bluuebunny/crossref_metadata_2025 huggingface dataset:
Infection and inflammation
Authors: Waldmann Carl , Rhodes Andrew , Soni Neil , Handy Jonathan
Published: August 2019

This chapter discusses infection and inflammation and includes discussion on the general principles of infection control (involving discussion on ventilator-associated pneumonia, urinary catheters, antimicrobial stewardship and resistance, and prevention of transmission of infection), human immunodeficiency virus (HIV; HIV testing in the critical care setting, antiretroviral therapy in the critically ill patient, Pneumocystis jiroveci pneumonia, cryptococcal meningitis, and toxoplasmosis encephalitis), severe falciparum malaria, vasculitides in the intensive care unit, source control (prophylaxis, antibiotics, abscess, necrotic tissue, and infected foreign body), selective decontamination of the digestive tract (including discussion on theory, potential pathogenic microorganisms, and typical protocol), markers of infection, and adrenal insufficiency and sepsis.
Pain and postoperative intensive care
Authors: Waldmann Carl , Rhodes Andrew , Soni Neil , Handy Jonathan
Published: August 2019

This chapter discusses pain and postoperative intensive care and includes discussion on pain management in the intensive care unit (ICU; including the causes and incidence of pain in the ICU, adverse effects of pain, assessment of pain in the ICU, and methods of pain relief in the ICU) and intensive care for the high-risk surgical patient (throughout the whole process). The chapter also covers the acute surgical abdomen in the ICU (and the complications thereof) and the medical patient with surgical problems (such as ischaemia of the bowel, acalculous cholecystitis, gallstone ileus, intra-abdominal hypertension, and soft-tissue infections).
Maternal critical care
Authors: Waldmann Carl , Rhodes Andrew , Soni Neil , Handy Jonathan
Published: August 2019

The UK maternal mortality rate is one of the lowest in the world, at 9.8/100 000 maternities. However, for every maternal death there are at least 70 women who develop severe maternal morbidity, and this rate is rising with increasing body mass index, maternal age, and pre-existing disease. The commonest ‘direct’ cause of death because of pregnancy is thrombosis, and ‘indirect’ cause from a pre-existing problem is cardiovascular disease. The confidential mortality reports and recommendations on mortality MBRRACE-UK have resulted in major improvements in common obstetric problems such as venous thromboebolism, pre-eclampsia, and haemorrhage. Nowadays focus is also directed to examining causes of and improving management of morbidity (as opposed to mortality), often from other disorders such as infection, cardiac, and respiratory disease, resulting in the need for critical care. This chapter discusses maternal critical care, enhanced maternity care, and includes discussion on common conditions causing illness in pregnancy, obstetric emergencies, and reviews and guidelines. There are sections on venous thromboembolism, pre-eclampsia, massive obstetric haemorrhage, obstetric sepsis, cardiac disease, neurological emergencies, liver failure, diabetic emergencies, amniotic fluid embolism, and complications of anaesthesia.
Intensive care unit organization and management
Authors: Waldmann Carl , Rhodes Andrew , Soni Neil , Handy Jonathan
Published: August 2019

This chapter discusses ICU organization and management and includes discussion on consent on the ICU, rationing in critical care, ICU layout, medical staffing, ICU staffing (both nursing and staffing for supporting professions), fire safety in the ICU, legal issues and the Coroner, patient safety, Severity of Illness Scoring systems, comparison of ICUs, critical care disaster planning, health technology assessment, transfer of the critically ill patient, aeromedical evacuation, outreach and medical emergency teams, critical care follow-up, rehabilitation, and managing antibiotic resistance.
Overview of Normal Thoracic Imaging Anatomy
Authors: Rosado-de-Christenson Melissa L.
Published: August 2019

Overview of normal thoracic imaging anatomy provides a review of the normal anatomic markings of the thorax with emphasis on radiographic and CT anatomy. Chest radiography allows visualization and evaluation of various anatomic structures in the thorax including the lungs, airways, hila, thoracic vessels (including pulmonary and systemic), mediastinum, pleura and chest wall (including soft tissues and skeletal structures). The various mediastinal interfaces are also discussed including the anterior and posterior junction lines, the right paratracheal stripe, the azygoesophageal recess and the paravertebral stripes. The anatomy of the hila on lateral chest radiography is also presented. These anatomic landmarks are illustrated using a series of normal radiographic and computed tomographic (CT) images. Knowledge of normal imaging anatomy allows identification of anatomic alterations as manifestations of thoracic disease.
Vascular Catheters
Authors: Ternes Tyler H.
Published: August 2019

Vascular catheters are hollow tubes used to gain access to the circulatory system. They are typically placed via large caliber vessels. Smaller caliber peripherally inserted central catheters (PICC) may be inserted via an antecubital vein. Vascular catheters are often placed temporarily for patients requiring intravenous drugs, fluid resuscitation, dialysis, or hemodynamic monitoring. For longer-term access, subcutaneous ports may be placed surgically. The ideal tip position for most central catheters is at the superior cavoatrial junction. Pulmonary artery catheters (PACs) are occasionally used in critically ill and postoperative patients for various purposes, including hemodynamic monitoring, but their use has generally decreased. An intraaortic baloon pump (IABP) consists of a long inflatable balloon mounted on a catheter used in patients with critical heart failure, with the goal of improving coronary flow. Follow-up radiographs are obtained after vascular catheter placement to exclude malposition or resultant complications.
Upper and Middle Lobe Atelectasis
Authors: Walker Christopher M.
Published: August 2019

