FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT has no role in further characterization of an indeterminate adnexal lesion in pregnancy, given the accuracy of US and MRI. MRI Pelvis Without and With IV Contrast Gadolinium-based contrast agents should not be routinely administered to pregnant patients [95]. Free gadolinium is toxic and thus administered in its chelated form. Gadolinium has been shown to cross the placenta and enter fetal circulation in nonhuman primate models. It has potential but is unclear or has unknown risks of exposure to the developing fetus [95,96]. A study by Ray et al [97] in 2016 showed a slightly increased risk of stillbirth or neonatal death (17.6/1,000 in exposed fetuses versus 6.9/1,000 in fetuses not undergoing MRI) and slightly increased risk of childhood rheumatological, inflammatory, or infiltrative skin conditions. Gadolinium-based contrast agents are category C drugs as determined by the FDA, with adverse effects in animal studies without adequate studies in humans, and their use in pregnancy is restricted to situations where the potential benefits of imaging far outweigh the potential risk to the fetus [98]. A study by Thomassin-Naggara et al [99] in 2017 demonstrated an overall accuracy of MRI in up to 88% in pregnant patients using the ADNEX MR score in a subset of 36 masses. In this study, 7 of 31 patients received gadolinium contrast based on radiologist discretion during the examination, with all 7 demonstrating malignant tumors on final pathology. MRI Pelvis Without IV Contrast MRI without contrast is useful for the evaluation of an US indeterminate adnexal lesion in pregnant patients who cannot receive gadolinium. MRI does not use ionizing radiation and is deemed safe in pregnant patients [95]. Up to 22% to 24% of adnexal masses remain indeterminate after US evaluation [61,62]. MRI can be helpful in the setting of indeterminate masses, large lesions >10 cm in size, and determination of origin in adnexal masses.
Clinically Suspected Adnexal Mass No Acute Symptoms. FDG-PET/CT Skull Base to Mid-Thigh FDG-PET/CT has no role in further characterization of an indeterminate adnexal lesion in pregnancy, given the accuracy of US and MRI. MRI Pelvis Without and With IV Contrast Gadolinium-based contrast agents should not be routinely administered to pregnant patients [95]. Free gadolinium is toxic and thus administered in its chelated form. Gadolinium has been shown to cross the placenta and enter fetal circulation in nonhuman primate models. It has potential but is unclear or has unknown risks of exposure to the developing fetus [95,96]. A study by Ray et al [97] in 2016 showed a slightly increased risk of stillbirth or neonatal death (17.6/1,000 in exposed fetuses versus 6.9/1,000 in fetuses not undergoing MRI) and slightly increased risk of childhood rheumatological, inflammatory, or infiltrative skin conditions. Gadolinium-based contrast agents are category C drugs as determined by the FDA, with adverse effects in animal studies without adequate studies in humans, and their use in pregnancy is restricted to situations where the potential benefits of imaging far outweigh the potential risk to the fetus [98]. A study by Thomassin-Naggara et al [99] in 2017 demonstrated an overall accuracy of MRI in up to 88% in pregnant patients using the ADNEX MR score in a subset of 36 masses. In this study, 7 of 31 patients received gadolinium contrast based on radiologist discretion during the examination, with all 7 demonstrating malignant tumors on final pathology. MRI Pelvis Without IV Contrast MRI without contrast is useful for the evaluation of an US indeterminate adnexal lesion in pregnant patients who cannot receive gadolinium. MRI does not use ionizing radiation and is deemed safe in pregnant patients [95]. Up to 22% to 24% of adnexal masses remain indeterminate after US evaluation [61,62]. MRI can be helpful in the setting of indeterminate masses, large lesions >10 cm in size, and determination of origin in adnexal masses.