Generative Adversarial Network-Based Image Conversion Among Different Computed Tomography Protocols and Vendors: Effects on Accuracy and Variability in Quantifying Regional Disease Patterns of Interstitial Lung Disease

Objective@#To assess whether computed tomography (CT) conversion across different scan parameters and manufacturers using a routable generative adversarial network (RouteGAN) can improve the accuracy and variability in quantifying interstitial lung disease (ILD) using a deep learning-based automated software. @*Materials and Methods@#This study included patients with ILD who underwent thin-section CT. Unmatched CT images obtained using scanners from four manufacturers (vendors A-D), standard- or low-radiation doses, and sharp or medium kernels were classified into groups 1–7 according to acquisition conditions. CT images in groups 2–7 were converted into the target CT sty le (Group 1: vendor A, standard dose, and sharp kernel) using a RouteGAN. ILD was quantified on original and converted CT images using a deep learning-based software (Aview, Coreline Soft). The accuracy of quantification was analyzed using the dice similarity coefficient (DSC) and pixel-wise overlap accuracy metrics against manual quantification by a radiologist. Five radiologists evaluated quantification accuracy using a 10-point visual scoring system. @*Results@#Three hundred and fifty CT slices from 150 patients (mean age: 67.6 ± 10.7 years; 56 females) were included. The overlap accuracies for quantifying total abnormalities in groups 2–7 improved after CT conversion (original vs. converted: 0.63vs. 0.68 for DSC, 0.66 vs. 0.70 for pixel-wise recall, and 0.68 vs. 0.73 for pixel-wise precision; P < 0.002 for all). The DSCs of fibrosis score, honeycombing, and reticulation significantly increased after CT conversion (0.32 vs. 0.64, 0.19 vs. 0.47, and 0.23 vs. 0.54, P < 0.002 for all), whereas those of ground-glass opacity, consolidation, and emphysema did not change significantly or decreased slightly. The radiologists’ scores were significantly higher (P < 0.001) and less variable on converted CT. @*Conclusion@#CT conversion using a RouteGAN can improve the accuracy and variability of CT images obtained using different scan parameters and manufacturers in deep learning-based quantification of ILD.

Gant Infrascapular Rheumatoid Nodules Mimicking Elastofibroma Dorsi:A Case Report

Rheumatoid nodules are the most common extra-articular presentations of rheumatoid arthritis. Although rheumatoid nodules can develop anywhere in the body, they develop most commonly in the subcutaneous region, where they are easily exposed to repetitive trauma or pressure. However, an infrascapular presentation has not yet been reported. We report a case of giant bilateral rheumatoid nodules that developed in the infrascapular area, complicating its distinction from elastofibroma dorsi on radiological examination.

Systemic Manifestations of Immunoglobulin G4-Related Disease: A Pictorial Essay

Immunoglobulin G4 (IgG4)-related disease is a systemic fibro-inflammatory disease characterized by pathologic findings in various organs. Imaging is critical for the diagnosis and treatment assessment of patients with IgG4-related disease. In this pictorial essay, we review the key features of multiple imaging modalities, typical pathologic findings, and differential diagnosis of IgG4-related disease. This systematic pictorial review can further our understanding of the broad-spectrum manifestations of this disease.

Systemic Manifestations of Immunoglobulin G4-Related Disease: A Pictorial Essay

Immunoglobulin G4 (IgG4)-related disease is a systemic fibro-inflammatory disease characterized by pathologic findings in various organs. Imaging is critical for the diagnosis and treatment assessment of patients with IgG4-related disease. In this pictorial essay, we review the key features of multiple imaging modalities, typical pathologic findings, and differential diagnosis of IgG4-related disease. This systematic pictorial review can further our understanding of the broad-spectrum manifestations of this disease.

A Case of Spontaneous Chronic Expanding Hematoma in the Thorax / 결핵및호흡기질환

A chronic expanding hematoma (CEH) in the thorax is a rare and specific condition of chronic empyema. CEHs in the thorax are often associated with tuberculosis and/or previous surgical procedures. While the incidental detection of a pleural mass and dyspnea are common clinical manifestations, a few cases present with hemoptysis. We encountered a case of CEH in the thorax. This case is unique in that it developed without a prior history of tuberculosis or surgery and presented with massive hemoptysis accompanied by bronchopleural fistula. We report the third case of CEH in the thorax in Korea with a summary of the clinical characteristics of previous cases.

