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.

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.

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.

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.

Congenital Bronchial Atresia / 결핵

Congenital bronchial atresia is a rare anomaly, which results from a congenital focal obliteration of a proximal segmental or subsegmental bronchus, with normal development of the distal structures. The short atretic segment leads to the accumulation of mucus within the distal bronchi, forming a bronchocele and air trapping of the alveoli supplied by these bronchi. The diagnostic CT features include the presence of a branching opacity and the bronchocele, which radiate from the hilum and are surrounded by an area of hyperlucency.

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.

Pulmonary Complications in Renal Transplantation

PURPOSE: To evaluate the radiographic and CT findings of pulmonary complications other than pulmonary edema arising from renal transplantation. MATERIALS AND METHODS: Among 393 patients who had undergone renal transplantation at our hospital during a previous ten-year period, 23 with pulmonary complications other than pulmonary edema were included in this study. The complications involved were infection caused by CMV (n=6), bacteria (n=4), fungus (n=4), tuberculosis (n=2), varicella (n=1) or chlamydia (n=1), and malignancy involving lung cancer (n=4) or Kaposi's sarcoma (n=1). Two chest radiologists reviewed all images. RESULTS: The complications manifesting mainly as pulmonary nodules were lung cancer(4/4), tuberculosis (1/2), and Kaposi's sarcoma(1/1). Pulmonary consolidation was a main feature in bacterial infection(4/4), fungal infection(3/4), tuberculosis(1/2), chlamydial infection(1/1), and varicellar pneumonia(1/1). Ground-glass attenuation was a main CT feature in CMV pneumonia(4/6), and increased interstitial marking was a predominant radiographic feature in CMV pneumonia(2/6). CONCLUSION: The main radiologic features described above can be helpful for differential diagnosis of the pulmonary complications of renal transplantation.

Radiologic Findings of Cystic Fibrosis in a Korean Child at Follow Up Study: Case Report

Cystic fibrosis is a hereditary disease involving recessive transmission. The fundamental abnormality consists of the production of abnormal secretion from a variety of exocrine glands such as salivary and sweat glands and those of the pancreas, colon, and tracheobronchial trees. Cystic fibrosis is the most common lethal genetically transmitted disease among whites, but is uncommon in Asians, including Koreans. Although a case involving a Korean was reported in 1988, the focus was diagnosis rather than the radiological findings. In the case of cystic fibrosis we now describe, the focus is inverted: we enphasise the reported in 1988, focusing on radiologic findings.

Aspiration Pneumonia in Patients with Cleft Palate

PURPOSE: To assess the incidence of aspiration pneumonia in infants with cleft palate and to compare the incidence between complete and incomplete types of cleft palate. MATERIALS AND METHODS: A review of medical records revealed 100 infants who had undergone initial surgery to repair cleft palate in our hospital during a recent three-year period. Aspiration pneumonia was defined as the coexistence of pneumonia at chest radiography with a history of frequent choking during feeding. The anatomic distribution of aspiration pneumonia was analyzed, and the incidences of aspiration pneumonia in infants with complete and incomplete cleft palate were compared. RESULTS: Among 100 children, aspiration pneumonia was found in 35 (35%). Those with complete and incomplete cleft palate showed similar incidences of the condition (27 of 70 [39%] vs 8 of 30 [27%], p=0.36). Pneumonia was most commonly seen in the left lower lobe (11 of 35), followed by the right upper and lower lobes. CONCLUSION: Aspiration pneumonia is frequently associated with infants with cleft palate. There is no statistical difference in the incidence of aspiration pneumonia between the complete and the incomplete cleft palate group.

Diagnostic Accuracy and Evaluation of Myocardial Viability by Cardiac Magnetic Resonance Imaging in Acute Myocardial Infarction: A Comparison with Thallium-201 Myocardial SPECT

PURPOSE: To assess the usefulness of cardiac MR imaging (MRI) in the diagnosis of acute myocardial infarction and in the assessment of myocardial viability in comparision with Tl-201 SPECT. MATERIALS AND METHODS: We retrospectively studied 17 patients who complained of chest pain and dyspnea with cardiac MRI . The patients were evaluated for the presence or absence of high signal intensity on T2-weighted image (T2WI), abnormal wall motion on 2D - FIESTA, perfusion defect on Gd-DTPA enhanced T1WI, and delayed myocardial enhancement on 15-minutes delay Gd-DTPA enhanced T1WI. The results were correlated with the images on Tl-201 SPECT, taken at rest and stress, through which reversibility of perfusion defect was assessed. RESULTS: Both cardiac MRI and Tl-201 SPECT proved to be useful methods for diagnosing acute myocardial infarction. In order of decreasing correspondence, T2WI, Tl-201 SPECT, delayed enhancement study, and wall motion images all showed significant statistical correlation with the clinical diagnosis of myocardial infarction. Perfusion MRI, on the other hand, showed no significant statistical difference was found between Tl-201 SPECT and cardiac MRI. The results on T2WI showed high accordance with those on Tl-201 SPECT, while delayed myocardial enhancement and wall motion studies showed no agreement with Tl-201 SPECT. CONCLUSION: Cardiac MRI is useful method for diagnosis of acute myocardiac infarction. With respect to the assessment of myocardial viability, the results obtained on cardiac MRI showed high agreement with those on Tl-201 SPECT. However, further study is necessary at this point for standardization and establishment of the methods for assessing myocardial viability on cardiac MRI.

