title: Agenesis of the corpus callosum: an MR imaging analysis of associated abnormalities in the fetus.
abstract: OBJECTIVE
  Anomalies associated with callosal agenesis (ACC) found postnatally have been well documented. However, to our knowledge, no detailed MR imaging analysis of associated anomalies has been reported in a large cohort of fetuses with ACC. This study will assess those anomalies and compare them with postnatal cohorts of ACC, to identify associated fetal brain abnormalities that may give insight into etiology and outcome.
  
  
  METHODS
  All cases of ACC diagnosed on fetal MR imaging during an 11-year period were retrospectively reviewed, including fetal MR imaging, postnatal MR imaging, and autopsy findings. Neurodevelopmental outcome was classified as poor in children with seizures and/or severe neurodevelopmental impairment or in cases of neonatal death.
  
  
  RESULTS
  Twenty-nine cases of ACC were identified. Median gestational age was 26.14 weeks (range, 19.71-36.43 weeks). Twenty-three fetuses had delayed sulcation and/or too-numerous cortical infoldings (abnormal morphology). Fifteen fetuses had cerebellar and/or brain stem abnormalities. Fetal MR imaging findings suggested a genetic syndrome in 5 fetuses and an acquired etiology or genetic/metabolic disorder in 2 fetuses. Findings were confirmed in 8 cases with postnatal MR imaging, except for delayed sulcation and small vermis, and in 4 cases with autopsy, except for periventricular nodular heterotopia and abnormalities in areas not examined by autopsy. Neurodevelopmental outcome was good in 7 and poor in 9 children. Abnormal sulcal morphology and/or infratentorial abnormalities were present in those with poor outcome and absent in those with good outcome.
  
  
  CONCLUSIONS
  ACC is infrequently isolated in fetuses. Abnormal sulcation is common and suggests more diffuse white matter dysgenesis in these fetuses.
authors.affiliation: Department of Radiology, University of California, San Francisco, San Francisco, Calif., USA.
authors.forename: P H
authors.initials: PH
authors.lastname: Tang
authors.forename: A I
authors.initials: AI
authors.lastname: Bartha
authors.forename: M E
authors.initials: ME
authors.lastname: Norton
authors.forename: A J
authors.initials: AJ
authors.lastname: Barkovich
authors.forename: E H
authors.initials: EH
authors.lastname: Sherr
authors.forename: O A
authors.initials: OA
authors.lastname: Glenn
mesh_terms: D055673:Acrocallosal Syndrome / Q000401:mortality / Q000473:pathology*; D061085:Agenesis of Corpus Callosum; D015331:Cohort Studies; D003337:Corpus Callosum / Q000473:pathology; D005260:Female; D005315:Fetal Diseases / Q000401:mortality / Q000473:pathology*; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012189:Retrospective Studies