Polyacrylamide hydrogel as a soft tissue filling material has been on the market for only a decade or so, due to the lack of basic research and clinical feasibility reports related to it. There are many controversies about its safety. According to the relevant literature, the incidence of complications caused by this can be as high as 32.9%. The main manifestations are: 1. hard nodes and masses: scattered, variable-sized, tough, fixed hard nodes and masses in both breasts and outside the breast area, which are difficult to distinguish from breast fibroids and are mostly confirmed by MRI to be pseudotumors formed by the injected material. 2. pain: intermittent pinprick-like pain in the breast, which is obvious at night at rest, or persistent pain in the chest wall. 3. severe displacement of the injected material: due to different locations, it occurs when lying down or standing up, respectively. or upright, manifested as a mass in the chest wall and axilla, extending to the rib margin and upper arm, which may slowly increase in size due to position change, and palpable masses or protrusions on the body surface, including left and right breast injections penetrating through the chest wall; chest wall pain without palpable masses, confirmed by MRI as displacement of the injections as far as the rib margin of the ipsilateral midclavicular line. 4, deterioration of handfeel and abnormal breast morphology: visible as bilateral breast shrinkage, in an 5. Infection and ulceration: the skin on the surface of the breasts was flushed and painful to touch, accompanied by an increase in local skin temperature, and the aspirate was confirmed to be a mixture of injected material and pus; the patient’s puerperium showed swelling of both breasts, epidermal ulceration, and a large amount of mucous gel-like material and milk mixture overflow. For the management of postoperative complications, surgical removal should be the main focus. The good or bad results of surgery are related to the results of MRI examination. For patients with more concentrated injections that do not invade the pectoralis major muscle or the posterior interstitial space of the pectoralis major muscle, the treatment results are satisfactory; for patients with scattered injections that infiltrate the pectoralis major muscle and produce displacement, the treatment results are poor. Regarding the question of whether breast augmentation can be performed again after breast injection: in principle, it is not recommended to perform breast augmentation again, but if MRI indicates no infiltration of the pectoralis major muscle and the patient strongly requests it, the implantation can be performed reluctantly after the patient is informed of the possible complications. Theoretically, the pectoralis major muscle can separate the prosthesis from the injection, but in practice, due to the communication between the lateral edge of the pectoralis major muscle and the posterior mammary space, it still cannot avoid the communication between the prosthesis and the injection. In practice, we often encounter patients whose MRI shows no infiltration of the pectoralis major muscle still have injectable particles discharged from the axillary incision during surgery.MRI shows infiltration of the pectoralis major muscle should be regarded as a contraindication to implantation of breast augmentation, because 1, severe displacement and invasion of the pectoralis major muscle, after implantation of the prosthesis increases the possibility of chronic exudation; 2, the injectable infiltrates the muscle layer, which can directly cause pain from pectoralis major muscle inflammation, and the pectoralis major muscle and If the pectoralis major muscle is in contact with the implant, the infection will directly affect the implant, resulting in surgical failure; 3, the pectoralis major muscle is invaded, and the feel of the implant is poor. Regarding the timing of breast augmentation surgery, there is no significant difference between immediate implantation and staged implantation. As the injected HPG redistributes under the effect of gravity and pressure and infiltrates into the surrounding tissues, hard nodes and masses of uneven levels and different sizes are formed in the breast tissue. Although some users claim that they can be completely removed, the actual formed hard nodes are far more difficult to remove than imagined and cannot be removed, especially those with a diameter of less than 1 cm. In patients with dispersed injections, the actual amount removed does not exceed 70%. The gel infiltrates into the interior of the gland and can even reach below the nipple, blocking the breast ducts and causing acute mastitis and breast abscesses in lactating women, whose effects on the baby are not yet known. The hard nodules produced after HPG injection affect the screening of breast tumors and cause great psychological stress to the patient. After HPG injection, a certain number of patients develop severe displacement of the anterior sternum, axilla and even the upper arm, failure to close the lumen, and chronic exudation, which are never mentioned in user reports but are frequently reported in complications around the world. Whether the cause of its occurrence is related to the inflammatory response of the tissue stimulated by HPG, etc. needs further confirmation. The importance of MRI examination in the diagnosis of post-polyacrylamide hydrogel injection breast augmentation complications is particularly proposed: as it can clarify the distribution range of the injected material, etc., it plays an important role in selecting the procedure, guiding the intraoperative operation and judging the prognosis. Complications of polyacrylamide hydrogel injection breast augmentation can only be partially relieved after surgery because they cannot be completely removed. Re-implantation of the implant after removal requires great caution, especially in patients with pectoralis major muscle invasion or severe displacement, whose late changes still need further observation and study