CT Findings of Esophageal Perforation

PURPOSE: To determine which CT findings are useful for the early diagnosis of esophageal perforation, and on the basis of these findings, to assess the accuracy of prediction of the perforation site. MATERIALS AND METHODS: A review of medical records indicated that between January 1995 and December 2001, 36 patients with esophageal perforation were admitted to our hospital. Thirteen of these [M:F=8:5; age: 28-69 (mean, 52.4) years], who had undergone CT chest scanning, were included in this study. The causes of esophageal perforation were trauma (n=5), infectious diseases (n=4), Boerhaave syndrome (n=1), lung cancer (n=1), esophageal cancer (n=1), and idiopathic (n=1). Two chest radiologists unaware of the clincal findings reviewed the CT scans and predicted whether the upper or lower esophagus was perforated. RESULTS: The most common CT finding was extraluminal air at the posterior mediastinum (n=11), while other findings included pulmonary consolidation (n=10), pleural effusion (n=7), discontinuity of the esophageal wall (n=6) and subcutaneous emphysema (n=4), fluid collection around the esophagus (n=4), esophageal wall thickening (n=4), pneumothorax (n=2), and lung abscess (n=2). The perforation site was accurately predicted in 76.9% of cases (10/13). CONCLUSION: The CT findings which help the diagnosis of esophageal perforation, and prediction of the sites at which it occurs, are extraluminal air or fluid collection, focal defect of the esophageal wall, and esophageal wall thickening.

Radiologic Findings of Childhood Lower Respiratory Tract Infection by Influenza Virus

PURPOSE: After the RS (respiratory syncytial) virus, the influenza virus is the most common cause of childhood lower respiratory tract infection. We assessed the radiologic findings of childhood lower respiratory tract infection by the influenza virus. MATERIALS AND METHODS: A total of 105 pediatric patients (76 males and 29 females; mean age, 2.4 years) with symptoms of respiratory tract infection were examined between March 1997 and April 2000. Nasopharyngeal aspirates were obtained and influenza virus infection was confirmed by direct or indirect immunofluorescent assays. Peribronchial infiltration, hyperinflation, atelectasis, pulmonary consolidation, and hilar lymphadenopathy were evaluated retrospectively at simple chest radiography. RESULTS: Bilateral perihilar peribronchial infiltration was noted in 78.1% of patients (n=82), hyperinflation in 63.8% (n=67), atelectasis in 3.8% (n=4; segmental 50%, lobar 50%), and pulmonary consolidation in 16.2% [n=17; segmental 70.6% (n=12), lobar 29.4% (n=5)]. Hilar lymphadenopathy was noted in one patient in whom there was no pleural effusion, and subglottic airway narrowing in 12 of 14 in whom the croup symptom complex was present. CONCLUSION: The major radiologic findings of influenza virus infection were bilateral perihilar peribronchial infiltration and hyperinflation. In some patients, upper respiratory tract infection was combined with subgolttic airway narrowing. Atelectasis or pleural effusion was rare.

Positional Shifting of HRCT Findings in Patients with Pulmonary Edema

PURPOSE: To assess the value of positional shifting to a gravity-dependent area, as revealed by HRCT, in differ-entiating pulmonary edema (PE) from other conditions. MATERIALS AND METHODS: Sixteen consecutive patients in whom plain radiographs suggested the presence of pulmonary edema but the clinical findings were indefinite underwent HRCT of the lung. For initial scanning they were in the supine position, and then in the prone position. Findings of ground-glass opacity, interlobular septal thickening and peribronchovascular interstitial thickening were analyzed in terms of the presence and degree of shifting to a gravity-dependent area, a grade of high, intermediate or low being assigned. RESULTS: PE was diagnosed in 8 of 16 cases, the remainder being designated as non-pulmonary edema (NPE). Ground-glass opacity was observed in all 16, while the degree of positional shifting was found to be high in ten (PE:NPE=6:4), intermediate in four (PE:NPE=2:2), and low in two (PE:NPE=0:2). There was no significant difference between the two groups (p > 0.05). Interlobular septal thickening was observed in all but two NPE cases; the degree of shifting was high in six (PE:NPE=6:0), intermediate in one (PE), and low in seven (PE:NPE=1:6). Shifting was significantly more prominent in PE than in NPE cases (p<0.05). Peribronchovas-cular interstitial thickening was positive in all PE cases and one NPE case, with no positional shifting. CONCLUSION: Positional shifting of interlobular septal thickening to a gravity-dependent area, as demonstrated by HRCT, is the most specific indicator of pulmonary edema.

Esophageal tubular duplication complicated with intraluminal hematoma: a case report

Esophageal tubular duplication is a rare congenital anomaly. We experienced a patient with esophageal tubular duplication who presented with a swallowing difficulty which was aggravated after a gastrofiberscopic examination. Preoperative diagnosis was intramural hematoma of the esophagus due to trauma caused by endoscopy. Surgical specimen revealed that hematoma was located within a duplicated lumen of the esophagus. The radiologic and endoscopic findings are discussed in correlation with its pathology.

Esophageal tubular duplication complicated with intraluminal hematoma: a case report

Esophageal tubular duplication is a rare congenital anomaly. We experienced a patient with esophageal tubular duplication who presented with a swallowing difficulty which was aggravated after a gastrofiberscopic examination. Preoperative diagnosis was intramural hematoma of the esophagus due to trauma caused by endoscopy. Surgical specimen revealed that hematoma was located within a duplicated lumen of the esophagus. The radiologic and endoscopic findings are discussed in correlation with its pathology.