Upper and middle lobe atelectasis discusses the radiographic and computed tomography (CT) manifestations of upper and middle lobe atelectasis. The most common radiographic signs of right upper lobe atelectasis include upward and medial displacement of the minor fissure, superior displacement of adjacent structures such as the hilum and main bronchus, and ipsilateral shift of the mediastinal structures. The S sign of Golden results from a centrally obstructing lung cancer as the cause of the atelectasis and manifests as a reverse S configuration of the minor fissure outlined by atelectatic lung and central mass. Left upper lobe atelectasis manifests with a veil-like opacity on frontal radiography with leftward shift of upper mediastinal structures such as the trachea and upward shift of the left main bronchus and left hemidiaphragm. The Luftsichel sign or air crescent sign may be seen and represents the hyperexpanded superior segment of the left lower lobe outlining the transverse aortic arch. Lobar atelectasis in the inpatient setting is most commonly secondary to an obstructing mucus plug. Lobar atelectasis in the outpatient setting is often a heralding sign of a centrally obstructing lung cancer and should be further evaluated with contrast-enhanced CT and/or bronchoscopy.
Subsegmental and Rounded Atelectasis
Authors: Walker Christopher M.
Published: August 2019

The chapter titled subsegmental and rounded atelectasis discusses the radiographic and computed tomography (CT) appearances of subsegmental and rounded atelectasis. Subsegmental atelectasis is linear or platelike atelectasis confined to a single subsegment or extending across multiple subsegments of lung. It is seen in a variety of pulmonary and abdominal conditions including prolonged shallow breathing, pulmonary thromboembolic disease, diaphragmatic dysfunction, and pneumonia. Rounded atelectasis is folded or collapsed lung that develops adjacent to an area of pleural thickening, fibrosis, or effusion. There are several imaging features that must be present before confidently diagnosing rounded atelectasis including significant contact with adjacent pleural abnormality, signs of volume loss, acute angles with the pleura, and the comet tail sign. If these criteria are met, CT followup is sufficient in most cases.
Introduction to Emergency Chest Radiology
Authors: Bhalla Sanjeev
Published: August 2019

Because of its low cost and relative ease of performance, the chest radiograph is often used as a first line of imaging in the Emergency Department. One must have a structured approach to this deceptively simple exam. The first step of imaging interpretation should be an understanding of the clinical context of the examination (chest pain, dyspnea, blunt or penetrating trauma, for example). The second step should be comparison with any prior imaging. The third step should involve a careful search for any abnormal lucency. The final step should be to focus on the integrity of 9 lines, stripes and interfaces of the mediastinum. Using these simple steps in the analysis of all chest radiographs will allow for the highest diagnostic yield.
Thoracic Vascular Injury
Authors: Raptis Constantine
Published: August 2019

Although rare, vascular injury represents one of the most feared complications of penetrating and blunt trauma. These life-threatening injuries can often be cured safely if detected early, especially in the era of vascular stenting. Original detection of aortic injury often relies on chest radiography and findings of mediastinal widening with displacement of structures away from the aortic isthmus. Great vessel injury may manifest with a mediastinal hematoma seen superiorly and on the right. Chest radiography is notoriously nonspecific as many causes of mediastinal widening may be encountered. Chest CT has become the standard for diagnosing thoracic vascular injury and relies on the identification of direct findings of vascular injury.
Pulmonary Complications of Sickle Cell Anemia
Authors: Raptis Constantine
Published: August 2019

“Sickle cell disease” describes the spectrum of pathology in patients with at least one HbS chain and one other abnormal β‎ globin chain. Although patients with sickle cell disease often present with a simple community acquired pneumonia, acute chest syndrome must be considered in patients presenting with chest pain and fever, as it carries an increased risk of mortality, especially in adults. A few other entities, including rib infarction and subdiaphragmatic pathologies, can mimic the symptoms of acute chest syndrome. Finally, the findings of sickle cell disease on chest radiography will be discussed. Radiologists must be familiar with these findings in order to accurately interpret imaging studies, especially when the history of sickle cell is not provided.
Pulmonary Hypertension
Authors: Raptis Constantine
Published: August 2019

Pulmonary hypertension (PH) is defined as a pulmonary capillary wedge pressure >25 mm Hg. Patients tend to present with nonspecific symptoms centered on worsening dyspnea. The causes of PH are classified according to the Dana Point classification which groups causes of PH based on shared pathophysiology and treatments. In the initial work up of patients with PH, the goal of imaging is determine if there are findings of PH and to look for clues to the underlying cause so that patients are treated appropriately. MRI can be useful in the follow up of patients with PH, as it can evaluate for changes in the right ventricle.
Pleural Thickening and Calcification
Authors: Walker Christopher M.
Published: August 2019

