Deduced Respiratory Scores on COVID-19 Patients Learning from Exertion-Induced Dyspnea.

Dyspnea is one of the most common symptoms of many respiratory diseases, including COVID-19. Clinical assessment of dyspnea relies mainly on self-reporting, which contains subjective biases and is problematic for frequent inquiries. This study aims to determine if a respiratory score in COVID-19 patients can be assessed using a wearable sensor and if this score can be deduced from a learning model based on physiologically induced dyspnea in healthy subjects. Noninvasive wearable respiratory sensors were employed to retrieve continuous respiratory characteristics with user comfort and convenience. Overnight respiratory waveforms were collected on 12 COVID-19 patients, and a benchmark on 13 healthy subjects with exertion-induced dyspnea was also performed for blind comparison. The learning model was built from the self-reported respiratory features of 32 healthy subjects under exertion and airway blockage. A high similarity between respiratory features in COVID-19 patients and physiologically induced dyspnea in healthy subjects was observed. Learning from our previous dyspnea model of healthy subjects, we deduced that COVID-19 patients have consistently highly correlated respiratory scores in comparison with normal breathing of healthy subjects. We also performed a continuous assessment of the patient's respiratory scores for 12-16 h. This study offers a useful system for the symptomatic evaluation of patients with active or chronic respiratory disorders, especially the patient population that refuses to cooperate or cannot communicate due to deterioration or loss of cognitive functions. The proposed system can help identify dyspneic exacerbation, leading to early intervention and possible outcome improvement. Our approach can be potentially applied to other pulmonary disorders, such as asthma, emphysema, and other types of pneumonia.

Thoracic Manifestations of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is one of the most common chronic systemic inflammatory diseases and the most common chronic inflammatory arthritis. Classically a progressive symmetric polyarthritis, RA is characterized by inflammation, erosions, bone loss, and joint destruction. Up to half of patients with RA exhibit extra-articular manifestations (EAMs), which may precede articular disease and are more common in patients with seropositive RA (patients with detectable serum levels of rheumatoid factor and/or anticitrullinated peptide antibodies). Cardiovascular and pulmonary EAMs are the largest contributors to morbidity and mortality in RA and may be especially devastating. Imaging has a significant role in diagnosing these EAMs and assessing response to treatment. Although treatment with disease-modifying antirheumatic drugs has redefined the natural history of RA and helped many patients achieve low disease activity, patients are at risk for treatment-related complications, as well as infections. The clinical features of drug-induced lung disease and infection can overlap considerably with those of EAMs, presenting a diagnostic challenge. Radiologists, by recognizing the imaging characteristics and evolution of these various processes, are essential in diagnosing and distinguishing among EAMs, treatment-related complications, and unrelated processes and formulating an appropriate differential diagnosis. Moreover, recognizing these disease processes at imaging and contextualizing imaging findings with clinical information and laboratory and pathologic findings can facilitate definitive diagnosis and proper treatment. The authors review the articular and extra-articular thoracic imaging manifestations of RA, including cardiovascular, respiratory, and pleural diseases, as well as treatment-related complications and common infections. ©RSNA, 2021.

Overview of Interventional Pulmonology for Radiologists.

Interventional pulmonology is a growing field specializing in minimally invasive procedures of the mediastinum, lungs, airways, and pleura. These procedures have both diagnostic and therapeutic indications and are performed for benign and malignant diseases. Endobronchial US has been combined with transbronchial needle aspiration to extend tissue sampling beyond the airways and into the lungs and mediastinum. Recent innovations extending the peripheral access of bronchoscopy include electromagnetic navigational bronchoscopy and thinner bronchoscopes. An important indication for therapeutic bronchoscopy is the relief of central airway obstruction, which may be severe and life threatening. Techniques for restoring patency of the central airways include mechanical debulking and multiple modalities for ablation, stent placement, and balloon bronchoplasty. Bronchoscopic lung volume reduction improves quality of life in certain patients with severe emphysema and is an important less invasive alternative to lung volume reduction surgery. Bronchial thermoplasty is likewise a nonpharmacologic treatment in patients with severe uncontrolled asthma. Many of these procedures have unique selection criteria that require precise evaluations at preprocedure imaging. Postprocedure imaging is also essential in determining outcome success and the presence of complications. Radiologists should be familiar with these procedures as well as the relevant imaging features in both planning and later surveillance. Evolving techniques that may become more widely available in the near future include robotic-assisted bronchoscopy, bronchoscopic transparenchymal nodule access, transbronchial cryobiopsy, ablation of early-stage cancers, and endobronchial intratumoral chemotherapy. An invited commentary by Wayne et al is available online. ©RSNA, 2021.

