On Doppler ultrasound of the portal vein, the hepatic vein waveform shows a monophasic flat pattern instead of the normal triphasic waveform. This finding is MOST consistent with:
- A Portal hypertension with hepatic sinusoidal congestion ✓
- B Budd-Chiari syndrome
- C Normal variant in obese patients
- D Superior vena cava obstruction
Correct answer: A. Portal hypertension with hepatic sinusoidal congestion
Explanation
The normal hepatic vein Doppler waveform is triphasic (reflecting right atrial pressure changes). A monophasic (flat or damped) waveform indicates loss of normal venous pulsatility, most commonly seen in hepatic parenchymal disease causing sinusoidal congestion (cirrhosis, portal hypertension). Budd-Chiari syndrome shows absent or reversed hepatic vein flow, not merely monophasic flow. SVC obstruction would affect venous return globally. Some waveform dampening can occur in obesity but is not the primary cause.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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