B speculation appears uneven echogenic flat plaques are generally not stable plaques, and their stability is between stable and unstable plaques. Atherosclerotic plaques can be divided into two categories according to their degree of stability, stable and unstable plaques. Stable plaques have less lipid content, a large amount of smooth muscle tissue and collagen tissue wrapped around the plaque, and the plaque is stable and not easy to rupture; whereas unstable plaques have a high content of lipid and are floppy, with less smooth muscle tissue and a thinner fibrous cap, and the plaque is unstable and easy to rupture. Stable plaques generally show strong echoes under the ultrasound probe, unstable plaques generally show low echoes, and the stability of unevenly echogenic plaques is in between the above two types of plaques. If unevenly echogenic flat plaques are detected, it is necessary to have regular follow-ups and proper treatment under the guidance of a doctor to avoid adverse consequences such as embolism caused by plaque detachment.