Assessment of the Suitability of the Fleischner Society Imaging Guidelines in Evaluating Chest Radiographs of COVID-19 Patients.

BACKGROUND: The Fleischner Society established consensus guidelines for imaging in patients with coronavirus disease 2019 (COVID-19). We investigated the prevalence of pneumonia and the adverse outcomes by dividing groups according to the symptoms and risk factors of patients and assessed the suitability of the Fleischner society imaging guidelines in evaluating chest radiographs of COVID-19 patients. METHODS: From February 2020 to May 2020, 685 patients (204 males, mean 58 ± 17.9 years) who were diagnosed with COVID-19 and hospitalized were included. We divided patients into four groups according to the severity of symptoms and presence of risk factors (age > 65 years and presence of comorbidities). The patient groups were defined as follows: group 1 (asymptomatic patients), group 2 (patients with mild symptoms without risk factors), group 3 (patients with mild symptoms and risk factors), and group 4 (patients with moderate to severe symptoms). According to the Fleischner society, chest imaging is not indicated for groups 1-2 but is indicated for groups 3-4. We compared the prevalence and score of pneumonia on chest radiographs and compare the adverse outcomes (progress to severe pneumonia, intensive care unit admission, and death) between groups. RESULTS: Among the 685 COVID-19 patients, 138 (20.1%), 396 (57.8%), 102 (14.9%), and 49 (7.1%) patients corresponded to groups 1 to 4, respectively. Patients in groups 3-4 were significantly older and showed significantly higher prevalence rates of pneumonia (group 1-4: 37.7%, 51.3%, 71.6%, and 98%, respectively, P < 0.001) than those in groups 1-2. Adverse outcomes were also higher in groups 3-4 than in groups 1-2 (group 1-4: 8.0%, 3.5%, 6.9%, and 51%, respectively, P < 0.001). Patients with adverse outcomes in group 1 were initially asymptomatic but symptoms developed during follow-up. They were older (mean age, 80 years) and most of them had comorbidities (81.8%). Consistently asymptomatic patients had no adverse events. CONCLUSION: The prevalence of pneumonia and adverse outcomes were different according to the symptoms and risk factors in COVID-19 patients. Therefore, as the Fleischner Society recommended, evaluation and monitoring of COVID-19 pneumonia using chest radiographs is necessary for old symptomatic patients with comorbidities.

Leg paralysis after AstraZeneca COVID-19 vaccination diagnosed as neuralgic amyotrophy of the lumbosacral plexus: a case report.

The ongoing global administration of vaccines for coronavirus disease 2019 (COVID-19) means that increasing numbers of patients are likely to present with post-vaccination complications. We describe the first reported case of neuralgic amyotrophy (NA) involving the lumbosacral plexus occurring after AstraZeneca COVID-19 vaccination. The patient presented with acute-onset leg paralysis following administration of the vaccine. Based on the clinical, electrodiagnostic, and radiologic findings, the patient was diagnosed with post-vaccination NA. We speculate that the COVID-19 vaccine elicited an immune-mediated inflammatory response to the injected antigen due to inflammatory immunity in a patient with predisposed susceptibility to NA.

Sclerotic bone lesions caused by non-infectious and non-neoplastic diseases: a review of the imaging and clinicopathologic findings.

Bone sclerosis is a focal, multifocal, or diffuse increase in the density of the bone matrix on radiographs or computed tomography (CT) imaging. This radiological finding can be caused by a broad spectrum of diseases, such as congenital and developmental disorders, depositional disorders, and metabolic diseases. The differential diagnosis can be effectively narrowed by an astute radiologist in the light of the clinical picture and typical findings on imaging. Some of these lesions are rare and have been described as case reports and series in the literature. This article aims to collate the clinical-radiologic findings of non-infectious and non-neoplastic causes of bone sclerosis with relevant imaging illustrations.

Common Extensor Complex Is a Predictor to Determine the Stability in Simple Posterolateral Elbow Dislocation: Analysis of MR Images of Stable vs. Unstable Dislocation.

Simple posterolateral elbow dislocations (SPLED) may be treated nonoperatively using closed reduction, followed by controlled mobilization. However, the extent of soft tissue injuries might affect the choice of treatment, rehabilitation approach, and prognosis. The purpose of this study is to compare the characteristics of soft tissue injuries between patients with unstable and stable SPLED using MRI findings. Thirty MRIs of elbows with SPLED (unstable group (n = 15); stable group (n = 15)) were randomly reviewed by two experienced musculoskeletal radiologists. Soft tissue injuries were characterized as an intact, partial tear or complete tear for the: medial collateral ligament (MCL) complex, common flexor complex, lateral collateral ligament (LCL) complex, common extensor complex, anterior capsule, and posterior capsule. Moderate to substantial interobserver reliability and substantial to perfect intraobserver reliability were observed for medial and lateral complexes in SPLED. The proportion of soft-tissue injuries of the common extensor complex were significantly different between the unstable (four partial tears and 11 complete tears) and stable groups (11 partial tears and four complete tears). In conclusion, based on MRI findings, the degree of common extensor complex injuries may be a predictor of stability and help inform treatment decisions for SPLED.

