Objective: It is unknown whether artificial intelligence-based computer-aided detection (AI-CAD) can enhance the accuracy of chest radiograph (CR) interpretation in real-world clinical practice. We aimed to compare the accuracy of CR interpretation assisted by AI-CAD to that of conventional interpretation in patients who presented to the emergency department (ED) with acute respiratory symptoms using a pragmatic randomized controlled trial. Materials and Methods: Patients who underwent CRs for acute respiratory symptoms at the ED of a tertiary referral institution were randomly assigned to intervention group (with assistance from an AI-CAD for CR interpretation) or control group (without AI assistance). Using a commercial AI-CAD system (Lunit INSIGHT CXR, version 2.0.2.0; Lunit Inc.). Other clinical practices were consistent with standard procedures. Sensitivity and false-positive rates of CR interpretation by duty trainee radiologists for identifying acute thoracic diseases were the primary and secondary outcomes, respectively. The reference standards for acute thoracic disease were established based on a review of the patient’s medical record at least 30 days after the ED visit. Results: We randomly assigned 3576 participants to either the intervention group (1761 participants; mean age ± standard deviation, 65 ± 17 years; 978 males; acute thoracic disease in 472 participants) or the control group (1815 participants; 64 ± 17 years; 988 males; acute thoracic disease in 491 participants). The sensitivity (67.2% [317/472] in the intervention group vs. 66.0% [324/491] in the control group; odds ratio, 1.02 [95% confidence interval, 0.70–1.49]; P = 0.917) and false-positive rate (19.3% [249/1289] vs. 18.5% [245/1324]; odds ratio, 1.00 [95% confidence interval, 0.79–1.26]; P = 0.985) of CR interpretation by duty radiologists were not associated with the use of AI-CAD. Conclusion AI-CAD did not improve the sensitivity and false-positive rate of CR interpretation for diagnosing acute thoracic disease in patients with acute respiratory symptoms who presented to the ED.

We performed a point seroprevalence survey of measles among healthcare workers (HCWs) at two Korean teaching hospitals in 2019. A total of 2,830 HCWs underwent an antibody test.The overall seropositivity of measles was 93.1%. The seroprevalence of measles was lowest in HCWs aged 20 - 24 years (81.2%), followed by those aged 25 - 29 years (90.1%). The rates of anti-measles IgG positivity were significantly different between the two hospitals (97.0% vs.89.4%, P <0.001). These results suggest that the seropositivity of measles in HCWs may differ depending on the hospital's vaccination policy.

OBJECTIVE: To compare a high acceleration three-dimensional (3D) T1-weighted gradient-recalled-echo (GRE) sequence using the combined compressed sensing (CS)-sensitivity encoding (SENSE) method with a conventional 3D GRE sequence using SENSE, with respect to image quality and detectability of solid focal liver lesions (FLLs) in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced liver MRI. MATERIALS AND METHODS: A total of 217 patients with gadoxetic acid-enhanced liver MRI at 3T (54 in the preliminary study and 163 in the main study) were retrospectively included. In the main study, HBP imaging was done twice using the standard mDixon-3D-GRE technique with SENSE (acceleration factor [AF]: 2.8, standard mDixon-GRE) and the high acceleration mDixon-3D GRE technique using the combined CS-SENSE technique (CS-SENSE mDixon-GRE). Two abdominal radiologists assessed the two MRI data sets for image quality in consensus. Three other abdominal radiologists independently assessed the diagnostic performance of each data set and its ability to detect solid FLLs in 117 patients with 193 solid nodules and compared them using jackknife alternative free-response receiver operating characteristics (JAFROC). RESULTS: There was no significant difference in the overall image quality. CS-SENSE mDixon-GRE showed higher image noise, but lesser motion artifact levels compared with the standard mDixon-GRE (all p < 0.05). In terms of lesion detection, reader-averaged figures-of-merit estimated with JAFROC was 0.918 for standard mDixon-GRE, and 0.953 for CS-SENSE mDixon-GRE (p = 0.142). The non-inferiority of CS-SENSE mDixon-GRE over standard mDixon-GRE was confirmed (difference: 0.064 [−0.012, 0.081]). CONCLUSION: The CS-SENSE mDixon-GRE HBP sequence provided comparable overall image quality and non-inferior solid FFL detectability compared with the standard mDixon-GRE sequence, with reduced acquisition time.
Acceleration ; Artifacts ; Consensus ; Dataset ; Humans ; Liver ; Magnetic Resonance Imaging ; Methods ; Noise ; Retrospective Studies ; ROC Curve