Multilobulated thymoma with an acute angle: a new predictor of lung invasion.

OBJECTIVE: Imaging features of thymomas such as lobulation, infiltration into lung, and adjacent lung abnormality have been associated with lung invasion but are unreliable. The goal of this study was to develop a more objective and reproducible method for predicting lung invasion by thymomas. SUBJECTS AND METHODS: Fifty-four thymomas resected from 2007 to 2017 were included for analysis. Pre-operative CT scans for these thymomas were reviewed, and multiple features were evaluated, including the interface of each thymoma with the adjacent lung. A multilobulated thymoma with at least one acute angle between lobulations was considered suspicious for lung invasion. Two blinded radiologists then tested this hypothesis by reviewing all 54 CT scans and using this single criterion to predict lung invasion. RESULTS: Twelve thymomas invaded the lung. All lung-invasive thymomas were multilobulated. Twenty-nine thymomas had a multilobulated interface with the lung. Multilobulated thymomas were more likely to invade the lung than thymomas with a single lobulation or no lobulation (p = 0.0008). Using the criterion of multilobulation with at least one acute angle between lobulations to predict lung invasion, the two readers achieved a sensitivity of 67-83%, specificity of 93-98%, positive predictive value of 77-89%, and negative predicted value of 91-95%. Nine lung-invasive thymomas also invaded mediastinal structures or disseminated to the pleura. CONCLUSIONS: A multilobulated thymoma with at least one acute angle between lobulations predicts lung invasion with a high degree of accuracy. When lung invasion is suspected, the findings are indicative of a locally aggressive tumor, and the pleura and mediastinal structures should also be closely inspected for invasion. KEY POINTS: • A multilobulated thymoma with at least one acute angle between lobulations is predictive of lung invasion. • Coronal and sagittal reformations and thin sections are helpful in challenging cases. • Lung invasion indicates a locally aggressive tumor, and the pleura and other mediastinal structures should also be closely inspected for invasion.

Complications of Intravesical BCG Immunotherapy for Bladder Cancer.

An earlier incorrect version appeared online. This article was corrected on December 14, 2018.

Screening for Lung Cancer: Communicating With Patients.

OBJECTIVE: The purposes of this article are to detail the experience of a single-center academic institution in applying the patient-centered approach to a lung cancer screening program and to examine how this approach can expand to other aspects of follow-up imaging of lung nodules. CONCLUSION: As the practice of patient-centered radiology gains attention, diagnostic radiologists are findings new ways to become more involved in patient care. A lung cancer screening program is one opportunity for radiologists to consult with and educate patients.

Mediastinal and Pleural MR Imaging: Practical Approach for Daily Practice.

Radiologists in any practice setting should be prepared to use thoracic magnetic resonance (MR) imaging for noncardiac and nonangiographic applications. This begins with understanding the sequence building blocks that can be used to design effective thoracic MR imaging protocols. In most instances, the sequences used in thoracic MR imaging are adapted from protocols used elsewhere in the body. Some modifications, including the addition of electrocardiographic gating or respiratory triggering, may be necessary for certain applications. Once protocols are in place, recognition of clinical scenarios in which thoracic MR imaging can provide value beyond other imaging modalities is essential. MR imaging is particularly beneficial in evaluating for benign features in indeterminate lesions. In lesions that are suspected to be composed of fluid, including mediastinal cysts and lesions composed of dilated lymphatics, MR imaging can confirm the presence of fluid and absence of suspicious enhancement. It can also be used to evaluate for intravoxel lipid, a finding seen in benign residual thymic tissue and thymic hyperplasia. Because of its excellent contrast resolution and potential for subtraction images, MR imaging can interrogate local treatment sites for the development of recurrent tumor on a background of post-treatment changes. In addition to characterization of lesions, thoracic MR imaging can be useful in surgical and treatment planning. By identifying nodular sites of enhancement or areas of diffusion restriction within cystic or necrotic lesions, MR imaging can be used to direct sites for biopsy. MR imaging can help evaluate for local tumor invasion with the application of "real-time" cine sequences to determine whether a lesion is adherent to an adjacent structure or surface. Finally, MR imaging is the modality of choice for imaging potential tumor thrombus. By understanding the role of MR imaging in these clinical scenarios, radiologists can increase the use of thoracic MR imaging for the benefit of improved decision making in the care of patients. ©RSNA, 2018.

