Assumptions of gCBF correction

Assumptions of gCBF correction

• Assumes subject gCBF values are are not condition dependent.
  • very large activation sites which do not have corresponding sites of decreased rCBF will result in an overestimation of gCBF and will cause non-activated sites to appear as being slightly activated in the SPM’95 analysis, thus reducing the apparent magnitude of the activation.
  • studies where gCBF may vary considerably (e.g. pharmacological activations) are inappropriate for traditional SPM’95 analysis since a large gCBF change may affect rCBF changes non-linearly.