Spectral Computed Tomography (CT): A Clearer Way to See Inside the Body
Spectral Computed Tomography (CT), often called dual-energy CT or multi-energy CT, represents one of the most important advancements in modern diagnostic imaging. While traditional CT scanners measure the total X-ray attenuation passing through tissues, spectral CT takes this a step further by separating the X-ray beam into different energy levels. This gives radiologists a deeper, more detailed look at the composition of tissues, materials, and abnormalities inside the body.
At the core of spectral CT is the idea that different substances absorb X-rays differently depending on the energy of the beam. For example, calcium, iodine, and soft tissues each have unique energy-dependent signatures. By capturing data at multiple energy levels, a spectral CT scanner can distinguish between these materials with far greater accuracy than conventional CT. This results in clearer images, fewer artifacts, and more precise information about what is happening inside the body.
One of the major advantages of spectral CT is improved tissue characterization. Radiologists can separate materials that would otherwise appear similar on a standard CT scan. This is particularly useful in identifying kidney stones, analyzing bone mineral content, evaluating liver lesions, and distinguishing between blood clots and iodine contrast. The technology also reduces metal artifacts, making it easier to image patients with implants, prosthetics, or surgical hardware.
Another key benefit is the ability to create virtual monoenergetic images. These images simulate what the scan would look like if performed at a single X-ray energy level. The result is reduced noise, enhanced contrast, and sharper visualization of blood vessels and organs. In some cases, spectral CT can even reduce the need for high doses of contrast agents, which is an advantage for patients with kidney problems or allergies.