Hepatic Cysts: The presence of multiple focal hypodensities with fluid attenuation within the liver parenchyma, which are grossly unchanged compared to prior studies, strongly suggests hepatic cysts. This diagnosis is further supported by the lack of dilated intrahepatic biliary radicles and the unremarkable nature of other abdominal organs.

Hemangiomas: Although less likely than hepatic cysts, hemangiomas could present as hypodensities on imaging, especially if they are small. However, their appearance and behavior might differ slightly from cysts, and they are generally more vascular.
Focal Fatty Changes or Focal Fatty Sparing: These conditions can cause areas of altered attenuation in the liver but are typically more diffuse or have a characteristic distribution pattern, which doesn't perfectly match the described focal hypodensities.
Simple Hepatic Adenomas or Other Benign Tumors: While possible, these would be less likely given the stability of the lesions over time and their fluid attenuation, which is more characteristic of cysts.

Metastases: Although the lesions are described as unchanged and have fluid attenuation, it's crucial not to miss the possibility of metastatic disease, especially if there's a known primary malignancy. Metastases can sometimes have a cystic appearance, especially if they have undergone necrosis.
Abscesses: While the description and stability of the lesions make this less likely, abscesses can present as fluid-filled lesions in the liver. The clinical context (e.g., fever, elevated white blood cell count) would be critical in raising suspicion for this diagnosis.
Intrahepatic Cholangiocarcinoma: This is a malignancy of the bile ducts within the liver and can present as a mass or cystic lesion. It's essential to consider this, especially if there are any risk factors or if the lesions show any signs of growth or irregularity.

Polycystic Liver Disease (PLD): Characterized by numerous cysts scattered throughout the liver, PLD is a rare condition that could be considered if the number of cysts is exceptionally high and there's a family history or associated conditions like polycystic kidney disease.
Biliary Hamartomas (Von Meyenburg Complexes): These are benign, usually small, lesions that can be multiple and scattered throughout the liver. They are a rare cause of multiple small hypodensities.
Ciliated Hepatic Foregut Cyst: A rare, benign cystic lesion thought to arise from foregut tissue. It's an uncommon cause of a cystic liver lesion but should be considered in the differential diagnosis of cystic liver lesions, especially if other common causes are ruled out.