Diagnosis of ovarian torsion by three-dimensional power Doppler in first trimester of pregnancy.

Three-dimensional ultrasonography in power Doppler mode (3D power Doppler) allows the appropriate quantitative assessment of the ovarian tissue vascularization. The present case is of an ovarian torsion in a pregnant woman at 6.5 weeks with ovarian hyperstimulation syndrome due to in vitro fertilization. Gray-scale images of endovaginal two-dimensional ultrasonography revealed enlargement of the right ovary and multiple peripheral follicles. Two-dimensional ultrasonography in color Doppler mode revealed the absence of venous flow and reduction in arterial flow to the impaired ovary. 3D power Doppler allowed the appropriate quantitative assessment of tissue vessel density of the impaired ovary, which greatly influenced the decision for conservative surgical treatment. The 3D power Doppler assessment performed after the surgery confirmed the integrity of the ovarian tissue. 3D power Doppler can help in the selection of patients with ovarian torsion for conservative surgical treatment.