Spectral CT material decomposition for non-invasive quantitative assessment of metabolic and elemental abnormalities in liver cirrhosis: a narrative review

Metabolic and elemental abnormalities caused by chronic liver disease are frequently underestimated in the clinical assessment of liver cirrhosis, despite their impact on disease progression and prognosis. Spectral computed tomography (CT) exploits energy-dependent differences in X-ray attenuation to achieve non-invasive, single-scan quantitative detection of liver components, overcoming the limitation of conventional imaging, which can only evaluate morphology. This narrative review summarizes recent advances and technical limitations of spectral CT material decomposition for metabolic and elemental assessment in liver cirrhosis. Virtual iron content (VIC) can quantify hepatic iron deposition and, in selected populations, is associated with fibrosis severity, although its role as an independent fibrosis-staging tool remains to be established. Liver fat content measured by multimaterial decomposition (MMD) agrees well with Magnetic resonance imaging proton density fat fraction (MRI-PDFF), and low-dose scanning may suffice for detection. Currently, liver calcium quantification has only been validated using phantom studies, and relevant clinical research remains scarce; routine spectral CT cannot directly quantify trace elements such as zinc and copper. The fusion of photon counting CT (PCCT) and deep learning algorithms is expected to eventually overcome the technical bottleneck of trace element quantification. In summary, spectral CT promotes the imaging assessment of liver cirrhosis from morphological characterization to metabolic quantification. Combining new hardware and artificial intelligence can improve detection efficiency; further technical and multicenter clinical validation is required before clinical translation.