Complementary use of T2-weighted and postcontrast T1- and T2∗-weighted imaging to distinguish sites of reversible and irreversible brain damage in focal ischemic lesions in the rat brain

Lanens, D.; Spanoghe, M.; Audekerke, Johan Van; Øksendal, Audun N.; Linden, Annemie Van der; Dommisse, Roger

doi:10.1016/0730-725x(94)00106-d

Cited by 14 publications

(16 citation statements)

References 20 publications

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“…1-3) was relatively larger than that in other photochemical models [4][5][6][7]17]. (3) Unlike other photochemical models, the evolution and imaging characteristics of rat brain ischemic lesion in this model have not been evaluated yet with a noninvasive MR imaging, which should be beneficial to testing neuroprotective effects of compounds and other potential diagnostic and therapeutic strategies.…”

Section: Discussionmentioning

confidence: 96%

“…3 Bar chart comparing RLS between 1 and 24 h after MCA occlusion determined by with different techniques. Asterisk denotes a statistically significant difference (p < 0.05) [16,18,19], criticisms of the photochemical model in the literature include its end-arterial occlusive nature, frequent absence of a penumbra etc., which apparently refer to the PIT model in which rat brain ischemic lesion was restricted only to the cortex [4][5][6][7]. On the contrary, our study confirmed that the mismatched region resulting from subtracting DWI by PWI, i.e., penumbra, exists in this PIT model of proximal MCA occlusion, which is believed to feature a possible "reperfusion-like phenomenon" [8], and could serve as a platform for assessing the therapeutic or neuroprotective effects of candidate anti-stroke agents.…”

Section: Penumbra In Proximal Pit Modelmentioning

confidence: 99%

“…Several methods to achieve the occlusion of middle cerebral artery (MCA) in rats have been described. Among them, photochemically induced thrombosis (PIT) is a basic method that induces various types of MCA occlusion that closely resemble various types of focal cerebral ischemia in humans [4][5][6][7][8][9]. Actually, the extent and severity of focal cerebral ischemic lesions can be different depending on whether a distal MCA occlusion [4][5][6][7] or proximal MCA occlusion is induced [8,9].…”

Section: Introductionmentioning

confidence: 98%

“…Actually, the extent and severity of focal cerebral ischemic lesions can be different depending on whether a distal MCA occlusion [4][5][6][7] or proximal MCA occlusion is induced [8,9]. Many of the photothrombosis studies have involved occlusion of end arteries rather than MCA [4][5][6][7]. The PIT model of proximal MCA occlusion adopted in this study was first introduced by Umemura, but not for the purpose of imaging studies [10].…”

Section: Introductionmentioning

confidence: 98%

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Rat cerebral ischemia induced with photochemical occlusion of proximal middle cerebral artery: a stroke model for MR imaging research

Chen

Suzuki²,

Nagai³

et al. 2004

MAGMA

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A stroke model in rats with photochemically induced thrombosis (PIT) of proximal cerebral middle artery (MCA) is introduced for magnetic resonance imaging (MRI) study. Thirty-seven rats subjected to surgical and optical procedures for inducing the PIT models were scanned using a 1.5-T scanner with T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and contrast-enhanced perfusion-weighted imaging (PWI) at 1 h and 24 h after MCA occlusion. The penumbra evolution and PWI-derived parameters including relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) were monitored; and the relative lesion size (RLS) was compared with the final RLS on the gold standard triphenyl tetrazolium chloride (TTC) staining at 24 h. The results showed that the focal cerebral ischemic lesions were detectable in all rats with different MR approaches. The lesion on PWI at 1 h and on all MR images at 24 h was matched well with that seen on TTC staining; the peri-infarct area decreased from 6.2 +/- 7.2% of the brain volume at 1 h to 0.3 +/- 5.6% at 24 h. Compared to that in the contralateral hemisphere, rCBV in ischemic region was 52.6 +/- 21.4 and 40.0 +/- 15.8% (p > 0.05), and rCBF was 64.6 +/- 11.2 and 47.3 +/- 11.1% (p < 0.05) at 1 h and 24 h respectively. The present PIT model in rats has been successfully adopted for MRI research, which might be feasible for certain stroke studies and should be beneficial for the evaluation on effects of potential diagnostic and therapeutic approaches.

