[1] Univ Copenhagen, Fac Hlth & Med Sci, Glostrup Hosp, Danish Headache Ctr, DK-2600 Glostrup, Denmark
[2] Univ Copenhagen, Fac Hlth & Med Sci, Glostrup Hosp, Dept Neurol, DK-2600 Glostrup, Denmark
[3] Leiden Univ, Med Ctr, Dept Radiol, Div Image Proc, NL-2300 RA Leiden, Netherlands
[4] Univ Copenhagen, Gentofte Hosp, Dept Clin Biochem, DK-2600 Glostrup, Denmark
[5] Univ Copenhagen, Fac Hlth & Med Sci, Glostrup Hosp, Funct Imaging Unit,Diagnost Dept, DK-2600 Glostrup, Denmark
[6] Univ Copenhagen, Fac Hlth & Med Sci, Bispebjerg Hosp, Dept Clin Biochem, DK-2600 Glostrup, Denmark