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Objective: To explore the value of three-dimensional arterial spin labeling (ASL) combined with diffusion weighted imaging (DWI) in evaluation on ischemic penumbra (IP) and prognosis of patients with acute cerebral infarction (ACI). Methods: Data of 45 ACI patients were retrospectively analyzed. Brain ASL images and DWI of all patients were collected. According to the improved Rankin scale (mRS) score at the end of the third month of follow-up, the patients were divided into good prognosis group, medium prognosis group and poor prognosis group. The presence of IP was assessed according to the measured maximum DWI high signal area (SDWI) and ASL abnormal perfusion area (SASL). The values of cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) of the infarct lesion (IL), brain tissue near the edge of the lesions (BNL) and the corresponding contra area were recorded, and the relative values (rCBF and rADC) of lesion side/contra were calculated. CBF and ADC values of IL of BNL and contra area in different prognostic groups were compared, as well as of rCBF and rADC in different prognostic groups. The diagnostic efficacy of rCBF of IL and BNL for evaluating poor prognosis of ACI patients were analyzed, respectively, so as the combined diagnostic efficacy. The correlation between rCBF or rADC and mRS score were analyzed. Results: Totally 40 ACI patients showed hypoperfusion in the IL areas, and IP was present in 23 of them. The difference of prognosis between patients with IP and those without IP was statistically significant (χ2=6.742, P=0.034). CBF and ADC values of IL of 3 groups, the CBF values of BNL in good and medium prognosis groups were lower than those in contra area (all P<0.05). There were statistical differences of rCBF of IL between poor prognosis group and good or medium prognosis group (both P<0.05), while no statistical difference of rCBF of BNL in 3 groups was found (F=3.20, P=0.05). AUC of rCBF of IL or BNL assessing poor prognosis of ACI was 0.92 and 0.79, the optimal cutoff values was 0.41 and 0.93, and the Youden indexs was 0.72 and 0.57, respectively. AUC of combined diagnosis was 0.94, and Youden index was 0.79. The rCBF of IL was negatively correlated with mRS score (r=-0.642, P<0.001). Conclusion: Three-dimensional ASL combined with DWI could be used to evaluate IP and prognosis of ACI patients, providing references for the formulation of ACI treatment plan.
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Objective To explore the value of MRA-DWI mismatch (MDM) in predicting ischemic penumbra in acute posterior cerebral infarction with basilar artery occlusion. Methods From September 2015 to July 2018, 58 acute posterior cerebral infarction patients with basilar artery occlusion within 24 hours from symptom onset in the Department of Neurology, the Fourth Affiliated Hospital of China Medical University were retrospectively recruited. The thirty-eight patients with DWI- ASPECTS ≥7 were divided into the MDM-P group and twenty patients with DWI- ASPECTS 0. 05); the differences in NIHSS (3 [2, 12] vs. 11[4, 26], Z=2.434) and DWI-ASPECTS (8[7, 8]vs. 4[3, 5] , Z = 12.950)were statistically significant (all P 0. 05), but significant difference in reperfusion therapy (42.9% [9/21] vs. 67. 6% [25/37], χ2 =3.372) and MDM-P (85.7% [18/21] vs. 54. 1% [20/37], χ2 =5.944) (all P<0.05). Logistic regression analysis showed MRA-DWI mismatch (OR, 4. 914, 95% CI 1. 158 -20. 860, P = 0. 031) was an independent predictor of early neurological deterioration in acute posterior cerebral infarction. Conclusions MRA-DWI mismatch may be a predictor of END in acute posterior cerebral infarction with basilar artery occlusion, indicating that ischemic penumbra may be present in these patients, and it provides evidence for guiding reperfusion therapy.
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Revascularization has become an effective treatment for acute ischemic stroke. New theories, techniques and instruments of revascularization are emerging. The relevant theory and technology of revascularization were discussed via summarizing the latest clinical trial results of revascularization in this article.
