Biomedical subjects
Publications and source records attributed to E J Stern.
The authors' experience in a radiology department suggested to them that there is a wide range of beliefs among practitioners regarding proper placement of nasogastric and feeding tubes. Improper positioning can cause serious problems, as they explain. Indications for different tube positions, complications of incorrect tube placement, and directions for proper positioning are discussed and illustrated.
Pulmonary emphysema is a pathological diagnosis. The clinical diagnosis of emphysema can be difficult because correlations between results of lung function tests and the extent of emphysema are poor. Features of chronic bronchitis or asthma may overlap with emphysema, making the clinical diagnosis more challenging. Nonetheless, the diagnosis of pulmonary emphysema can be made with relative confidence on the basis of clinical and radiological criteria. Despite not detecting mild emphysema and underestimating the severity of disease, CT--and high-resolution CT in particular--is the best noninvasive modality for detecting or corroborating pulmonary emphysema. This review focuses on several important aspects of pulmonary emphysema: (1) the definition and pathological characterization, (2) techniques of CT imaging, (3) CT findings and their correlation with pathophysiological data, and (4) quantification with CT.
Explore the source record for details and available documents.
RATIONALE AND OBJECTIVES: The authors conducted a survey of dedicated thoracic radiologists and tabulated their preferences for reconstruction algorithm, display, and photography of computed tomography (CT) scans of the chest. METHODS: Data were derived from a mail survey of 343 active members of the Society of Thoracic Radiology and based on a set of 20 questions about the display and photography of chest CT scans. The response rate was 35.4%. RESULTS: There were 119 usable replies from 31 states and 8 countries. Although there was considerable variation, the questionnaire indicates that the "typical" dedicated thoracic radiologist, regardless of practice setting, uses a standard reconstruction algorithm for chest CT and prints images on a laser imager using the "sharp" setting with a 12-on-1 format. Window settings for evaluating the lung are window-width 1500 HU and window-level -600 HU. Window settings for evaluating the mediastinum are window-width 350 HU and window-level 40 HU. CONCLUSIONS: Although there is wide variation in the preferences used to display and photograph chest CT scans, most thoracic radiologists have similar display preferences.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Desktop computer hardware and software provide many new and accessible avenues for increased academic productivity, but some activities may have legal implications. The advent of technologies such as scanners, the ever-increasing number of electronic bulletin boards, and the development of the "information superhighway" affect the concept of copyright and require authors and publishers to reconsider their legal rights and obligations when they create or publish new works or modify existing ones. For example, with desktop scanners, almost any image, published or otherwise, can be copied, enhanced, and manipulated. Moreover, many radiologists have access to copyrighted digital radiologic teaching file images, such as those from the University of Iowa or the University of Washington, which are available (and "downloadable") on the Internet. Because "downloading" (or "uploading") a document or image is essentially making a copy of that document or image, copyright laws and the rights that they afford authors are involved.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Areas of variable lung attenuation in a lobular or multilobular distribution are occasionally seen on CT or high-resolution CT scans of the lungs [1], although never as a normal finding. This mosaic pattern of lung attenuation presents a challenge to the radiologist when deciding which are the abnormal regions of lung--those of low attenuation, those of high attenuation, or both. We have observed three categories of disease known to cause a CT mosaic pattern of lung attenuation: small-airway disease, vascular lung disease, and infiltrative disease. Diseases from each of these categories can cause similar patterns of mosaic lung attenuation on CT scans. However, it is sometimes possible to distinguish among these categories by using additional CT findings. We illustrate the known causes of a CT mosaic pattern of lung attenuation and highlight distinguishing features.
Explore the source record for details and available documents.
