Arjen Lindenholz

34 CHAPTER 2 Figure 7 . B1-inhomogeneity artifacts on a 7T MR FLAIR images of a 42-year-old female with a recent left-sided ischemic stroke. ( A ) A transverse 3T FLAIR image, repetition time 10000 ms, echo time 120 ms, inversion time 2800 ms, acquired voxel size 0.75 × 1.27 × 4.00 mm 3 , reconstructed voxel size 0.4 × 0.4 × 4.0 mm 3 , field-of-view 230 x 182 × 129 mm 3 , scan duration 2:00 minutes. No B0- or B1-inhomogeneity artifacts are seen on the image. Some patient motion is present in the image. Two hyperintense lesions are present; along the posterior margin of the left putamen and in the left insular region (white arrowheads). ( B ) A transverse 7T FLAIR image, repetition time 8000 ms, echo time 300 ms, inversion time 2200 ms, acquired voxel size 0.8 × 0.8 × 0.8 mm 3 , reconstructed voxel size 0.5 × 0.5 × 0.5 mm 3 , field-of-view 250 x 250 × 190 mm 3 , scan time 10 minutes 48 seconds. The image is affected by B1-imhomogeniteity artefacts, best seen in both temporal lobes (white arrows). The two hyperintense lesions are seen in much more detail compared to the 3T MR image in ( A ) (white arrowheads). Conclusion We described the added value and emerging applications of 7T MRI in the clinical evaluation of cerebrovascular disorders. 7T MRI has been proven superior to lower field-strength MRI for the evaluation of the intracranial vessel lumen and vessel walls, and allows to study the brain parenchyma for microvascular pathology on a submillimeter scale.