**Core Concept**
The "starry sky" appearance in ultrasound imaging of the liver is a characteristic feature of a specific pathological condition. This appearance is due to the presence of numerous small, hyperechoic foci scattered throughout the liver parenchyma, resembling the night sky.

**Why the Correct Answer is Right**
The correct answer is related to the presence of fatty change in the liver. In this condition, the liver cells (hepatocytes) accumulate large amounts of triglycerides, leading to the formation of microvesicular steatosis. When viewed on ultrasound, these microvesicular fat droplets appear as numerous small, hyperechoic foci, creating the "starry sky" appearance. This is due to the difference in echogenicity between the fatty liver tissue and the surrounding normal liver tissue.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the "starry sky" appearance is not typically associated with cirrhosis, which is characterized by a more coarsened and irregular liver texture.
* **Option B:** This option is incorrect because hemangiomas are typically hyperechoic lesions with a characteristic "chocolate cake" appearance, but they do not create a diffuse "starry sky" pattern.
* **Option C:** This option is incorrect because metastatic disease can cause a variety of ultrasound patterns, including hyperechoic or hypoechoic lesions, but it is not typically associated with a diffuse "starry sky" appearance.

**Clinical Pearl / High-Yield Fact**
When interpreting ultrasound images of the liver, it's essential to remember that the "starry sky" appearance is a characteristic feature of fatty liver disease. This can be a key diagnostic clue in patients with suspected liver pathology.

**Correct Answer:** C. Fatty liver disease.