MRA refers to Magnetic Resonance Angiography, which can be used for the diagnosis of neurological diseases, cardiovascular system diseases, pelvic and abdominal organ diseases, and so on. Magnetic resonance angiography utilizes the magnetic resonance phenomenon, which produces a “flow-void effect” in the blood in the MR imaging plane, to show the local large vessels and their branches, so as to determine whether there are any related diseases. The advantages of this method are non-invasive, convenient, time-saving, and no radiation damage. Clinically, it can be used to examine neurological diseases, such as intracranial vascular stenosis or occlusion, cerebral vascular malformation, intracranial aneurysm, etc.; cardiovascular diseases, such as cardiomyopathy, pericardial tumor, etc.; pelvic and abdominal diseases, such as hepatocellular carcinoma, hepatic hemangioma, hepatic cysts, ovarian tumors, uterine tumors, etc.. The scope of application of MRA examination needs to be evaluated by specialized physicians.