34 - CT Angiography of the Chest

Summary

INDICATIONS

The most common clinical indication for a CT scan of the chest in the ED is to assist with the rapid diagnosis and treatment of a potentially life-threatening cause of chest pain. The three most common life-threatening conditions facing patients with chest pain in the ED are myocardial ischemia, pulmonary embolism, and aortic dissection. With the advent of multidetector row CT technology and improvements in the temporal and spatial resolution of modern CT scanners, all three entities can be diagnosed with excellent reliability.

DIAGNOSTIC CAPABILITIES

Coronary heart disease is the leading cause of death in the United States, responsible for about 817,000 deaths each year (1). Multidetector CT (MDCT) coronary angiography has emerged as a highly sensitive tool to diagnose both obstructive and nonobstructive coronary artery disease. Modern scanners that employ 16- and 64-slice multidetector row technology with cardiac gating enable rapid and continuous coverage of the heart with excellent visualization of both the lumen and vessel wall of the coronary arteries (2,3). The sensitivity and specificity of 64-slice CT exceed 95% for the diagnosis of significant coronary artery disease (4). With adequate patient preparation, reliable images can be obtained with a rapid 8- to 10-s scan time.

Pulmonary embolism is a common disorder, with an estimated annual incidence of 25 to 70 per 100,000 (5).