Areas of variable lung attenuation forming a "mosaic pattern" are occasionally seen on computed tomography (CT) or high-resolution CT (HRCT) images of the lungs. This CT mosaic pattern of lung attenuation is a nonspecific finding that can reflect the presence of vascular disease, airway abnormalities, or ground-glass interstitial or air-space infiltrates. However, it is often possible to distinguish among these categories. In small airways disease and pulmonary vascular disease, the pulmonary vessels within the lucent regions of lung are small relative to the vessels in the more opaque lung. In infiltrative diseases, the vessels are more uniform in size throughout the different regions of lung attenuation. The distinction of small airways disease from primary vascular disease requires the use of paired inspiratory/expiratory CT scans. The terms "mosaic perfusion" or "mosaic oligemia" have also been used to describe this heterogeneous pattern of lung attenuation. We believe that the term "mosaic pattern of lung attenuation" is preferable when describing areas of variable lung attenuation because the term "mosaic perfusion" implies pulmonary vascular pathology.
RATIONALE AND OBJECTIVES: A method for facilitating the creation and management of radiologic teaching files is described. METHODS: A digital dictation system was integrated with a personal computer data base. The data base is maintained with user-friendly, graphically oriented software. Radiologists can dictate any examination for the teaching file from any dictation station in the department with minimal interruption of their clinical activities. The data base resides on a file server, thus providing department-wide access for radiologists and students. RESULTS: Attending radiologists and residents have responded favorably to the system. Maintenance and retrieval of teaching files are facilitated by using a computer for otherwise tedious aspects of information management. Data are stored in a well-organized manner, thus increasing the value of the teaching file while reducing redundant data entry. CONCLUSION: Computer technology can facilitate the maintenance of radiologic teaching files. Radiology departments that have a convenient, department-wide method for entering cases--such as a digital dictation system and existing computer network--are ideal for the technique that we describe.
We describe the use of computed tomography (CT) in diagnosing and documenting diaphragmatic paralysis in a patient with right lung cancer that invaded the mediastinum. The patient was unable to breath hold during CT scanning, and the images were degraded by motion artifact. Motion artifact, however, was noted only in the left lung. In patients with suspected phrenic nerve dysfunction who are having chest CT for any reason, we suggest obtaining several dynamic images at the lung bases during forced exhalation. The lack of motion artifact in the lung parenchyma may be useful for diagnosing phrenic nerve injury and hemidiaphragm paralysis.
Acute aortic dissection (AAD) is the most common emergency affecting the aorta. Noninvasive imaging allows prompt and reliable diagnosis of AAD and has largely supplanted aortography. However, atypical imaging features and diagnostic pitfalls can delay lifesaving therapy. An intimal flap is the characteristic feature of AAD. If there is flow within both lumina, typical imaging features are probably present. If the false lumen is thrombosed or there is no intimal tear to permit flow through the false lumen, a distinct intimal flap may not be present. Secondary signs of AAD include an intramural or periaortic acute thrombus, which manifests as a high-attenuation cuff or crescent on unenhanced computed tomographic scans. Other conditions that can reduce the conspicuity of the intimal flap include atypical configurations of the flap, such as seen with short dissections or with multiple false channels, in which case the flaps are complex. Finally, aortic anomalies may cause confusion.
PURPOSE: To assess postmortem radiologic and pathologic findings by using modern imaging and autopsy techniques in two recent cases of judicial hangings. MATERIALS AND METHODS: Cervical spine radiography; computed tomography (CT) of the head, neck, and chest; magnetic resonance (MR) imaging of the head and cervical spine; and vertebral angiography were followed by a complete autopsy, including head and neck dissection. RESULTS: The first case (subaural knot) showed cervical spine ligamentous injury and partial disruption of the vertebral arteries without vertebral subluxation or injury to the cervical cord. The second case (submental knot) showed complete ligamentous disruption and subluxation at C2-3 with complete cord transection. In both cases, minimally displaced transverse process fractures were present, and CT and MR imaging of the head showed diffuse subarachnoid hemorrhage. CONCLUSIONS: The extent and distribution of injuries differed markedly in the two cases. The first case involved loss of consciousness probably from subarachnoid hemorrhage or cerebral hypoxia, followed by death due to cerebral anoxia. The second case involved a major spinal cord injury with subarachnoid hemorrhage.