title: Quantification of intracranial contribution to rheoencephalography by a numerical model of the head.
abstract: OBJECTIVE
  Partial contributions of intracranial and extracranial circulation to rheoencephalography (REG) remain uncertain. The main goal of this work is to determine theoretically the capability of REG techniques to reflect intracranial blood flow.
  
  
  METHODS
  Head and current injection electrodes were computationally modeled to assess REG sensitivity to brain and scalp conductivity changes. Data obtained were related to tissue perfusions to calculate the partial contribution of cerebral blood perfusion to REG I, REG II and monopolar REG and to assess their amplitudes.
  
  
  RESULTS
  When REG I and monopolar REG were used, the theoretical maximum of intracranial contribution was reached with large current injection electrodes, being 8% for REG I and 12% for monopolar REG. However, some specific REG II electrode arrangements showed a nil contribution of the extracranial circulation and a minimum influence of the electrode size.
  
  
  CONCLUSIONS
  These results may explain the disagreement on REG origin and suggest a theoretically optimum electrode arrangement.
authors.affiliation: Laboratorio Integrado de Bioingeniería, Departamento de Ingeniería Electrónica, Universidad Politécnica de Valencia, Cno. de Vera S/N, 46022, Valencia, Spain. jjperez@eln.upv.es
authors.forename: J J
authors.initials: JJ
authors.lastname: Pérez
authors.forename: E
authors.initials: E
authors.lastname: Guijarro
authors.forename: J A
authors.initials: JA
authors.lastname: Barcia
mesh_terms: D001921:Brain / Q000098:blood supply* / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003198:Computer Simulation; D004553:Electric Conductivity; D004566:Electrodes; D004569:Electroencephalography / Q000379:methods / Q000592:standards; D006257:Head / Q000502:physiology; D006801:Humans; D008954:Models, Biological; D010992:Plethysmography, Impedance / Q000379:methods* / Q000592:standards; D012044:Regression Analysis; D012680:Sensitivity and Specificity