In screen film radiography, the choice of x-ray tube voltage kV affected the image contrast; this is no longer the case for any digital radiographic system. In this example, images were obtained of a pelvic phantom at three kV values using a commercial computed radiography CR imaging plates. All exposures were performed using phototiming. This image was generated at 60 kV, and required a relatively high radiation intensity of mAs.
Evaluation of a radiograph's quality requires some understanding of the technical factors involved in the production of an x-ray image. Without such understanding, the risk of making an interpretive error is increased. Much medical analysis is based on pattern recognition. Physicians come to recognize certain patterns as normal and others as abnormal, and the discernment of such patterns aids them in making diagnoses and other decisions. The interpretation of chest radiographs is no different. However, to accurately identify any pattern in a radiograph, you must first make sure that the study was obtained properly.
Although mistakes are rare, they do occur and you should verify details pertaining to your patient on every study you review. In this view, the mediastinum should have a normal width and a good inspiratory effort should results in full diaphragm expansion. AP projection is obtained with the patient in bed and lying flat or partly upright.
Chest X Ray is probably the most common imaging test. Few providers including MDs are comfortable interpreting their own films. Clinical decisions are too often made based on reports from non-clinicians. Having a systematic and repetitive approach is the key.