儿童寄生胎CT特征

目的 观察寄生胎（FIF）的CT特征。方法 回顾性分析12例经手术病理证实的FIF患儿，观察其CT特征表现。结果 12例FIF均为单胎寄生，其中10例为内生性FIF，2例为外生性；7例病灶位于腹膜后，此外颞部、纵隔、腹腔、骶尾部及阴囊各1例；病灶最大直径3.3~14.0 cm，平均约（7.92±2.97）cm；9例病灶形态规则，3例形态不规则。12例病灶内均可见钙化或骨化；10例病灶内发现椎骨或四肢长骨；11例可见脂肪；病灶包膜完整且较厚，厚度0.1~3.1 mm，平均（1.42±0.78） mm。增强扫描中11例病灶未见强化，6例包膜可见强化；11例未见供血动脉及引流静脉。结论 FIF较常见于腹膜后，病灶内见椎骨或四肢长骨、包膜完整、较厚并可见强化为其主要CT特征。

CT features of fetus in fetus in children

Objective To observe CT features of fetus in fetus (FIF) in children. Methods Data of 12 children with FIF confirmed by operation and pathology were retrospectively analyzed, and CT features of FIF were observed. Results Single parasitus was detected in all 12 children, including 10 intra-body FIF and 2 extra-body FIF. The lesions located in retroperitoneum in 7 cases, while the other 5 in temporal area, mediastinum, abdomen, sacrococcygeal region and scrotum, respectively (each n=1). The maximum diameter of lesions ranged from 3.3 cm to 14.0 cm, with an average of (7.92±2.97)cm. Regular shapes lesions were found in 9 cases, while 3 lesions were irregular. Calcifications or ossifications within FIF were observed in all 12 cases, while long bones of limbs or vertebrae were found in 10 cases. Fat was visible in 11 cases. The lesions were found with complete thick capsules, the thickness ranging from 0.1 mm to 3.1 mm, with an average of (1.42±0.78)mm. After administration of contrast agent, no enhancement of FIF was observed in 11 cases, but capsule enhancement was observed in 6 cases. No feeding artery nor draining vein were observed in 11 cases. Conclusion FIF often occurred in retroperitoneum. The main CT features of FIF included long bones of limbs or vertebrae within the lesions, with thick and complete capsule which might enhance after delivery of contrast agent.