Female teenager with acute right lower quadrant pain

US of ovarian torsion
Sagittal grayscale US of the right ovary (above) shows the right ovary to be enlarged and to contain a large central hypoechoic cyst. The right ovary was 4 times larger in size than the normal left ovary. Sagittal spectral doppler US of the right ovary (below) shows arterial flow to be present in the right ovary, but the amount of arterial flow was decreased when compared to the arterial flow to the left ovary.

The diagnosis was ovarian torsion around an ovarian cyst.