Nodular Transformation–driven Circulatory Remodeling in Biliary Atresia–induced Pediatric Biliary Cirrhosis: A Three-dimensional Phase-Contrast CT Rendering

Background In pediatric biliary cirrhosis secondary to biliary atresia (BA), hepatic lobules are disrupted to form pseudolobules. How the hepatic circulation is reorganized remains a poorly characterized issue. Purpose To reproduce the three-dimensional (3D) structural and remodeling alterations of BA-induced pseudolobules via phase-contrast CT (PCCT) and reveal their circulatory self-rescue mechanism. Materials and Methods In this retrospective study, residual donor normal liver tissue samples and BA-affected liver samples collected between November 2013 and April 2024 were imaged with PCCT. Combined with 3D visualization technology, the spatial anatomic morphologic characteristics of the veins, arteries, and sinusoidal system within the hepatic lobules were reproduced based on liver histopathologic examination. Key indexes such as the number of inlet and outlet venules, sinusoidal volume fraction, and anisotropy, were determined to characterize the structural remodeling of the circulatory pathway, from portal and arterial inflow through the sinusoidal exchange network to hepatic venous outflow, in patients with BA. All indicators were analyzed with generalized estimating equations, and the multiple test correction was performed by conducting Holm-Bonferroni correction, with <i>P</i> < .05 indicating statistical significance. Results Normal livers from three donors (median age, 36 months; IQR, 12-132 months; two male donors) and 25 patients with BA (median age, 7.00 months; IQR, 5.8-10 months; 17 male patients) were analyzed. The mean number of inlet venules decreased from 253.07 ± 70.99 (SD) in normal lobules to 138.80 ± 28.12 in pseudolobules (<i>P</i> < .001). The mean number of inlet arterioles increased from 3.93 ± 1.39 in normal lobules to 5.65 ± 2.43 in pseudolobules (<i>P</i> < .001). The number of outlet venules in pseudolobules decreased by 35% compared with that in normal lobules (mean, 105.02 ± 42.47 vs 161.96 ± 42.47; <i>P</i> < .001). In the sinusoidal system, the volume fraction in pseudolobules increased by 51% compared with that in normal lobules (mean, 40.42 ± 6.28 vs 26.72 ± 6.32; <i>P</i> < .001), especially in the inlet area, where this value nearly doubled (mean, 44.47 ± 4.73 vs 23.44 ± 5.95; <i>P</i> < .001). Mean anisotropy decreased from 0.53 ± 0.02 in normal lobules to 0.51 ± 0.03 in pseudolobules (<i>P</i> < .001). Conclusion The lobular circulation remodeling mechanism in BA-induced pseudolobules, from the inlet channel to the exchange network and outlet channel, was comprehensively revealed via PCCT. © RSNA, 2026 <i>Supplemental material is available for this article</i>.