How to Image Tendons Coils and patient position: Whether or not a coil should be used is based entirely on the anatomy to be imaged. Generally, surface coils improve images and should be used. For large areas, such as the thighs or pelvis, this approach is not practical, and surface coils are not used. Patients should be positioned as if the nearest joint were being imaged.…
How to Image Bone Marrow The most useful magnetic resonance imaging (MRI) sequences for evaluating the marrow are T1-weighted (T1W) and fat-suppressed T2-weighted (T2W) (either short tau inversion recovery [STIR] or fast spin echo [FSE] T2 with fat suppression) sequences. For brevity, when used in this chapter, “T2W” will refer to a “fluid-sensitive sequence” such as STIR or FSE with fat suppression. As discussed in the…
Although a detailed understanding of nuclear physics is not necessary to interpret magnetic resonance imaging (MRI) studies, it also is unacceptable to read passively whatever images you are given without concern for how the images are acquired or how they might be improved. Radiologists should have a solid understanding of the basic principles involved in acquiring excellent images. This chapter describes the various components that go…
The chest wall is a complex anatomic structure composed of muscles, bones, joints, and soft tissues that make up the area of the body between the neck and the abdomen. Pathologic processes that may involve the chest wall include congenital and developmental anomalies, trauma, inflammatory and infectious diseases, and soft tissue and bone tumors. Because the clinical presentation of patients with chest wall disorders is diverse…
Abnormalities of Diaphragmatic Motion: Diaphragmatic Paralysis, Weakness, and Eventration Etiology, Prevalence, and Epidemiology The diaphragm is the primary muscle of ventilation, and dysfunction of the diaphragm is an underrecognized cause of dyspnea. Dysfunction of the diaphragm can be classified as paralysis, weakness, or eventration and is usually suggested by elevation of a hemidiaphragm on chest radiography. Some of the more common causes of unilateral diaphragmatic paralysis…
Mediastinal masses are relatively uncommon and include a wide variety of abnormalities of neoplastic, congenital, vascular, and lymphatic etiology that most radiologists encounter infrequently. Imaging plays a critical role in the identification and evaluation of mediastinal lesions, facilitating the formulation of focused differential diagnoses and guiding clinical management. In some cases mediastinal masses demonstrate imaging characteristics that can suggest a specific diagnosis; in other instances the…
Mediastinitis refers to a focal or diffuse inflammation of the tissues located in the mediastinum. The mediastinum lies between the right and left pleural cavities and extends from the thoracic inlet to the diaphragm. Mediastinitis can be classified into acute and chronic forms. Acute mediastinitis is usually a catastrophic disorder manifesting with a sudden and dramatic onset and a high mortality rate when the diagnosis is…
Etiology, Prevalence, and Epidemiology Pneumomediastinum, also known as mediastinal emphysema, refers to the presence of free air or other gas in the mediastinal space. Pathologically, the major sources of entry of air to the mediastinum are (1) through the skin and chest wall, as commonly seen in penetrating trauma; (2) from the neck; (3) from a tear or defect in the esophagus or the trachea, allowing…
The pleura may be affected by primary neoplasms or become involved by secondary spread of intrathoracic or extrathoracic tumors. Primary pleural tumors account for approximately 10% of all pleural neoplasms, the most common of which include malignant pleural mesothelioma (MPM) and solitary fibrous tumor. Other primary neoplasms include lymphoma, lipomatous tumors such as lipoma and liposarcoma, synovial sarcoma, and vascular sarcomas such as epithelioid hemangioendothelioma. Secondary…
Etiology Benign pleural thickening caused by fibrosis is the second most common pleural abnormality, the most common one being effusion. Pleural fibrosis has a number of causes and is the outcome of many pleural diseases and a potential complication of every inflammatory condition that affects the lungs. The pleura show a variety of patterns of fibrosis. These may be either localized (apical caps, pleural plaques) or…