OBJECTIVE: To investigate whether computed tomography (CT) and fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) may be applied to distinguish thymic epithelial tumors (TETs) from benign cysts in the anterior mediastinum. MATERIALS AND METHODS: We included 262 consecutive patients with pathologically proven TETs and benign cysts 5 cm or smaller who underwent preoperative CT scans. In addition to conventional morphological and ancillary CT findings, the relationship between the lesion and the adjacent mediastinal pleura was evaluated qualitatively and quantitatively. Mean lesion attenuation was measured on CT images. The maximum standardized uptake value (SUVmax) was obtained with FDG-PET scans in 40 patients. CT predictors for TETs were identified with multivariate logistic regression analysis. For validation, we assessed the diagnostic accuracy and inter-observer agreement between four radiologists in a size-matched set of 24 cysts and 24 TETs using a receiver operating characteristic curve before and after being informed of the study findings. RESULTS: The multivariate analysis showed that post-contrast attenuation of 60 Hounsfield unit or higher (odds ratio [OR], 12.734; 95% confidence interval [CI], 2.506–64.705; p = 0.002) and the presence of protrusion from the mediastinal pleura (OR, 9.855; 95% CI, 1.749–55.535; p = 0.009) were the strongest CT predictors for TETs. SUVmax was significantly higher in TETs than in cysts (5.3 ± 2.4 vs. 1.1 ± 0.3; p < 0.001). After being informed of the study findings, the readers' area under the curve improved from 0.872–0.955 to 0.949–0.999 (p = 0.066–0.149). Inter-observer kappa values for protrusion were 0.630–0.941. CONCLUSION: Post-contrast CT attenuation, protrusion from the mediastinal pleura, and SUVmax were useful imaging features for distinguishing TETs from cysts in the anterior mediastinum.
Humans ; Logistic Models ; Mediastinum ; Multivariate Analysis ; Pleura ; Positron-Emission Tomography ; ROC Curve ; Thymus Neoplasms ; Tomography, X-Ray Computed

STUDY DESIGN: A cross-sectional study. OBJECTIVES: To provide reference data for the study and treatment of thoracic scoliosis. SUMMARY OF LITERATURE REVIEW: There have been no reports on the prevalence of thoracic scoliosis in Korea. MATERIALS AND METHODS: From August 2011 to October 2012, radiographs of patients under 80 years of age who underwent routine chest radiographs were retrospectively reviewed. Based on their age when the chest radiographs were obtained, the patients were divided into 8 groups. The prevalence and angle of the curve of thoracic scoliosis were investigated in each age group, and the prevalence of thoracic scoliosis according to sex, the direction of the curve, number of vertebrae in the major curve, the location and rotation of the apical vertebrae, and osteophyte location were examined. RESULTS: The prevalence of thoracic scoliosis was 2.4% (621 patients), and female patients (3.0%, 375 of 12471) showed a higher prevalence than male patients (1.8%, 246 of 13654) (p<0.001). Right curvature was present in 445 patients and left curvature in 176 patients. In each age group, the prevalence and degree of thoracic scoliosis were 1.1% (14.2°±3.2°), 2.3% (17.4°±7.7°), 2.5% (17.0°±8.9°), 1.9% (15.8°±5.9°), 1.3% (15.5°±6.6°), 2.1% (18.0°±13.6°), 2.9% (14.3°±3.6°), and 6.1% (16.2°±4.8°), respectively. The mean curvature in all scoliosis patients was 16.0°±7.0°. The angle of the curve was significantly different by sex (15.4°±7.1° for males, 16.8°±7.6° for females). The average curve angle of patients with thoracic scoliosis was 16.0°±7.0°, among whom it was 10°–20° in 533 patients, 20°–30° in 64, 30°–40° in 11, and over 40° in 13. CONCLUSIONS: This study could be used as a reference point for the study and treatment of thoracic scoliosis.
Cross-Sectional Studies ; Female ; Humans ; Korea ; Male ; Osteophyte ; Prevalence ; Radiography ; Radiography, Thoracic ; Retrospective Studies ; Scoliosis ; Spine ; Thoracic Vertebrae ; Thorax

