Abstract
This study assessed the sensitivity of contrast-enhanced dynamic echo-planar imaging to subtotal stenosis of the middle cerebral artery as a model of mildly compromised cerebral blood supply. Dynamic data was analyzed in terms of the relative cerebral blood volume (rCBV) and bolus peak arrival time (BPAT), and the prognostic utility of these parameters was compared with measurements of the regional apparent diffusion coefficient of water (ADC) with the goal of identifying tissue at risk of future infarct. Dynamic echo-planar MRI in conjunction with bolus administration of a magnetic susceptibility contrast agent was used in a cat model of acute, unilateral cerebral ischemia, induced by partial occlusion (stenosis) of the right middle cerebral artery. The contrast agent transit was analyzed in terms of the regional time of arrival of the peak bolus-induced signal loss as well as the time integral of agent concentration, Pixel-by-pixel maps of cerebrovascular parameters (rCBV, BPAT) were constructed along with spatial maps of the ADC, derived from diffusion-weighted MR images at the same anatomical level. Arterial stenosis was maintained for a 6 h period, after which histological determination of tissue viability was obtained. Maps of BPAT showed sensitivity to mild flow perturbations not detectable from cerebral blood volume estimations from the same bolus injection or from determinations of the apparent diffusion coefficient of water. Of nine animals subjected to subtotal stenosis, BPAT identified compromised tissue in all nine after 1 h of stenosis. No animals had differences in rCBV or ADC at this point. Stenosis was maintained for 6 h in 7 of the cats. After 6 h, two cats had developed identifiable injury on ADC and rCBV maps. Of the remaining five, where rCBV and ADC appeared normal even after 6 h, three exhibited abnormal histological staining, whereas two indeed appeared normal. In the other two cats where initial subtotal stenosis was later made total, the anatomical region identified as “compromised” during stenosis, by the appearance of delayed bolus peak arrival, matched the area of subsequent infarct after total occlusion of the same vessel. Echo planar imaging in conjunction with bolus administration of a magnetic susceptibility contrast agent appears sensitive to mild perturbations to blood supply. These perturbations may not be resolved on synthesized maps of relative cerebral blood volume or apparent diffusion coefficient. Although “compromised” blood supply does not necessarily lead to infarct (over the 6-h course of this study), it may represent tissue particularly at risk of infarct in the event of further insult.
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Belliveau JW, Rosen BR, Kantor HL, Rzedzian RR, Kennedy DN, McKinstry RC, Vevea JM, Cohen MS, Pykett IL, Brady TJ (1990) Functional cerebral imaging by susceptibility-contrast NMR. Magn Reson Med 14: 538–546
Hamberg L, MacFarlene R, Tasdemiroglu E, Boccalini P, Hunter GH, Belliveau JW, Moskowitz MA, Rosen BR (1993) Measurement of cerebrovascular changes in cats after transient ischemia using dynamic magnetic resonance imaging. Stroke 24: 444–451
Rosen BR, Belliveau JM, Vevea JM, Brady TJ (1990) Perfusion imaging with NMR contrast agents. Magn Reson Med 14: 249–265
Kucharczyk J, Roberts TPL, Moseley ME, Watson A (1993) Applications of contrast-enhanced perfusion-sensitive MR imaging in the diagnosis of cerebrovascular disorders. J Magn Reson Imaging 3(1): 241–245
Kucharczyk J, Vexler Z, Roberts TPL, Asgari H, Mintorovitch J, Derugin N, Watson A, Moseley ME (1993) Echo-planar perfusion-sensitive imaging of acute cerebral ischemia. Radiology 188: 711–717
Roberts TPL, Vexler ZS, Derugin N, Moseley ME, Kucharczyk J (1993) High-speed MR imaging of ischemic brain injury following partial stenosis of the middle cerebral artery. J Cereb Blood Flow Metab 13: 940–946