Pleural thickening and calcification discusses the radiographic and computed tomography (CT) manifestations of benign pleural thickening and pleural calcification. Benign pleural thickening must be differentiated from malignant pleural thickening and their differentiating characteristics will be discussed. Pleural plaque is the most common manifestation of asbestos exposure and carries no risk of malignant degeneration. The most common imaging appearance is bilateral sharply demarcated, multifocal areas of discontinuous pleural thickening that often calcifies over time. Pleural plaques spare the apical and costophrenic sulcus pleura and has a predilection for the diaphragmatic pleura. Diffuse pleural thickening is associated with hemothorax, empyema, connective tissue disorders, and asbestos exposure. It is generally unilateral, causes blunting of the costophrenic angle, spans multiple rib interspaces, and is irregular in shape. When diffuse pleural thickening calcifies and is associated with volume loss in the affected lung, it is termed fibrothorax.
Pleural Neoplasms
Authors: Walker Christopher M.
Published: August 2019

Pleural neoplasms discusses the radiographic and computed tomography (CT) manifestations of primary and secondary pleural neoplasms. Four CT features suggest malignant pleural thickening including nodular pleural thickening, circumferential pleural thickening, pleural thickening measuring greater than 1 cm in thicknesss, and thickening of the mediastinal pleural surface. The most common pleural malignancy is metastatic disease, generally from adenocarcinomas of the lung, breast, or gastrointestinal tract. Thymoma may spread to the pleura via direct extension or drop metastases. Mesothelioma is uncommon but is the most common primary pleural malignancy and is almost universally associated with asbestos exposure. It manifests with rind-like pleural thickening which may involve interlobar fissures and often causes volume loss in the affected hemithorax. Localized fibrous tumor of the pleura usually arises from the visceral pleural surface and manifests as a lobular or smooth pleural mass usually in the mid or lower hemithorax.
Cavitation
Authors: Betancourt Sonia L.
Published: August 2019

Cavitation is low-attenuation or lucency within a consolidation, nodule, or mass. While infection is the most common etiology of cavitation, other entities should also be considered. Cavitation of nodules, masses or consolidations is often related to infection, but can also occur in septic embolism, vasculitides, and pulmonary infarction. Aspiration pneumonia may manifest with cavitation and is common in institutionalized patients with altered state of consciousness. Anaerobes and enterobacteria are common etiologic agents. Mycobacterium tuberculosis should always be considered in patients with upper lobe cavitary disease. These patients should be isolated until etiology is proven. Aspergillus spp, nocardia spp, and Pneumocystis jiroveci should be considered in immunocompromised patients. Staphylococcus aureus is the most common cause of septic emboli. In patients without clinical evidence of infection, granulomatosis with polyangiitis and metastatic disease should be considered.
Tuberculosis
Authors: Betancourt Sonia L.
Published: August 2019

Tuberculosis (TB) is an airborne infection caused by Mycobacterium tuberculosis, an obligate aerobe, nonmotile, non-spore-forming bacillus. TB is a major cause of morbidity and mortality especially in developing countries. Patients with impaired cellular immunity including HIV (+), elderly, prisoners, and indigents and homeless patients have an increased susceptibility for active TB disease. Primary infection usually resolves without complications in immunocompetent patients. The most common radiologic manifestations of primary TB in children are consolidation and lymphadenopathy. Progressive primary TB with widespread hamatogenous dissemination may rarely occur. Patchy or nodular opacities in the upper lobes with associated cavitation are characteristic radiologic findings of active infection. While this pattern often correlates with relatively spared immunity, it denotes highly infectious individuals who require isolation.CT is very sensitive for the detection of bronchogenic spread of infection manifesting with discrete nodules, tree-in-bud opacities and cavitation.Miliary TB refers to hematogenous spread of infection.
Mycoplasma and Viral Pneumonia
Authors: Palacio Diana
Published: August 2019

Mycoplasma pneumoniae and viruses remain among the most common causes of community acquired pneumonia (CAP), and account for approximately 30% or more of all cases. M. pneumoniae is a bacterium that lacks a cell wall, which results in certain microbiologic features absent in other bacteria. The combination of centrilobular nodules, peribronchial thickening and lobular ground-glass attenuation on CT is the most suggestive pattern identified in patients with M. pneumoniae pneumonia. Although cellular bronchiolitis is a non-specific finding, a patchy or clustered distribution should raise the possibility of infectious etiology, with the most likely causative agents being M. pneumoniae, tuberculosis and viral bronchiolitis. The radiologic findings of adult viral and M. pneumoniae pneumonias are variable and depend on the host and the virulence of the pathogen. The imaging findings in this chapter overlap with those found in in pneumonias caused by atypical microorganisms (e.g. virus, PCP pneumonia, etc.). CT imaging of immunocompetent patients with suspected viral or mycoplasma pneumonia is not indicated unless there is suspicion of complications. CT may be performed in patients with normal, equivocal, or nonspecific radiographic findings. Conversely, CT is often indicated in immunocompromised patients with a normal chest radiograph and suspected pulmonary infection.
The Immunocompromised Patient: Non-AIDS
Authors: Bueno Juliana
Published: August 2019

