Letter from the Editor

Article Outline

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The introduction of simultaneous dual-source/dual-energy computed tomography (CT) scanning is one of the recent technological advances in CT imaging. Dual-source scanners consist of 2 separate CT scanning systems mounted at a 90-degree angle to each other. Each system is composed of an x-ray tube and a corresponding detector. These 2 tubes operate independently of each other with regard to peak tube voltage and tube current. This technique allows the acquisition of multidetector CT data either at a single energy level or at 2 different photon energy levels during a single acquisition. When running both tubes at the same voltage, a high temporal resolution is achieved that is used primarily for the evaluation of coronary arteries. When operating the x-ray tubes at different tube voltages, 2 different x-ray spectra are simultaneously produced resulting in improved characterization and differentiation of various tissues. The dual-energy data can be manipulated in several ways to generate clinically useful information.

The increasing concern regarding the carcinogenic risk of ionizing radiation because of wide spread use of CT has led investigators to search for ways to decrease the dose of radiation to the patient. One of the advantages of dual-energy CT is the potential to reduce the amount of radiation by eliminating the need for a noncontrast phase by generating a “virtual noncontrast” phase from the postcontrast acquisition. This may obviate the need of noncontrast acquisition, thus decreasing radiation dose.

The dual-energy procedure not only reduces the need of multiple scans to the patient but also opens up new clinical fields of application for computed tomography. The potential clinical applications of dual-energy CT are under intensive clinical evaluation and research in pioneering medical centers throughout the world. I have chosen to concentrate on applications which have been extensively investigated and have already shown potential benefits.

I am very grateful for the outstanding contributions by world-renowned researchers who are exploring applications for this exciting new technology. I hope this issue will familiarize radiologists with the new field.