Search

Infectious diseases, including parasitic diseases, which are commonly associated with poverty and poor sanitation, continue to cause significant morbidity, disability, and mortality in Latin America and the Caribbean region. This article reviews the epidemiology, pathophysiology, and cardiothoracic imaging manifestation of several communicable diseases endemic to this region.

Background Infected coronary artery aneurysms (ICAA) represent a rare but potentially fatal complication of pre-existent atherosclerotic or non-atherosclerotic coronary artery disease, percutaneous coronary artery intervention, endocarditis or extracardiac infection. Methods A retrospective analysis of four cases in addition to 51 infected coronary artery aneurysms from the literature, for a total of 55 ICAA was performed. Clinical and morphological information including age, sex, clinical presentation, microbial cultures, size, location and associated abnormalities as well as patient outcome was reviewed. Results 83% of affected patients were adult males, with an average age of 55.24 years. The right coronary artery was the most commonly affected vessel (40%). In nearly 80% of the time, the responsible organism was either Staphylococcus aureus (53.3%), or Streptococcus (20%) infection. ICAA are typically large, on average 3.4 cm in diameter and can measure up to 9 cm. On contrast enhanced CT, imaging features include lobulated contour or saccular shape (54.2%) with thick wall or mural thrombus (87.5%). Associated abnormal appearance of the pericardium with either pericardial fluid, thickening or loculation is common (79.2%). Conclusion ICAA are typically large, and characterized by a thick wall with a lobulated or saccular shape. Association with mediastinal, chest wall or pericardial abnormalities are common. This combination of findings, in the setting of fever, known infection, or recent coronary intervention should raise concern for ICAA.

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.

Left ventricular aneurysms may be repaired by the linear technique or endoventricular circular patch plasty technique. Choice of technique should be based on the individual patient, including cavity and aneurysm geometry. In this article, we describe the principles underlying decision making with 2 illustrative cases.

Developmental lung anomalies represent a heterogeneous group of diverse, yet related abnormalities that involve the lung parenchyma, pulmonary vasculature or a combination of both-which usually present prenatally and in early childhood. However, a substantial number of cases go unnoticed during childhood and present either incidentally or with recurrent respiratory infections progressing into adulthood. Defective development of the tracheobronchial tree and the pulmonary vasculature are proposed to cause these developmental anomalies. Encountering these lung anomalies in adults is a diagnostic challenge given their rarity and they are often mistaken as other serious pathological conditions, resulting in unnecessary diagnostic tests and procedures. The developmental lung anomalies in adults can be broadly divided into three categories: bronchopulmonary anomalies encompassing congenital bronchial atresia, bronchogenic cysts, congenital lobar emphysema and congenital pulmonary airway malformations. Vascular anomalies include pulmonary agenesis-aplasia- hypoplasia complex, unilateral absence of the pulmonary artery, pulmonary artery sling, partial anomalous pulmonary venous return, pulmonary venous varix and pulmonary arteriovenous malformations. Finally combined lung parenchymal-vascular anomalies of the lung involve hypogenetic lung (scimitar) syndrome and bronchopulmonary sequestration. This article discusses the spectrum of these developmental anomalies of the lung, their etiopathogenesis, clinical and radiographic presentations in adults and management in brief.

