Benefits and Limitations of Portable Chest Radiography

摘要

Approximately 68 million chest radiography examinations are performed in the United States yearly.1 It is the most requested and performed radiological procedure, especially for patients who are admitted to medical institutions for various illnesses.1'2 Chest radiography is used to achieve clinical objectives such as monitoring medically inserted devices (eg, central venous lines, tracheal tubes, chest tubes, nasogastric tubes) and detecting pulmonary conditions.2"4 Chest radiography can be performed in the radiology department, or bedside with a portable radiography machine. Chest radiographs obtained in the department are of higher diagnostic value than are those obtained bedside.3 The 2 standard views for chest radiography (ie, upright posterior-anterior and lateral positioning) can be performed only in the department. Portable chest radiographs obtained bedside typically are performed while the patient is supine or semierect (anterior-posterior), which causes the heart shadow to appear magnified on the image. In addition, portable chest radiography use increases geometrical distortion, which can be caused by decreased source-to-image distance.3 These limitations compromise the image quality of portable chest radiographs compared with chest radiographs obtained in the department.