Photon-Counting CT for Liver Fibrosis: Comparable with MR Elastography

A recent study published in the journal Radiology has validated the use of photon-counting computed tomography (PCCT) for assessing liver fibrosis by comparing its effectiveness against magnetic resonance (MR) elastography and histopathologic analysis. The researchers set out to explore the capability of PCCT-derived extracellular volume fraction (ECV) in staging liver fibrosis efficiently.

From July 2024 to July 2025, the study involved 157 participants suspected of having hepatic malignancies who underwent both PCCT and MRI at Ruijin Hospital. Out of these, 139 participants (average age 62 years, predominantly male) were eventually included for detailed analysis. The researchers evaluated the correlation between PCCT-derived ECV and MR elastography–derived liver stiffness measurement (LSM), with histopathology serving as the reference standard.

ECV demonstrated a strong correlation with LSM (Spearman ρ = 0.84; P < .001) on an intraparticipant level. Using histopathologic findings as the reference, the area under the receiver operating characteristic curve (AUC) values for ECV in identifying fibrosis at stages F2 or higher, F3 or higher, and F4 were impressive, at 0.99, 0.98, and 0.98, respectively. The study's equivalence analysis further indicated that ECV and LSM had comparable diagnostic performances, with calculated differences in AUC ranging from -0.021 to 0.055 depending on the fibrosis stage.

Furthermore, ECV offered robust agreement with histopathologic staging across various participant subgroups—those with coexisting steatosis or inflammation, as well as individuals with a BMI of 25 or higher—exhibiting weighted κ coefficients ≥ 0.86 and P < .001 in all cases.

Overall, this study suggests that PCCT-derived ECV is not only strongly correlated with LSM but also offers an equivalent diagnostic performance for staging liver fibrosis. This advancement in imaging technology potentially allows for more accessible and non-invasive assessment of liver fibrosis, providing a valuable alternative to existing methods. The promising results advocate for the integration of PCCT-derived ECV into liver fibrosis staging protocols and support its clinical feasibility.