44 10. Higashida RT, Halbach VV, Dowd CF, Dormandy B, Bell J, Hieshima GB. Intravascular balloon dilatation therapy for intra- cranial arterial vasospasm: patient selection, technique and clini- cal results. Neurosurg Rev 1992;15:89–95. 11. Eskridge JM, McAuliffe W, Song JK, et al. Balloon angioplasty for the treatment of vasopasm: results of first 50 cases. Neurosurgery 1998;42:510–517. 12. Firlik AD, Kaufman AM, Jungreis CA, Yonas H. Effect of translu- minal angioplasty on cerebral blood flow in the management of symptomatic vasospasm following aneurysmal subarachnoid hemorrhage. J Neurosurg 1997;86:830–839. 13. Wintermark M, Maeder P, Thiran JP, Schnyder P, Meuli R. Quantitative assessment of regional cerebral blood flows by perfusion CT studies at low injection rates: a critical review of the underlying theoretical models. Eur Radiol 2001;11: 1220–1230. 14. Wintermark M, Fischbein NJ, Smith WS, Ko NU, Quist M, Dillon WP. Accuracy of dynamic perfusion CT with deconvolution in Majoie et al. detecting acute hemispheric stroke. AJNR Am J Neuroradiol 2005;26:102–112. 15. Eskridge JM, Song JK. A practical approach to the treatment of vasospasm. AJNR Am J Neuroradiol 1997;18:1653–1660. 16. Hoeffner EG, Case I, Jain R, et al. Cerebral perfusion CT: tech- nique and clinical applications. Radiology 2004;231:632–644. 17. Grubb RL, Raichle ME, Eichling JO, Gado MH. Effects of subarachnoid hemorrhage on cerebral blood volume, blood flow and oxygen utilization in humans. J Neurosurg 1977;46:446–453. 18. Miles KA, Griffiths MR. Perfusion CT: a worthwile enhancement? Brit J Radiol;76:220–231. 19. Kealey SM, Loving VA, Delong DM, Eastwood JD. User-defined vascular input function curves: influence on mean perfusion parameter values and signal-to-noise ratio. Radiology 2004;231: 587–593. 20. Sanelli PC, Lev MH, Eastwood JD, Gonzalez RG, Lee TY. The effect of varying user-selected input parameters on quantitative values in CT perfusion maps. Acad Radiol 2004;11:1085–1092. Neurocritical Care ♦ Volume 6, 2007