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Section: Discussionmentioning

confidence: 96%

Section: Penumbra In Proximal Pit Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Rat cerebral ischemia induced with photochemical occlusion of proximal middle cerebral artery: a stroke model for MR imaging research

Chen

Suzuki²,

Nagai³

et al. 2004

MAGMA

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“…After photothrombosis, the brain lesion grows and matures as a function of time spreading from the unrecoverable ischemic core to adjacent tissues, which represent the salvageable penumbra (Lanens et al, 1995). The lesion reaches maximal size 24 h after ischemia (Grome et al, 1988).…”

Section: Discussionmentioning

confidence: 99%

Cytoprotective Efficacy and Mechanisms of the Liposoluble Iron Chelator 2,2′-Dipyridyl in the Rat Photothrombotic Ischemic Stroke Model

Demougeot¹,

Hoecke²,

Bertrand³

et al. 2004

J Pharmacol Exp Ther

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We examined the efficacy of the liposoluble iron chelator 2,2Ј-dipyridyl (DP) in reducing histological damage in rats submitted to cerebral ischemia and the mechanisms involved in the potential cytoprotection. For this purpose, DP (20 mg/kg, i.p.) was administered 15 min before and 1 h after induction of cortical photothrombotic vascular occlusion in rat. Histological studies were performed to assess infarct volume (at days 1 and 3 postischemia) and astromicroglial activation (at day 3 postischemia). Damage to endothelial and neuronal cells was evaluated at day 1 postischemia by quantitative measurements of Evans Blue extravasation and N-acetylaspartate levels, respectively. Cerebral blood flow was recorded in the ischemic core by laser-Doppler flowmetry within the 15 min to 2 h period after photothrombosis. At 4-h postischemia, radical oxygen species (ROS) production was evaluated by measuring brain glutathione concentrations. The cortical expression of the proteins heme oxygenase-1 (HO-1) and hypoxia-inducible factor-1␣ (HIF-1␣) was analyzed by Western blotting at day 1 postischemia. Infarct volume and ischemic damage to endothelial and neuronal cells were significantly reduced by DP treatment. This cytoprotection was associated with a reduction in ROS production, perfusion deficits, and astrocytic activation. DP treatment also resulted in significant changes in HO-1 (ϩ100%) and HIF-1␣ (Ϫ50%) protein expression at the level of the ischemic core. These results report the efficacy of the liposoluble iron chelator DP in reducing histological damage induced by permanent focal ischemia.

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Investigation of mechanisms underlying transient T2 normalization in longitudinal studies of ischemic stroke

Lin

Schmidt

McKinstry

et al. 2002

Magnetic Resonance Imaging

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Purpose: To determine if the phenomenon of transient normalization of T2 relaxation in the subacute stage of ischemic stroke is associated with either magnetic susceptibility effects secondary to hemorrhage or changes in tissue water content. Materials and Methods:We utilized a rat model of transient, focal, cerebral ischemia. The possibility of hemorrhage was evaluated with T2*-weighted (T2*W) imaging and histology. Changes in water content were assessed by brain wet-to-dry weight.Results: Susceptibility effects were not evident in T2*W images, and neither red blood cells nor unchelated Fe(III) was found in hematoxylin and eosin (H-E)-or Prussian Blue-stained sections, respectively. However, between the peak of T2 contrast and the point of transient T2 normalization, water content consistently decreased by an average of 3%. Conclusion:Transient T2 normalization is associated with normalization of water content and can occur without evidence of hemorrhage.

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Complementary use of T2-weighted and postcontrast T1- and T2∗-weighted imaging to distinguish sites of reversible and irreversible brain damage in focal ischemic lesions in the rat brain

Cited by 14 publications

References 20 publications

Rat cerebral ischemia induced with photochemical occlusion of proximal middle cerebral artery: a stroke model for MR imaging research

Rat cerebral ischemia induced with photochemical occlusion of proximal middle cerebral artery: a stroke model for MR imaging research

Cytoprotective Efficacy and Mechanisms of the Liposoluble Iron Chelator 2,2′-Dipyridyl in the Rat Photothrombotic Ischemic Stroke Model

Investigation of mechanisms underlying transient T2 normalization in longitudinal studies of ischemic stroke

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