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare, heterogeneous neuroendocrine neoplasms of the autonomous nervous system of chromaffin cell origin that may arise within the adrenal medulla (PCCs) or the sympathetic and parasympathetic paraganglia (PGLs). Currently referred to by the umbrella term pheochromocytomas-paragangliomas (PPGLs), these distinct tumors are characterized by specific histopathology as well as biological and clinical profiles. PPGLs may occur as part of hereditary syndromes (40% of cases) or as sporadic tumors. Currently, there are 12 different hereditary syndromes with characteristic genetic abnormalities, at least 15 well-characterized driver genes and distinct tumor metabolic pathways. Based on the Cancer Genome Atlas (TCGA) taxonomic schemata, PPGLs have been classified into three main clusters of specific genetic mutations and tumor pathways with clinical, biochemical, and prognostic implications. Imaging plays a pivotal role in the initial diagnosis, tumor characterization, evaluation of treatment response, and long-term surveillance. While MDCT and MRI help in the anatomic localization, SPECT, and PET using different radiotracers are crucial in the functional assessment of these tumors. Surgery, chemotherapy, and radiotherapy are currently available treatment options for PPGLs; antiangiogenic drugs are also being used in treating metastatic disease. Evolving knowledge regarding the different genetic abnormalities involved in the pathogenesis of PPGLs has identified potential therapeutic targets that may be utilized in the discovery of novel drugs.

Rib fractures are the most common thoracic injury after minor blunt trauma. Although rib fractures can produce significant morbidity, the diagnosis of injuries to underlying organs is arguably more important as these complications are likely to have the most significant clinical impact. Isolated rib fractures have a relatively low morbidity and mortality and treatment is generally conservative. As such, evaluation with standard chest radiographs is usually sufficient for the diagnosis of rib fractures, and further imaging is generally not appropriate as there is little data that undiagnosed isolated rib fractures after minor blunt trauma affect management or outcomes. Cardiopulmonary resuscitation frequently results in anterior rib fractures and chest radiographs are usually appropriate (and sufficient) as the initial imaging modality in these patients. In patients with suspected pathologic fractures, chest CT or Tc-99m bone scans are usually appropriate and complementary modalities to chest radiography based on the clinical scenario. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Background Chest tube management protocols, particularly in patients with alveolar-pleural air leak due to recent surgery or trauma, are limited by concerns over safety, especially concerns about rapid and occult development of pneumothorax. A continuous, real-time monitor of pneumothorax could improve the quality and safety of chest tube management. We developed a rat model of pneumothorax to test a novel approach of measuring electrical impedance within the pleural space as a monitor of lung expansion. Materials and methods Anesthetized Sprague–Dawley rats underwent right thoracotomy. A novel impedance sensor and a thoracostomy tube were introduced into the right pleural space. Pneumothorax of varying volumes ranging from 0.2 to 20 mL was created by syringe injection of air via the thoracostomy tube. Electrical resistance measurements from the pleural sensor and fluoroscopic images were obtained at baseline and after the creation of pneumothorax and results compared. Results A statistically significant, dose-dependent increase in electrical resistance was observed with increasing volume of pneumothorax. Resistance measurement allowed for continuous, real-time monitoring of pneumothorax development and the ability to track pneumothorax resolution by aspiration of air via the thoracostomy tube. Pleural resistance measurement demonstrated 100% sensitivity and specificity for all volumes of pneumothorax tested and was significantly more sensitive for pneumothorax detection than fluoroscopy. Conclusions The electrical impedance-based pleural space sensor described in this study provided sensitive and specific pneumothorax detection, which was superior to radiographic analysis. Real-time, continuous monitoring for pneumothorax has the potential to improve the safety, quality, and efficiency of postoperative chest tube management.

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.

This online presentation reviews the anatomy and physiology of the pericardium and the role of MRI in diagnosis of pericardial abnormalities.

