Acute arterial ischemic and hemorrhagic stroke, PRES and CSVT. Axial DWI and ADC (shown in A-B and C-D in each of the 4 sets of images, respectively) MRIs of the brain demonstrate increased DWI signal with corresponding decreased ADC signal, consistent with restricted diffusion along the left MCA territory most consistent with acute arterial ischemic stroke. Axial T1-weighted MRI (E), axial T2-weighted MRI (F), axial FLAIR (G), and axial GRE (H) images in patients with SCA demonstrate ill- defined mixed intensity focus within the right basal ganglia region with surrounding vasogenic edema. The lesion demonstrates T1 hyperintensity with hypointensity on axial T2 and GRE consistent with hemorrhage. Also seen is intraventricular extension of blood (F, arrow). GRE MR sequences are most sensitive for the detection of intracranial hemorrhage and may demonstrate more diffuse signal loss than the actual lesion, also known as blooming, as seen in this case. Axial FLAIR (I) and coronal FLAIR images MR (J-K) of the brain demonstrates bilateral near symmetric hyperintense signal involving the parieto-occipital lobes with superior frontal involvement, in a distribution and pattern most consistent with PRES. There is both subcortical (I, K arrows) and cortical involvement. Axial DWI (L) demonstrates no corresponding increased signal to suggest for restricted diffusion. Transverse (M) and coronal (N), maximum intensity projection images from a phase contrast MRV. There is no signal within the right transverse sinus due to thrombosis. Axial T1-weighted MRI (O) demonstrates a small well-defined hyperintense focus within the right occipital white matter with hypointensity on axial GRE (P), consistent with hemorrhagic venous infarction secondary to thrombosis.