Adverse Initial CT Findings Associated with Poor Prognosis of Coronavirus Disease.

BACKGROUND: The predictors of poor prognosis in patients with coronavirus disease 2019 (COVID-19) using computed tomography (CT) have not been investigated in a large cohort. Therefore, the purpose of this study was to investigate the adverse initial CT features to predict poor prognosis in COVID-19. METHODS: From February to April 2020, 281 COVID-19 patients who underwent CT at the time of admission were included. We divided the patients into the severe and non-severe disease groups. The severe group included patients with severe pneumonia or critical events. Intensive care unit admission or death were the critical events in this study. We compared the clinical and CT findings between the severe and non-severe groups and investigated the prognostic factors and critical events of the severe group using the regression analysis. RESULTS: Among the 281 patients, 36 (12.8%) patients were in the severe group and 245 (87.2%) patients were in the non-severe group. Critical events occurred in 10 patients (3.6%). In the severe group, patients showed significantly more pneumonia with consolidation, crazy-paving appearance, pleural effusion, and higher CT scores than those in the non-severe group (all, P < 0.05). In the multivariate regression, pleural effusion (odds ratio [OR], 8.96; 95% confidence interval [CI], 1.81-44.42; P = 0.007), CT score > 5 (OR, 3.70; 95% CI, 1.44-9.53; P = 0.007), old age (> 77 years, OR, 9.96; 95% CI, 3.78-26.28; P < 0.001), and elevated C-reactive protein (OR, 4.15; 95% CI, 1.62-10.6; P = 0.003) were significant prognostic factors of severe disease. CT score > 5 (OR, 7.29; 95% CI, 1.37-38.68; P = 0.020), pleural effusion (OR, 5.67; 95% CI, 1.04-30.8; P = 0.045) and old age (OR, 8.6; 95% CI, 1.80-41.0; P = 0.007) were also significant predictors of critical events. CONCLUSION: Pleural effusion and the extent of pneumonia on initial CT scans are associated with poor prognosis in patients with COVID-19.

Determination of magnetic resonance imaging criteria for diagnosis of adhesive capsulitis.

The objective of this study was to identify optimal magnetic resonance imaging (MRI) parameters and their cutoff values for diagnosing adhesive capsulitis (AC). One hundred shoulder MRI images with stage 2 AC (AC group) and 100 MRI images without AC (control group) were randomly reviewed by two experienced shoulder specialists. They were asked whether MRI findings were compatible with AC and measurement of MRI parameters. Sensitivity, specificity, and accuracy were calculated. Correlation between MRI parameters and the range of motions was also analyzed. The mean capsular thickness in the axillary recess (AR) (5.9 mm in the AC group vs. 3.6 mm in the control group) on coronal oblique T2-weighted images and the rotator interval (RI) (7.2 mm vs. 4.8 mm, respectively) on oblique sagittal proton-density images were significantly greater in the AC group than in the control group, whereas the width of RI showed no significant difference between two groups. The highest diagnostic cutoff values were 4.5 mm for the AR and 6 mm for the RI, with sensitivity (91% and 88%, respectively), specificity (90% and 90%), and accuracy (90% and 89%). Capsular thickness in the AR and RI was significantly correlated with external rotation (P = 0.047) and internal rotation (P = 0.023). On conventional MRI, capsular thickness greater than 4.5 mm in the AR or 6 mm in the RI can be an optimal criterion for diagnosing AC. Capsular thickness in the AR and RI was correlated with the range of rotational motion.

Cutaneous osteosarcoma arising from a burn scar.

Tumors that develop in old burn scars are usually squamous cell carcinomas. Sarcomas have also been reported, albeit rarely. To our knowledge, there has been only one case report of an extraskeletal osteosarcoma arising in a prior burn scar reported in the English-language literature, mainly discussing the clinicopathological features. Herein, we present a case of cutaneous osteosarcoma visualized as a mineralized soft-tissue mass arising from the scar associated with a previous skin burn over the back. This seems to be the first report describing the imaging features of a cutaneous osteosarcoma from an old burn scar.

Non-Hodgkin's lymphoma at the medial clavicular head mimicking Tietze Syndrome.

We present a case of Non-Hodgkin's lymphoma involving medial clavicular head, which was initially diagnosed as Tietze syndrome. Non-Hodgkin's lymphoma arising from medial clavicular head is extremely rare, and CT, MRI findings have not been reported.