Immunosuppression may be primary (i.e. congenital) or secondary (i.e acquired). Because immunodeficiencies constitute an extensive and highly heterogenous group of diseases, imaging interpretation must be performed in light of the underlying condition and/or treatment timeline whenever possible. Secondary immunodeficiencies include those occurring in bone marrow transplant (BMT) and solid organ transplant recipients and in patients on chronic corticosteroid therapy. Familiarity with the time course of immune dysfunction following BMT is essential for providing a narrow differential diagnosis in cases of opportunistic infection. Opportunistic infections in BMT recipients can be categorized based on the post-transplant phase: Neutropenic phase (<30 days, before engraftment); Early phase (30-100 days, after engraftment); Late phase (>100 days). A normal chest radiograph does not exclude infection in immunocompromissed patients with respiratory symptoms; further assessment with chest CT should always be considered in order to detect subtle imaging abnormalities. Infectious bronchiolitis manifesting with centrilobular nodules and diffuse ground-glass opacities on CT is commonly seen in immunocompromised patients.
Lung Cancer: Nodules and Masses
Authors: Benson Ryo E. C.
Published: August 2019

The chapter titled Nodules and Masses discusses these frequent imaging manifestations of primary lung cancer. A lung nodule is a roughly spherical, circumscribed density that measures < 3 cm. A lung mass is larger than 3 cm. Lung cancer may manifest as a solitary pulmonary nodule or mass. Most solitary pulmonary nodules on radiographs are benign, and the majority represent granulomas and intrapulmonary lymph nodes. Larger lung nodules and lung masses are more likely to be malignant. Nodule assessment includes determination of size, morphology, attenuation, metabolic activity, enhancement characteristics and growth. A solid lung nodule that is stable for 2 years is generally presumed benign. Sub-solid (part-solid and ground-glass nodules) often represent indolent lung cancer, and different follow-up and management guidelines apply. Confident diagnosis of benign nodules such as granulomas is important, as these lesions do not require imaging follow-up.
Hamartoma and Benign Tumor-like Lesions
Authors: Ternes Tyler H.
Published: August 2019

Pulmonary hamartomas are benign neoplasms comprised of various mesenchymal components. The presence of chondroid calcification (popcorn appearance) and/or macroscopic fat can be diagnostic of hamartoma. Very slow growth is an expected finding. Treatment of pulmonary hamartoma is usually conservative. Surgical resection can be considered if the CT findings are nondiagnostic, if biopsy is inconclusive, or if the lesion demonstrates rapid growth. Surgery should also be considered in patients with central lesions and postobstructive atelectasis or infection. Hamartomas account for the majority of benign lung neoplasms. Other benign neoplasms occurring in the lungs and airways include lipoma, chondroma, and leiomyoma and are very rare. If a pulmonary chondroma is diagnosed, additional investigation should be considered to exclude concurrent leiomyosarcoma and extraadrenal paraganglioma (Carney Triad).
Airways Disease
Authors: Little Brent P.
Published: August 2019

Pulmonary hamartoma is a benign neoplasm of the lung. It accounts for the majority of benign lung tumors. A hamartoma is composed of a variety of mesenchymal elements that may include cartilage, calcification, fat, epithelial cells, and smooth muscle. While benign, they are considered true neoplasms, and may demonstrate slow growth. Hamartomas are most commonly discovered in the 6th decade of life. Men have a 2-to-3 fold increased incidence compared to women. Most hamartomas are discovered incidentally. However, patients may rarely present with symptoms such as cough, hemoptysis, or recurrent pneumonia due to lesion proximity to the airway. On CT, hamartoma classically manifests as a small pulmonary nodule with intrinsic chondroid calcification and fat. These findings are essentially diagnostic of hamartoma. However, only 60% of hamartomas contain macroscopic fat, and even fewer (15%) exhibit characteristic “popcorn” calcification. Most hamartomas do not require resection, unless they are symptomatic. Other benign lesions also occur in the lung, but are much less common. A chondroma differs from a hamartoma in that is entirely comprised of cartilage. Chondromas are a component of Carney triad, which is also comprised of gastric leiomyosarcomas and extraadrenal paragangliomas. Lipomas and leiomyomas are other rare benign neoplasms, composed of fat and smooth muscle, respectively. Benign neurogenic neoplasms may also occur within the central airways.
Introduction to Connective Tissue Disorders and Autoimmune Conditions
Authors: Martínez-Jiménez Santiago
Published: August 2019

A variety of pathologic processes affect the connective tissues. The chapters that follow this one address some of these conditions with special emphasis on autoimmune disorders (e.g. rheumatoid arthritis, scleroderma, systemic lupus erythematosus, dermatomyositis/polymyositis, Sjögren syndrome, mixed connective tissue disease, and vasculitis), amyloidosis and eosinophilic lung disease. An autoimmune response is an immune response that targets an antigen within the host and attacks healthy body tissues. This often involves T and B lymphocytes in a response that is very similar to an allergic reaction. While the presence of an auto-antibody is often an essential component of the autoimmune response, its mere presence does not define the disease. In addition to the presence of auto-antibodies, the presence of soft tissue damage is required, thus auto-antibodies may be present in the absence of an inflammatory process. Amyloidosis is a pathologic entity with protean manifestations, often thought of as a single disease rather a group of diseases that share a similar pathophysiologic event: the deposition of proteins within the soft tissues. The term eosinophilic lung disease encompasses a wide variety of pathologic conditions that range from idiopathic diseases to systemic vasculitides and, in some cases, a response to parasitic infestation.
Systemic Sclerosis
Authors: Martínez Felipe
Published: August 2019

