Aerial enhancement and venous phase washout in a liver mass larger than 2 cm is diagnostic for
**Core Concept**
The question tests the ability to differentiate between various liver lesions based on their imaging characteristics, specifically the enhancement pattern and washout on contrast-enhanced imaging. This is a critical skill in radiology, as it helps in making an accurate diagnosis and guiding management decisions.
**Why the Correct Answer is Right**
Hepatocellular carcinoma (HCC) typically exhibits arterial enhancement and venous phase washout on contrast-enhanced imaging. This is due to the abnormal blood supply to the tumor, which is characterized by increased arterial flow and decreased venous drainage. As a result, HCC often shows early arterial enhancement and delayed washout on venous phase imaging, which is a hallmark feature of this malignancy.
**Why Each Wrong Option is Incorrect**
**Option A:** Hemangioma typically shows intense and prolonged enhancement on both arterial and venous phases, with a characteristic "light bulb" appearance. This is due to its rich vascular supply and the presence of Kupffer cells, which take up contrast agents.
**Option B:** Focal nodular hyperplasia (FNH) often exhibits a "central scar" and typically shows uniform enhancement on both arterial and venous phases. This is due to its benign nature and the presence of a central fibrotic scar.
**Option C:** Hepatic adenoma typically shows early arterial enhancement, but it often shows persistent enhancement on venous phase imaging, rather than washout. This is due to its benign nature and the presence of a rich vascular supply.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the imaging characteristics of liver lesions can vary depending on the size and location of the lesion, as well as the presence of underlying liver disease. Therefore, a combination of imaging modalities, including ultrasound, CT, and MRI, should be used to make an accurate diagnosis.
**✓ Correct Answer: D. Hepatocellular carcinoma**