with bevacizumab were done. Patients were divided into those who showed response to bevacizumab (bevacizumab only group) and others who were switched to the dexamethasone implant due to lack of response to bevacizumab (switching group). Volumetric OCT biomarkers such as central macular thickness (CMT), inner and outer cystoid macular edema (CME) volume, serous retinal detachment (SRD) volume, retinal volume (CME + SRD volume) within the 6-mm Early Treatment of Diabetic Retinopathy Study circle were calculated. OCT biomarkers were followed up throughout treatment. @*Results@#Among total of 144 eyes, 113 patients were included in the bevacizumab only group and 31 patients were included in the switching group. Compared to the bevacizumab only group, the switching group showed higher baseline CMT (558.00 ± 209.60 µm vs. 454.96 ± 125.88 µm, p = 0.003), larger inner CME (6.02 ± 1.43 mm3 vs. 5.12 ± 0.87 mm3, p = 0.004) and SRD volume (0.32 ± 0.40 mm3 vs. 0.11 ± 0.09 mm3, p = 0.015) and higher proportion of patients with SRD (58.06% vs. 31.86%, p = 0.008). In the switching group, CMT, inner CME and SRD volume all showed significant reduction after switching to the dexamethasone implant. @*Conclusions@#DME with large SRD and inner nuclear layer edema volume may be more effectively treated with the dexamethasone implant than bevacizumab.
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Background@#In the coronavirus disease 2019 (COVID-19) era, surgical resident education depends largely on virtual materials.With the help of point-of-view (POV) cameras, educational videos have become widely used for surgical training. A video recorded from the surgeon’s POV helps demonstrate the procedure. We made training movies of the surgical approach to distal radius fractures for residents using a head-mounted video recording system with a laser point targeting device (LPTD). @*Methods@#A 15-minnute movie of the trans-flexor carpi radialis approach for distal radius fractures was made. A POV camera was assembled with an LPTD and strapped on the surgeon’s head. This enabled maintenance of the surgical field while recording the procedure. A shorter version of the clip was also made to investigate trainee preference. We asked 24 trainees to watch the two versions of the video and complete a short questionnaire. @*Results@#All trainees felt that the movie made with a POV camera was more efficient than existing materials. Only 1 (4.2%) felt that the laser pointer hindered the view. Four of the 23 trainees (16.7%) felt dizzy while watching the video. Of the two versions, 16 trainees (66.7%) preferred the shorter, edited version. The average score for the video was 8.42 out of 10. @*Conclusions@#A video recording system in the operating room that uses an LPTD-POV camera is an efficient way to produce educational material, particularly for surgical residents during the COVID-19 era.
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Purpose@#The aim of this study was to assess the diagnostic role of fine-needle aspiration cytology (FNAC) and analyze factors associated with false-negative FNAC results in patients with parathyroid incidentaloma who were referred for ultrasonography (US)-guided fine-needle aspiration (FNA) of thyroid nodules. @*Methods@#In this study, 121 patients with suspected parathyroid lesions were enrolled. The patients underwent US-guided FNAC with measurements of washout parathyroid hormone (PTH) between January 2015 and May 2020. The diagnostic performance of FNAC for the diagnosis of parathyroid lesions was assessed using surgical results and elevated washout PTH as a reference standard. The clinical and radiologic features associated with false-negative results on FNAC for the diagnosis of parathyroid lesions were evaluated. @*Results@#Among the 121 nodules assessed, 38 were parathyroid lesions (31.4%), and 83 were non-parathyroid lesions (68.6%). The diagnostic performance of FNAC for parathyroid incidentaloma showed a sensitivity of 31.6% (12/38), specificity of 100% (83/83), positive predictive values of 100% (12/12), negative predictive values of 76.1% (83/109), and accuracy of 78.5% (95/121). The FNAC results of non-parathyroid lesions included thyroid nodules, lymph nodes, neurogenic tumors, and fat tissue. True-positive results on FNAC were significantly associated with performing FNA twice (58.3% vs. 23.1%, P=0.043). @*Conclusion@#Considering the low sensitivity of FNAC, measuring washout PTH in addition to FNAC may help accurately diagnose parathyroid incidentaloma on thyroid US. Further, the falsenegative rate for FNAC can be reduced by obtaining two or more FNA samples.
