In recent years, ultrasound has become the study of choice for evaluating the abdominal aorta for aneurysmal dilatation. Sonography is noninvasive, relatively inexpensive, easily performed, and does not involve any ionizing radiation.
It is an imaging technique in which a high-frequency sound wave produced from the vibration of a transducer crystal is directed through the abdomen where some of the sound is absorbed and continues to traverse, and some is reflected back to the transducer. The sound received by the transducer is converted back into a representative image of the area previously traversed. If the information received is stored in an analogue scan converter or in digital memory before displaying the image, the technique is called a "static B scan." A single image is produced that can be viewed after a small delay. With real time, the two-dimensional B-scan images are generated at a speed high enough to give the