聚丙烯酰胺水凝胶注射隆乳取出前行MRI检查的意义

Significance of MRI before surgery to remove polyacrylamide hydrogel used for augmentation mammaplasty

目的分析聚丙烯酰胺水凝胶（polyamide hydrogel，PAMHG）注射隆乳后取出术前行磁共振成像（MRI）检查的意义。方法采用Philips 3．0T磁共振仪及4通道乳腺相控阵线圈，对20例共40只乳房曾注射PAMHG隆乳后取出术前的行双侧横轴位T1WI、T2WI脂肪抑制（fat saturation，FS）及矢状位T2WI-FS平扫，其中8例用磁显葡胺（Gd-DTPA，0．1mmol／kg，2．0ml／s静脉团注）行THRIVE动态增强。对MRI表现与手术、病理结果对照分析。结果PAMHG于T1WI表现为与腺体相等信号，T2WI表现为明显高信号。PAMHG内见不同程度低信号间隔100％（40／40），与周围组织相间分布，无光滑囊壁90％（36／40），见T1WI及T2WI低信号、光滑均匀囊壁10％（4／40）。MRI发现PAMHG皮下硬结70％（28／40），腺体内硬结20％（8／40），胸大肌下条带状弥散硬结100％（40／40），乳腺肋间肌肌间隙出现PAMHG游走10％（4／40）。所有PAMHG隆乳材料均无对比增强；1例于乳腺腺体内发现不规则结节状增强。T2WI上所见PAMHG范围、表现与手术所见一致。结论PAMHG取出术前T2WI-FS可以准确评价其分布范围及并发症，MRI平扫同时进行动态增强扫描可以鉴别腺体内的硬结并及时发现伴发的乳腺癌，对临床取出PAMHG具有重要的指导意义。

Objective To evaluate the significance of MRI before surgery to remove polyacrylamide hydrogel （PAMHG） which has been used for augmentation mammaplasty. Methods Twenty female patients with 40 breasts, having been injected PAMHG as augmentation mammaplasty, under went bilateral breast axial TIWI, T2WI fat saturation （FS） and sagittal T2WI FS by 4 channal phased-assay breast coil at 3.0T （Philips） before removal surgery, in which 8 patients underwent axial muhiphase contrast-enhanced MRI with THRIVE after Gd-DTPA （2.0 ml/s, 0. 1 mmol/kg） administration. The results of MRI were compared with that of operation and pathology. Results PAMHG showed iso intensity compared with breast gland on T1WI and hyperintensity on T2WI-FS. Low signal septa were noted within PAMHG in 40 breasts （20 patients）, 90 % （36/40） PAMHG without capsule, 10 % （4/40） with smooth capsule which showing homogenous low signal on T1WI and T2WI FS. Subcutaneous lump of PAMHG was 70 % （28/40）, lump of that in breast gland was 20 （8/40）. Diffuse gel along spatium intermusculare of pectoralis major was 100 %（40/40）, that along spatium intermusculare of intercostal muscle was 10% （4/40）. All PAMHG in breast of the 8 pa tients showed no enhancement, an irregular enhanced mass was found in gland of 1 patient. All distributions of PAMHG and appearances of its complications on T2WI-FS were consistent with the results of operation. Conclusions T2WI-FS can accurately display the distribution of PAMHG and its complication before removal surgery. MRI plane scan combined with multiphase contrast-enhanced MRI can differentiate PAMHG from the lesions in the gland and find the breast carcinoma, so that it can guide clinicians before surgery to remove PAMHG used for augmentation mammaplasty.