Arjen Lindenholz

67 The Use and Pitfalls of Intracranial Vessel Wall Imaging 3 Figure 9. Vessel wall MRI in a 47-year-old male with a clinically proven primary angiitis of the Central Nervous System (PACNS). Although biopsy was inconclusive, DSA showed extensive central and peripheral segmental arterial narrowing. (A and C) 3T coronal maximum intensity projections (maxIPs) of the 3D TOF-MRA and (B and D) 3T transverse postcontrast T 1 -weighted vessel wall images (voxel size 0.5 x 0.5 x 1.0 mm 3 ) at presentation (A and B) and 7 months after immunosuppressive therapy (C and D) . At presentation, the TOF-MRA shows multi-segmental luminal narrowing in PCA and MCA (respective open and white arrowheads in (A) ) and left distal ICA (right arrow), while the corresponding vessel wall images (voxel size 0.5 x 0.5 x 1.0 mm 3 ) (B) show more extensive disease, with clear concentric vessel wall enhancement of the left distal ICA-A1-M1 bifurcation (right arrow) as well as the right distal ICA (left arrow). After therapy, a reduction in the multi-segmental luminal narrowing can be seen on the TOF-MRA (respective open and white arrowheads in (C) ), while T 1 -weighted vessel wall MR images shows resolution of vessel wall enhancement in both distal ICAs (white arrows).