Real-time and power Doppler imaging of fetal adrenal hemorrhage

Adrenal hemorrhages are not uncommon in newborns, but they may occur before birth. The incidence of adrenal hemorrhages based on extensive necropsy has been estimated as about 1.7 per 1000 births. With the increasing use of ultrasonography, prenatal recognition of fetal adrenal hemorrhages has become more common in recent years. We report an echogenic abdominal mass, which was found at 36 weeks of gestation using real-time ultrasound, and was enlarged during the 2-week follow-up period. No trauma history was noted during the pregnancy. Since the mass was close to the kidney, we performed power Doppler imaging to localize the lesion and tried to make a differential diagnosis. The left adrenal mass was posterior to the stomach and was without pulsatile blood flow inside. After birth, sonography confirmed a solid homogenous adrenal mass in the newborn. Seven days after birth, the persistent adrenal echogenic mass without resolution by computerized tomography led to a diagnosis of neuroblastoma. The mass was removed by surgery and adrenal hemorrhage diagnosed. The outcome of the adrenal hemorrhage was excellent. The differential diagnosis in unilateral adrenal mass is difficult from the images of 2-D ultrasound since similar pictures may occur among them. In this case, accurate localization of an adrenal mass is feasible using power Doppler imaging (PDI) before birth by determining its blood supply from the middle suprarenal artery. At the same time, fetal adrenal hemorrhages can be demonstrated as an avascular mass, which is the major difference from adrenal tumors. In conclusion, PDI offered more information to localize the adrenal glands from other lesions by separating the blood supply. In addition, the avascular adrenal mass favors the prenatal diagnosis of adrenal hemorrhage.