In patients with alveolar-to-pleural air leak due to recent surgery or trauma, clinicians tend to manage chest tubes with suction therapy. Nonsuction therapy is associated with shorter chest tube duration but also a higher risk of pneumothorax. We sought to develop an intrapleural electrical impedance sensor for continuous, real-time monitoring of pneumothorax development in a porcine model of air leak as a means of promoting nonsuction therapy. Using thoracoscopy, 2 chest tubes and the pleural impedance sensor were introduced into the pleural space of 3 pigs. Continuous air leak was introduced through 1 chest tube by carbon dioxide insufflation. The second chest tube was placed to suction then transitioned to no suction at increasingly higher air leaks until pneumothorax developed. Simultaneously, real-time impedance measurements were obtained from the pleural sensor. Fluoroscopy spot images were captured to verify the presence or absence of pneumothorax. Statistical Analysis Software was used throughout. With the chest tube on suction, a fully expanded lung was identified by a distinct pleural electrical impedance respiratory waveform. With transition of the chest tube to water seal, loss of contact of the sensor with the lung resulted in an immediate measurement of infinite electrical impedance. Pneumothorax resolution by restoring suction therapy was detected in real time by a return of the normal respiratory impedance waveform. Pleural electrical impedance monitoring detected pneumothorax development and resolution in real time. This simple technology has the potential to improve the safety and quality of chest tube management.

Complications following cardiothoracic surgery are responsible for prolonged hospital stay, increase cost in patient care and increased morbidity and mortality. Vascular complications in particular are significant contributors to poor patient outcome due to either hemorrhage or thrombosis and ischemia. Evaluation of vascular complications in the postoperative patient requires a rapid and reliable imaging approach. Vascular complications after cardiothoracic surgery include pulmonary artery thrombosis, pseudoaneurysm, pulmonary vein thrombosis, vascular fistulas, stenosis and infarction. Multidetector CT (MDCT), often the imaging modality of choice, offers a one-stop-shop capability to visualize the entire cardiothoracic vasculature, airways, lung parenchyma, mediastinum and chest wall with excellent temporal and spatial resolution.

High-order switched DC-DC converters, such as SEPIC, Ćuk and Zeta, are classic energy processing elements, which can be used in a wide variety of applications due to their capacity to step-up and/or step-down voltage characteristic. In this paper, a novel methodology for analyzing the previous converters operating in discontinuous conduction mode (DCM) is applied to obtain full-order dynamic models. The analysis is based on the fact that inductor currents have three differentiated operating sub-intervals characterized by a third one in which both currents become equal, which implies that the current flowing through the diode is zero (DCM). Under a small voltage ripple hypothesis, the currents of all three converters have similar current piecewise linear shapes that allow us to use a graphical method based on the triangular shape of the diode current to obtain the respective non-linear average models. The models’ linearization around their steady-state operating points yields full-order small-signal models that reproduce accurately the dynamic behavior of the corresponding switched model. The proposed methodology is applicable to the proposed converters and has also been extended to more complex topologies with magnetic coupling between inductors and/or an RC damping network in parallel with the intermediate capacitor. Several tests were carried out using simulation, hardware-in-the-loop, and using an experimental prototype. All the results validate the theoretical models.

Radiologists consciously or unconsciously encounter bronchiolitis on images frequently. The purpose of this article is to simplify the concept of bronchiolitis to facilitate the formulation of a succinct and accurate differential diagnosis and suggest potential causes for the imaging findings. Direct and indirect signs of bronchiolitis that are seen on computed tomographic images are detailed. The most common causes of bronchiolitis are covered, including several distinct entities to be considered in specific clinical scenarios. In order of prevalence, the top two causes of bronchiolitis are infection and aspiration. Less common entities include respiratory bronchiolitis and hypersensitivity pneumonitis, which tend to manifest with ground-glass centrilobular nodules. Some types of bronchiolitis affect specific ethnic groups or are associated with a characteristic clinical history. For example, diffuse panbronchiolitis typically affects Japanese subjects. Constrictive bronchiolitis should be considered in lung transplant recipients with ongoing rejection. Given the high frequency of bronchiolitis, radiologists should develop a systematic approach to both cellular and constrictive bronchiolitis. Recognition of specific clinical or imaging characteristics may be sufficient for providing a relevant differential diagnosis.

