title: Accuracy of neurosonography and MRI in clinical management of fetuses referred with central nervous system abnormalities.
abstract: OBJECTIVE
  To assess the accuracy of expert neurosonography (two- and three-dimensional NSG) in the characterization of major fetal central nervous system (CNS) anomalies seen at a tertiary referral center and to report the differential clinical usefulness of magnetic resonance imaging (MRI) used as a second-line diagnostic procedure in the same cohort.
  
  
  METHODS
  This was a retrospective analysis of all 773 fetuses with confirmed CNS abnormalities referred to our center between 2005 and 2012. The following variables were analyzed: gestational age at NSG and MRI, NSG and MRI diagnoses, indication for MRI (confirmation of NSG findings; diagnostic doubt; search for possible additional brain anomalies), association with other malformations, diagnostic accuracy of NSG vs MRI (no additional clinical value for either MRI or NSG; additional information with clinical/prognostic significance on MRI relative to NSG; additional information with clinical/prognostic significance on NSG relative to MRI, NSG and MRI concordant but incorrect) and final diagnosis, which was made at autopsy or postnatal MRI/surgery.
  
  
  RESULTS
  CNS malformations were associated with other anomalies in 372/773 (48.1%) cases and were isolated in the remaining 401 (51.9%) cases. NSG alone was able to establish the diagnosis in 647/773 (83.7%) cases. MRI was performed in 126 (16.3%) cases. The indication for MRI was: confirmation of NSG diagnosis in 59 (46.8%) cases; diagnostic query (in the case of inconclusive or uncertain finding on NSG) in 20 (15.9%) cases; search for possible additional brain anomalies in 47 (37.3%) cases. NSG and MRI were concordant and correct in 109/126 (86.5%) cases. Clinically relevant findings were evident on MRI alone in 10/126 (7.9%) cases (1.3% of the whole population) and on NSG alone in 6/126 (4.8%) cases; in all six of these cases, MRI had been performed at < 24 weeks of gestation. In one case, both NSG and MRI diagnoses were incorrect. The main type of malformation in w ich MRI played an important diagnostic role was space-occupying lesions, MRI identifying clinically relevant findings in 42.9% (3/7) of these cases.
  
  
  CONCLUSIONS
  (1) In a tertiary referral center with good NSG expertise in the assessment of fetal CNS malformations, MRI is likely to be of help in a limited proportion of cases; (2) MRI is more useful after 24 weeks of gestation; (3) the lesions whose diagnosis is most likely to benefit from MRI are gross space-occupying lesions.
authors.affiliation: Fetal Medicine and Cardiology Unit, Department of Gynecology and Obstetrics, University Federico II of Naples, Naples, Italy; Fetal Medicine and Surgery Unit, Giannina Gaslini Institute, Genoa, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Paladini
authors.forename: M
authors.initials: M
authors.lastname: Quarantelli
authors.forename: G
authors.initials: G
authors.lastname: Sglavo
authors.forename: G
authors.initials: G
authors.lastname: Pastore
authors.forename: A
authors.initials: A
authors.lastname: Cavallaro
authors.forename: M R
authors.initials: MR
authors.lastname: D'Armiento
authors.forename: M
authors.initials: M
authors.lastname: Salvatore
authors.forename: C
authors.initials: C
authors.lastname: Nappi
mesh_terms: D002490:Central Nervous System / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000196:embryology*; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009421:Nervous System Malformations / Q000000981:diagnostic imaging* / Q000196:embryology; D011247:Pregnancy; D011379:Prognosis; D011859:Radiography; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal / Q000379:methods*
keywords: 3D ultrasound; CNS; fetus; magnetic resonance imaging; space-occupying lesion