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@#【Objective】To explore the image evaluation value of multi-model CT in the treatment of acute ischemic stroke with Solitaire stent embolectomy. 【Methods】 A total of 62 patients diagnosed with acute ischemic stroke from January 2015 to June 2016 in Guangdong Second Provincial General Hospital were included in this study. Multi- model CT inspection，including CT scan（NCCT），CT angiography（CTA）and CT perfusion imaging（CTP），was performed in all patients within 3~8 h. The improved vascular TICI classification standard（mTICI）was used to assess vascular embolization，and we evaluated the responsible vessels and blood perfusion state by CTA and CTP blood vessels ，to determine the feasibility of embolectomy with Solitaire stent preliminarily. The patients underwent multi-mode CT examination 24 h after stent embolization to evaluate the responsible vessels. NIHSS was used to assess the neurological function at admission and 72 h after stent embolization.【Results】A total of 34 patients with indication of stent thrombus removal were selected by multi-mode CT examination from 62 patients. Re-examination of multi-mode CT after stent thrombus removal showed that 30 of the 34 cases（30/34，the successful rate was 88.2%）gained success in vascular recanalization. Before the stent thrombus removal of the 34 patients，CTP imaging showed ischemic penumbra（IP），and there was significant decrease in cerebral blood flow（CBF）and slight decrease in cerebral blood volume（CBV），significantly prolonged peak time （TTP） and mean transit time （MTT） compared with the contralateral image area. The difference is statistically significant（P < 0.01）. After the stent thrombus removal，the relative cerebral blood flow（rCBF）and relative cerebral blood volume（rCBV）were elevated，the relative peak time（rTTP）and relative mean transit time（rMTT）were shortened. The difference is statistically significant（P < 0.01）. Compared with admission，there is significant statistical difference in the NIHSS score of patients 72 h after operation（P < 0.01）.【Conclusion】Multi-model CT has guiding effect and important evaluation value in the treatment of acute ischemic stroke patients with Solitaire stent thrombolysis.
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Acute ischemic stroke (AIS) is the most common cerebrovascular disease with high morbidity, mortality and disability. The imaging evaluation of ischemic penumbra has great clinical implication for early diagnosis and reperfusion therapy of AIS. Here, we reviewed the evaluation methods, advangtages and disadvangtages of computed tomography (CT) and magnetic resonance imaging for ischemic penumbra, and discussed the advantages of one-stop multi-modal CT.
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Objective To investigate the difference in infarction characteristics between large artery atherosclerosis and cardioembolism acute ischemic stroke (AIS). Methods A retrospective study was done on 99 AIS patients, who were admitted to Emergency Room of our hospital and underwent multi-modal computed tomography (CT) after admission and before treatment. Forty-six of 99 AIS patients had large artery atherosclerosis and 53 had cardioembolism. The NIHSS score and GCS score on admission, infraction core and ischemic penumbra volumes and the volume difference, and vascular occlusion rates of posterior circulation and large artery were compared between the two groups. Results Compared with the cardioembolism group, the NHISS score was significantly lower and the GCS score was significantly higher in the large artery atherosclerosis group (9.5 [2.0, 16.0] vs 15.0 [6.0, 24.0], Z=2.31, P0.05). The large artery occlusion rate and posterior circulation occlusion rate were both significantly different between the large artery atherosclerosis and cardioembolism groups (30.43% [14/46] vs 50.94% [27/53] and 36.96% [17/46] vs 9.43% [5/53]; χ2=11.82 and 6.77, both P<0.001). Conclusion The clinical symptoms, cerebral changes and intracranial large artery changes are different in AIS patients with large artery atherosclerosis and cardioembolism. Etiology evaluation based on clinical features and multi-modal CT examination can help to accurately assess the ischemic state of AIS patients.
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Objective To evaluate the applied values of susceptibility weighted imaging (SWI) in acute ischemic stroke.Methods Totally 40 patients with acute ischemic stroke were included within 72 hours after symptom onset.They adopted multimodal magnetic resonance imaging examination,including regular magnetic resonance imaging sequence (T1WI,T2WI),time of flight MR angiography (TOF-MRA),diffusion weighted imaging (DWI) and susceptibility weighted imaging (SWI).Furthermore,12 of the 40 patients received dynamic susceptibility contrast enhanced perfusion weighted imaging (DSCPWI) examination.Results Of the 40 patients,12 ones had positive results for multiple lesions of cerebral microbleeds (CMBs) by SWI,and the detection rate was 30％.There were 24 patients showed susceptibility vessel sign (SVS) in SWI,and the susceptibility rate was 60％.In the 12 patients received DSC-PWI examination simultaneously,there were 7 cases had the anomaly range by SWI larger than that by DWI while similar to that by DSC-PWI.Conclusion SWI can show SVS and CMBs clearly,estimate ischemic penumbra,know intracranial conditions completely and supply reliable basis for individualized treatment.
