Vasa previa or not? A special parachute type of placenta caused dispute in ultrasonography diagnosis: A case report.Hong Ling1, Wu Jiahan1.1 Department of Obstetrics and Gynecology, Ningbo Women and Children Hospital, Ningbo 315010, ChinaCorresponding AuthorWu JiahanNo. 339 Liuting Street, Haishu District, Ningbo, Zhejiang Province, China.Telephone number +86 13805840722  e-mail 3014078594@qq.comCo-authorHong LingNo. 339 Liuting Street, Haishu District, Ningbo, Zhejiang Province, China.Telephone number +86 13655742069  e-mail 409180445@qq.comshortened running title: Vasa previa or not? MRI for parachute placenta