OBJECTIVES: To provide reference data for the study and treatment of thoracic scoliosis.SUMMARY OF LITERATURE REVIEW: There have been no reports on the prevalence of thoracic scoliosis in Korea. MATERIALS AND METHODS: From August 2011 to October 2012, radiographs of patients under 80 years of age who underwent routine chest radiographs were retrospectively reviewed. Based on their age when the chest radiographs were obtained, the patients were divided into 8 groups. The prevalence and angle of the curve of thoracic scoliosis were investigated in each age group, and the prevalence of thoracic scoliosis according to sex, the direction of the curve, number of vertebrae in the major curve, the location and rotation of the apical vertebrae, and osteophyte location were examined. RESULTS: The prevalence of thoracic scoliosis was 2.4% (621 patients), and female patients (3.0%, 375 of 12471) showed a higher prevalence than male patients (1.8%, 246 of 13654) (p<0.001). Right curvature was present in 445 patients and left curvature in 176 patients. In each age group, the prevalence and degree of thoracic scoliosis were 1.1% (14.2°±3.2°), 2.3% (17.4°±7.7°), 2.5% (17.0°±8.9°), 1.9% (15.8°±5.9°), 1.3% (15.5°±6.6°), 2.1% (18.0°±13.6°), 2.9% (14.3°±3.6°), and 6.1% (16.2°±4.8°), respectively. The mean curvature in all scoliosis patients was 16.0°±7.0°. The angle of the curve was significantly different by sex (15.4°±7.1° for males, 16.8°±7.6° for females). The average curve angle of patients with thoracic scoliosis was 16.0°±7.0°, among whom it was 10°–20° in 533 patients, 20°–30° in 64, 30°–40° in 11, and over 40° in 13. CONCLUSIONS This study could be used as a reference point for the study and treatment of thoracic scoliosis.

OBJECTIVE: In a proof of concept study, we compared no-touch radiofrequency ablation (NtRFA) in bipolar mode with conventional direct tumor puncture (DTP) in terms of local tumor control (LTC), peritoneal seeding, and tumorigenic factors, in the rabbit VX2 subcapsular hepatic tumor model. MATERIALS AND METHODS: Sixty-two rabbits with VX2 subcapsular hepatic tumors were divided into three groups according to the procedure: DTP-RFA (n = 25); NtRFA (n = 25); and control (n = 12). Each of the three groups was subdivided into two sets for pathologic analysis (n = 24) or computed tomography (CT) follow-up for 6 weeks after RFA (n = 38). Ultrasonography-guided DTP-RFA and NtRFA were performed nine days after tumor implantation. LTC was defined by either achievement of complete tumor necrosis on histopathology or absence of local tumor progression on follow-up CT and autopsy. Development of peritoneal seeding was also compared among the groups. Serum hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) were measured via ELISA (Elabscience Biotechnology Co.) after RFA for tumorigenic factor evaluation. RESULTS: Regarding LTC, there was a trend in NtRFA (80%, 20/25) toward better ablation than in DTP-RFA (56%, 14/25) (p = 0.069). Complete tumor necrosis was achieved in 54.5% of DTP-RFA (6/11) and 90.9% of NtRFA (10/11). Peritoneal seeding was significantly more common in DTP-RFA (71.4%, 10/14) than in NtRFA (21.4%, 3/14) (p = 0.021) or control (0%). Elevations of HGF, VEGF or IL-6 were not detected in any group. CONCLUSION: No-touch radiofrequency ablation led to lower rates of peritoneal seeding and showed a tendency toward better LTC than DTP-RFA.
Autopsy ; Biotechnology ; Catheter Ablation* ; Enzyme-Linked Immunosorbent Assay ; Follow-Up Studies ; Hepatocyte Growth Factor ; Interleukin-6 ; Necrosis ; Punctures ; Rabbits* ; Vascular Endothelial Growth Factor A

