title: Prevalence of subdural collections in children with macrocrania.
abstract: OBJECTIVE
  The relationship between enlarged subarachnoid spaces and subdural collections is poorly understood and creates challenges for clinicians investigating the etiology of subdural collections. The purpose of this study was to determine the prevalence of subdural collections on cross sectional imaging in children with macrocephaly correlating with subarachnoid space enlargement.
  
  
  METHODS
  The radiology information system of a large pediatric medical center was reviewed for "macrocrania" and "macrocephaly" on reports of cranial MRI/CT examinations in children <24 months of age, over a 24-month period. Head circumference was obtained from the clinical record. Studies were reviewed blindly for subdural collection presence and subarachnoid space size. Children with prior cranial surgery, parenchymal abnormalities, hydrocephalus, or conditions predisposing to parenchymal volume loss were excluded. Chart review was performed on those with subdural collections.
  
  
  RESULTS
  Imaging from 177 children with enlarged head circumference was reviewed. Nine were excluded, for a final cohort of 168 subjects (108 with enlarged subarachnoid space). Subdural collections were identified in 6 (3.6%), all with enlarged subarachnoid space (6/108, 5.6%). In 4, subdural collections were small, homogeneous, and nonhemorrhagic. In 2, the collections were complex (septations or hemorrhage). Two children were reported as victims of child abuse (both with complex collections). No definitive etiology was established in the other cases.
  
  
  CONCLUSIONS
  The prevalence of subdural collections in imaged children with macrocrania was 3.6%, all occurring in children with enlarged subarachnoid space. Our results suggest that enlarged subarachnoid space can be associated with some subdural collections in this cohort. Despite this, we believe that unexpected subdural collections in children should receive close clinical evaluation for underlying causes, including abusive head trauma.
authors.affiliation: Department of Pediatrics, Mayerson Center for Safe and Healthy Children.
authors.forename: M V
authors.initials: MV
authors.lastname: Greiner
authors.forename: T J
authors.initials: TJ
authors.lastname: Richards
authors.forename: M M
authors.initials: MM
authors.lastname: Care
authors.forename: J L
authors.initials: JL
authors.lastname: Leach
mesh_terms: D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D004388:Dura Mater / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006408:Hematoma, Subdural / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D058627:Megalencephaly / Q000175:diagnosis* / Q000453:epidemiology*; D009820:Ohio / Q000453:epidemiology; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013346:Subarachnoid Space / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*