Fig 4.

Two examples of discrepancies between 7T MR imaging and histology. Histologic sections (magnification ×10) with Van Gieson elastic (a) and H&E (b) staining, with corresponding 7T MR images of the T1- (c), PD- (d), T2- (e), and T2*-weighted (f) sequences. Cross-section of the right posterior cerebral artery (a1–f1) and left ICA (a2–f2) of subject 5. a1–f1, Histologic examination shows a fatty streak (black arrow, a1–b1), which is not seen as signal heterogeneity of the vessel wall on the MR images. A hypointense area away from the fatty streak can be appreciated on the MR images (dashed white arrow, d1–f1), but this does not correspond with any vessel wall pathology on histology, apart from intima-media artifacts. a2–f2, Histologic examination shows minor intimal thickening on the PD-, T2-, and T2*-weighted MR images. A hypointense line can be seen within a large part of the vessel wall (dashed white arrow, d2–f2), which corresponds to intima-media artifacts on the histologic sections (black arrow, a2–b2).