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OBJECTIVE: To investigate whether the diffusion tensor imaging-derived metrics are capable of differentiating the ischemic penumbra (IP) from the infarct core (IC), and determining stroke onset within the first 4.5 hours. MATERIALS AND METHODS: All procedures were approved by the local animal care committee. Eight of the eleven rats having permanent middle cerebral artery occlusion were included for analyses. Using a 7 tesla magnetic resonance system, the relative cerebral blood flow and apparent diffusion coefficient maps were generated to define IP and IC, half hour after surgery and then every hour, up to 6.5 hours. Relative fractional anisotropy, pure anisotropy (rq) and diffusion magnitude (rL) maps were obtained. One-way analysis of variance, receiver operating characteristic curve and nonlinear regression analyses were performed. RESULTS: The evolutions of tensor metrics were different in ischemic regions (IC and IP) and topographic subtypes (cortical, subcortical gray matter, and white matter). The rL had a significant drop of 40% at 0.5 hour, and remained stagnant up to 6.5 hours. Significant differences (p < 0.05) in rL values were found between IP, IC, and normal tissue for all topographic subtypes. Optimal rL threshold in discriminating IP from IC was about -29%. The evolution of rq showed an exponential decrease in cortical IC, from -26.9% to -47.6%; an rq reduction smaller than 44.6% can be used to predict an acute stroke onset in less than 4.5 hours. CONCLUSION: Diffusion tensor metrics may potentially help discriminate IP from IC and determine the acute stroke age within the therapeutic time window.
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Animals , Rats , Animal Care Committees , Anisotropy , Cerebrovascular Circulation , Diffusion Tensor Imaging , Diffusion , Gray Matter , Infarction, Middle Cerebral Artery , Models, Animal , ROC Curve , StrokeABSTRACT
Objective To evaluate the diagnostic ability of fusion images of SWI and DWI in ischemic penumbra(IP)of patients with acute ischemic stroke(AIS).Methods 47 AIS patients were retrospective analyzed.Two neuroradiologists analyzed the fusion images of SWI and DWI respectively.SDM was defined as that the hypo-intensity signals of intramedullary or sulcal veins were dilated or increased on fusion images compared with contralateral areas.The results compared with the PDM,which was considered as the“gold standard”.Areas under the receiver operating characteristic curve(AUC)were used to assess the efficacy of SDM which determined by fusion images and compared to PDM.Chi-square test was used to analyze the consistency between the two neuroradiologists and also the consistency between SDM and PDM in IP assessment Results The fusion images of SWI and DWI had a high diagnostic efficacy compared to PDM, AUC of the two radiologists were 0.885,0.877,the diagnostic sensitivity were 84.2%,78.9% and specificity were 92.9%,96.4%respectively.There was also a high consistency in SDM assessment through fusion images between the two neuroradiologists (Kappa=0.908,P >0.05). Conclusion Fusion images of SWI and DWI have a high diagnostic efficacy in IP assessment,which may be considered as a simple approach for IP assessment in patients with AIS.
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Objectives To investigate the effects of nerve nutrient factors and inhibitory factors on neuronal regen? eration and axonal reconstruction at ischemic neocortical penumbra after focal cerebral ischemia in rats. Methods The rat model of middle cerebral artery ischemia was established using suture-occluded method. The pathological morpholo? gy of brain tissue was examined by using HE staining. The expression levels of GAP-43 SYN, nutrient factor (BDNF VEGF Ang1) and inhibitory factor (NogoA NogoR RhoA) were determined by using Western blotting technique. Results The number of neurons in ischemic penumbra was significantly decreased in model group (P<0.01) than in sham-operat? ed group. The expression levels of GAP-43 were significantly decreased (P<0.05) while the expression levels of NogoA NgR and RhoA in the thalamus were significantly increased (P<0.05) in model group than in sham-operated group. The expression levels of SYN and nutrient factors (BDNF VEGF Ang1) were not different between the model group and sham-operated group. Conclusion The increase in nerve inhibitory factors may contribute to the down-regulation of neu?rogenesis at ischemic neocortical penumbra after focal cerebral ischemia in rats.
