There are hundreds of neural compounds in the human brain, and 1H-MRS can measure the following common ones, among which the components measured at long echo time (TE) and short echo time are different. 1.N-acetylaspartate (NAA): NAA is an important neurological marker that exists only in neurons and axons in mature brain tissue and decreases significantly when neurons are damaged. NAA-specific elevation is seen in Canavan’s disease, a hereditary cerebral leukodystrophy caused by the lack of NAA hydrolase. 2, choline compound peak (Cho): Cho reflects the total choline content in the brain, including phosphorylcholine, phosphatidylcholine and phosphoglycerylcholine, the peak is located at 3.2ppm displacement. Its change reflects the degree of nerve cell damage, and the peak of Cho is increased in demyelinating diseases and brain tumors, while it is decreased in patients with reduced myelin. 3.Creatine (Cr) peak: Cr reflects the sum of creatine and creatine phosphate and is located at 3.0 ppm shift, which can directly reflect the energy metabolism. Because the Cr value does not generally change with pathology, it is usually used clinically as a reference value to standardize the intensity of metabolic signals, i.e., NAA/Cr, Cho/Cr, etc. are usually calculated. However, in highly malignant tumors, the energy metabolism cannot be carried out normally, so it cannot be used as a reference value. 4. Under normal conditions, mass spectrometry does not detect lactate peaks (Lac) because the concentration is too low to be detected. Under pathological conditions, such as altered energy metabolism (cerebral infarction, some brain tumors, brain abscesses and mitochondrial encephalopathy, etc.), abnormal lactate peaks can appear at 1.32 ppm because aerobic metabolism does not proceed normally. 5, inositol (mI): mI is thought to exist only in glial cells, so it is used as a marker of glial. In demyelinating diseases and Alzheimer’s disease, mI can be increased. 6, free lipid (Lip): Lip peak is located at 0. 9~1. 3ppm, which is not detected in normal brain tissue because it is bound to macromolecules in the cell membrane and myelin sheath. The normal 1H-MRS usually shows three peaks in the order of NAA, Cr, and Cho (sometimes Cho is higher than Cr). Sometimes mI peaks may appear, but the peaks are lower. 1H-MRS and brain tumors 1H-MRS can provide information on the increase and decrease of different metabolites, including cell membrane proliferation, neuronal damage, abnormal energy metabolism and necrosis. It has been shown that 1H-MRS can distinguish intracranial tumors from cerebral infarcts, primary tumors from metastases, and can assess the malignancy of tumors, especially if the new lesions produced after radiotherapy for malignant tumors are tumor recurrence or radiation encephalopathy. An important feature that distinguishes tumors from other non-tumor diseases such as infarcts or abscesses is that 1H-MRS in tumors shows lower Cr and NAA peaks and higher Cho peaks, whereas in infarcts or abscesses all three are lowered, and the Cho peak is found to increase with increasing malignancy in gliomas, and the lipid peak is found to increase gradually. The highest Cho peak was found in medulloblastoma, and Cr decreased significantly and almost disappeared. The highest lipid peak in metastases is used to differentiate them from the primary tumor. Extracerebral tumors, such as meningiomas or nerve sheath tumors, show significantly reduced or even absent NAA because there are no neuronal cells outside the brain tissue. The difference between tumor recurrence and post-radiotherapy encephalopathy is the increase in peak Cho, which is due to the decrease in peak Cho, decrease in NAA and even absence of NAA due to degenerative necrosis caused by injury.