Influence of forearm rotation on proximal radioulnar joint congruency and translational motion using computed tomography and computer-aided design technologies.

PURPOSE: The contact areas of the articular surfaces in the proximal radioulnar joint (PRUJ) change, depending on the rotational position of the forearm. We investigated the in vivo congruency index of the PRUJ and translational motion of the radial head relative to the lesser sigmoid notch with forearm rotation. METHODS: Computed tomography scans of 12 healthy adult elbows were obtained in 3 forearm positions: full supination, neutral, and full pronation. The translation of the center of the radial head at the level of the PRUJ was measured using computer techniques, and a computer-aided design (CAD) program was used for analysis of the congruency index. The radius of the radial head and lesser sigmoid notch, as well as the distance between the radial head and lesser sigmoid notch, were used as parameters of the congruency index. RESULTS: The mean translation of the radial head was 1.17 mm. The mean ratio of the radius of the radial head to the lesser sigmoid notch was 0.83:1 in neutral position, 0.77:1 in pronation, and 0.92:1 in supination. In supination, the ratio of the radius was more congruent than in neutral and pronation. The mean ratio of the distance between the radial head and the lesser sigmoid notch was 0.15:1 in neutral position, 0.11:1 in pronation, and 0.10:1 in supination. In neutral position, the distance was significantly greater than those in the pronation and supination. CONCLUSIONS: In supination, the PRUJ was the most congruent, and the distance between the radial head and the lesser sigmoid notch was minimal (0.10:1). Our findings confirmed the changes of PRUJ congruency during forearm rotation, and this implies changes of intrinsic osseous stability of the PRUJ during forearm rotation.

Articular surface area of the coronoid process and radial head in elbow extension: surface ratio in cadavers and a computed tomography study in vivo.

PURPOSE: To quantify the articular surface area ratio of the radial head to the coronoid process to gain a better understanding of the stress distribution across these articulations and possibly to explain the patterns of osteoarthritis that are commonly seen in the elbow. METHODS: Thirty cadaveric elbows were harvested and dissected to allow measurement of the radial head and coronoid process articular surfaces. The articular surface areas were measured using the Image J program (National Institutes of Health, Chicago, IL). Twelve men were recruited for this study, and all received a computed tomography (CT) scan of the elbow. A 3-dimensional image of the proximal radioulnar articular surface was created using volume rendering. All specimens were measured 3 times by 2 observers. RESULTS: In the cadaveric measurements, the mean area of the radial head articular fossa was 247.3 +/- 52.6 mm(2) (mean +/- SD). The mean area of the medial facet of the coronoid process was 232.29 +/- 36.5 mm(2), and the mean area of the lateral facet was 141.9 +/- 33.3 mm(2). The articular surface area ratio of radial head to coronoid process was 1:1.5. In the CT measurement, the mean area of the radial head articular fossa was 258.9 +/- 26.3 mm(2). The mean area of the coronoid process articular surface was 376.9 +/- 37.0 mm(2). The articular surface area ratio of radial head to coronoid process was 1:1.46. CONCLUSIONS: The ratio of articular surface area of radial head to coronoid process is 1:1.51 in cadavers and 1:1.46 using a CT in vivo, which is the reverse of the reported force transmission ratio across the elbow joint.

Venous thromboembolism in Korean patients undergoing major orthopedic surgery: a prospective observational study using computed tomographic (CT) pulmonary angiography and indirect CT venography.

In patients undergoing major orthopedic surgery, data of deep venous thrombosis (DVT) and pulmonary embolism (PE) are lacking as studied by computed tomographic (CT) pulmonary angiography and indirect CT venography (CTPA-CTV). A prospective observational study was performed for 363 Korean patients undergoing major orthopedic surgery to determine the incidence of venous thromboembolism (VTE), especially proximal DVT and PE. The incidence of VTE was 16.3% (n=59). Of them, 8 patients (2.2%) were symptomatic. The rate of VTE was the highest in patients who underwent total knee replacement (40.4%), followed by hip fracture surgery (16.4%), and total hip replacement (8.7%; P<0.001). The incidence of PE was 6.6% (n=24). Of them, 4 patients (1.1%) were symptomatic. Forty-one patients (11.3%) were in the proximal DVT or PE group. Based on multivariate analysis, total knee replacement and age > or =65 yr were significant risk factors for proximal DVT or PE in patients undergoing major orthopedic surgery (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.1-5.1; P=0.025; and OR, 2.1; 95% CI, 1.0-4.4; P=0.046, respectively). Taken together, the overall incidence of PE was 6.6% and rate of symptomatic PE rate was 1.1%. Knee joint replacement and age > or =65 yr were significant risk factors for proximal DVT or PE.