Typical features of ovarian torsion are present on the initial scan - diffuse ovarian edema and a "whirlpool" appearance of the adnexal vessels.  There is however definite and quite pronounced ovarian vascularity. In the context of patient's symptoms concurrently improving this may well represent a degree of hyperemia following de-torsion. 

As the patient's symptoms had resolved, no laparoscopy was performed despite the scan findings.  Scan performed two weeks later demonstrates a striking resolution of ovarian edema, supporting the suspicion of spontaneous de-torsion.

Incidentally, note the presence of multiple small peripherally arranged follicles in both ovaries, with bilateral ovarian volume >10cc. The appearance fits the ultrasound criteria for polycystic ovarian morphology. However the patient is 20 years old, and therefore only on the cusp of the age category where PCOS ultrasound criteria may be applied. It would be best therefore to avoid overstating the significance of these findings in the clinical report.