Figure 2: (A–C) Initial MRI scan of the patient’s head, showing (arrows) areas of hyperintensity within the left side of the pons on FLAIR (A) and corresponding areas of hypointensity on diffusion-weighted imaging (B) and hyperintensity on the apparent diffusion coefficient map (C) consistent with chronic infarction (> 3 wk old). (D–F) Vessel wall MRI of the basilar artery using 3D T1 SPACE before gadolinium (E) and after gadolinium injection (F) showing smooth, concentric enhancement of the basilar vessel wall (arrowheads). Sequence parameters: echo time 12 ms, repetition time 700 ms, voxel size 0.8 × 0.8 × 0.9 mm. Material: Siemens 3 T MAGNETOM Skyra MRI scanner, 20-channel head and neck coil. (D) Corresponding CT angiography showing severe stenosis of the basilar artery without evidence of vessel wall plaque or calcification. (G) Coronal MRI maximum intensity projection reconstruction of the intracranial arteries using time-of-flight technique showing multifocal stenosis of the basilar artery and proximal stenosis of the bilateral posterior cerebral arteries. (H–I) Computed tomography angiography of the thorax with reconstruction along the longitudinal axis of the aorta, showing increased diameter of the ascending aorta, measuring 43.1 mm × 38.4 mm (H), and increased thickness of the aortic wall (I) consistent with aortitis. Note: ACA = anterior cerebral artery, Bas. a. = basilar artery, CT = computed tomography, FLAIR = fluid-attenuated inversion recovery, ICA = internal carotid artery, MCA = middle cerebral artery, MRI = magnetic resonance imaging, PCA = posterior cerebral arteries, SPACE = Sampling Perfection with Application-optimized Contrast using different flip angle Evolution, Vert. a. = vertebral artery.