This paper presents an analytical study of an input current-mode control based on a linear matrix inequalities (LMI) for a non-inverting buck-boost converter. The LMI control technique makes better the dynamic response of this converter in comparison with previous research works, where its currents has been regulated using a classical analogue PI controller with an additional pole. The main features of the selected converter are its voltage step-up and step-down properties, high efficiency, wide bandwidth and low input and output current ripples. All of these converter’s properties allows it to be used as a modular converter capable of being positioned at any converter locations in hybrid systems, which are formed by varying-voltage-sources, current controlled dc-dc converters and auxiliary storage devices such as batteries or capacitors. The designed state-feedback controller has the following aims, among others: pole placement constraints, control effort limitation, and decay rate and bandwidth improvement. The use of state-space averaging (SSA) method allows to describe LMI constraints which guarantees stability and provide good performances under a close loop pole region and control signal bound. The theoretical analysis have been simulated by means of Matlab and PSIM on an 800-W coupled-inductor buck-boost dc-dc switching converter.

Crests, bands, chords, and membranes can be seen within the different cardiac chambers, with variable clinical significance. They can be incidental or can have clinical implications by causing hemodynamic disturbance. It is crucial to know the morphology and orientation of normal structures, aberrant or accessory muscles, and abnormal membranes to diagnose the hemodynamic disturbance associated with them. Newer generation computed tomographic scanners and faster magnetic resonance imaging sequences offer high spatial and temporal resolution allowing for acquisition of high resolution images of the cardiac chambers improving identification of small internal structures, such as papillary muscles, muscular bands, chords, and membranes. They also help in identification of other associated complications, malformations, and provide a road map for treatment. In this article, we review cross-sectional cardiac imaging findings of normal anatomical variants and distinctive imaging features of pathologic bands, chords, or membranes, which may produce significant hemodynamic changes and clinical symptomatology.

We describe the case of a bleeding trauma patient who received tranexamic acid (TXA) during air transport who subsequently developed multiple intra-cardiac thrombi. The administration of TXA during transport may be associated with this unusual presentation.

Myocardial infarction (MI) remains one of the leading contributors to overall mortality and morbidity in the modern world, even with recent advances in medicine. Various complications can arise following an MI, particularly with delayed or inadequate treatment. Even though many of these complications are uncommon, they can have a significant impact on patient outcomes. Some of these complications can be diagnosed based on clinical, laboratory and echocardiographic evaluation. Other times, however, cardiac MR and multidetector CT are necessary in their diagnosis and proper evaluation. Accurate detection of these complications is an important aspect of optimising prompt and effective patient care, leading to better clinical outcomes. It is the goal of this article to review the role of cross-sectional imaging in patients with post-MI as well as the characteristic imaging findings and differential diagnosis of common and uncommon complications of MI.

Background Intravascular ballistic embolization is a rare complication of missile injury. Because of its rarity, much remains to be known about its presentation, pathophysiology, complications, and management. In this study, we analyze case reports of ballistic embolization in the last 30 years and available cases from our institution to determine the likely patient, the nature of the embolization, the possible complications, and a general management strategy. Methods A PubMed search was performed in search of missile embolization cases from 1988 to 2018 in the English language, including only cases of intravascular emboli. Cases resulting from combat and explosive devices were excluded. In addition, five cases from our institution were included in the analysis. Results A total of 261 cases were analyzed. The most common presentation was that of a young man (reflecting the demographics of those sustaining gunshot wound injuries) with injury to the anterior torso from a single gunshot wound. Venous entry was most common, most often through large-caliber vessels. There was roughly equal involvement of the right and left circulation. Left circulation emboli were frequently symptomatic, with ischemia being the most frequent sequela. In contrast, a right circulation embolus was rarely associated with significant complications. Conclusions Despite its rarity, ballistic embolization should be considered in gunshot injury with known large-vessel injury when an exit wound is not identified. In particular, signs of ischemia distant from the injury site warrant timely investigation to maximize tissue salvageability. We present a management strategy model for consideration.

