Eur Radiol (2011) 21:875–881 DOI 10.1007/s00330-010-1952-y NEURO Distribution of cerebral blood flow in the caudate nucleus, lentiform nucleus and thalamus in patients with carotid artery stenosis Nolan S. Hartkamp & Reinoud P. H. Bokkers & H. Bart van der Worp & M. J. P. van Osch & L. Jaap Kappelle & Jeroen Hendrikse Received: 24 May 2010 / Revised: 1 August 2010 / Accepted: 17 August 2010 / Published online: 18 September 2010 # The Author(s) 2010. This article is published with open access at Springerlink.com Abstract Objective To investigate the influence of internal carotid artery (ICA) stenosis on the distribution of blood flow to the caudate nucleus, lentiform nucleus, and thalamus. Methods We studied 18 healthy control subjects, 20 patients with a unilateral asymptomatic ICA stenosis, and 15 patients with a recently symptomatic unilateral ICA stenosis. The contribution of the ICAs and the basilar artery to the perfusion of the deep brain structures was assessed by perfusion territory selective arterial spin labeling (ASL) MRI. Differences were tested with a two-tailed Fishers’ exact test. Results The caudate nucleus was predominantly supplied with blood by the ipsilateral ICA in all groups. In 4 of the 15 (27%) the symptomatic patients, the caudate nucleus partially received blood from the contralateral ICA, compared to none of the 18 healthy control subjects (p = 0.03). The lentiform nucleus and the thalamus were predominantly supplied with blood by the ipsilateral ICA and basilar artery respectively in all groups. N. S. Hartkamp (*) : R. P. H. Bokkers : J. Hendrikse Department of Radiology, University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands e-mail: n.s.hartkamp@umcutrecht.nl H. B. van der Worp : L. J. Kappelle Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands M. J. P. van Osch Department of Radiology, C.J. Gorter Institute of High Field MRI, Leiden University Medical Center, Leiden, The Netherlands Conclusion In patients with a symptomatic ICA stenosis, the caudate nucleus may be supplied with blood by the contralateral ICA more often than in healthy controls. Keywords Magnetic resonance imaging . Cerebral hemodynamics . Perfusion . Basal ganglia . Carotid artery stenosis Introduction There is wide variation in the perfusion territories of the brain-feeding arteries, which is most pronounced in those supplying the deep brain structures [1–3]. The caudate nucleus, lentiform nucleus, and thalamus are supplied with blood from groups of different perforating arteries that branch either from the anterior, middle and posterior cerebral artery or from the posterior communicating artery [2, 4–7]. In addition to the normal variability, there may be a shift in the perfusion territories of the brain-feeding arteries in patients with steno-occlusive disease of the ICA, due to the recruitment of collateral blood pathways [8, 9]. Perfusion territory selective arterial spin labeling magnetic resonance imaging (ASL-MRI) has recently been intro- duced to visualize the perfusion territories of the individual brain-feeding arteries [10, 11]. ASL-MRI is a non-invasive technique for imaging whole-brain cerebral perfusion that uses radiofrequency pulses to magnetically label blood and does not require gadolinium-based contrast agents. The aim of our study was to investigate the influence of ICA stenosis on the distribution of cerebral blood flow to the caudate nucleus, lentiform nucleus and thalamus with perfusion territory selective ASL-MRI in patients with