Presentation
Under investigation for abdominal bloating and raised ALT. Incidental left lobe liver lesion on ultrasound.
Patient Data
9 mm, hypoechoic, slightly ill-defined intrahepatic lesion in the periphery of segment 3 on B-mode ultrasound.
Doppler images demonstrate a feeding artery reaching the lesion from the dorsal aspect.
The intralesional vessels show ramification from one point (slightly extcentric to the dorsal aspect).
No artifacts on pre-contrast image (split screen).
Centrifugal filling is well-visualized scrolling through the cine-loop of the early arterial phase. Contrast arrival time at 18 sec.
Even a small non-enhancing area is seen in the center in the late phase (210 sec).
Case Discussion
Focal nodular hyperplasia can be diagnosed by contrast-enhanced ultrasound with high specificity.
B-mode ultrasound alone can not confirm the diagnosis, but sensitive color Doppler parameters can greatly increase the specificity:
- decrease the field-of-view and depth if possible
- apply zoom
- decrease the pulse repetition frequency (scale)
- look for tortuous feeding artery
- assess the vascular pattern (typically spoke-wheel)
Contrast-enhanced ultrasound provides excellent spatial and temporal resolution. Early arterial centrifugal filling is seen fully completed by portal venous phase. There is sustained hyper-enhancement or iso-enhancement during portal venous phase. No wash-out in late phase. The central scar is often visualized by the late phase.