A wide spectrum of solid tumors can develop in the mediastinum of adults. Like for any other tumor evaluation, the location and morphology play equally important role for lesion characterization. Compartmentalizing the mediastinal masses greatly narrows the number of possible differential diagnosis. Cross sectional imaging mainly with computed tomography (CT) and magnetic resonance imaging (MRI) are the preferred modalities of choice as they can establish the presence, location and morphology of the lesion allowing to suggest a possible diagnosis.

This article reviews the imaging findings of pediatric mediastinal tumors and tumor-like lesions. The classification of the mediastinum is discussed with normal imaging appearance of the thymus in pediatric age group followed by a discussion on multiple mediastinal lesions in different compartments with emphasis on their imaging characteristics.

Despite significant improvements in the diagnosis and treatment of tuberculosis achieved during the last 3 decades, tuberculosis still remains one of the deadliest communicable diseases worldwide. Tuberculosis is still present in all regions of the world, with a more significant impact in developing countries. This article reviews the most common imaging manifestations of primary and postprimary tuberculosis, their complications, and the critical role of imaging in the diagnosis and follow-up of affected patients.

Thoracic venous injuries are predominantly attributed to traumatic and iatrogenic causes. Gunshot wounds and knife stabbings make up the vast majority of penetrating trauma whereas motor vehicle collisions are the leading cause of blunt trauma to the chest. Iatrogenic injuries, mostly from central venous catheter complications are being described in growing detail. Although these injuries are rare, they pose a diagnostic challenge as their clinical presentation does not substantially differ from that of arterial injury. Furthermore, the highly lethal nature of some of these injuries provides limited literature for review and probably underestimates their true incidence. The widespread use of multi-detector computed tomography (MDCT) has increased the detection rate of these lesions in hemodynamically stable patients that survive the initial traumatic event. In this article, we will discuss and illustrate various causes of injury to each vein and their supporting CT findings while briefly discussing management. The available literature will be reviewed for penetrating, blunt, and iatrogenic injuries to the vena cava, innominate, subclavian, axillary, azygos, and pulmonary veins.

Hypertrophic cardiomyopathy (HCM) is a heterogeneous group of diseases related to sarcomere gene mutations exhibiting heterogeneous phenotypes with an autosomal dominant mendelian pattern of inheritance. The disorder is characterized by diverse phenotypic expressions and variable natural progression, which may range from dyspnea and/or syncope to sudden cardiac death. It is found across all racial groups and is associated with left ventricular hypertrophy in the absence of another systemic or cardiac disease. The management of HCM is based on a thorough understanding of the underlying morphology, pathophysiology, and clinical course. Imaging findings of HCM mirror the variable expressivity and penetrance heterogeneity, with the added advantage of diagnosis even in cases where a specific mutation may not yet be found. The diagnostic information obtained from imaging varies depending on the specific stage of HCM-phenotype manifestation, including the prehypertrophic, hypertrophic, and later stages of adverse remodeling into the burned-out phase of overt heart failure. However, subtle or obvious, these imaging findings become critical components in diagnosis, management, and follow-up of HCM patients. Although diagnosis of HCM traditionally relies on clinical assessment and transthoracic echocardiography, recent studies have demonstrated increased utility of multidetector computed tomography (CT) and particularly cardiac magnetic resonance (MR) imaging in diagnosis, phenotype differentiation, therapeutic planning, and prognostication. In this article, we provide an overview of the genetics, pathophysiology, and clinical manifestations of HCM, with the spectrum of imaging findings at MR imaging and CT and their contribution in diagnosis, risk stratification, and therapy.