Systemic sclerosis (SSc), or scleroderma is a chronic autoimmune disorder of small vessels and connective tissue characterized by organ fibrosis, small vessel vasculopathy and disease-specific antibodies. It results in multi system organ fibrosis. The skin, lungs, heart, gastrointestinal tract and kidneys are frequently affected. Skin involvement is typical. Clinically evident pulmonary disease is seen in 25% of affected patients, but autopsy reports demonstrate some degree of pulmonary involvement in all patients with the systemic form of the disease. Pulmonary disease is second only to esophageal fibrosis and has surpassed renal disease as the leading cause of death. Systemic sclerosis associated-interstitial lung disease (SSc-ILD) and pulmonary vascular disease are the two major lung manifestations of SSc. Pulmonary hypertension is the leading cause of death. A normal chest radiograph does not exclude SSc-ILD. High resolution CT (HRCT) should be part of the initial evaluation of patients with SSc, even when pulmonary symptoms are not present. The radiologist should be able to recognize signs of early pulmonary fibrosis and pulmonary hypertension on radiography and HRCT due to the proven benefit of adequate therapy in overall outcome and mortality.
Introduction to Iatrogenic Conditions
Authors: Bhalla Sanjeev
Published: August 2019

Post-therapy imaging interpretation can be challenging. In most practices, the main thoracic interventions include drug therapy, surgery and radiation therapy. In certain practices, especially in the absence of stereotactic radiation, radiofrequency ablation and cryoablation have gained a foothold. Post -therapeutic changes in the lung may be divided into two main categories: local and diffuse. Local changes are usually seen with radiation and percutaneous therapies. Diffuse changes mainly include organizing pneumonia and alveolar damage. The latter may be seen after both medical and surgical intervention. Two key questions must be answered when dealing with the treated patient: what was the prior therapy and when was the treatment. Both questions will help determine the significance of the imaging findings.
Introduction to Mediastinal Abnormalities
Authors: Rosado-de-Christenson Melissa L.
Published: August 2019

The mediastinum is the space between the pleura and lungs, extends from the thoracic inlet to the diaphragm, and contains various organs and structures that may be affected by a variety of disease processes including neoplasms, other acquired conditions and congenital anomalies. The abnormal mediastinum is typically initially identified on chest radiography because of a mediastinal contour abnormality or mass. The radiologist must assess the frontal chest radiograph to determine whether the lesion manifests as a focal, diffuse or multifocal mediastinal abnormality. The lesion must then be localized to a specific mediastinal compartment using the lateral chest radiograph. This allows the formulation of a focused differential diagnosis and recommendations for further evaluation and management that often involve contrast-enhanced chest CT and less frequently MRI. These studies allow further characterization of the lesion and identification of associated findings such as lymphadenopathy, skeletal involvement and locally invasive behavior. Cross-sectional imaging usually allows categorization of mediastinal abnormalities as vascular, surgical or non-surgical lesions. Benign pathognomonic conditions that do not require further treatment may also be confidently diagnosed.
Primary Mediastinal Neoplasms
Authors: Rosado-de-Christenson Melissa L.
Published: August 2019

neoplasms and lymphoma characteristically affect the anterior mediastinum while neurogenic neoplasms typically occur in the paravertebral regions. Patients with mediastinal neoplasms may be asymptomatic or may present because of symptoms of compression or local invasion. Patients with thymoma may also present with paraneoplastic syndromes including myasthenia gravis. Thymoma is the most common primary anterior mediastinal neoplasm and usually manifests as a unilateral soft tissue mass with lobular contours that may exhibit local invasion or drop pleural metastases. Mature teratoma often demonstrates a spherical morphology and cystic change; intrinsic fat attenuation in such a lesion is virtually diagnostic. Malignant germ cell neoplasms almost exclusively affect men and manifest as anterior mediastinal soft tissue masses that may be homogeneous or exhibit areas of low attenuation from central necrosis and are indistinguishable from lymphoma with nodal coalescence on imaging. Neurogenic neoplasms are paravertebral lesions that may produce skeletal erosion and intraspinal extension and are optimally evaluated with MRI. Imaging diagnosis of primary mediastinal neoplasms requires identification of a mediastinal mass, placement of the mass in a specific mediastinal compartment and characterization of the lesion with cross-sectional imaging to formulate a focused differential diagnosis and appropriate management recommendations.
Glandular Enlargement
Authors: Carter Brett W.
Published: August 2019

Glandular enlargement in the mediastinum is usually due to hyperplasia of thymus in the anterior mediastinum or thyroid enlargement with intramediastinal growth. Thymic enlargement is typically due to rebound hyperplasia associated with chemotherapy, radiation therapy, and stresses. Rebound thymic hyperplasia manifests as diffuse, symmetric enlargement of the thymus. MRI may be helpful in distinguishing thymic hyperplasia from neoplastic involvement of the thymus, as the former lose signal on opposed-phase T1-weighted MR imaging. Thyroid goiters may originate in the neck and migrate into the mediastinum or arise from an ectopic focus of mediastinal thyroid tissue. Goiters manifest as mediastinal masses that are similar in appearance to the thyroid gland, with intrinsic hyperdensity, hyperenhancement, foci of calcification and cystic change.
Introduction to Developmental Abnormalities
Authors: Rosado-de-Christenson Melissa L.
Published: August 2019