Finelli DA, Hopkins AL, Selman WR, Crumrine RC, Bhatti SU, Lust WD (1992) Evaluation of experimental early acute cerebral ischemia before the development of edema: use of dynamic contrast enhanced and diffusion-weighted MR scanning. Magn Reson Med 27: 189–197
Minematsu K, Li L, Sotak CH, Davis MA, Fisher M (1992) Reversible focal ischemic injury demonstrated by diffusion-weighted MR imaging in rats. Stroke 23: 1304–1311
Edelman RR, Mattle HP, Atkinson DJ, Hill T, Finn JP, Mayman C, Ronthal M, Hoogewoud H, Kleefield J (1990) Cerebral blood flow: assessment with dynamic contrast-enhanced T2s-weighted MR imaging at 1.5 T. Radiology 176: 211–220
Villringer A, Rosen BR, Belliveau JW, Ackerman JL, Lauffer RB, Buxton RB, Chao Y-S, Wedeen VJ, Brady TJ (1988) Dynamic imaging with lanthanide chelates in normal brain: contrast due to magnetic susceptibility effects. Magn Reson Med 6: 164–174
Rocklage SM, Moseley ME, Kucharczyk J, Norman D, Quay SC (1990) Early detection of perfusion deficits caused by regional cerebral ischemia in cats. T2-weighted magnetic susceptibility MRI using a nonionic dysprosium contrast agent. Invest Radiol 25(1): S37-S38
Weisskoff RM, Chesler D, Boxerman JL, Rosen BR (1993) Pitfalls in MR measurement of tissue blood flow with intravascular tracers. Which mean transit time? Magn Reson Med 29(4): 553–558
Derugin N, Roberts TPL (1994) A new and reproducible technique for experimental middle cerebral artery stenosis. Microsurgery 15: 70–72
LeBihan D (1990) Magnetic resonance imaging of perfusion. Magn Reson Med 14: 283–292
Kucharczyk J, Chew W, Derugin N, Moseley ME, Rollin C, Berry I, Norman D (1989) Nicardipine reduces ischemic brain injury. Magnetic resonance imaging/spectroscopy study in cat. Stroke 20: 268–274
Bose B, Jones SC, Lorig R, Friel HT, Weinstein M, Little JR (1988) Evolving focal ischemia in cats: spatial correlation of nuclear magnetic resonance imaging, cerebral blood flow, tetrazolium staining and histopathology. Stroke 19(1): 28–37
Bruggen N van, Cullen BM, King MD, Doran M, Williams SR, Gadian DG, Cremer JE (1992) T2- and diffusion-weighted magnetic resonance imaging of a focal ischemic lesion in rat brain. Stroke 23: 576–582
Kucharczyk J, Moseley ME, Kurhanewicz J, Norman D (1989) MRS of ischemic/hypoxie brain disease. Invest Radiol 24(12): 951–954
Strong AJ, Tomlinson BE, Venables GS, Gibson G, Hardy JA (1983) The cortical ischaemic penumbra associated with occlusion of the middle cerebral artery in the cat. 2. Studies of histopathology, water content, and in vitro neurotransmitter uptake. J Cereb Blood Flow Metab 3(1): 97–107
Heiss WD (1983) Flow thresholds of functional and morphological damage of brain tissue. Stroke 14(3): 329–331
Hossmann KA (1989) Calcium antagonists for the treatment of brain ischemia: a critical appraisal. In: Krieglstein J (ed) Pharmacology of cerebral ischemia. CRC Press, Boca Raton
Truwit CL, Kucharczyk J (1992) Reversible cerebral ischemia. Neuroimaging Clin North Am 2(3): 577–595
Derlon JM, Bouvard G, Petit MC, Viader F, Lechevalier B, Morin B, Houtteville JP (1992) Hemodynamic assessment of carotid artery obstructive lesions: comparison of PET and SPECT. In: Schmiedek P, Einhäupl K, Kirsch CM (eds) Stimulated cerebral blood flow. Springer, Berlin Heidelberg New York, pp 94–110
Buell U, Reichle W, Kaiser HJ, Isensee K, Bares R, Altenhoefer C, Ringelstein EB (1992) Cerebral blood flow to cerebral blood volume relationship as a correlate to cerebral perfusion reserve. In: Schmiedek P, Einhäupl K, Kirsch CM (eds) Stimulated cerebral blood flow. Springer, Berlin Heidelberg New York, pp 111–120
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Roberts, T.P.L., Vexler, Z.S., Vexler, V. et al. Sensitivity of high-speed “perfusion-sensitive” magnetic resonance imaging to mild cerebral ischemia. Eur. Radiol. 6, 645–649 (1996). https://doi.org/10.1007/BF00187665
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DOI: https://doi.org/10.1007/BF00187665