A 29-year-old woman presented with involuntary left limb twitching and jaw grinding. Magnetic resonance angiography at 3 T showed loss of the right middle cerebral artery flow signal and collateral vascular supply from the vertebrobasilar circulation (Figure 1). Dynamic contrast-enhanced perfusion magnetic resonance imaging revealed normal perfusion in the areas of the brain supplied by these collateral vessels but increased transit time in the right frontal lobe due to delayed perfusion by the leptomeningeal collateral circulation (Figure 2). Internal carotid artery dissection was subsequently confirmed by catheter angiography.
Lee CEC, Ng HBI, Yip CW, Lim CCT. Imaging Collateral CirculationMagnetic Resonance Angiography and Perfusion Magnetic Resonance Imaging at 3 T. Arch Neurol. 2005;62(3):492-493. doi:10.1001/archneur.62.3.492