The introduction to developmental abnormalities summarizes the types of developmental thoracic anomalies and variants that may affect the adult patient. These abnormalities can be categorized based on their anatomic location within the thorax and may affect the airways, lung, pleura, mediastinum, heart, blood vessels, diaphragm and chest wall. Assessment of central tracheobronchial morphology is important in the determination of visceral-atrial situs. Airway anatomic variants are common but do not usually produce symptoms or require treatment. There is great variability in the fissural anatomy of the lung with frequent incomplete and accessory fissures. Intralobar sequestration may affect children, adolescents or adults and is confirmed by visualization of systemic blood supply to abnormal lung parenchyma. Developmental abnormalities may also affect the mediastinum and the cardiovascular system. Symptomatic patients may present in adulthood with intra- and extracardiac shunt lesions. Developmental lesions may also affect the systemic arteries and veins and may result in anomalous pulmonary venous return to the right heart. These lesions are typically evaluated with chest CT and/or MRI. Diaphragmatic developmental lesions in adults include Bochdalek and Morgagni hernias. Congenital anomalies may also affect the chest wall osseous structures and soft tissues.
Sequestration
Authors: Cummings Kristopher W.
Published: August 2019

Sequestration refers to nonfunctioning pulmonary tissue that is isolated from the tracheobronchial tree and derives its arterial blood supply from the systemic circulation. Intralobar sequestrations are more commonly encountered in the adult population and are characterized by a lack of a separate pleural covering and frequent pulmonary venous drainage. In contrast, extralobar sequestrations are commonly diagnosed in childhood and are surrounded by a separate covering (typically the pleura) with frequent systemic venous drainage. Sequestrations may be encountered in asymptomatic adults as an incidental finding, and may mimic malignancy. Sequestrations may also be found in symptomatic adults because of repeated super-infection. Characteristic features on CT and MR are emphasized in this chapter.
Abnormal Aorta and Aortic Branching
Authors: Cummings Kristopher W.
Published: August 2019

Abnormal aorta and aortic branching discusses congenital variants of the aortic arch and great vessel branching. While many of these anomalies are incidental imaging findings in asymptomatic individuals, lesions such as a double aortic arch and right aortic arch with aberrant left subclavian artery produce vascular rings which can cause respiratory or esophageal symptoms. Certain anomalies such as a right aortic arch with mirror image branching are very frequently associated with other congenital cardiac abnormalities. Another common aortic congenital abnormality that may be diagnosed in early adulthood is aortic coarctation, frequently manifesting with upper extremity hypertension. As many of these lesions are first detected on chest radiography, the radiographic appearance and classification of these abnormalities is discussed in detail and supplemented by additional information that can be obtained with CT and MR.
Diseases of the Chest Wall and Diaphragm
Authors: Bhalla Sanjeev
Published: August 2019

The chapter titled chest wall and diaphragm discusses a variety of thoracic abnormalities. Chest wall conditions can be divided into masses, fluid-like processes and congenital variants. The variety of masses encountered in the chest wall is reflective of the tissue of origin. The approach to the chest wall lesion is be guided by three main considerations: the patient’s age, the acuity of the process and the tissue of origin. The desmoid tumor, for example, is a lesion characteristically seen in young adults. Presenting symptoms can also be helpful as infection, hematoma and malignant lesions are more often associated with chest pain. The diaphragm also has a variety of conditions that may manifest on thoracic imaging including masses, defects and anomalies of function. When the innervation is paralyzed, the entire hemidiaphragm may be elevated. Focal defects results in characteristic hernias.
A multiwavelength study of a massive, active galaxy at z ∼ 2: coupling the kinematics of the ionized and molecular gas
Authors: Loiacono Federica , Talia Margherita , Fraternali Filippo , Cimatti Andrea , Di Teodoro Enrico M , Caminha Gabriel B
Published: August 2019

We report a multiwavelength study of the massive ($M_{\star } \gtrsim 10^{11} \rm {M}_{\odot }$), z ∼ 2 star-forming galaxy GMASS 0953, which hosts an obscured AGN. We combined near-infrared observations of the GNIRS, SINFONI and KMOS spectrographs to study the kinematics of the [O  iii] λ5007 and H α emission lines. Our analysis shows that GMASS 0953 may host an ionized disc extending up to 13 kpc, which rotates at a velocity of $V_{\rm {ion}} = 203^{+17}_{-20}$  km s−1 at the outermost radius. Evidence of rotation on a smaller scale (R ∼ 1 kpc) arises from the CO(J = 6–5) line. The central velocity $V_{\rm {CO}} = 320^{+ 92}_{-53}$  km s−1 traced by the molecular gas is higher than Vion, suggesting that the galaxy harbours a multiphase disc with a rotation curve that peaks in the very central regions. The galaxy appears well located on the z = 0 baryonic Tully–Fisher relation. We also discuss the possibility that the [O  iii] λ5007 and H α velocity gradients are due to a galactic-scale wind. Besides, we found evidence of an AGN-driven outflow traced by a broad blueshifted wing affecting the [O  iii] λ5007 line, which presents a velocity offset Δv = −535 ± 152  km s−1 from the systemic velocity. Because of the short depletion time-scale (τdep ∼ 108 yr) due to gas ejection and gas consumption by star formation activity, GMASS 0953 may likely evolve into a passive galaxy. However, the role of the AGN in depleting the gas reservoir of the galaxy is quite unclear because of the uncertainties affecting the outflow rate.
Are the planetary orbital effects of the solar dark matter wake detectable?
Authors: Iorio Lorenzo
Published: August 2019

