Which imaging modality is first-line for evaluating Budd-Chiari syndrome?

• A. Abdominal ultrasound with Doppler
• B. CT abdomen
• C. MRI
• D. Plain X-ray

Answer: (A)

When Budd-Chiari syndrome is suspected, the first imaging test to order is abdominal ultrasound with Doppler. This modality directly assesses the hepatic venous outflow and can reveal the obstruction or thrombosis in the hepatic veins or the inferior vena cava, which is the defining feature of this condition. Doppler adds functional information by showing blood flow patterns: absent or markedly reduced flow in the affected veins, abnormal flow directions, or collateral channels. Ultrasound is quick, widely available, noninvasive, and inexpensive, and it often provides enough information to confirm obstruction and guide further testing.

If ultrasound doesn’t fully define the anatomy or if more detail is needed to plan treatment, CT with contrast or MRI with MR venography can map the extent of obstruction, evaluate for underlying causes (like compression by a tumor or IVC involvement), and assess liver parenchyma. Plain X-ray offers little to no diagnostic value for Budd-Chiari.