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Objective@#To evaluate the computed tomography (CT) features for diagnosing metastatic cervical lymph nodes (LNs) in patients with differentiated thyroid cancer (DTC) and validate the CT-based risk stratification system suggested by the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) guidelines. @*Materials and Methods@#A total of 463 LNs from 399 patients with DTC who underwent preoperative CT staging and ultrasound-guided fine-needle aspiration were included. The following CT features for each LN were evaluated: absence of hilum, cystic changes, calcification, strong enhancement, and heterogeneous enhancement. Multivariable logistic regression analysis was performed to identify independent CT features associated with metastatic LNs, and their diagnostic performances were evaluated. LNs were classified into probably benign, indeterminate, and suspicious categories according to the K-TIRADS and the modified LN classification proposed in our study. The diagnostic performance of both classification systems was compared using the exact McNemar and Kosinski tests. @*Results@#The absence of hilum (odds ratio [OR], 4.859; 95% confidence interval [CI], 1.593–14.823; P = 0.005), strong enhancement (OR, 28.755; 95% CI, 12.719–65.007; P < 0.001), and cystic changes (OR, 46.157; 95% CI, 5.07–420.234; P = 0.001) were independently associated with metastatic LNs. All LNs showing calcification were diagnosed as metastases. Heterogeneous enhancement did not show a significant independent association with metastatic LNs. Strong enhancement, calcification, and cystic changes showed moderate to high specificity (70.1%–100%) and positive predictive value (PPV) (91.8%–100%). The absence of the hilum showed high sensitivity (97.8%) but low specificity (34.0%). The modified LN classification, which excluded heterogeneous enhancement from the K-TIRADS, demonstrated higher specificity (70.1% vs. 62.9%, P = 0.016) and PPV (92.5% vs. 90.9%, P = 0.011) than the K-TIRADS. @*Conclusion@#Excluding heterogeneous enhancement as a suspicious feature resulted in a higher specificity and PPV for diagnosing metastatic LNs than the K-TIRADS. Our research results may provide a basis for revising the LN classification in future guidelines.
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Background@#Treating osteoporosis in patients with a distal radius fracture (DRF) became paramount at the Fracture Liaison Service. Spinal sagittal imbalance emerged as a risk factor for subsequent fractures. Therefore, here we investigated the spinal profile of patients with DRF to investigate its association with a history of falls and prevalent vertebral fractures. @*Methods@#We reviewed the cases of 162 women presenting with DRF and 162 age-matched women without fracture who underwent an osteoporosis evaluation including bone mineral density (BMD) and lateral spine imaging. We compared the incidence of prevalent vertebral fracture and sagittal vertical axis (SVA) to measure spinal sagittal imbalance. We also performed a regression analysis of the risks of prevalent vertebral fracture, such as age, body mass index (BMI), BMD, and SVA. @*Results@#The SVA was significantly smaller (indicating more stable sagittal balance) in patients with a DRF versus controls (16 mm vs. 34 mm, respectively; p<0.001). The incidence of a prevalent vertebral fracture was similar between groups (12% vs. 15%, respectively; p=0.332). In both groups, the SVA was significantly greater in those with versus without a vertebral fracture. The vertebral fracture was significantly associated with age and SVA but not BMI or spinal BMD. @*Conclusions@#Spinal sagittal balance was superior in DRF patients, yet the frequency of prevalent vertebral fractures was similar. The identification of this unique spinal profile in patients with DRF may increase our understanding of osteoporotic fractures.