Recently, there has been some discussion in the literature about the effects of the anisotropy in the spatial density of dark matter in the Solar neighbourhood arising from the motion of the Sun through the Galactic halo. In particular, questions have been asked about the orbital motions of the Solar system’s planets and whether these motions can be effectively constrained by the radiotechnical observations collected by Cassini. I show that the semilatus rectum p, the eccentricity e, the inclination I, the longitude of the ascending node Ω, the longitude of perihelion ϖ, and the mean anomaly at epoch η of a test particle of a restricted two-body system affected by the gravity of a dark matter wake undergo secular rates of change. In the case of Saturn, they are completely negligible, being at the order of ≃0.1 millimetres per century and ≃0.05–2 nanoarcseconds per century: the current (formal) accuracy level in constraining any anomalous orbital precessions is of the order of ≃0.002–2 milliarcseconds per century for Saturn. I also numerically simulate the Earth–Saturn range signature Δρ(t) arising from the dark matter wake over the same time span (2004–2017) as covered by the Cassini data record. I find that it is as low as ${\simeq}0.1{-}0.2\, \mathrm{m}$, while the existing range residuals, computed by astronomers without modelling any dark matter wake effect, are of the order of ${\simeq}$ 30 m. The local dark matter density ϱDM would need to be larger than the currently accepted value of $\varrho _\mathrm{DM}=0.018\, \mathrm{M}_\odot \, \mathrm{pc}^{-3}$ by a factor of 2.5 × 106 in order to induce a geocentric Kronian range signature large enough to make it discernible in the present-day residuals.
The strongly interacting binary scenarios of the enigmatic supernova iPTF14hls
Authors: Gofman Roni Anna , Soker Noam
Published: August 2019

We argue that some scenarios for the enigmatic supernova (SN) iPTF14hls and its progenitor require a strong binary interaction. We examine scenarios that attribute the extra power of iPTF14hls to a magnetar, to a late fallback on to the neutron star (NS) that launches jets, to an interaction of the ejecta with a circumstellar matter (CSM), or to a common envelope jets SN (CEJSN). For each of these four scenarios, we study the crucial process that supplies the extra energy and conclude that a binary companion to the progenitor must be present. For the magnetar scenario and late jets we claim that a companion should spin-up the pre-collapse core, in the ejecta-CSM scenario we find that the formation of the equatorial CSM requires a companion, and in the CEJSN where a NS spirals-in inside the giant envelope of the progenitor and launches jets the strong binary interaction is built-in. We argue that these types of strong binary interactions make the scenarios rare and explain the enigmatic nature of iPTF14hls. We further study processes that might accompany the binary interaction, in particular, the launching of jets before, during and after the explosion and their observational consequences. We do not consider the difficulties of the different scenarios and neither do we determine the best scenario for iPTF14hls. We rather focus on the binary nature of these scenarios that might as well explain other rare types of SNe.
Bacteremia in Childhood Life-Threatening Infections in Urban Gambia: EUCLIDS in West Africa
Authors: Secka F , Herberg J A , Sarr I , Darboe S , Sey G , Saidykhan M , Wathuo M , Kaforou M , Antonio M , Roca A , Zaman S M A , Cebey-López M , Boeddha N P , Paulus S , Kohlfürst D S , Emonts M , Zenz W , Carrol E D , de Groot R , Schlapbach L , Martinon-Torres F , Bojang K , Levin M , van der Flier M , Anderson S T
Published: August 2019

Background

The limited availability of microbiology services in sub-Saharan Africa impedes accurate diagnosis of bacterial pathogens and understanding of trends in prevalence and antibiotic sensitivities. We aimed to characterize bacteremia among hospitalized children in The Gambia and to identify factors associated with bacteremia and mortality.

Methods

We prospectively studied children presenting with suspected severe infection to 2 urban hospitals in The Gambia, between January 2013 and September 2015. Demographic and anthropometric data, clinical features, management, and blood culture results were documented. Urine screens for antibiotic activity were performed in a subset of participants.

Results

Of 411 children enrolled (median age, 29 months; interquartile range, 11–82), 79.5% (325 of 409) reported prehospital antibiotic use. Antimicrobial activity by urinary screen for antibiotic activity was detected in 70.8% (n = 80 of 113). Sixty-six bacterial pathogens were identified in 65 (15.8%) participants and Staphylococcus aureus predominated. Gram-positive organisms were more commonly identified than Gram-negative (P < .01). Antibiotic resistance against first-line antimicrobials (ampicillin and gentamicin) was common among Gram-negative bacteria (39%; range, 25%–100%). Factors significantly associated with bacteremia included the following: gender, hydration status, musculoskeletal examination findings, admission to the Medical Research Council The Gambia at London School of Hygiene & Tropical Medicine hospital, and meeting sepsis criteria. Those associated with increased mortality were presence of a comorbidity, clinical pallor, tachypnea, and altered consciousness. Tachycardia was associated with reduced mortality.