Posterior Diaphragmatic Defect Detected on Chest CT: the Incidence according to Age and the Lateral Chest Radiographic Appearances

PURPOSE: We wanted to investigate the incidence of posterior diaphragmatic defect on chest CT in various age gropus and its lateral chest radiographic appearances. MATERIALS AND METHODS: The chest CT scans of 78 patients of various ages with posterior diaphragmatic defect were selected among 1,991 patients, and they were analyzed for the incidence of defect in various age groups, the defect location and the herniated contents. Their lateral chest radiographs were analyzed for the shape of the posterior diaphragm and the posterior costophrenic sulcus. RESULTS: The patients' ages ranged from 34 to 87 with the tendency of a higher incidence in the older patients. The defect most frequently involved the medial two thirds (n= 49, 50.4%) and middle one third (n=36, 37%) of the posterior diaphragm. The retroperitoneal fat was herniated into the thorax through the defect in all patients, and sometimes with the kidney (n=8). Lateral chest radiography showed a normal diaphragmatic contour (n=51, 49.5%), blunting of the posterior costophrenic sulcus (n=41, 39.8%), focal humping of the posterior diaphragm (n=7, 6.8%), or upward convexity (n=4, 3.9%) of the posterior costophrenic sulcus on the affected side. CONCLUSION: The posterior diaphragmatic defect discovered in asymptomatic patients who are without a history of peridiaphragmatic disease is most likely acquired, and this malady increases in incidence according to age. An abnormal contour of the posterior diaphragm or the costophrenic sulcus on a lateral chest radiograph may be a finding of posterior diaphragmatic defect.

Multilocular Thymic Cyst Associated with Mediastinal Teratoma: A Case Report

Multilocular thymic cyst (MTC) has been reported to develop in concert with various mediastinal neoplasms that have intrinsic inflammatory components, such as thymoma, thymic carcinoma, Hodgkin's disease, and seminoma. However, development of mediastinal teratoma without intrinsic inflammation in association with MTC has rarely been reported. Here, we report the findings of a case of MTC associated with mediastinal mature cystic teratoma on computed tomography (CT) with CT-histopathologic correlation.

Multilocular Thymic Cyst Associated with Mediastinal Teratoma: A Case Report

Multilocular thymic cyst (MTC) has been reported to develop in concert with various mediastinal neoplasms that have intrinsic inflammatory components, such as thymoma, thymic carcinoma, Hodgkin's disease, and seminoma. However, development of mediastinal teratoma without intrinsic inflammation in association with MTC has rarely been reported. Here, we report the findings of a case of MTC associated with mediastinal mature cystic teratoma on computed tomography (CT) with CT-histopathologic correlation.

Radiological Findings of Pleural and Mediastinal Diseases / 결핵및호흡기질환

Radiological analysis of chest lesions detected on chest radiographs or CT scans begins with their classification into parenchymal, pleural, or extrapleural lesions according to their presumed origin. The mediastinum is divided anatomically into the anterior, middle, and posterior mediastinal compartments, and localizing a mediastinal mass to one of these divisions can locationfacilitate their differential diagnosis. A differential diagnosis of a mediastinal mass is usually based on a number of findings, including its ; the structure from which it is arising; whether it is single, multifocal (involving several different areas or lymph node groups), or diffuse; its size and shape; its attenuation (fatty, fluid, soft-tissue, or a combination of these); the presence of calcification along with its characteristics and amount; and its opacification following the administration of contrast agents.

Pulmonary Manifestations of Systemic Lupus Erythematosus

Pulmonary involvement is more common in systemic lupus erythematosus (SLE) than in any other connective tissue disease, and more than half of patients with SLE suffer from respiratory dysfunction during the course of their illness. Although sepsis and renal disease are the most common causes of death in SLE, lung disease is the predominant manifestation and is an indicator of overall prognosis. Respiratory disease may be due to direct involvement of the lung or as a secondary consequence of the effect of the disease on other organ systems.