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Purpose@#Radiofrequency ablation (RFA) and ethanol ablation (EA) are effective and safe for benign symptomatic thyroid nodules (BSTNs). However, relatively little is known about the effects of these procedures on patients’ quality of life (QoL). This prospective, multicenter study evaluated the effects of RFA and EA on changes in thyroid-specific QoL in patients with BSTNs and assessed the volume reduction and safety of these procedures. @*Methods@#Eighty-six consecutive patients with 86 BSTNs were prospectively included from two medical centers. RFA was performed for 55 BSTNs with solidity ≥50% and EA was performed for 31 BSTNs with solidity <50%. QoL was evaluated using an 11-scale, multiple-choice thyroid-specific QoL questionnaire. Nodule characteristics and QoL were evaluated at diagnosis and 1, 6, and 12 months after treatment. Overall QoL was rated from 0 (good) to 4 (poor). @*Results@#The mean longest size and volume of the index nodule were 4.2±1.5 cm and 21.6±22.1 mL, respectively. Patients received 1.1 treatments on average (range, 1 to 2). Significant post-treatment volume reductions were noted; however, the EA group showed a higher volume reduction than the RFA group at 1 (78.7%-16.1% vs. 49.1%-15.8%), 6 (86.3%-21.7% vs. 73.0%-14.5%), and 12 (90.9%-14.9% vs. 80.3%-12.4%) months. The score for each scale of the QoL questionnaire improved significantly during follow-up (all P<0.001). Overall QoL improved significantly, from 1.7±0.9 at diagnosis to 0.6±0.7 at the 12-month follow-up (P<0.001). There were no major complications. @*Conclusion@#Both RFA and EA are safe and effective in reducing nodule volume and improving thyroid-specific QoL in patients with BSTNs.
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The traditional approach to diagnosis and management of Zenker’s diverticulum is open surgical treatment. More recently, however, endoscopic technique is also frequently used for Zenker’s diverticulum because it has advantages of shortening operation time, postoperative hospitalization and reducing the complication such as recurrent laryngeal nerve injury. A 75-year-old male, who was diagnosed with Zenker’s diverticulum, underwent a secondary open diverticulectomy after failed attempt at rigid transoral endoscopic diverticulotomy. Here we report this case with a review of literature.
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Background@#Sexual dimorphism is important for sex determination in the field of forensics. However, sexual dimorphism is commonly assessed using cone beam computed tomography (CBCT) rather than three-dimensional (3D) modeling software; therefore, studies using a more accurate measurement approach are necessary. This study assessed the sexual dimorphism of the MS using a 3D modeling program to obtain information that could contribute to the fields of surgery and forensics. @*Methods@#The CBCT data of 60 patients (age, 20∼29 y; 30 males and 30 females) admitted to the Department of Orthodontics at the Dankook University School of Dentistry were provided in Digital Imaging and Communications in Medicine (DICOM) format.The left MS and right MS were modeled based on the DICOM files using the Mimics (version 22; Materialise, Leuven, Belgium) 3D program and converted to stereolithography (STL) files used to measure the width, length, and height of the MS, infraorbital foramen (IOF), right MS, and left MS. The average of three repeated measurements was calculated, and a reliability test was performed to ensure data reliability (Cronbach’s α =0.618). A canonical discriminant analysis was performed using a standard approach (left: Box’s M=0.096; right: Box’s M=0.115). @*Results@#Males had greater values for all parameters (MS width, MS length, MS height, IOF, right MS, left MS) than females. The discriminant analysis identified six independent variables (MS width, MS height, MS length, IOF, right MS, left MS) that could identify sex. The left MS and right MS correctly identified the sex of 81.7% and 71.7% of the patients, respectively, with the left MS having higher accuracy. @*Conclusion@#This study confirmed that, for Korean individuals, the left MS has a better ability to identify sex than the right MS. These results may contribute to sex identification in the fields of surgery and forensics.
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Although differentiated thyroid cancer has an excellent prognosis and low mortality, its recurrence rate has been reported to be very high. While surgery is recommended as the standard treatment for recurrent thyroid cancer, reoperation may increase the incidence of complications due to fibrosis and anatomical distortion. In patients with high surgical risk or those who refuse repeated surgery, ultrasonography-guided ablation techniques including radiofrequency ablation, ethanol ablation, and laser ablation are suggested as alternative treatments. In this manuscript, we introduce an anatomy-based management concept for radiofrequency ablation for recurrent thyroid cancer, and present a review of the relevant literature, including indications, basic techniques, clinical outcomes, and complications.
