To investigate the diagnostic value of contrast-enhanced ultrasound (CEUS) in hepatic sinusoidal obstructive syndrome (HSOS) following chemotherapy for colorectal cancer.

This prospective study consecutively enrolled patients with colorectal liver metastases who were scheduled for liver surgery or biopsy after chemotherapy at the Sixth Affiliated Hospital of Sun Yat-sen University from December 2024 to May 2025. All patients underwent CEUS. Time-intensity curve (TIC) analysis was performed to obtain time to peak (TTP), peak intensity (PI), and area under the curve (AUC). PI differences at different time points (ΔPI), liver-kidney differences (ΔLK=PI_liver - PI_kidney), and liver-spleen differences (ΔLS=PI_liver - PI_spleen) were calculated. Pathological scoring of HSOS-related features (hepatic sinusoid dilatation and nodular regenerative hyperplasia) was performed on liver parenchyma adjacent to the tumor (＞10 mm away). Non-parametric tests were employed to compare differences in clinical data, laboratory tests, and CEUS parameters among different pathological types. Logistic regression analyses were performed to identify predictors of moderate-to-severe sinusoidal dilatation. The area under the receiver operating characteristic curve (AUROC) was used to evaluate the diagnostic efficacy of CEUS parameters for different pathological types.

A total of 117 patients ( median age 58 years; 51 females) were enrolled. In the late and postvascular phases of CEUS (at 2, 5, and 10 minutes), HSOS demonstrated inhomogeneous perfusion of hepatic parenchyma, with the PI of the superficial liver parenchyma significantly lower than that of the middle liver parenchyma (P＜0.05). Alanine aminotransferase and PI_{1 min} on CEUS increased with the severity of sinusoidal dilation [19.0 (16.5, 22.0) U/L vs 22.5 (14.3, 40.6) U/L vs 31.1 (16.8, 52.9) U/L vs 37.3 (29.3, 115.2) U/L, H=9.396, P=0.025; -47.8 (-49.8, -45.4) dB vs -41.9 (-44.5, -39.3) dB vs -41.7 (-44.2, -37.5) dB vs -38.4 (-39.0, -36.1) dB, H=8.345, P=0.039]. Multivariate logistic regression identified TTP and AUC as independent predictors of moderate-to-severe sinusoidal dilation (OR=1.051 and 1.002, P=0.035 and 0.019, respectively). The combined model of TTP and AUC yielded an AUROC of 0.678 (sensitivity 75.5%, specificity 57.4%) for diagnosing moderate-to-severe sinusoidal dilatation. Univariate logistic regression showed that ΔLS_{5 min} was a predictor of mild nodular regenerative hyperplasia (OR=0.786, P=0.019, AUROC=0.836), and ΔPI_{10to2 min} was a predictor of moderate nodular regenerative hyperplasia (OR=1.145, P=0.040, AUROC=0.661).

Quantitative CEUS has the potential to provide objective imaging evidence for the early diagnosis of HSOS.