In a pregnant patient with suspected pheochromocytoma, what is the preferred imaging modality?

• A. Ultrasound abdomen
• B. CT abdomen
• C. MRI abdomen
• D. PET scan

Answer: (C)

In pregnancy, locating a suspected pheochromocytoma should be done with imaging that avoids fetal radiation while still accurately identifying adrenal tumors. MRI of the abdomen fits this need because it uses no ionizing radiation and provides excellent soft-tissue contrast, making it highly effective for visualizing adrenal glands and detecting pheochromocytomas.

CT would expose the fetus to ionizing radiation, which is undesirable during pregnancy, even though it’s very good at detecting adrenal tumors. Ultrasound is safe but often limited for adrenal localization due to body habitus and operator dependence, and may not reliably characterize or locate the tumor. PET involves radioactive tracers and substantial radiation exposure, making it less suitable in this setting.

Thus, the preferred imaging modality is MRI of the abdomen, ideally without gadolinium, to minimize fetal risk while allowing accurate tumor localization.