What tests are best for diagnosing liver cancer? There are three ways to diagnose liver cancer

Among various imaging examinations, CT can best reflect the pathological morphology of the liver, such as the size, shape, location, number of lesions, and the presence or absence of hemorrhage and necrosis within the lesions. The invasiveness of the lesions can be understood from the edge of the lesions, and the invasion of the portal vein can be understood from the cancer thrombus and invasion of the portal vein. CT is considered to be the preferred non-invasive diagnostic method to supplement ultrasound imaging to estimate the extent of the lesions.

CT manifestations of liver cancer, plain scan manifestations: lesions are generally low-density, lower than the surrounding liver parenchyma density, and some lesions are surrounded by a layer of lower-density ring shadow (halo sign). The nodular type has clearer edges, while the massive and mixed types have more blurred and partially clear edges. Enhanced manifestations: After intravenous injection of iodine contrast agent, the density of the lesion and liver tissue is increased to a certain extent, which is called enhancement. Including:

Dynamic enhanced scanning; using bolus dynamic scanning or spiral CT rapid scanning, in the early stage (hepatic artery stage) the lesion shows high-density enhancement, which is higher than the surrounding normal liver tissue for 10 to 30 seconds, and then the lesion density decreases rapidly, approaching the normal liver tissue with equal density, which is easy to miss at this stage; the lesion density continues to decrease and the liver tissue shows low-density lesions, which can last for several minutes. The early enhanced images of dynamic scanning can easily detect satellite lesions with a diameter of less than 1 cm or 1 to 2 cm, and are also prone to the discovery of small lesions.

Non-dynamic scanning: ordinary scanning takes at least 15 seconds each time, so the liver layer where the lesion is located may fall into any stage of the above dynamic scanning and present different densities. Most of the lesions fall into the low-density stage, so the lesions are significantly lower than those in plain scanning. Manifestations of invasion of the portal vein system and other systems: The rate of cancer thrombosis in the portal vein system of primary liver cancer is high, and the difference between the unenhanced cancer thrombus and the obviously enhanced blood is large due to the long enhancement, showing strip-like filling defects that cause irregular or non-developed images of the portal vein trunk or branch vessels. A small number of patients have cancer thrombosis in the inferior vena cava. Portal invasion can cause dilatation of the intrahepatic bile duct, occasional retroperitoneal lymphadenopathy, ascites, etc. Lung metastasis appears abnormal in chest CT examination, which is more sensitive than chest X-ray.

In recent years, new CT machines have been continuously updated, and CT examination technology has been continuously improved, especially the combination of angiography and CT, such as direct injection of contrast agent into the hepatic artery for CT enhancement CTA (CT-Angiography), injection of contrast agent into the superior mesenteric artery or splenic artery for CT tomography during the portal venous phase (CTAp), and Lipiodol-ct (Lp-CT) for CT plain scan 2 to 3 weeks after injection of iodized oil into the hepatic artery during angiography. These methods have a better detection rate for small liver cancer, especially small liver cancers of 1 cm or less than 1 cm than CT dynamic scanning. However, among the above methods, CT plain scan plus enhancement is still the routine, and CTA and CTAp are the most effective methods for confirming suspicious lesions or small liver cancers.