How to detect gallbladder cancer at an early stage by examination and follow-up? At present, it is believed that a combination of multiple diagnostic tools can effectively detect abnormal gallbladder lesions at an early stage, and the combination of tumor markers + ultrasound + MRI is generally recommended. Tumor marker measurement The measurement of tumor markers provides a lot of help for gallbladder cancer diagnosis. For example, serum carcinoembryonic antigen (CEA) >4ng/ml has 93% specificity and 50% sensitivity in diagnosing gallbladder cancer with clinical manifestations; CA199 serum level >20U/ml has 79.2% sensitivity and 89.2% specificity. However, it may not be elevated in early cancerous cases, or when combined with other GI diseases and certain tumors, the test may show false positive results, so it must be combined with imaging tests. Ultrasound and MRI Ultrasound is the simplest and most reliable way to show the gallbladder. It is the ideal tool for gallbladder cancer screening because it is simple, non-invasive and can be used repeatedly, and has a diagnostic accuracy of over 90%, making it the first choice for gallbladder disease diagnosis. With the continuous replacement of instruments, it is now possible to clearly observe not only the size of the gallbladder lesion, but also the blood flow of the lesion to determine whether cancer has occurred, and to observe whether there are obvious lymph node metastases and whether the liver is involved, and experienced examiners can even determine which layer of the gallbladder is involved in the lesion. MRI has become an ideal tool for detecting gallbladder cancer because of its good tissue contrast and multifaceted imaging features, which can detect thickening of the gallbladder wall, infiltration of the liver parenchyma, and metastatic enlargement of the surrounding lymph nodes.