First Trimester Vaginal Bleeding RPOC may be identified by MRI, but MRI has little role in making the diagnosis of RPOC. RPOC and GTD may both manifest as an enhancing endometrial mass but are usually distinguishable on clinical grounds [74]. Contrast-enhanced pelvic MRI may be helpful to evaluate the extent of myometrial invasion and local extrauterine spread of GTD [75]. Uterine AVM can also be diagnosed with MRI [76]. CT An early IUP may be recognized on CT, but it is usually due to unintentional imaging of the pregnancy [67]. Because of its ionizing radiation, CT is generally not performed to evaluate vaginal bleeding in the first trimester of pregnancy. CT may identify an ectopic pregnancy [68], but reported cases of ectopic pregnancy diagnosed on CT were often performed for other reasons or in patients not known to be pregnant [77,78]. When a patient is clinically unstable, emergent care should generally not be delayed by additional imaging with CT or MRI. RPOC may be identified by CT, particularly when an enhancing mass is seen, but CT has little role in making the diagnosis of RPOC and the findings overlap those of GTD [74]. In patients with GTD, CT may be helpful in evaluating the extent of extrauterine spread [75]. Summary of Recommendations Transvaginal and transabdominal US are the most appropriate imaging modalities in patients with abnormal vaginal bleeding in the first trimester of pregnancy. Transvaginal US is generally the preferred modality. Transabdominal US is often complementary to transvaginal US and may sometimes be adequate alone. Although there are references that report on studies with design limitations, 6 good-quality studies provide good evidence. Safety Considerations in Pregnant Patients Imaging of the pregnant patient can be challenging, particularly with respect to minimizing radiation exposure and risk.
First Trimester Vaginal Bleeding. First Trimester Vaginal Bleeding RPOC may be identified by MRI, but MRI has little role in making the diagnosis of RPOC. RPOC and GTD may both manifest as an enhancing endometrial mass but are usually distinguishable on clinical grounds [74]. Contrast-enhanced pelvic MRI may be helpful to evaluate the extent of myometrial invasion and local extrauterine spread of GTD [75]. Uterine AVM can also be diagnosed with MRI [76]. CT An early IUP may be recognized on CT, but it is usually due to unintentional imaging of the pregnancy [67]. Because of its ionizing radiation, CT is generally not performed to evaluate vaginal bleeding in the first trimester of pregnancy. CT may identify an ectopic pregnancy [68], but reported cases of ectopic pregnancy diagnosed on CT were often performed for other reasons or in patients not known to be pregnant [77,78]. When a patient is clinically unstable, emergent care should generally not be delayed by additional imaging with CT or MRI. RPOC may be identified by CT, particularly when an enhancing mass is seen, but CT has little role in making the diagnosis of RPOC and the findings overlap those of GTD [74]. In patients with GTD, CT may be helpful in evaluating the extent of extrauterine spread [75]. Summary of Recommendations Transvaginal and transabdominal US are the most appropriate imaging modalities in patients with abnormal vaginal bleeding in the first trimester of pregnancy. Transvaginal US is generally the preferred modality. Transabdominal US is often complementary to transvaginal US and may sometimes be adequate alone. Although there are references that report on studies with design limitations, 6 good-quality studies provide good evidence. Safety Considerations in Pregnant Patients Imaging of the pregnant patient can be challenging, particularly with respect to minimizing radiation exposure and risk.