Learning objectives
The main objectives of the current Electronic Presentation are to describe the physics principles of Dual-Energy Computed Tomography (DECT) and its role in everyday clinical practice. We will also provide several examples of different physiological and pathological conditions.
Background
CT images are a map of tissue density for each voxel, expressed in Hounsfield Units (HU). Materials with different element composition can present similar attenuation coefficients, resulting in similar shades of gray on conventional CT. In particular, to distinguish between calcium and iodine can be challenging, making often necessary to acquire unenhanced CT scan before contrast agent administration [1].
Because every material present a specific attenuation profile, a rapid and available technique to perform tissue characterization is to acquire CT scans with at least two...
Findings and procedure details
DECT scanners
Several categories of CT scanners with DE imaging capabilities are currently available (Fig. 2). The most common is the dual-source DE CT system: it uses two x-ray tubes (a high-energy tube and a low-energy tube) and two corresponding detectors [4]. In our Department we use a detector-based spectral CT system, which uses one x-ray tube and two layers within the detector; the superficial layer absorbs low-energy x-ray photons, the deep layer absorbs high-energy photons. Finally, a single-source DE CT system is available, based...
Conclusion
Dual-energy CT offers new applications and possibilities unavailable with conventional CT, useful for everyday practice, at comparable or even reduced radiation doses.
Personal information and conflict of interest
E. Boninsegna; Mantua/IT - nothing to disclose S. Crosara; Mantua/IT - nothing to disclose E. Simonini; Mantua/IT - nothing to disclose C. Sozzi; Mantua/IT - nothing to disclose E. Piovan; Mantua/IT - nothing to disclose S. Colopi; Mantua/IT - nothing to disclose
References
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Patino M, Prochowski A, Agrawal MD, et al. Material Separation Using Dual-Energy CT: Current and Emerging Applications.Radiographics. 2016;36(4):1087–1105. doi:10.1148/rg.2016150220.
Alvarez RE, Macovski A. Energy-selective reconstructions in X-ray computerized tomography.Phys Med Biol. 1976;21(5):733–744. doi:10.1088/0031-9155/21/5/002.
Coursey CA, Nelson RC, Boll DT, et al. Dual-energy multidetector CT: how does it work, what can it tell us, and when can we use it in abdominopelvic imaging?.Radiographics. 2010;30(4):1037–1055. doi:10.1148/rg.304095175.
Graser A, Johnson TR, Hecht EM,...