Conclusions

The bacteremia rate in children with suspected childhood life-threatening infectious diseases in The Gambia is high. The pattern of pathogen prevalence and antimicrobial resistance has changed over time compared with previous studies illustrating the importance of robust bacterial surveillance programs in resource-limited settings.
Recent Trends and Effectiveness of Antiretroviral Regimens Among Men Who Have Sex With Men Living With HIV in the United States: The Multicenter AIDS Cohort Study (MACS) 2008–2017
Authors: Li Xiuhong , Brown Todd T , Ho Kenneth S , Witt Mallory D , Phair John , Jacobson Lisa P
Published: August 2019

Objective

We evaluated trends and population effectiveness (tolerability, HIV suppression) of current combination antiretroviral therapy (cART) regimens mindful of treatment guidelines.

Method

Trend analyses included 18 017 person-visits (1457 men) on cART during 2008–2017 in the Multicenter AIDS Cohort Study. Effectiveness analyses of current regimens used 3598 person-visit–pairs (745 men) on cART in 2014–2017. Inverse-probability-of-treatment-and-censoring weighted Poisson regression with robust variances was used to evaluate the association between regimens and switching, adherence and HIV RNA <20 copies/mL.

Results

Integrase strand transfer inhibitor (INSTI)-based regimen usage has increased since 2008. Almost 90% of cART initiators started with INSTI-cART in 2016–2017; cART adherence was stable around 90% and 83%–85% suppressed virus (<20 cp/mL). Commonly used regimens in 2014–2017 contained disoproxil fumarate/emtricitabine (TDF/FTC) backbone with efavirenz (EFV, n = 1161 person-visits), elvitegravir/cobicistat (EVG/c, n = 551), rilpivirine (RPV, n = 492), darunavir/ritonavir (DRV/r, n = 351), or atazanavir (ATV)/r (n = 333). Others were dolutegravir/abacavir/lamivudine (DTG/ABC/3TC, n = 401) and EVG/c/tenofovir alafenamide/FTC (EVG/c/TAF/FTC, n = 309). Compared to EFV/TDF/FTC users, ATV/r+TDF/FTC users switched more (rate ratio [RR] = 1.80, 95% confidence interval (CI), 1.17–2.76), while those on DTG/ABC/3TC (RR [95% CI] = 0.16 [0.08–0.31]) or EVG/c/TAF/FTC (RR [95% CI] = 0.12 [0.06–0.27]) switched less. The rate of suppressed HIV RNA was 15% (95% CI, 2%–26%) lower among younger EVG/c/TDF/FTC users and 18% (95% CI, 3%–34%) higher in older DRV/r+TDF/FTC users; adherence did not differ by regimen.

Conclusions

Consistent with guidelines, recent cART initiators started with INSTI-cART, which was associated with less switching early after initiation. Factors beyond those studied here, such as need for salvage therapy, unique personal characteristics, drug interactions, and cost may influence treatment decisions.
Lessons Learned From a Randomized Controlled Trial of Short-Course Intravenous Antibiotic Therapy for Erysipelas and Cellulitis of the Lower Limb (Switch Trial)
Authors: Clarke Marcus C , Cheng Allen C , Pollard James Gd , Birch Mark , Cowan Raquel U , Linke Jake A , Walton Aaron L , Friedman N Deborah
Published: August 2019

Background

The diagnosis of cellulitis is made clinically without a gold standard diagnostic test, and cellulitis has many disease mimics. There is currently no consensus for optimal antimicrobial treatment duration or method of antimicrobial delivery.

Methods

This was a randomized controlled open-label multicenter trial to determine the safety and efficacy of 24 hours of intravenous (IV) therapy compared with ≥72 hours of IV therapy, both followed by oral therapy to a maximum of 7–10 days’ duration for the treatment of lower limb cellulitis.

Results

Over 40 months, 80 patients were recruited. Thirty-nine patients were assigned to 24 hours of IV antibiotics and 41 to ≥72 hours of IV antibiotics. The mean duration (range) of IV antibiotics in the 24-hour group was 25.5 (17–40) hours, and in the ≥72-hour group it was 78 (41.5–210) hours. Three patients in the 24-hour arm and 4 patients in the ≥72-hour arm were excluded from the analysis due to withdrawal from the trial. Analysis of the remaining patients revealed that 6 patients (4 in the intervention arm and 2 in the control arm) did not achieve an adequate response to therapy. Only 1 patient experienced self-limiting adverse effects of treatment.

Conclusions

The noninferiority of short-course IV therapy cannot be determined from this trial. Challenges included resource limitations for recruitment, misdiagnosis, participant withdrawal, and subjective responses to therapy based on visual assessment by treating clinicians. Further studies are needed to determine if short-course IV therapy is a suitable treatment option.

Australia Council of Clinical Trials Registry No

ACTRN12613001366741.