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Purpose@#We evaluated the use of three criteria to determine the need for additional treatment of cystic thyroid nodules after their recurrence following ethanol ablation (EA). @*Methods@#In total, 154 patients (male:female=30:124; mean age, 53.4 years; range, 23 to 79 years) with 154 thyroid nodules (49 cystic and 105 predominantly cystic nodules) who presented between January 2014 and August 2017 were enrolled. All patients underwent follow-up ultrasonography (US) 1 month after EA, and were divided into therapeutic success and failure groups. Therapeutic success was defined as the absence of any residual fluid or sufficient volume reduction (≥50%) with improvement of nodule-related symptoms. The therapeutic failure was defined according to three previously suggested criteria for recommending additional treatment: nodules with ≥1 mL of remnant fluid (criterion 1), volume reduction <50% (criterion 2), and demonstration of a solid component with vascularity (criterion 3). @*Results@#Thyroid nodules treated by EA showed significant volume reduction (18.4±21.6 mL to 4.2±6.5 mL [1-month follow-up] to 1.9±3.3 mL [final follow-up], P<0.001) and improvement in clinical problems. Therapeutic failure were 26 patients according to criteria 1, 14 patients according to criteria 2, and 35 patients according to criteria 3. Additional treatment was unnecessary in 81.3%, 70.0%, and 77.8% of patients deemed to need it according to criteria 1, 2, and 3, respectively. @*Conclusion@#The choice to perform additional treatment after EA should be made according to a combination of clinical problems and US features. Understanding this concept will be useful in planning further treatment following US-guided EA.
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Purpose@#The diagnostic performance of thyroid biopsy is influenced by several factors, including differences in the Bethesda categorization for malignancy, the inclusion or exclusion of non-diagnostic results, the definition used for the final diagnosis, and the definition of an inconclusive diagnosis. The purpose of this study was to provide an understanding of the factors influencing the diagnostic performance of thyroid biopsy. @*Methods@#We collected data retrospectively between January and December 2013 from a cohort of 6,762 thyroid nodules from 6,493 consecutive patients who underwent biopsy. In total, 4,822 nodules from 4,553 patients were included. We calculated the biopsy sensitivity according to the inclusion of different Bethesda categories in the numerator and the exclusion of non-diagnostic results, as well as the diagnostic accuracy according to different definitions of a benign diagnosis. We obtained the conclusive and inconclusive diagnosis rates. @*Results@#The sensitivity increased when more Bethesda categories were included in the numerator and when non-diagnostic results were excluded. When a benign thyroid nodule diagnosis was defined as benign findings on surgical resection, concordant benign results on at least two occasions, or an initial benign biopsy result and follow-up for more than 12 months, the accuracy was higher than when the diagnosis was based on surgical resection alone (68.7% vs. 91.1%). A higher conclusive diagnosis rate was obtained (78.3% vs. 72.8%, P<0.001) when Bethesda categories I and III were considered inconclusive. @*Conclusion@#Understanding the concepts presented herein is important in order to appropriately interpret the diagnostic performance of thyroid biopsy.
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Objective@#Central nervous system involvement in coronavirus disease 2019 (COVID-19) has been increasingly reported. We performed a systematic review and meta-analysis to evaluate the incidence of radiologically demonstrated neurologic complications and detailed neuroimaging findings associated with COVID-19. @*Materials and Methods@#A systematic literature search of MEDLINE/PubMed and EMBASE databases was performed up to September 17, 2020, and studies evaluating neuroimaging findings of COVID-19 using brain CT or MRI were included. Several cohort-based outcomes, including the proportion of patients with abnormal neuroimaging findings related to COVID-19 were evaluated. The proportion of patients showing specific neuroimaging findings was also assessed. Subgroup analyses were also conducted focusing on critically ill COVID-19 patients and results from studies that used MRI as the only imaging modality. @*Results@#A total of 1394 COVID-19 patients who underwent neuroimaging from 17 studies were included; among them, 3.4% of the patients demonstrated COVID-19-related neuroimaging findings. Olfactory bulb abnormalities were the most commonly observed (23.1%). The predominant cerebral neuroimaging finding was white matter abnormality (17.6%), followed by acute/subacute ischemic infarction (16.0%), and encephalopathy (13.0%). Significantly more critically ill patients had COVID-19-related neuroimaging findings than other patients (9.1% vs. 1.6%; p = 0.029). The type of imaging modality used did not significantly affect the proportion of COVID-19-related neuroimaging findings. @*Conclusion@#Abnormal neuroimaging findings were occasionally observed in COVID-19 patients. Olfactory bulb abnormalities were the most commonly observed finding. Critically ill patients showed abnormal neuroimaging findings more frequently than the other patient groups. White matter abnormalities, ischemic infarctions, and encephalopathies were the common cerebral neuroimaging findings.