Fibrosing mediastinitis is a rare disorder characterized by the invasive proliferation of fibrous tissue within the mediastinum. This fibrosis can result in compression of intrathoracic structures including the pulmonary vasculature leading to clinical symptoms and complications like pulmonary hypertension. Here, we present two cases of young patients with fibrosing mediastinitis complicated by pulmonary artery stenosis requiring medical and endovascular management with excellent results. Keywords: Fibrosing mediastinits, Pulmonary artery stenosis, Pulmonary hypertension

Rib fractures are the most common thoracic injury after minor blunt trauma. Although rib fractures can produce significant morbidity, the diagnosis of injuries to underlying organs is arguably more important as these complications are likely to have the most significant clinical impact. Isolated rib fractures have a relatively low morbidity and mortality and treatment is generally conservative. As such, evaluation with standard chest radiographs is usually sufficient for the diagnosis of rib fractures, and further imaging is generally not appropriate as there is little data that undiagnosed isolated rib fractures after minor blunt trauma affect management or outcomes. Cardiopulmonary resuscitation frequently results in anterior rib fractures and chest radiographs are usually appropriate (and sufficient) as the initial imaging modality in these patients. In patients with suspected pathologic fractures, chest CT or Tc-99m bone scans are usually appropriate and complementary modalities to chest radiography based on the clinical scenario. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Chest radiographs are obtained as a standard part of clinical care. Rapid advancements in medical technology have resulted in a myriad of new medical devices, and familiarity with their imaging appearance is a critical yet increasingly difficult endeavor. Many modern thoracic medical devices are new renditions of old designs and are often smaller than older versions. In addition, multiple device designs serving the same purpose may have varying morphologies and positions within the chest. The radiologist must be able to recognize and correctly identify the proper positioning of state-of-the-art medical devices and identify any potential complications that could impact patient care and management. To familiarize radiologists with the arsenal of newer thoracic medical devices, this review describes the indications, radiologic appearance, complications, and magnetic resonance imaging safety of each device. ©RSNA, 2018.

Intrathoracic paragangliomas are uncommon and only represent 1%-2% of paragangliomas. They are most commonly found in mediastinal compartments (aortopulmonary window or posterior mediastinum). Computed tomography, magnetic resonance, and specific nuclear medicine radiotracers are routinely used to characterize these lesions and help exclude other more common conditions. Selective angiography is currently used for preoperative embolization and mapping of the vascular supply before surgical resection, rather than for diagnostic purposes alone.

Multinodular lung disease is routinely encountered on chest computed tomography (CT). Pulmonary nodules may be categorized as perilymphatic, random, or centrilobular, based on their CT distribution. Recognition of the pattern of distribution allows the differential diagnosis to be narrowed to a few common diseases. This review illustrates the CT appearance and provides a practical differential diagnosis of each pattern of nodules.

RationaleThe demographic, physiological, and computed tomography (CT) features associated with pneumothorax in smokers with and without chronic obstructive pulmonary disease (COPD) are not clearly defined.ObjectivesWe evaluated the hypothesis that pneumothorax in smokers is associated with male sex, tall and thin stature, airflow obstruction, and increased total and subpleural emphysema.MethodsThe study included smokers with and without COPD from the COPDGene Study, with quantitative chest CT analysis. Pleural-based emphysema was assessed on the basis of local histogram measures of emphysema. Pneumothorax history was defined by subject self-report.Measurements and main resultsPneumothorax was reported in 286 (3.2%) of 9,062 participants. In all participants, risk of prior pneumothorax was significantly higher in men (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.08-2.22) and non-Hispanic white subjects (OR, 1.90; 95% CI, 1.34-2.69). Risk of prior pneumothorax was associated with increased percent CT emphysema in all participants and participants with COPD (OR, 1.04 for each 1% increase in emphysema; 95% CI, 1.03-1.06). Increased pleural-based emphysema was independently associated with risk of past pneumothorax in all participants (OR, 1.05 for each 1% increase; 95% CI, 1.01-1.10). In smokers with normal spirometry, risk of past pneumothorax was associated with non-Hispanic white race and lifetime smoking intensity (OR, 1.20 for every 10 pack-years; 95% CI, 1.09-1.33).ConclusionsAmong smokers, pneumothorax is associated with male sex, non-Hispanic white race, and increased percentage of total and subpleural CT emphysema. Pneumothorax was not independently associated with height or lung function, even in participants with COPD. Clinical trial registered with www.clinicaltrials.gov (NCT00608764).

