Heart disease remains the leading cause of death among men and women in the world. The majority of cardiac morbidity worldwide is secondary to atherosclerotic coronary disease. In this article, we discuss our experience using dual exposure, dual-energy lateral chest x-ray (CXR) technique to detect coronary calcium. Similar to other reports demonstrating opportunistic detection on imaging studies, here we demonstrate the added value of detection of coronary calcium on the lateral CXR. This technique reinforces the importance of "knowing where to look" and to recognize the appearance of coronary calcium wherein subtle cardiac motion can be a useful artifact in the accurate detection of coronary calcium. In addition, we discuss correlating coronary calcium burden with age, elaborate on the physics behind coronary calcium detection, and how best to optimize imaging technique. Lastly, we show other uses of dual-energy lateral CXR technique to illustrate where using material decomposition and subtle motion can better define contours in the mediastinum and lung.

In the last two decades, our military and federal health care facilities have transitioned from traditional X-rays exposing film screen systems, developed much like photographic film, to an entirely digital detection system that affords computer processing of images and digital image and report distribution. While health care providers are well aware of the practicality of these advancements, they may not be aware of the improved diagnostic capabilities afforded by these new methods. In this report, we outline how application of physical principles of X-rays, with digital detectors and computer data manipulation, can present images demonstrating chest and heart diseases that were previously not readily visible by traditional film screen systems. More recently, dual-energy, dual-exposure systems have been implemented. This commentary is to educate the medical community so that they may better understand not only the written report but the information on the images being provided, along with potential pitfalls to avoid. Specifically, we demonstrate improved detection of pulmonary nodules and coronary atherosclerosis with the dual-energy technique.