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Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1–2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.
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Indications of fiberoptic laryngeal laser surgery (FLS) procedure have broadened by the development of flexible fiberoptic endoscopes and flexible laser systems. FLS procedure performed under local anesthesia and it is the unique value of FLS. The surgery can be performed on patients who are impossible to undergo general anesthesia and difficult to be exposed by laryngeal microsurgery. Main indication of FLS procedure was small to moderate sized hemorrhagic vocal polyp, but we experienced a case of huge vocal polyp with difficult laryngeal exposure treated by FLS procedure under local anesthesia. The vocal polyp was removed successfully without vocal fold scar through fiberoptic laryngeal laser surgery under local anesthesia.
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Background@#Tachycardia-polyuria syndrome is characterized by polyuria occurring because of tachycardia with a heart rate of ≥ 120 beats/min lasting ≥ 30 min. We report such a case occurring after swan-ganz catheterization.Case: A 41-year-old male was scheduled for living-donor liver transplantation. After general anesthesia, atrial fibrillation occurred during swan-ganz catheterization, and polyuria developed 1 h later. During the anhepatic phase, the patient’s heart rate increased further, and cardioversion was performed. After a normal sinus rhythm was achieved, the patient’s urine output returned to normal. @*Conclusions@#The patient’s polyuria seemed related to the iatrogenic atrial fibrillation occurring during swan-ganz catheterization. Although we did not measure atrial natriuretic peptide, an increase in its concentration may have been the main mechanism of polyuria, as natriuresis was observed.
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The diagnostic and treatment methods of multiple myeloma (MM) have been rapidly evolving owing to advances in imaging techniques and new therapeutic agents. Imaging has begun to play an important role in the management of MM, and international guidelines are frequently updated. Since the publication of 2015 International Myeloma Working Group (IMWG) criteria for the diagnosis of MM, whole-body magnetic resonance imaging (MRI) or low-dose whole-body computed tomography (CT) and 18F-fluorodeoxyglucose positron emission tomography/CT have entered the mainstream as diagnostic and treatment response assessment tools. The 2019 IMWG guidelines also provide imaging recommendations for various clinical settings. Accordingly, radiologists have become a key component of MM management. In this review, we provide an overview of updates in the MM field with an emphasis on imaging modalities.
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Objective@#Preoperative differentiation between inverted papilloma (IP) and its malignant transformation to squamous cell carcinoma (IP-SCC) is critical for patient management. We aimed to determine the diagnostic accuracy of conventional imaging features and histogram parameters obtained from whole tumor apparent diffusion coefficient (ADC) values to predict IP-SCC in patients with IP, using decision tree analysis. @*Materials and Methods@#In this retrospective study, we analyzed data generated from the records of 180 consecutive patients with histopathologically diagnosed IP or IP-SCC who underwent head and neck magnetic resonance imaging, including diffusion-weighted imaging and 62 patients were included in the study. To obtain whole tumor ADC values, the region of interest was placed to cover the entire volume of the tumor. Classification and regression tree analyses were performed to determine the most significant predictors of IP-SCC among multiple covariates. The final tree was selected by cross-validation pruning based on minimal error. @*Results@#Of 62 patients with IP, 21 (34%) had IP-SCC. The decision tree analysis revealed that the loss of convoluted cerebriform pattern and the 20th percentile cutoff of ADC were the most significant predictors of IP-SCC. With these decision trees, the sensitivity, specificity, accuracy, and C-statistics were 86% (18 out of 21; 95% confidence interval [CI], 65–95%), 100% (41 out of 41; 95% CI, 91–100%), 95% (59 out of 61; 95% CI, 87–98%), and 0.966 (95% CI, 0.912–1.000), respectively. @*Conclusion@#Decision tree analysis using conventional imaging features and histogram analysis of whole volume ADC could predict IP-SCC in patients with IP with high diagnostic accuracy.
