Final answer:
The initial imaging study for suspected ovarian torsion is transvaginal ultrasound because it is safe, non-invasive, and does not involve radiation exposure.
Step-by-step explanation:
The initial imaging study recommended for suspected ovarian torsion is a transvaginal ultrasound (TVU). This imaging technique is preferred because it is the least invasive, does not use ionizing radiation, and provides sufficient detail for the evaluation of ovarian structure and blood flow. Other imaging methods, like computed tomography (CT) scans, may also construct detailed images, but they involve exposure to X-rays. Similarly, magnetic resonance imaging (MRI) offers excellent detail without radiation but is less commonly used as the first-line imaging due to higher cost and less availability in acute settings. TVU is commonly used in gynecology due to its safety, particularly in patients who may be of childbearing capacity, as it is important to avoid radiation exposure during pregnancy.