In the case of an adolescent female experiencing menorrhagia and severe pelvic pain, which imaging study is most helpful in assessing for anatomical causes?

In the scenario of an adolescent female with menorrhagia and severe pelvic pain, the use of ultrasound is the most appropriate imaging study for assessing anatomical causes. Ultrasound is a non-invasive, readily available, and cost-effective first-line imaging modality that allows for the evaluation of the internal reproductive organs, including the uterus and ovaries. It can effectively identify structural abnormalities such as fibroids, polyps, or ovarian cysts that may contribute to heavy menstrual bleeding and pelvic pain.

Transabdominal or transvaginal ultrasound can provide detailed images and help to establish a diagnosis quickly. Furthermore, it does not involve exposure to ionizing radiation, making it particularly suitable for the young female population. In cases where ultrasound findings are inconclusive or further detail is needed, additional imaging studies like MRI may be considered, but typically that is not the first line of investigation.

Overall, given the clinical presentation and need for anatomical assessment in young women, ultrasound stands out as the most beneficial initial imaging study.