Final answer:
Ultrasonography is the ideal imaging study for pelvic anatomy and adnexal structures due to its safety and effectiveness, especially during pregnancy.
Step-by-step explanation:
The best imaging study for evaluating pelvic anatomy and adnexal structures is ultrasonography. This modality uses ultrasonic waves to visualize internal body structures safely, including organs and tendons, making it ideal for visualizing the female reproductive system. During pregnancy, ultrasound is the technique of choice because it does not use ionizing radiation, unlike CT or PET scans, which can be harmful to the developing fetus. Additionally, ultrasonography is useful in diagnosing conditions like endometriosis, as evidenced by its role in procedures such as laparoscopy. For examining fetal growth and development, ultrasound's safety profile and detailed imaging capabilities make it the preferred method over more hazardous radiologic studies.