Etiology, Prevalence, and Epidemiology Pleural effusion is the accumulation of fluid in the pleural space resulting from disruption of the homeostatic forces responsible for the movement of pleural fluid. Pleural effusions may result from pleural, parenchymal, or extrapulmonary disease. Approximately 1 million people develop this abnormality each year in the United States. Clinical Presentation The oncotic pressures on both sides of the parietal and visceral pleura…
Pneumothorax is the presence of air between the parietal and visceral pleura in the pleural cavity. It is caused most frequently by trauma or blunt or penetrating injury, which may be accidental or iatrogenic. If it is not caused by trauma, it is referred to as spontaneous; this may be primary (not associated with an underlying cause) or secondary to preexisting significant pulmonary disease. Pneumothorax may…
Lung Transplantation Complications Lung transplantation can prolong life in a variety of diseases that cause progressive respiratory failure. As of 2015, more than 55,000 adult lung transplantations and almost 4000 heart-lung transplantations had been performed worldwide, more than 3500 a year. The most common indications for lung transplantation in adults have been chronic obstructive pulmonary disease (COPD), pulmonary fibrosis and other interstitial lung diseases (ILDs), and…
Chest radiography is the primary imaging modality used in the intensive care unit (ICU), given its portability, rapid image acquisition, and immediate bedside return of information on the preview screen. Of consequence, it is of utmost importance that both radiologists and intensivists are adept in reading these studies. Portable ICU radiographs are obtained in an anteroposterior (AP) view in which the x-ray beam traverses the patient…
A spectrum of cardiopulmonary diseases can be treated surgically. Surgical procedures in the thorax include lung resection, lung transplantation, cardiovascular and mediastinal surgery, as well as pleural and cavitary space reduction procedures. This chapter reviews the surgical procedures, indications, and imaging findings in the postoperative setting, both expected and unexpected, including potential complications. In the intensive care unit, postoperative findings, such as malposition of support lines…
Blunt thoracic trauma is a common indication for hospital admission, with the predominant cause of trauma being motor vehicle collisions. The thorax is the fourth most injured area in unrestrained passengers, but it is the most commonly injured area in individuals who are restrained by a seat belt. Other common causes of blunt thoracic trauma include falls from heights of greater than 10 feet and motor…
Radiation therapy is an important modality in the management of patients with intrathoracic malignant neoplasms and primary and secondary chest wall neoplasms. Radiation therapy for these tumors usually results in radiation of the adjacent lung, and radiation-induced lung injury has been reported in association with treatment of lung, breast, esophageal, and thymic neoplasms and in lymphoma and pleural mesothelioma. Adverse effects of radiation therapy on the…
Etiology The number of drugs recognized to cause an adverse pulmonary reaction of one kind or another is reported to be more than 600 and continues to rise yearly with the advent of new medications. Pharmacologic groups associated with pulmonary toxicity include chemotherapeutic agents, antimicrobials, antiinflammatory agents, cardiovascular drugs, and illicit drugs. Drug reactions are usually the result of either direct (toxic and idiosyncratic reactions) or…
Aspiration refers to the misdirection of contents of the oral or upper gastrointestinal tract that have passed through the trachea and larynx and entered the lung. The diagnosis rests mostly on the history of presenting illness, medical history, vital signs, and chest radiograph. Aspiration includes a spectrum of clinical and radiologic manifestations secondary to chemical pneumonitis or bacterial pneumonia that range from asymptomatic focal inflammatory reactions…
The most common pneumoconioses are silicosis, coal workers' pneumoconiosis, and asbestosis (see Chapters 61 and 62 ). There are numerous rare pneumoconioses related to variable occupational dust exposures. Hard metal lung disease, aluminum pneumoconiosis, talc pneumoconiosis, welders' pneumoconiosis, and chronic beryllium disease are discussed here. The high-resolution computed tomography (HRCT) findings of these uncommon pneumoconioses vary and are relatively nonspecific; however, there are predominant and characteristic…