Understanding Spectral Computed Tomography (CT)
Spectral Computed Tomography (CT), also known as dual-energy or multi-energy CT, represents a significant advancement in medical imaging by moving beyond conventional grayscale visualization. Unlike traditional CT systems that use a single X-ray energy level, spectral CT captures data at multiple energy levels, enabling enhanced tissue characterization and material differentiation.
At the core of spectral CT technology is the principle that different materials interact with X-rays in unique ways depending on the photon energy. By analyzing how tissues absorb low- and high-energy X-rays, spectral CT systems can distinguish substances that may appear similar on standard CT images. This capability allows radiologists to extract more diagnostic information from a single scan without increasing radiation exposure.
One of the most notable benefits of spectral CT is its ability to perform material decomposition. This feature enables the identification and separation of specific materials such as iodine, calcium, fat, and uric acid. For example, iodine maps help visualize blood flow and tissue perfusion, while calcium suppression techniques improve the assessment of vascular structures. These capabilities enhance diagnostic confidence in a wide range of clinical applications.
Spectral CT also improves lesion detection and characterization. In oncology, it helps differentiate benign from malignant lesions by analyzing contrast uptake patterns and tissue composition. In abdominal imaging, spectral CT aids in evaluating liver lesions, kidney stones, and pancreatic abnormalities. Certain types of kidney stones, such as uric acid and calcium-based stones, can be accurately classified, allowing physicians to choose appropriate treatment strategies.