肾钙乳的临床MRI表现及其诊断价值

MR Manifestations and its Diagnostic Value of Renal Milk of Calcium

目的探讨肾钙乳的MRI表现及其诊断价值。方法回顾性分析经MRI检查并经临床随访确诊的18例肾钙乳患者的MRI表现,并与其X线及CT表现对照。结果 18例肾钙乳全部经MRI检查确诊(准确率100%),典型MRI表现为肾实质内圆形囊性病灶,17例T_1WI呈明显低信号,T_2WI表现为病灶上部呈明显高信号,病灶下部呈明显低信号,两者之间构成水平状高低信号界面,即典型"半月征",此征象在压脂T_2WI上显示更加清晰。另1例在T_1WI上钙乳表现为高信号,其上缘隆起,颇似"盘中盛果"。18例KUB平片(卧位及站立位)分别表现为典型"麻饼征"和"半月征";18例CT扫描表现为病灶下部为高密度,病灶上部为低密度,两者之间构成水平状高低密度界面,改变体位扫描见高密度钙乳的位置始终位于囊腔最低处。结论肾钙乳具有特征性MRI表现,诊断准确率高,无辐射,是值得推荐的诊断方法。

Objective To evaluate the MRI features and diagnostic value of renal milk of calcium（ RMC）. Methods The MRI findings of 18 patients with clinically followed-up proven RMC were retrospectively analyzed,and compared with X-ray and CT findings. Results All 18 cases of RMC were confirmed with MRI,Typical MR appearance is a circular cystic lesion in the kidney. Out of 18 patients,17 RMC showed long T_1 manifestations,T_2WI was characterized by upper lesions with a significantly high signal,lower lesions with significantly low signal,a horizontal between high and low signal interface,that is the typical half moon sign; this sign showed more clearly on fat suppression T_2WI. 1 RMC showed high signal on T_1WI,with raised edges,just like fruit in plant sign. Supine and standing KUB show the typical character of sesame cake sign and half moon sign,respectively; 18 cases which underwent CT scan study showed that the lesions lower for high density,the upper part of lower density,constitutes a level between high and low density interface,high density of RMC always located in the lowest level of the lesion with change of scanning position. Conclusion MR has the characteristic signs to aid in the diagnosis of RMC,with high diagnosis accuracy and less radiation. This diagnostic method is recommended.