Dendriform Pulmonary Ossification in the Absence of Usual Interstitial Pneumonia: CT Features and Possible Association With Recurrent Acid Aspiration.

OBJECTIVE: Dendriform pulmonary ossification (DPO) is a rare lung disease in which mature bone is present in the peripheral interstitium of the lung. It typically occurs in patients with usual interstitial pneumonia (UIP). We assessed patients with CT findings of DPO without UIP to determine possible causative factors and to assess the clinical and CT course. We hypothesized that DPO without UIP would be a unique entity. MATERIALS AND METHODS: We retrospectively reviewed CT reports for the word "ossification." Two observers reviewed each examination for micronodules 1-5 mm in diameter in the peripheral interstitium (subpleural and perifissural spaces and interlobular septa), some of which had high attenuation on mediastinal windows, presence of contiguous clusters of nodules resulting in a branching pattern, and lack of findings of UIP or focal lung disease. We reviewed the electronic medical records and follow-up CT and clinical information in all eligible patients. RESULTS: The study population consisted of 52 men with a median age of 79 years old. Seventy-five percent of the patients had gastroesophageal reflux disease, obstructive sleep apnea, or a chronic neurologic disorder. No progressive pulmonary symptoms were attributed directly to DPO, and no patient developed pulmonary fibrosis or suffered clinical decline from DPO. CT showed minimal progression or remained stable at follow-up (77% for at least 1 year, 25% for over 4 years). CONCLUSION: DPO in the absence of UIP occurs in elderly men and appears to be associated with chronic aspiration of gastric acid. The course is indolent.

The King laryngeal tube: a mimic of esophageal intubation in the emergency department.

The King Airway is a temporary airway device used primarily in the pre-hospital setting and typically exchanged for an endotracheal tube upon arrival to the emergency department. Since this usually occurs before imaging, many radiologists are unfamiliar with the King Airway. This lack of familiarity can have important consequences for the patient and treating team. The purpose of this article is to raise awareness of the King Airway among radiologists, emphasize appropriate positioning, and review the imaging complications of incorrect positioning.

Current Imaging of Idiopathic Pulmonary Fibrosis.

The major role of imaging (CT) in usual interstitial pneumonia (UIP)/idiopathic pulmonary fibrosis (IPF) is in the initial diagnosis. We propose several modifications to existing guidelines to help improve the accuracy of this diagnosis and to enhance interobserver agreement. CT detects the common complications and associations that occur with UIP/IPF including acute exacerbation, lung cancer, and dendriform pulmonary ossification and is useful in informing prognosis based on baseline fibrosis severity. Serial CT imaging is a topic of great interest; it may identify disease progression before FVC decline or clinical change.

Imaging of the rare cystic lung diseases.

When discussing cystic lung diseases, a certain group of diseases tends to receive the majority of attention. Other less frequently discussed cystic lung diseases are also important causes of morbidity in patients. Etiologies include genetic syndromes, lymphoproliferative diseases, infections, exogenous exposures, and a developmental abnormality. This review article focuses on the clinical and imaging features of these other cystic lung diseases.

Metastatic Mature Teratoma and Growing Teratoma Syndrome in Patients with Testicular Non-Seminomatous Germ Cell Tumors.

Metastatic mature teratoma is a common radiologic and histopathologic finding after chemotherapy for metastatic non-seminomatous germ cell tumors. The leading theory for these residual tumors is the selective chemotherapy resistance of teratomas versus the high chemotherapy sensitivity of the embryonal components. Growing teratoma syndrome is a relatively rare phenomenon defined as an enlarging residual mass histologically proven to be a mature teratoma in the setting of normal serum tumor markers. Metastatic mature teratomas should be resected because of their malignant potential and occasional progression to growing teratoma syndrome with the invasion of the surrounding structures. CT is the preferred imaging modality for post-chemotherapy surveillance and should cover all sites of potential metastatic disease. This article reviews the clinical, pathologic, and multimodality imaging features of metastatic mature teratomas in patients with primary testicular non-seminomatous germ cell tumors.

Fluid-filled Cystic Lesions of the Lungs.

A pulmonary cyst usually refers to an air-filled space with a smooth, thin wall. Fluid-filled cystic lesions of the lungs include a range of etiologies such as true cysts, congenital malformations, infections, and benign and malignant neoplasms. With relatively little solid component, these lesions often have similar imaging appearances to one another. This article focuses on key imaging features and clinical characteristics that can be used to narrow the differential diagnosis.

