title: Hippocampal volumetry: Normative data in the Indian population.
abstract: BACKGROUND
  Mesial temporal sclerosis (MTS) is the most common cause of temporal lobe epilepsy. Quantitative analysis of the hippocampus using volumetry is commonly being used in the diagnosis of MTS and is being used as a marker in prognostication of seizure control. Although normative data for hippocampal volume (HV) is available for the western population, no such data is available for the Indian population.
  
  
  OBJECTIVE
  The aim of the study was to establish normative data for HV for the Indian population, which can aid in the accurate diagnosis of MTS.
  
  
  METHODS
  Magnetic resonance imaging (MRI) scans of 200 healthy volunteers were acquired using a 3 Tesla (3T) MRI scanner. Manual segmentation and volumetry was done using Siemens Syngo software. The data was analyzed using two tailed t-test to detect associations between HV and age, gender, and education. The data so obtained was also correlated with the data available from the rest of the world.
  
  
  RESULTS
  A mean HV of 2.411 cm(3) (standard deviation -0.299) was found in the study, which was significantly smaller when compared to the data from the western population. The right hippocampus was larger than the left, with a mean volume of 2.424 cm(3) and 2.398 cm(3), respectively. HV was detected to be significantly higher in males. No association was found between HV and age and education.
  
  
  CONCLUSIONS
  The values obtained in this study may be adopted as a standard in the evaluation of patients with intractable epilepsy.
authors.affiliation: Department of Neuro Imaging and Interventional Radiology, National Institute of Mental Health and Neuroscience, Banglore, Karnataka, India.
authors.forename: Aravind Narayan
authors.initials: AN
authors.lastname: Mohandas
authors.affiliation: Department of Neuro Imaging and Interventional Radiology, National Institute of Mental Health and Neuroscience, Banglore, Karnataka, India.
authors.forename: Rose Dawn
authors.initials: RD
authors.lastname: Bharath
authors.affiliation: Department of Neuro Imaging and Interventional Radiology, National Institute of Mental Health and Neuroscience, Banglore, Karnataka, India.
authors.forename: Parthipulli Vasuki
authors.initials: PV
authors.lastname: Prathyusha
authors.affiliation: Department of Neuro Imaging and Interventional Radiology, National Institute of Mental Health and Neuroscience, Banglore, Karnataka, India.
authors.forename: Arun K
authors.initials: AK
authors.lastname: Gupta
keywords: Manual hippocampal volumetry; manual hippocampal segmentation; mesial temporal sclerosis; normative data