title: Fetal suprarenal masses--assessing the complementary role of magnetic resonance and ultrasound for diagnosis.
abstract: OBJECTIVE
  To assess the value and complementary roles of fetal MRI and US for characterization and diagnosis of suprarenal masses.
  
  
  METHODS
  We conducted a multi-institutional retrospective database search for prenatally diagnosed suprarenal masses between 1999 and 2012 and evaluated the roles of prenatal US and fetal MRI for characterization and diagnosis, using postnatal diagnosis or surgical pathology as the reference standard. Prenatal US and fetal MRI were assessed for unique findings of each modality.
  
  
  RESULTS
  The database yielded 25 fetuses (gestational age 20-37 weeks) with suprarenal masses. Twenty-one fetuses had prenatal US, 22 had MRI, 17 had both. Postnatal diagnoses included nine subdiaphragmatic extralobar sequestrations, seven adrenal hemorrhages, five neuroblastomas (four metastatic), two lymphatic malformations, one duplex kidney with upper pole cystic dysplasia, and one adrenal hyperplasia. Ultrasound was concordant with MRI for diagnoses in 12/17 (70.6%) cases. Discordant diagnoses between US and MRI included three neuroblastomas and two adrenal hemorrhages. In the three neuroblastomas US was equivocal and MRI was definitive for neuroblastoma, demonstrating heterogeneous, intermediate-signal solid masses and liver metastases. In the two cases of adrenal hemorrhage US was equivocal and MRI was definitive with signal characteristics of hemorrhage. In 2/4 neuroblastomas, Doppler US demonstrated a systemic artery suggesting extralobar sequestration; however MRI signal characteristics correctly diagnosed neuroblastoma. All cases of extralobar sequestration were correctly diagnosed by US and MRI.
  
  
  CONCLUSIONS
  US and MRI both accurately detect suprarenal masses. MRI complements US in equivocal diagnoses and detects additional findings such as liver metastases in neuroblastoma.
authors.affiliation: Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, USA.
authors.forename: Siobhan M
authors.initials: SM
authors.lastname: Flanagan
authors.affiliation: Department of Radiology, Stanford University, Lucile Packard Children's Hospital, 725 Welch Road, MC 5913, Stanford, 94305, CA, USA. rubesova@stanford.edu.
authors.forename: Erika
authors.initials: E
authors.lastname: Rubesova
authors.affiliation: Department of Radiology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Diego
authors.initials: D
authors.lastname: Jaramillo
authors.affiliation: Department of Radiology, Stanford University, Lucile Packard Children's Hospital, 725 Welch Road, MC 5913, Stanford, 94305, CA, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Barth
mesh_terms: D000307:Adrenal Gland Diseases / Q000175:diagnosis* / Q000196:embryology; D000311:Adrenal Glands / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000473:pathology; D002140:California; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D064847:Multimodal Imaging / Q000379:methods*; D010414:Pennsylvania; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000379:methods*
keywords: Fetus; Magnetic resonance imaging; Mass; Prenatal; Suprarenal; Ultrasound