Carcinoid tumors are a rare biologically heterogeneous group of neuroendocrine tumors with a spectrum ranging from benign indolent to aggressive metastatic tumors. They belong to the category of amine precursor uptake and decarboxylase tumors, or apudomas. The most common sites for primary locations are the gastrointestinal and respiratory tracts; however, any organ can be involved. The clinical presentation depends on location, aggressiveness, production of biologically active amines and peptides, paraneoplastic syndromes, and tendency for metastasis. Their reported age-adjusted incidence has increased in recent years, partly due to improved detection at radiologic imaging and endoscopy. Not a ll neuroendocrine cell tumors are carcinoids. Numerous systems have been proposed regarding their nomenclature and classification. Cross-sectional and functional imaging plays an important role in diagnosis, lesion characterization, and staging. Awareness of nomenclature, classification, common sites of involvement, and imaging presentation are pivotal for making the diagnosis. Knowledge of the diverse clinical, pathologic, and radiologic spectrum of carcinoid tumors involving various organs of the body is important for diagnosis and patient management. ©RSNA, 2017.

Hamartomas are tumours composed of mesenchymal tissues such as cartilage, fat, connective tissue and smooth muscle and can be found in virtually any organ system. These masses commonly develop sporadically, but are also seen in certain syndromes such as tuberous sclerosis or Carney triad. While their imaging appearance varies depending on the organ they arise from, findings are usually unique and a diagnosis can be confidently made. Radiologists must be aware of the clinical and imaging presentations of these lesions with the particular goal of avoiding unnecessary studies or invasive procedures. Furthermore, knowledge of common syndromic entities is crucial, as the radiologist may be the first to suggest the diagnosis.

Lymphoid tissue is a normal component of the lung and manifests as intrapulmonary lymph nodes, bronchus-associated lymphoid tissue (BALT), peripheral lymphocytic aggregates, solitary lymphocytes, and phagocytic cells. Pulmonary lymphoid lesions are thought to develop as a consequence of anomalous stimulation and response of the bronchus-associated lymphoid tissue and manifests as a spectrum of lymphoproliferative disorders that may be reactive or neoplastic. Reactive disorders are polyclonal abnormalities and include nodular lymphoid hyperplasia, lymphocytic interstitial pneumonia, follicular bronchiolitis, angiofollicular hyperplasia, and enlarged intrapulmonary lymph nodes. Affected patients are often asymptomatic. Imaging findings include focal nodules, diffuse bilateral centrilobular nodules, and hilar or mediastinal masses.

Single coronary artery is a rare congenital anomaly in which a single artery arises from the aorta. The anomalous single trunk supplies blood to the entire heart. It is classified according to its origin, branching pattern, and course. The presence of a single coronary artery can be an isolated finding or associated with additional cardiac anomalies. Diagnosis is important because of therapeutic implications, although it is an incidental finding. As with any other coronary anomalies, its recognition is more common today because of increasing use of multidetector CT. The objective of this article is to review the classification of single coronary artery anomaly and its clinical significance and to illustrate the imaging findings on multidetector CT.

