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. Author manuscript; available in PMC: 2015 Jul 1.
Published in final edited form as: J Magn Reson Imaging. 2014 Oct 1;42(1):23–41. doi: 10.1002/jmri.24768

Figure 10.

Figure 10

SWI can provide important information in the setting of stroke, as in this 50-year-old male who presented with acute dissection and occlusion of the right internal carotid artery in the neck. Diffusion-weighted image (a) showed a small infarct in the right frontal white matter (dashed white arrow) Parametric map of mean transit time, from dynamic-contrast enhanced MR perfusion (b) showed a large area of delayed perfusion (large white arrows) in the right MCA territory, demarcating a large penumbra. SWI image at the level of the circle of Willis (c) showed abnormal hypointense signal in the right MCA (open white arrow) compared to the normal hyperintense signal in the left MCA (open black arrow), indicating slow flow or intravascular thrombus or markedly elevated intra-arterial deoxyhemoglobin. SWI image at the level of the lateral ventricles (d) showed markedly prominent cortical and deep medullary veins in the right hemisphere (small solid white arrows), matching the penumbra. The prominent veins indicate high levels of deoxyhemoglobin, indicating increased oxygen extraction. SWI parameters are: 3T, TE = 20 msec, TR = 29 msec, FA = 15°, FOV 230 mm × 172 mm, matrix 448 × 336, 2 mm thick acquisition displayed with 16 mm minIP.