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Objective: To observe the effect of water extract and active fractions from Huanglian Jiedu Decoction (HJD) (total alkaloids, total favonoids, and total iridoids) on the activation of astrocytes and expression of connexin 43 (Cx43) in ischemic penumbra of rats after focal cerebral ischemia. Methods: The rat model of middle cerebral artery ischemia was established using suture-occluded method. The male SD rats were randomly divided into Sham-operation, model, water extract of HJD (800 mg/kg), total alkaloids (44 mg/kg), total flavonoids (50 mg/kg), and total iridoids (80 mg/kg) groups. They were ig administered for continuous 7 d, once daily. The histopathologic changes of brain in rats were observed by HE staining. The expression of GFAP and Cx43 was detected by immunofluorescence assay and RT-PCR was used to detect the gene expression of Cx43. Results: In the model group, the number of neurons in ischemic penumbra of rats was significantly decreased and the expression of GFAP, Cx43, and Cx43 protein was obviously increased compared with Sham-operation group (P<0.01). The three active fractions from HJD (total alkaloids, total favonoids, and total iridoids) could increase the number of neurons in the ischemic penumbra of rats and decrease the expression of GFAP, Cx43, and Cx43 protein obviously compared with the model group (P<0.05, 0.01). Conclusion: The active fractions (total alkaloids, total favonoids, and total iridoids) could inhibit the over activation of astrocytes and the expression of Cx43, so as to protect the neurons in ischemic penumbra.
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Objective To determine the safety and efficacy of intra-arterial recombinant tissue plasminogen activator (r-tPA) for the treatment of acute cerebral infarction (ACI) in patients under the guidance of computed tomography perfusion-based selection within a 6-9 hour window.Methods Sixtythree ACI patients selected by using computed tomography perfusion imaging (CTPI) identifying thresholds for salvageable penumbra were randomly (random number) assigned to the group treated with intra-arterial thrombolysis with r-tPA (group A,n =30) or to the group managed with conventional anti-platelet aggregation agent (group B,n =33) within a 6-9 hour window.The National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale score (mRS) and Barthel Index (BI) were used for evaluating therapeutic efficacy.Global brain digital subtraction angiography (DSA) was done pre-and posttreatment to observe the recanalization of occluded vessels in the group A.All patients were monitored with CT scan within 24 hours to determine the cerebral hemorrhage,an unexpected complication of thrombolysis.Results Compared with pre-treatment,there were significant differences in NIHSS 24 hours after treatment in the group A and 7 days after treatment in both groups (P ＜ 0.01).However,there were no significant differences in NIHSS 24 hours after treatment in the group B.More improvements in NIHSS at 24 hours and 7 days after treatment were observed in the group A than those in group B (P ＜ 0.01),and more patients with favorable outcomes identified by mRS and BI in the group A than those in the group B (P =0.017 and P =0.016,respectively).In addition,twenty patients were showed successful recanalization in the group A and there were 2 cases of cerebral hemorrhage occurred in the group A,and there was no significant difference in the incidence of cerebral hemorrhage within 24 hours between the two groups (P ＞ 0.05).Conclusions Intra-arterial thrombolysis with r-tPA for treatment of acute cerebral infarction was safe and effective within a 6-9 hour window under the guidance of CTPI.