Imaging Features of Primary Immunodeficiency Disorders.

Primary immunodeficiency disorders (PIDs), which are humoral, combined, and innate defects of the immune system, are relatively uncommon and may go undiagnosed in patients experiencing recurrent infections, resulting in increased morbidity and mortality. PIDs are clinically characterized by a broad spectrum of disorders, including repeated infections, autoimmune disorders, lymphoproliferative diseases, congenital anomalies, and increased risk of malignancy. Cardiothoracic imaging plays a crucial role in the diagnosis of PIDs owing to the high rates of repeated respiratory infections leading to bronchiectasis and other forms of chronic lung disease. Although PIDs as a group may seem similar in terms of radiologic features and clinical manifestations, there are specific entities that are pertinent to each PID on an individual level. For example, patients with common variable immunodeficiency may develop a unique granulomatous lymphocytic interstitial lung disease, and Good syndrome is associated with thymoma. Familiarity with the imaging characteristics of these disorders may expedite diagnosis and prognostication, and better direct therapy. Reviewing the thoracic manifestations of all PIDs is beyond the scope of this article; thus, the focus herein is on discussing the thoracic manifestations of the most common PIDs and their imaging features. © RSNA, 2021An earlier incorrect version appeared online. This article was corrected on March 25, 2021.

The bullseye sign: A variant of the reverse halo sign in COVID-19 pneumonia.

The predominant pulmonary imaging findings on chest CT in the novel 2019 coronavirus infection (COVID-19) are bilateral ground glass opacities. The reverse halo sign is uncommon. This is a report of the new "bullseye sign," which is considered a variant of the reverse halo sign and favored to represent a focus of organizing pneumonia. The specificity of this finding is unclear, however its presence should alert radiologists to the possibility of COVID-19 infection.

Major aortopulmonary collateral arteries in a case of unrepaired tricuspid and pulmonary atresia with single ventricle physiology.

Tricuspid and pulmonary atresia with single ventricle physiology and major aortopulmonary collateral arteries (MAPCAs) is a complex cyanotic congenital heart disease with heterogeneous pulmonary artery morphology and arborization. The complex anatomy and physiology, coupled with a dearth of existing literature, pose imitable challenges to treatment. Although the exact surgical algorithm is still unclear, the goal is a well-developed, low-resistance pulmonary vascular bed. A precise understanding of the blood supply to each lung is a requisite for successful surgery, and a multimodality and multidisciplinary approach is compulsory. Herein, we describe a case of tricuspid and pulmonary atresia with single ventricle, MAPCAs and aortopulmonary collateral arteries.

Mimics of Complications in the Postsurgical Aorta at CT.

Various surgical techniques of the aorta result in expected imaging appearances on CT images that resemble complications such as pseudoaneurysm, perigraft abscess, and dissection. Awareness of these techniques, understanding the clinical situation in which they are performed, and familiarity with the typical appearances and locations of these mimics are essential for accurate interpretation. CT imaging techniques such as electrocardiographic gating and inclusion of a precontrast series can help distinguish an expected postsurgical finding from a complication. Information in the medical record, particularly the operative note, can clarify challenging cases with unusual imaging features. This review article provides examples of expected postsurgical findings at CT mimicking complications. © RSNA, 2019.

Cough-induced costal cartilage fracture.

We present two cases of atraumatic costal cartilage fracture secondary to violent coughing. Although costal cartilage fractures due to trauma and bony rib fractures due to violent coughing have been described, to our knowledge there have been no prior reported cases of cough-induced costal cartilage fracture. It is important for radiologists to consider costal cartilage fractures, which are often more subtle than osseous injuries, in patients with chest pain, and understand that they may not always be preceded by direct trauma. Identifying this injury is clinically important and will prevent patients from undergoing unnecessary examinations to rule out a cardiac cause of chest pain or a pulmonary embolism.

Imaging of Thoracoabdominal Aortic Aneurysms.

Untreated thoracoabdominal aortic aneurysms are associated with an exceedingly high mortality rate, and surgery carries a high complication rate. Crawford's classification system of thoracoabdominal aortic aneurysms describes aneurysm morphology and stratifies patients on the basis of risk of major postoperative complications including mortality, spinal cord injury, and renal failure. Computed tomography and magnetic resonance angiography are essential for classifying thoracoabdominal aortic aneurysms and identifying other important features that impact prognosis and surgical management. Four-dimensional flow-sensitive magnetic resonance imaging is an emerging technique that may help predict complications and further impact timing of intervention.