In general, diagnoses on imaging are categorized as: positive, negative, and probable. Gliomas, the common ones include astrocytomas, glioblastomas major, ventricular meningiomas, and choroid plexus papillomas. The grading you are referring to may be grades I-IV of astrocytomas. On imaging, grade I Gross cellular astrocytomas are most commonly seen as cystic nodular tumors, the vast majority of which are located in the cerebellar hemispheres, and appear as hypointense, isointense, or mixed densities on plain scanning. Depending on the contents of the capsule, it is homogeneous and hypointense if it is pure fluid, and more dense if there is fresh hemorrhage or high protein content, with clear borders and usually without edema. On enhancement scan, there is ring-like enhancement with wall nodules. The solid type is mostly hypointense, and about 10% have calcification. Most of them have patchy or punctate calcification, and uneven enhancement is seen on enhanced scan.Grade II low-grade astrocytoma: equal or low density on plain scan, focal or diffuse infiltrative growth, 15%-20% of them have calcified foci, hemorrhage and necrosis are rare, and there is no edema in the surrounding area. On enhancement scan, the foci of the lesion usually have insignificant enhancement or mild uneven enhancement.Grade III interstitial astrocytoma On scanning, the lesion usually shows mixed density, mainly low density, and a few of them are equal or slightly high density, with hemorrhage, necrosis and cystic degeneration, and little calcification. The margins of the lesion are unclear, and different degrees of edema can be seen, with occupying effect. Enhanced scans show marked heterogeneous enhancement of the tumor, or ring-like enhancement, which is difficult to distinguish from glioblastoma multiforme.Grade IV Glioblastoma multiforme shows mixed densities on plain scans, and more than 95% of the foci are hypodense in the central part of the lesion due to necrotic cystic lesions. Hemorrhage is common and calcification is rare. The margins are indistinct, with marked peripheral edema and a significant occupying effect. The tumor often grows across the midline and infiltrates the contralateral cerebral hemisphere, typically butterfly-shaped, usually single, and a few may be multiple, and enhancement scan shows that the parenchymal part of the tumor is obviously strengthened, and it may be presented as a ring, with a thick and irregular wall, and wall nodules can be seen. Feng Fuqiang, Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, emphasized that typical lesions may have atypical imaging manifestations, and in our follow-up cases, there are many cases with grade I-II imaging manifestations that have micro-grade III-IV pathology, and of course, pathology sampling is also very relevant, so we have to not only do the grading of typical imaging manifestations, but also to do it appropriately. Therefore, imaging performance can only provide us with relevant clues, and pathologic examination is the gold standard.