A blood pool scan is also a scanning test for radionuclides. It is performed by labeling human serum albumin or red blood cells with certain nuclides such as 99mTc or 113mIndium, and then injecting this preparation into the body for another scan. This kind of nuclide scan is mainly used to differentiate hepatic hemangioma from hepatocellular carcinoma, which is mainly supplied by hepatic artery and there is no significant retention of nuclide-labeled red blood cells, while cavernous hemangioma is composed of a large number of capillary plexuses and nuclide-labeled red blood cells can stay in the hemangioma for a long time. Therefore, by dynamically observing the retention characteristics of nucleolin-labeled red blood cells in the occupying lesion, it is possible to distinguish primary hepatocellular carcinoma from cavernous hemangioma. The sensitivity of the blood pool scan is the same as that of the general isotope scan, and thus it is not possible to identify hepatocellular carcinoma and cavernous hemangioma less than 3 cm in diameter.