Research On MRI Diagnosis And Clinical Evaluation Of Breast Augmentation With PAHG

In 1997, Polyacrylamide hydrogel(PAHG) was introduced into China and used in clinical practice as a kind of injectable soft tissue filler. We have observed many patients developed varieties complications after PAHG injection. Lots of patients vist doctor and request to remove the PAHG injected in their breasts. Preoperative imaging techniques were needed to judge the extent of the PAHG accurately and evaluate the difficulties may present in operations. Through literature review, X-ray, ultrasound, CT, MRI, had been used . But the previous case reports only had a small sample and no objective comparison between them was obtained. Using the imaging means to judge the layers and extent of PAHG, guide operations, evaluate prognosis is important. Here's our study.Part 1: Retrospective analysis of 95 patients who had complications after breast augmentation mammaplasty with PAHG. all of them got the same procedure in our center from August 2005 to May 2007.42 patients, mean age 33. 5, had CT examinations preoperatively. We collected the diagnostic results and actual information in operations. And then, we calculated the sensitivity and specificity of CT to diagnose the PAHG in subcutaneous adipose tissue, mammary gland, retromammary space, pectoral is major, crevice under pectoralis major and intercostals muscle. The sensitivity in each layer is 19.05%, 9.52%, 96.20%, 80.33%, 58.33%, 41.67%. The specificity in each layer is 100.00%, 96.83%, 60.00%, 60.87%, 75.00%, 93.06%. To the other 53 patients, mean age 33.4, we selected MRI examinations preoperatively instead. The same calculation was made then. The sensitivity in each layer is 90.63%, 82.35%, 100.00%, 91.36%, 80.00%, 57.14%. The specificity in each layer is 91.89%, 93.26%, 75.00%, 92.00%, 95.06%, 97.83%.Part 2: Retrospective analysis of 83 patients who had complications after breast augmentation mammaplasty with PAHG, which was removed in our center from June 2006 to January 2008. All patients , mean age 34.0, had MRI examinations preoperatively. We divided the characters of imaging into 4 categories: prosthesis sign; pebble sign; honeycomb sign; flocc. sign. We recorded the PAHG trait corresponded to each sign. To the even prosthesis sign, 95. 37% of the PAHG trait is dilute and yellowish white jel. To the uneven prosthesis sign, 100.00% of the PAHG trait is viscous and yellowish white jel. To the honeycomb sign, 81.82% of the PAHG trait is semitransparent solid mass. In subcutaneous layer, 82. 14% of the PAHG trait is semitransparent solid nodules in pebble sign, and 58.83% of the PAHG trait is semitransparent solid mass in deeper layers. To the flocc. sign in subcutaneous layer, 81.25% of the PAHG trait is semitransparent solid mass; in breast gland , 78.57% of the PAHG trait is viscous and yellowish white jel; in retromammary space and muscle, 80.90% of the PAHG trait is semitransparent solid mass.Conclusion:MRI is better than CT in the diagnosis of the extent and layers of PAHG, especially in deep layers. MRI shoud be the best imaging technique in diagnosing the complications after breast augmentation mammaplasty with PAHG. There has evident correlations between MRI signs and PAHG trait. The same MRI sign may indicate different PAHG trait in various layers. MRI signs can help us to evaluate the PAHG trait, so as to predict the difficulties of operation and to improve the securities of operation.