Rib fracture is the most common thoracic injury, present in 10% of all traumatic injuries and almost 40% of patients who sustain severe nonpenetrating trauma. Although rib fractures can produce significant morbidity, the diagnosis of associated complications (such as pneumothorax, hemothorax, pulmonary contusion, atelectasis, flail chest, cardiovascular injury, and injuries to solid and hollow abdominal organs) may have a more significant clinical impact. When isolated, rib fractures have a relatively low morbidity and mortality, and failure to detect isolated rib fractures does not necessarily alter patient management or outcome in uncomplicated cases. A standard posteroanterior chest radiograph should be the initial, and often the only, imaging test required in patients with suspected rib fracture after minor trauma. Detailed radiographs of the ribs rarely add additional information that would change treatment, and, although other imaging tests (eg, computed tomography, bone scan) have increased sensitivity for detection of rib fractures, there are little data to support their use. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review process include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

We describe 2 cases of endobronchial pulmonary carcinoid tumor with superimposed Aspergillus colonization. The Aspergillus hyphae were associated with fibrin, ulcer debris, and granulomatous inflammation in part masking the carcinoid tumor. Presence of necrotic debris made diagnosis on biopsy difficult, and atypical carcinoid could not be ruled out. The association of carcinoid tumor with aspergillosis is rare and has been reported in 4 other cases thus far. A review of the literature reveals at least 35 cases of lung carcinoma with coexisting Aspergillus upon presentation. Most of these carcinomas are either cavitary squamous cell or adenocarcinomas harboring an aspergilloma. The other carcinomas are associated with bronchial obstruction as in carcinoids or are a minor component of a preexisting cavity raising the possibility of "scar carcinoma." As in aspergillomas not associated with carcinoma, upper lobe involvement predominates. Diagnosis can be challenging with delayed discovery of underlying neoplasm leading to suboptimal treatment.

Developmental lung anomalies are classified into 3 main categories: bronchopulmonary (lung bud) anomalies, vascular anomalies, and combined lung and vascular anomalies. These anomalies are uncommon, and patients are at times asymptomatic; hence, identifying a developmental lung anomaly in the adult can be a challenge. Pulmonary vascular anomalies include interruption or absence of the main pulmonary artery, anomalous origin of the left pulmonary artery from the right pulmonary artery, anomalous pulmonary venous drainage (partial or complete), and pulmonary arteriovenous malformations. Systemic vascular anomalies comprise persistent left superior vena cava, anomalies of azygos and hemiazygos systems, and anomalies of the thoracic aorta and its major branches. In this article, we present embryology, classification, epidemiology, clinical presentation, and imaging features of anomalous pulmonary venous connections, with special emphasis on multidetector computed tomography and magnetic resonance imaging. These state-of-art imaging techniques have facilitated accurate and prompt diagnosis of these anomalies.

Aneurysms of the pulmonary vasculature may arise from the pulmonary arteries, bronchial arteries, or pulmonary veins. Their pathophysiology and clinical presentation are variable depending on the underlying condition, some of which have significant morbidity and mortality. Consequently, imaging plays a central role in the diagnosis and treatment planning. This review article presents a classification of the different types of aneurysms that can affect the pulmonary vasculature and reviews the most common conditions associated with them and discusses their imaging presentation.

Cardiac magnetic resonance (CMR) imaging has significantly evolved in the past decade and is well established in the evaluation of coronary artery disease (CAD). The evaluation of cardiac anatomy and contractility by high-resolution CMR can be improved by using intravenous administration of gadolinium-based contrast agents. Delayed enhancement CMR imaging has become the gold standard for quantification of myocardial viability in CAD. Contrast-enhanced CMR imaging may circumvent the need for endomyocardial biopsy or localize the involved regions, thereby improving the diagnostic yield of this invasive procedure. The application of contrast-enhanced CMR as an advanced imaging technique for ischemic and nonischemic diseases is reviewed.

The objectives of this article were: (1) to review common and rare manifestations of systemic and pulmonary Langerhans cell histiocytosis, Rosai-Dorfman disease, Erdheim-Chester disease and juvenile xanthogranuloma; (2) to provide the reader with important pathologic, epidemiologic and clinical features of these diseases. The histiocytoses are a diverse group of diseases which typically manifest with multiorgan involvement. Understanding the pathologic, epidemiologic and clinical features of these entities can help the radiologist suggest an accurate diagnosis of histiocytosis when typical imaging features are encountered.