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Purpose@#To explore whether panretinal photocoagulation (PRP) improved retinal blood circulation in patients with diabetic retinopathy of various levels of severity based on changes in the retinal circulation time as measured by video fluorescein fundus angiography. @*Methods@#We recruited patients with severe diabetic retinopathy indicated for PRP; we performed video fluorescein fundus angiography before and after PRP. We measured changes in the arterial circulation time (ACT), arteriovenous passage time (APT), and venous filling time (VFT) in patients with diabetic retinopathy of varying severity, and compared the findings. We recorded HbA1c levels and hypertension status. @*Results@#We enrolled 33 patients, 17 with severe nonproliferative diabetic retinopathy (NPDR) and 16 with early proliferative diabetic retinopathy (PDR). After PRP, neither the ACT nor the APT changed significantly in patients with severe NPDR (p = 0.927, p = 0.138) or early PDR (p = 0.137, p = 0.268). After PRP, the VFT was significantly reduced in patients with both severe NPDR (p = 0.000) and early PDR (p = 0.022). The VFT reductions were similar in both groups (p = 0.217). @*Conclusions@#In patients with severe NPDR and early PDR, improvements in retinal blood circulation after PRP are reflected by reductions in the VFT evident on video fluorescein fundus angiography. We speculate that the improvements are similar in patients with severe NPDR and early PDR.
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Purpose@#To explore whether panretinal photocoagulation (PRP) improved retinal blood circulation in patients with diabetic retinopathy of various levels of severity based on changes in the retinal circulation time as measured by video fluorescein fundus angiography. @*Methods@#We recruited patients with severe diabetic retinopathy indicated for PRP; we performed video fluorescein fundus angiography before and after PRP. We measured changes in the arterial circulation time (ACT), arteriovenous passage time (APT), and venous filling time (VFT) in patients with diabetic retinopathy of varying severity, and compared the findings. We recorded HbA1c levels and hypertension status. @*Results@#We enrolled 33 patients, 17 with severe nonproliferative diabetic retinopathy (NPDR) and 16 with early proliferative diabetic retinopathy (PDR). After PRP, neither the ACT nor the APT changed significantly in patients with severe NPDR (p = 0.927, p = 0.138) or early PDR (p = 0.137, p = 0.268). After PRP, the VFT was significantly reduced in patients with both severe NPDR (p = 0.000) and early PDR (p = 0.022). The VFT reductions were similar in both groups (p = 0.217). @*Conclusions@#In patients with severe NPDR and early PDR, improvements in retinal blood circulation after PRP are reflected by reductions in the VFT evident on video fluorescein fundus angiography. We speculate that the improvements are similar in patients with severe NPDR and early PDR.
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Background@#Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains were first detected in hospitals in Korea between the late 2000s and early 2010s.However, there is limited information regarding the prevalence of CA-MRSA strains among hospital isolates and their phenotypic changes over the last decade. We investigated the prevalence trend of CA-MRSA strains isolated from different clinical specimens and their phenotypic changes between September 2009 and September 2019. @*Methods@#CA-MRSA strains were phenotypically identified by confirming their resistance to penicillin (PCN) and oxacillin (OXA) and evaluating their susceptibility to trimethoprimsulfamethoxazole, rifampin, fusidic acid, tetracycline, and at least one of the following four antimicrobials: clindamycin (CLI), erythromycin (ERY), ciprofloxacin (CIP), and gentamicin (GEN). A CA-MRSA strain that exhibited resistance to ERY, CLI, CIP, or GEN was classified as having resistance pattern I, II, III, or IV, respectively, regardless of its resistance to other antimicrobial agents. @*Results@#Of the 8,278 MRSA isolates identified in specimens obtained two days after admission, 1,385 (16.73%) were CA-MRSA strains. The prevalence of CA-MRSA strains increased from 12.2% to 26.6% (3.21% per period, P = 0.05). Resistance type analysis revealed an increasing trend in the prevalence of PCN/OXA-resistant (1.84%; P = 0.049) and PCN/OXA/ERY/CLI/CIP-resistant (0.98%; P = 0.04) CA-MRSA strains and in resistance pattern III strains (2.08%; P = 0.004). @*Conclusions@#The prevalence of CA-MRSA strains in Korea has increased significantly over the last decade, and CA-MRSA strains have gained phenotypic diversity beyond PCN/OXAresistance, including antimicrobial resistance to non-β-lactams, especially CIP.