BACKGROUND: To determine the natural progression of conservatively treated rotator cuff tears, we evaluated changes in radiologic and clinical parameters in patients whose recalcitrant tears were neglected after conservative treatment. METHODS: A total of 73 patients with recalcitrant rotator cuff tears in spite of conservative treatment were included in this study. We measured changes in tear size and in the extent of fatty infiltration of the rotator cuff by comparing the initial and final follow-up magnetic resonance imagings (MRIs). To determine factors influencing the change in tear size, we collected the medical history of patients taken at the time of initial admission. RESULTS: The average follow-up period was 20.1 months, and the average increase in tear size across this period was 6.2 mm. In terms of steroid injection, we found that the increases in tear size of the steroid injection group (p=0.049) and of the sub-group that had received more than three steroid injections (p=0.010) were significantly greater than that of the non-steroid injection group. CONCLUSIONS: We found that the increase in cuff tear size was on average 6.2 mm across the follow-up period, indicating that neglecting cuff tears may cause them to progress into more severe tears. We also observed that a history of steroid injection might be a possible risk factor for a worse prognosis of cuff tears. Therefore, we suggest that patients with rotator cuff tears and a history of steroid injection are recommended aggressive modes of treatment such as surgery.
Follow-Up Studies ; Humans ; Magnetic Resonance Imaging* ; Prognosis ; Retrospective Studies* ; Risk Factors ; Rotator Cuff* ; Tears*

BACKGROUND: To determine the natural progression of conservatively treated rotator cuff tears, we evaluated changes in radiologic and clinical parameters in patients whose recalcitrant tears were neglected after conservative treatment. METHODS: A total of 73 patients with recalcitrant rotator cuff tears in spite of conservative treatment were included in this study. We measured changes in tear size and in the extent of fatty infiltration of the rotator cuff by comparing the initial and final follow-up magnetic resonance imagings (MRIs). To determine factors influencing the change in tear size, we collected the medical history of patients taken at the time of initial admission. RESULTS: The average follow-up period was 20.1 months, and the average increase in tear size across this period was 6.2 mm. In terms of steroid injection, we found that the increases in tear size of the steroid injection group (p=0.049) and of the sub-group that had received more than three steroid injections (p=0.010) were significantly greater than that of the non-steroid injection group. CONCLUSIONS: We found that the increase in cuff tear size was on average 6.2 mm across the follow-up period, indicating that neglecting cuff tears may cause them to progress into more severe tears. We also observed that a history of steroid injection might be a possible risk factor for a worse prognosis of cuff tears. Therefore, we suggest that patients with rotator cuff tears and a history of steroid injection are recommended aggressive modes of treatment such as surgery.
Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Prognosis ; Retrospective Studies ; Risk Factors ; Rotator Cuff ; Tears

Sodium nitrite is commercially used as a coloring agent, food preservative, and corrosion inhibitor. Accidental poisoning with sodium nitrite from contaminated food and water causes gastrointestinal irritation, vasodilatation, and methemoglobinemia with subsequent tissue hypoxia. We describe an outbreak case of sodium nitrite-induced methemoglobinemia following the ingestion of noodles contaminated with industrial antifreeze. The eEight patients involved initially complained that their noodles tasted 'unpleasant' and soon afterwards experienced nausea, vomiting, dizziness, and fatigue. Some of them noted cyanosis on their lips and fingers. Subsequent investigations demonstrated a high methemoglobin concentration which was corrected by the intravenous administration of methylene blue three hours after the onset of symptoms. The patients made a prompt, uncomplicated recovery and were discharged home 4 four days later. Industrial antifreeze contains sodium nitrite and calcium nitrite. Because an accidental poisoning of industrial antifreeze causes fatal methemoglobinemia, emergency physicians should promptly identify its symptoms and institute treatment with methylene blue promptly. In addition, industrial agencies must caution construction businesses against such contamination events.
Administration, Intravenous ; Anoxia ; Calcium ; Commerce ; Corrosion ; Cyanosis ; Dizziness ; Eating ; Emergencies ; Fatigue ; Fingers ; Humans ; Lip ; Methemoglobin ; Methemoglobinemia ; Methylene Blue ; Nausea ; Sodium ; Sodium Nitrite ; Vasodilation ; Vomiting