目的 探讨卵巢单纯型无性细胞 瘤的影像学特征。方法 回顾分析15例经 病理证实卵巢单纯型无性细胞瘤的临床和 CT、MRI资料，总结其诊断要点。结果 年 龄范围：6-23岁，中位数：16岁；均单侧 发生，呈类圆形或分叶状(12/3)，边缘清 晰，15例行CT平扫+三期动态增强扫描， 病灶均以实性为主，5例呈均匀密度，8 例病灶内见小条片状，2例见较大片状坏 死；6例见点、条片状钙化。增强后，14 例动脉期轻度强化，静脉期及延迟期轻度 延迟强化。其中，12例病灶内见卵巢动 脉进入肿块内供血，且9例血管呈“间隔 状”排列。1例动脉期较明显强化，静脉 期及延迟期延迟强化；4例同时行MRI检 查，纤维间隔T1WI/T2WI均呈低信号，增 强后肿块轻度强化，“纤维血管间隔” 及包膜明显强化；出现腹膜后及子宫直肠 陷凹、盆腔髂血管旁淋巴结转移各1例， 均未见远处脏器转移；6例伴血清β-HCG 升高，2例伴LDH增高。结论 卵巢单纯型 无性细胞瘤好发青少年女性，密度较均 匀，血供丰富而实质强化却相对较轻，特 别是MRI增强后病灶内出现“纤维血管间 隔”、包膜明显强化，结合血清β-HCG、 LDH明显升高，大部可明确诊断；CT增强 后病灶内出现“血管间隔”对本病具有一 定诊断价值。

Objective To explore imaging features of pure ovarian dysgerminoma. Methods The clinical, CT and MRI findings in 15 pure ovarian dysgerminoma patients, confirmed by operation and pathology, were retrospectively analyzed. The imaging features and diagnosis were also discussed. Results The age range from 6 to 23 years(median age,16 years). 15 patients underwent CT plain scan and three-phase dynamic enhanced scan. In CT plain scans, 5 cases were in homogeneous density, 8 cases and 2 cases were small or large patchy necrosis of center. 6 cases had spot or strips calcification within the tumor. After contrast administration, solid part of tumors showed slight enhancement in arterial phase and mild degrees of delayed enhancement in venous phase and delayed phase in 14 cases. Among those, 9 cases demonstrated the vascular septa, arising from the ovarian arteries. In another case, the tumor was significantly enhanced at arterial phase, and was continuous enhanced in venous phase and delayed phase. The plain and enhanced MRI were performed in 4 cases. The main MRI features of the fibrous septa showed low signal in both T1WI and T2WI. After contrast administration, the capsule of tumors and fibrovascular septa was significantly enhanced. Pelvic lymph node metastasis was found in 1case, and retroperitoneal lymph nodes and rectovaginal pouch metastasis in 1 case, respectively. The serum HCG and LDH levels were significantly increased in 6 cases and 2cases, respectively. Conclusion The disease should be considered for pure ovarian dysgerminoma combined with the significantly increasing of the serum β-HCG or LDH levels, homogeneous density tumor of ovarian in a young adult women, hypervascular with mild enhancement, especially, the fibrovascular septa and capsule were showed on MRI examination. Enhanced CT scan manifested vascular septa within tumor has some value for diagnosis of pure ovarian dysgerminoma.