[1] Sahlgrens Univ Hosp, Dept Neurosurg, Bla Straket 5, S-41345 Gothenburg, Sweden
[2] Sahlgrens Acad, Inst Neurosci & Physiol, Gothenburg, Sweden
[3] St Olavs Univ Hosp, Dept Neurosurg, N-7006 Trondheim, Norway
[4] Karolinska Univ Hosp Huddinge, Dept Radiol, Stockholm, Sweden
[5] Karolinska Inst, Div Med Imaging & Technol, Dept Clin Sci Intervent & Technol CLINTEC, Stockholm, Sweden
[6] St Olavs Univ Hosp, Dept Pathol, Trondheim, Norway
[7] Norwegian Univ Sci & Technol, Dept Lab Med Childrens & Womens Hlth, Trondheim, Norway
[8] St Olavs Univ Hosp, Natl Norwegian Advisory Unit Ultrasound & Image G, N-7006 Trondheim, Norway
[9] Norwegian Univ Sci & Technol, Dept Neuromed & Movement Sci, Fac Med, N-7491 Trondheim, Norway
[10] St Olavs Univ Hosp, Dept Radiol & Nucl Med, N-7006 Trondheim, Norway
[11] Norwegian Univ Sci & Technol, Dept Circulat & Med Imaging, Fac Med & Hlth Sci, Trondheim, Norway
[12] SINTEF, Dept Med Technol, Trondheim, Norway
[13] Karolinska Univ Hosp, Dept Neurosurg, Stockholm, Sweden