Abstract:Objective: To analyze the MRI characteristics of fetal sacrococcygeal teratoma and to determine the value of prenatal MRI. Materials and Methods: From December 2009 to January 2012, 7 cases suspected of having fetal sacrococcygeal tumors by ultrasound, MRI was performed in all of the cases. Pregnant women aged 21~33 years, with the gestational age of 24 weeks to 37 weeks+5, the size, location, signal characteristics, and compressive effects of the masses were determined. Results: The sacrococcygeal teratoma appeared entirely cystic in six fetuses, mixed cystic and solid in 1, type Ⅰ in two patients, type Ⅱ in 2, and type Ⅲ in 1, type Ⅳ in 2, MRI findings of fetal sacrococcygeal teratomas were as follows: fetal sacrococcygeal region tumors with low T1 high T2 signal intensity, the sacrococcygeal teratomas with septa in two, intrapelvic and intraabdominal extent of the tumor in two. which was proved by follow-up or pathologic findings. Conclusion: Fetal sacrococcygeal teratomas had characteristic MR imaging appearances.