Differentiation of neoplastic from bland macroscopic portal vein thrombi using dual-energy spectral CT imaging: a pilot study.

OBJECTIVES: To assess the feasibility and value of dual-energy spectral computed tomography (DESCT) imaging for differentiating neoplastic from bland macroscopic portal vein (PV) thrombi. METHODS: Computed tomography (CT) images of 44 patients with macroscopic PV thrombus (bland group, n = 16; neoplastic group, n = 28) were reviewed. Iodine-based material decomposition images in the portal venous phase were reconstructed to compare the iodine indices between groups, including thrombus iodine density (I (T)), thrombus-aorta iodine density ratio (I (T)/I (A)), and thrombus-PV iodine density ratio (I (T)/I (P)). Differential diagnostic performances of DESCT were calculated in the subgroup of 21 patients with histopathological evidence (bland group, n = 12; neoplastic group, n = 9). RESULTS: The iodine indices of the neoplastic group were significantly higher than those in the bland group (P < 0.001). A threshold I (T) of 1.14 mg/mL, I (T)/I (A) of 0.17, and I (T)/I (P) of 0.17 in the portal venous phase yielded 100 %, 88.9 %, and 100 % sensitivity, and 91.7 %, 91.7 %, and 83.3 % specificity, respectively, in differentiating neoplastic from bland PV thrombi. CONCLUSIONS: DESCT imaging with quantification of thrombus iodine density in the portal venous phase appears to be a promising new method for distinguishing neoplastic from bland macroscopic PV thrombi. KEY POINTS: • Differentiating the nature of portal vein thrombus is of great clinical significance. • Iodine-based material decomposition imaging reflects iodine distribution after contrast media administration. • Dual-energy CT with iodine quantification can distinguish bland from neoplastic PV thrombi.