Cystic lesions of the liver

Liver cystic lesions, also known as liver cysts, are a symptom that can have a great impact on the patient's physical health. After all, the liver is an important organ in the human body. If there are some problems with the liver, it will naturally affect other functions of the body. There are many types of liver cystic lesions, such as simple liver cysts, polycystic liver and echinococcosis. These symptoms will be introduced in detail below!

1. Simple liver cyst

(1) CT examination: Plain scan shows a circular water-like density area in the liver parenchyma with sharp edges, clear boundaries, uniform density within the cyst, and a CT value of 0 to 20 HU. After enhanced scanning, the low-density area in the cyst is not enhanced. Due to the contrast of the surrounding enhanced liver parenchyma, the cyst boundary is clearer, and the thin cyst wall is generally not enhanced.

(2) MRI examination: Plain scan shows smooth and sharp edges, low signal on T1WI, high signal on T2WI, and uniform signal. The cyst wall was not enhanced on enhanced scanning.

(3) Key points for diagnosis: ① Single or multiple cysts; ② Clear boundaries and watery density or signal; ③ Thin cyst wall and no enhancement.

2. Polycystic liver disease

(1) CT and MRI examinations: CT and MRI have the same findings, that is, multiple cystic densities or signal shadows of varying sizes are displayed in the liver parenchyma. When cysts are multiple, normal liver tissue is often not visible between the cysts. Polycystic liver can coexist with polycystic kidney or polycystic pancreas, and the manifestations on CT and MRI are quite typical.

(2) Key points for diagnosis: ① Multiple cysts; ② Accumulation in multiple organs; ③ Family history.

3. Hepatic echinococcosis

(1) CT examination: Plain scan shows single or multiple low-density cystic lesions in the liver parenchyma that are of varying sizes, round or quasi-round, with sharp edges and clear boundaries, and a CT value of approximately 14 to 20 HU. At the same time, ring-shaped, semi-ring-shaped, strip-shaped or nodular calcifications may be seen. After enhanced scanning, the cyst shows no enhancement and the cyst wall is generally not displayed unless the cyst wall is calcified. Its characteristic manifestation is cyst within cyst, that is, there are daughter cysts of different sizes and numbers in the mother cyst, and the density of the early cyst is lower than that of the mother cyst. When multiple daughter cysts fill the mother cyst, it appears multi-chambered or honeycomb-like. If the daughter cysts are mainly distributed in the peripheral part of the mother cyst, it appears wheel-shaped. When infection, injury or cyst fluid leakage occurs, the inner and outer capsules may separate, with the following manifestations: ① The inner and outer capsules are partially separated, and the CT image shows "double-sided sign"; ② The inner capsule is completely separated, collapsed, curled up and suspended in the cyst fluid, which is the "water lily sign" or "ribbon sign".

(2) MRI examination: The MRI manifestation of granular echinococcal cysts is a round lesion with low signal on T1WI and high signal on T2WI. The signal is uniform, the boundary is clear, the border is smooth, and there is no edema around the cyst. Signs of cysts within cysts may also be seen, and the cysts show no obvious enhancement after enhanced scanning.

(3) Key points for diagnosis: ① Life history in pastoral areas; ② Cysts within cysts; ③ Calcification of cyst walls is common.