CT and MRI Diagnosis of Ovarian Dysgerminoma / 中国医学影像学杂志

ABSTRACT

Purpose Ovarian dysgerminoma has no specific symptoms or physical signs, which is thus prone to misdiagnosis before treatment. This paper aims to investigate CT and MRI clinical features of ovarian dysgerminoma, so as to provide an accurate basis for its clinical treatment and also improve patients'' life, quality.Materials and MethodsThe CT and MRI data of 13 patients with ovarian dysgerminoma proved by pathology were retrospectively analyzed. Three patients underwent plain and enhanced CT scan, 6 took plain and enhanced MRI scan on T1WI and T2WI with different angles of views, and 4 other patients were performed both CT and MRI scan.Results①Twelve patients had single lesions, and 1 was bilateral multiple ones. The diameter of the lesions ranged from 5.5 cm to 16.5 cm, with mean of (9.5±3.8) cm; in terms of pathological type, 11 belonged to single type and 2 were mixed.②The CT results showed that 6 were solid mass and 1 was cystic. On enhanced CT scan, 6 cases showed heterogeneous light-to-moderate enhancement, 4 had tumors with significantly enhanced blood vessels, and 1 showed heterogeneous significant enhancement at arterial phase; all cases presented continuous enhancement at venous phase.③The MRI manifestations demonstrated 8 were with solid mass, which displayed iso- or slightly hypointense signal on T1WI, and iso- or slightly hyperintense signal on T2WI. The enhanced scan showed that 5 cases had heterogeneous mild enhancement, 3 had moderate enhancement, and 4 were seen with tortuous tumor vessels at arterial phase; all displayed continuous enhancement at venous phase. In the one case of cystic mass, solid component had moderate enhancement at arterial phase and continuous enhancement at venous phase. In another case of multilocular cystic mass, the tumor separate and cyst were significantly enhanced at arterial phase, and were continuous enhanced with hyperintense at venous phase.Conclusion Ovarian dysgerminoma tumors present features such as large lesions with clear boundaries. Tumors of single type are likely to be solid mass with central necrosis; the plain CT scan shows isodensity; the plain MRI scan mainly shows isodensity on T1WI, and iso- or slight hyperintensity on T2WI; the enhanced scan presents slight to moderate enhancement. Tumors of mixed type demonstrate cystic mass; the solid and separate parts are significantly enhanced. The comprehensive analysis of imaging features of ovarian neoplasms could help to make a correct diagnosis before surgery.