title: Comparision between Brain Atrophy and Subdural Volume to Predict Chronic Subdural Hematoma: Volumetric CT Imaging Analysis.
abstract: OBJECTIVE
  Brain atrophy and subdural hygroma were well known factors that enlarge the subdural space, which induced formation of chronic subdural hematoma (CSDH). Thus, we identified the subdural volume that could be used to predict the rate of future CSDH after head trauma using a computed tomography (CT) volumetric analysis.
  
  
  METHODS
  A single institution case-control study was conducted involving 1,186 patients who visited our hospital after head trauma from January 1, 2010 to December 31, 2014. Fifty-one patients with delayed CSDH were identified, and 50 patients with age and sex matched for control. Intracranial volume (ICV), the brain parenchyme, and the subdural space were segmented using CT image-based software. To adjust for variations in head size, volume ratios were assessed as a percentage of ICV [brain volume index (BVI), subdural volume index (SVI)]. The maximum depth of the subdural space on both sides was used to estimate the SVI.
  
  
  RESULTS
  Before adjusting for cranium size, brain volume tended to be smaller, and subdural space volume was significantly larger in the CSDH group (p=0.138, p=0.021, respectively). The BVI and SVI were significantly different (p=0.003, p=0.001, respectively). SVI [area under the curve (AUC), 77.3%; p=0.008] was a more reliable technique for predicting CSDH than BVI (AUC, 68.1%; p=0.001). Bilateral subdural depth (sum of subdural depth on both sides) increased linearly with SVI (p<0.0001).
  
  
  CONCLUSIONS
  Subdural space volume was significantly larger in CSDH groups. SVI was a more reliable technique for predicting CSDH. Bilateral subdural depth was useful to measure SVI.
authors.affiliation: Department of Neurosurgery, School of Medicine, Chungnam National University, Daejeon, Korea.
authors.forename: Min-Wook
authors.initials: MW
authors.lastname: Ju
authors.affiliation: Department of Neurosurgery, School of Medicine, Chungnam National University, Daejeon, Korea.
authors.forename: Seon-Hwan
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, School of Medicine, Chungnam National University, Daejeon, Korea.
authors.forename: Hyon-Jo
authors.initials: HJ
authors.lastname: Kwon
authors.affiliation: Department of Neurosurgery, School of Medicine, Chungnam National University, Daejeon, Korea.
authors.forename: Seung-Won
authors.initials: SW
authors.lastname: Choi
authors.affiliation: Department of Neurosurgery, School of Medicine, Chungnam National University, Daejeon, Korea.
authors.forename: Hyeon-Song
authors.initials: HS
authors.lastname: Koh
authors.affiliation: Department of Neurosurgery, School of Medicine, Chungnam National University, Daejeon, Korea.
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Youm
authors.affiliation: Department of Neurosurgery, School of Medicine, Chungnam National University, Daejeon, Korea.
authors.forename: Shi-Hun
authors.initials: SH
authors.lastname: Song
keywords: Hematoma, subdural, chronic; Subdural space; Tomography, X-ray computed; Volumetric analysis