TY - JOUR
T1 - Evolution of regional changes in apparent diffusion coefficient during focal ischemia of rat brain
T2 - The relationship of quantitative diffusion NMR imaging to reduction in cerebral blood flow and metabolic disturbances
AU - Hoehn-Berlage, M.
AU - Norris, D. G.
AU - Kohno, K.
AU - Mies, G.
AU - Leibfritz, D.
AU - Hossmann, K. A.
PY - 1995
Y1 - 1995
N2 - Middle cerebral artery occlusion was performed in rats while the animals were inside the nuclear magnetic resonance (NMR) tomograph. Successful occlusion was confirmed by the collapse of amplitude on an electrocorticogram. The ultrafast NMR imaging technique UFLARE was used to measure the apparent diffusion coefficient (ADC) immediately after the induction of cerebral ischemia. ADC values of normal cortex and caudale- putamen were 726 ± 22 x 10-6 mm2/s and 659 ± 17 x 10-6 mm2/s, respectively. Within minutes of occlusion, a large territory with reduced ADC became visible in the ipsilateral hemisphere. Over the 2 h observation period, this area grew continuously. Quantitative analysis of the ADC reduction in this region showed a gradual ADC decrease from the periphery to the core, the lowest ADC value amounting to about 60% of control. Two hours after the onset of occlusion, the regional distribution of ATP and tissue pH were determined with bioluminescence and fluorescence techniques, respectively. There was a depletion of ATP in the core of the ischemic territory (32 ± 20% of the hemisphere) and an area of tissue acidosis (57 ± 19% of the hemisphere) spreading beyond that of ATP depletion. Regional CBF (rCBF) was measured autoradiographically with the iodo[14C]antipyrine method. CBF gradually decreased from the periphery to the ischemic core, where it declined to values as low as 5 ml 100 g-1 min-1. When reductions in CBF and in ADC were matched to the corresponding areas of energy breakdown and of tissue acidosis, the region of energy depletion corresponded to a threshold in rCBF of 18 ± 14 ml 100 g-1 min-1 and to an ADC reduction to 77 ± 3% of control. Tissue acidosis corresponded to a flow value below 31 ± 11 ml 100 g-1 min-1 and to an ADC value below 90 ± 4% of control. Thus, the quantification of ADC in the ischemic territory allows the distinction between a core region with total breakdown of energy metabolism and a corona with normal energy balance but severe tissue acidosis.
AB - Middle cerebral artery occlusion was performed in rats while the animals were inside the nuclear magnetic resonance (NMR) tomograph. Successful occlusion was confirmed by the collapse of amplitude on an electrocorticogram. The ultrafast NMR imaging technique UFLARE was used to measure the apparent diffusion coefficient (ADC) immediately after the induction of cerebral ischemia. ADC values of normal cortex and caudale- putamen were 726 ± 22 x 10-6 mm2/s and 659 ± 17 x 10-6 mm2/s, respectively. Within minutes of occlusion, a large territory with reduced ADC became visible in the ipsilateral hemisphere. Over the 2 h observation period, this area grew continuously. Quantitative analysis of the ADC reduction in this region showed a gradual ADC decrease from the periphery to the core, the lowest ADC value amounting to about 60% of control. Two hours after the onset of occlusion, the regional distribution of ATP and tissue pH were determined with bioluminescence and fluorescence techniques, respectively. There was a depletion of ATP in the core of the ischemic territory (32 ± 20% of the hemisphere) and an area of tissue acidosis (57 ± 19% of the hemisphere) spreading beyond that of ATP depletion. Regional CBF (rCBF) was measured autoradiographically with the iodo[14C]antipyrine method. CBF gradually decreased from the periphery to the ischemic core, where it declined to values as low as 5 ml 100 g-1 min-1. When reductions in CBF and in ADC were matched to the corresponding areas of energy breakdown and of tissue acidosis, the region of energy depletion corresponded to a threshold in rCBF of 18 ± 14 ml 100 g-1 min-1 and to an ADC reduction to 77 ± 3% of control. Tissue acidosis corresponded to a flow value below 31 ± 11 ml 100 g-1 min-1 and to an ADC value below 90 ± 4% of control. Thus, the quantification of ADC in the ischemic territory allows the distinction between a core region with total breakdown of energy metabolism and a corona with normal energy balance but severe tissue acidosis.
KW - ADC
KW - Diffusion NMR imaging
KW - Focal cerebral ischemia
KW - Ischemic core
KW - MCA occlusion
KW - Penumbra
KW - Rat
UR - http://www.scopus.com/inward/record.url?scp=0028811177&partnerID=8YFLogxK
U2 - 10.1038/jcbfm.1995.126
DO - 10.1038/jcbfm.1995.126
M3 - Article
C2 - 7593332
AN - SCOPUS:0028811177
SN - 0271-678X
VL - 15
SP - 1002
EP - 1011
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
IS - 6
ER -