Introduction

The “International Liver Disease – Hepatic Vascular Disease Column” is an academic column initiated by Dr. Xingshun Qi from the Department of Gastroenterology at General Hospital of Northern Theater Command, in collaboration with the editorial team of International Liver Disease. This column regularly collects and organizes research progress in the field of hepatic vascular diseases, selecting an important literature piece for detailed discussion every two weeks (Wednesday). The aim is to help readers understand the underlying mechanisms, inspire clinical research thinking, and apply knowledge effectively.

Article Summary

Budd-Chiari syndrome (BCS) refers to the obstruction of hepatic outflow from the hepatic veins to the inferior vena cava (IVC) at the right atrium-IVC junction. It is classified into primary Budd-Chiari syndrome (P-BCS) and secondary Budd-Chiari syndrome (S-BCS). Secondary BCS is often caused by external factors such as malignancies, while primary BCS is usually due to venous thrombosis or phlebitis, often associated with a hypercoagulable state. Chronic liver congestion caused by BCS can lead to histological changes such as nodular regenerative hyperplasia (NRH), cirrhosis, and focal nodular lesions in the liver, which may be misdiagnosed as small hepatocellular carcinoma (s-HCC). Long-term follow-up studies have shown that 17.6% of BCS patients may develop liver cancer. However, there is a lack of data that can effectively differentiate between benign hepatic lesions caused by BCS and small HCC. Therefore, distinguishing between these two conditions remains challenging.

An article titled “Multiparametric MRI Differentiates Small Hepatocellular Carcinoma (<3 cm) from Benign Liver Lesions Associated with Budd-Chiari Syndrome” was published in Frontiers in Oncology in November 2023. The study aimed to explore the value of MRI in distinguishing between small HCC and benign hepatic lesions in BCS patients.

Ghazal et al. selected patients diagnosed with BCS at Johns Hopkins Hospital from February 2005 to June 2018, including 12 patients with BCS and benign hepatic lesions. Additionally, 32 patients diagnosed with small HCC (<3 cm) were included. Compared to the s-HCC group, the BCS benign hepatic lesion group showed significant differences in the T1 signal intensity ratio of the lesion to the liver, T2 signal intensity ratio, and apparent diffusion coefficient (ADC) ratio (all P < 0.001, P < 0.001, and P = 0.045, respectively). Significant differences in enhancement signals were also observed in the portal venous phase and delayed phase between the two groups (P = 0.001). ROC analysis showed that the logistic model combining T1 signal ratio, T2 signal ratio, and portal venous enhancement signal ratio had an area under the curve (AUC) of 0.94, indicating a good ability to distinguish benign lesions.

In summary, specific MRI features help differentiate between small HCC and benign hepatic lesions associated with BCS.

Analysis of Important Research Results and Their Clinical Significance

1. Flowchart of the Included Population: 32 patients were diagnosed with small HCC (<3 cm); among them, 14 (43.8%) were confirmed by histopathology, and the remaining 18 were diagnosed based on imaging characteristics and elevated serum AFP levels.

1. After excluding BCS patients without MR examinations or those with no liver lesions on MRI, 12 BCS patients with benign hepatic lesions were included, totaling 35 hepatic lesions. Four lesions were confirmed as benign by histopathology, while the remaining 31 lesions showed no significant changes during at least one year of follow-up (median follow-up 60 months [12-168]), with AFP levels <15 ng/mL and imaging features consistent with benign lesions.

1. Baseline Characteristics of the Study Population: There was no significant difference in gender between the two groups. Serum AFP >15 ng/mL was observed in 59% of s-HCC patients, while none of the benign hepatic lesion group had AFP >15 ng/mL (P < 0.001). The lesion sizes were similar between the two groups (P = 0.135). s-HCC lesions had a higher venous washout rate (68.8%) compared to benign hepatic lesions (11.4%, P < 0.001). Benign hepatic lesions were more likely to have a central scar compared to s-HCC lesions (40% vs. 3%, P < 0.001).

1. Summary Statistics of Parameters between Benign and Malignant Lesion Groups: There were no significant differences in T1, T2 signal intensity, and ADC between the two groups (P = 0.069, 0.359, 0.236, respectively). Compared to the benign lesion group, the s-HCC group had lower T1 ratio (median 0.86 [IQR: 0.79-1.14] vs. 1.25 [IQR: 1.14-1.42], P < 0.001), higher T2 ratio (median 1.49 [IQR: 1.29-2.01] vs. 0.88 [IQR: 0.73-0.96], P < 0.001), and lower ADC ratio (0.98 ± 0.17 vs. 1.08 ± 0.18, P = 0.045).

1. ROC Curve Analysis: In figure a, the T1 ratio cutoff value was 1.05, with a correct classification rate of 81.03% and a sensitivity of 92.3%. The AUC for the T1 ratio was 0.81, indicating good discrimination for benign lesions.

1. In figure b, the T2 ratio cutoff value was 1.07, with a correct classification rate of 91.4% and a sensitivity of 93.8%. The AUC for the T2 ratio was 0.92, indicating good discrimination for malignant lesions.

1. MR Imaging of BCS Benign Hepatic Lesions and Small HCC: On T1-weighted imaging (T1WI), BCS benign hepatic lesions appeared as homogeneously or peripherally high signal, whereas small HCC appeared as homogeneous low signal.

1. On T2-weighted imaging (T2WI), BCS benign hepatic lesions appeared as homogeneously or peripherally low signal, whereas small HCC appeared as homogeneous high signal.

1. On diffusion-weighted imaging (DWI), BCS benign hepatic lesions had higher ADC than small HCC.

1. BCS benign hepatic lesions often showed high signal on the arterial phase and homogeneous high signal on the portal venous and delayed phases. In contrast, small HCC showed heterogeneous high signal on the arterial phase and low signal on the portal venous and delayed phases.

Summary and Outlook

This study identified specific MRI features that help distinguish small HCC (<3 cm) from benign hepatic lesions associated with BCS. However, it remains unclear how MRI features differ between small HCC patients with and without BCS. Long-term imaging follow-up is needed to evaluate the MRI characteristics of small HCC in BCS patients.

Translator: Yao Xiao, Department of Gastroenterology, General Hospital of Northern Theater Command, Graduate School of Liaoning University of Traditional Chinese Medicine.

Founder and Reviewer of the “International Liver Disease – Hepatic Vascular Disease” Column: Xingshun Qi, Director of the Department of Gastroenterology, General Hospital of Northern Theater Command, Adjunct Master’s Supervisor at China Medical University, Shenyang Pharmaceutical University, Dalian Medical University, and Jinzhou Medical University, and Adjunct Doctoral Supervisor at Northeastern University and China Medical University. He is a postdoctoral co-supervisor at the Postdoctoral Research Station of the General Hospital of Northern Theater Command, a representative of the Chinese Association for Science and Technology, Vice Chairman of the Pre-cancerous Lesions Committee of the Chinese Anti-Cancer Association, a member of several committees under the Chinese Medical Association, and a Senior Editorial Board Member of BMC Gastroenterology, Editorial Board Member of Therapeutic Advances in Gastroenterology, and Academic Editor of the Canadian Journal of Gastroenterology and Hepatology. He received the 2016 Outstanding Doctoral Dissertation Award of the Military, was listed among the Top Ten Talents in the 2019 Twelfth Youth Science and Technology Award of Liaoning Province, and was named an Elsevier Highly Cited Chinese Researcher in 2021, 2022, and 2023, among other accolades. According to Scopus, his H-index is 48, with a total of 8,060 citations.