A defect in blood flow filling at the plaque is a description of the intravascular condition on imaging that suggests that the blood flow condition at the plaque is not consistent with the adjacent lumen. Under normal conditions, the wall of the vessel is smooth, the lumen is smooth, and the blood flow is uniform throughout the lumen. If the wall of the vessel is thickened, calcified, or plaque is formed, a blood flow filling defect will appear in the process of imaging, suggesting that the lumen condition in the corresponding area is abnormal, and it is an indirect description of the plaque on the wall, which is necessary to determine the degree of stenosis through the filling defect. When the corresponding condition occurs, it is necessary to analyze and judge comprehensively with the clinical symptoms. If the filling defect is only slight, the blood pressure and blood lipids can be controlled through the application of drugs, such as levamlodipine benzenesulfonate tablets, atorvastatin, and so on. If severe stenosis occurs, causing obvious blood supply abnormality, surgery is needed under the guidance of clinicians. Once obvious symptoms such as headache, dizziness, chest pain or coma appear, it is necessary to consult a doctor for observation and treatment under the guidance of a clinician.