Nisa Thoongsuwan

Spectrum of blunt chest injuries.

IMAGING FOR BLUNT CHEST TRAUMA The chest radiograph remains the initial study for assessing patients sustaining blunt trauma to the chest, and many common injuries can be identified by the chest radiograph alone. However, in severely injured patients, the ideal upright, full inspiratory PA chest radiograph cannot be obtained. Portable supine radiographs, often suffering from poor positioning, poor inspiration, or artifact from an underlying backboard or overlying monitoring equipment, are generally the rule rather than the exception, and many injuries may be difficult to detect on these suboptimal studies. It is essential to identify on the chest radiograph life threatening conditions such as pneumothorax, hemothorax, abnormal mediastinum (possibly indicating aortic or other great vessel injury), and thoracic spine fracture, as well as malpositioned life support devices. The technical limitations of a chest radiograph should be declared when it is difficult or impossible to exclude a life-threatening injury, and alternative imaging studies should be suggested. CT of the chest, particularly with the development multidetector-row CT (MDCT) scanners, has become a common examination for imaging the trauma patient with known or suspected thoracic injury, as CT scanners are available in almost all trauma centers. The fast scanning time of MDCT allows for single-breath-hold scanning, fewer motion artifacts, and improved contrast bolus imaging. Additionally, thinner collimation provides isotropic voxels, allowing for multiplanar reformations while maintaining spatial resolution. Magnetic resonance imaging (MRI) has many advantages for imaging the chest, including no need for iodinated contrast material, lack of ionizing radiation, and multiplanar imaging capabilities. However, scan times can be lengthy, and monitoring critically ill patients can be difficult, limiting the role of MRI for evaluating trauma patients. This pictorial essay will review the spectrum of injuries that occur in the chest following blunt trauma, focusing on the radiographic and CT findings.

Morgagni hernia: CT findings.

The patient is a 30-year-old male who presented with stabbing retrosternal chest pain, anxiety attacks, and subsequent inability to work. Chest radiograph showed an enlarged cardiac silhouette with the right heart border expanded across the right chest, suggesting a soft tissue mediastinal mass. Subsequent chest computed tomography (CT) revealed an anterior diaphragmatic defect with a large mass of mesenteric fat and peritoneal vessels protruding into the anterior mediastinum, typical of a foramen of Morgagni hernia.

Trauma cases from Harborview Medical Center. Airway injury after acute chlorine exposure.

2Department of Medicine, Harborview Medical Center, University of Washington School of Medicine, Seattle, WA 98104-2499. 23-year-old man presented with hypoxia, progressive dyspnea, and cough after exposure to chlorine gas at an indoor pool after a leak from the maintenance room. An initial chest radiograph was normal. Thirty-six hours after exposure, his chest radiograph and thin-section CT showed diffuse nodular opacities consistent with acute small airways injury (Fig. 1). The patient was discharged home on corticosteroids and an albuterol inhaler.

Warfarin-induced tracheobronchial calcification

Calcification of the trachea and proximal bronchi is a common, normal finding on chest radiographs in the elderly population, especially in women. More extensive airway calcification is also a rare manifestation of many pathologic conditions. The authors report a case of pathologic tracheobronchial calcification associated with long-term warfarin therapy. Chest radiographs showed prominent, diffuse calcification of the tracheobronchial tree. Computed tomography showed extensive calcification of the airway walls, extending from the trachea to the lung periphery.

Trauma Cases from Harborview Medical Center

2Department of Medicine, Harborview Medical Center, University of Washington School of Medicine, Seattle, WA 98104-2499. 23-year-old man presented with hypoxia, progressive dyspnea, and cough after exposure to chlorine gas at an indoor pool after a leak from the maintenance room. An initial chest radiograph was normal. Thirty-six hours after exposure, his chest radiograph and thin-section CT showed diffuse nodular opacities consistent with acute small airways injury (Fig. 1). The patient was discharged home on corticosteroids and an albuterol inhaler.

Detection of Central Pulmonary Embolism on Computed Tomography Densitometry Images before Computed Tomography Pulmonary Angiography

ObjectiveThe purpose of this article is to describe the imaging findings of acute central pulmonary embolism on computed tomography (CT) densitometry images performed before contrast-enhanced CT pulmonary angiography. MethodsA retrospective review was conducted of reports from all CT pulmonary angiograms performed at our institution, and cases of acute central pulmonary embolism, defined as those with clot in the main, left, or right pulmonary arteries, were identified. Images of positive studies were reviewed on a picture archiving and communications system (PACS) workstation. ResultsA total of 1282 CT pulmonary angiograms were obtained for evaluation of possible acute pulmonary embolism, and 1 combined CT aortogram and pulmonary angiogram was performed for aortic dissection and acute pulmonary embolism. Two hundred fourteen (16.7%) examinations positive for acute pulmonary embolism were identified, 26 (12.1%, 2.0% of total examinations) of which had central clots. Of the 26 patients with central acute pulmonary embolism, 12 (46.1%, 5.6% of all positive studies and 0.9% of all CT pulmonary angiograms) had clots that were visible on the densitometry images. ConclusionAlthough an uncommon finding, acute central pulmonary embolism can be detected on CT densitometry performed to optimize opacification of the pulmonary arteries for CT pulmonary angiography and may prove useful in selected clinical situations.

Common errors and pitfalls in interpretation of the adult chest radiograph

The chest radiograph is the most commonly performed radiologic examination and is the imaging study that the majority of nonradiologist physicians are most likely to encounter in their clinical practice. Chest radiography, however, can be very complex and difficult to interpret accurately due to abnormalities that are quite subtle, technical variations, superimposing normal structures, and a myriad of normal anatomic variations. This article reviews and illustrates common errors made and pitfalls encountered in interpretation of the chest radiograph and is organized by the compartments of the thorax. Radiographic illustrations of many key points are provided, with CT correlation as appropriate.

Diffuse Pulmonary Opacity: White Stuff in the Lung—What Is It?

Diffuse pulmonary opacity or what we call “white stuff in the lung,” is a nonspecific radiographic finding frequently encountered in the critical care setting. The airspaces of the lungs may be filled with a variety of fluids, cells, and debris, but these are indistinguishable radiographically. However, ancillary findings may narrow the diagnostic considerations. This article reviews the different causes of diffuse lung opacification, organized by the type of material filling the airspaces, including transudative fluid, aspirated gastric and oropharyngeal secretions, alveolar cells, lymphocytes, protein, inflammatory exudate, and blood.