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Background: Stroke is a medical emergency with mortality rate higher than most forms of cancer. Acute ischemic stroke is a complex entity with variable clinical manifestations depending on the site and extent of infarction. Besides standard treatment given to the patients, neuroprotection is being targeted to antagonize molecular events that lead to irreversible ischemic injury. Methods: In this study, role of Citicoline in acute ischemic stroke was studied. It was open label study of 12 weeks duration undertaken in Medicine department (emergency unit) of Sri Guru Ram Das Institute of Medical Sciences and Research, Vallah, Amritsar. Total 40 patients were randomly divided into Group 1 and Group 2. Group 1 received standard treatment for acute ischemic stroke and Group 2 received citicoline in addition to standard treatment. Patients were assessed at admission and after every 24 hours till hospital discharge. Follow up of the patients was done at three weeks, six weeks and twelve weeks after discharge using National Institute of Health Stroke Scale (NIHSS), Modified Rankin Scale (MRS) and Modified Barthel Index (MBI). The data was statistically analysed using Mann Whitney test. Results: No significant difference was found between two groups with respect to MRS and MBI score throughout the study period. Statistically significant improvement was seen in citicoline group on NIHSS score by 2nd and 3rd day of admission and then on 12th week. Conclusions: Citicoline was found to be safe but with no statistically significant difference in treatment outcome between two groups.
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Chronic neurodegenerative processes have been identified in the rat forebrain after prolonged survival following hyperthermia (HT) initiated a few hours after transient global ischemia. Since transient global ischemia and ischemic penumbra share pathophysiological similarities, this study addressed the effects of HT induced after recirculation of focal brain ischemia on infarct size during long survival times. Adult male Wistar rats underwent intra-luminal occlusion of the left middle cerebral artery for 60 min followed by HT (39.0-39.5°C) or normothermia. Control procedures included none and sham surgery with and without HT, and middle cerebral artery occlusion alone. Part I: 6-h HT induced at recirculation. Part II: 2-h HT induced at 2-, 6-, or 24-h recirculation. Part III: 2-h HT initiated at recirculation or 6-h HT initiated at 2-, 6- or 24-h recirculation. Survival periods were 7 days, 2 or 6 months. The effects of post-ischemic HT on cortex and striatum were evaluated histopathologically by measuring the area of remaining tissue in the infarcted hemisphere at -0.30 mm from bregma. Six-hour HT initiated from 6-h recirculation caused a significant decrease in the remaining cortical tissue between 7-day (N = 8) and 2-month (N = 8) survivals (98.46 ± 1.14 to 73.62 ± 8.99 percent, respectively). When induced from 24-h recirculation, 6-h HT caused a significant reduction of the remaining cortical tissue between 2- (N = 8) and 6-month (N = 9) survivals (94.97 ± 5.02 vs 63.26 ± 11.97 percent, respectively). These data indicate that post-ischemic HT triggers chronic neurodegenerative processes in ischemic penumbra, suggesting that similar fever-triggered effects may annul the benefit of early recirculation in stroke patients over the long-term.
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Animals , Male , Rats , Brain Ischemia/complications , Cerebral Cortex/pathology , Fever/complications , Nerve Degeneration/etiology , Brain Ischemia/pathology , Chronic Disease , Rats, Wistar , Time FactorsABSTRACT
The measurement of pathologically low levels of tissue pO2 is an important diagnostic goal for determining the prognosis of many clinically important diseases including cardiovascular insufficiency, stroke and cancer. The target tissues nowaday have mostly been tumors or the myocardium, with less attention centered on the brain. Radiolabelled nitroimidazole or derivatives may be useful in identifying the hypoxic cells in cerebrovascular disease or traumatic brain injury, and hypoxic-ischemic encephalopathy. In acute stroke, the target of therapy is the severely hypoxic but salvageable tissue. 18F-MISO PET and 99mTc-EC-metronidazole SPECT in patients with acute ischemic stroke identified hypoxic tissues and ischemic penumbra, and predicted its outcome. A study using 123I-IAZA in patient with closed head injury detected the hypoxic tissues after head injury. Up till now these radiopharmaceuticals have drawbacks due to its relatively low concentration with hypoxic tissues associated with/without low blood-brain barrier permeability and the necessity to wait a long time to achieve acceptable target to background ratios for imaging in acute ischemic stroke. It is needed to develop new hypoxic marker exhibiting more rapid localization in the hypoxic region in the brain. And then, the hypoxic brain imaging with imidazoles or non-imidazoles may be very useful in detecting the hypoxic tissues, determining therapeutic strategies and developing therapeutic drugs in several neurological disease, especially, in acute ischemic stroke.
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Humans , Hypoxia , Blood-Brain Barrier , Brain Injuries , Brain , Craniocerebral Trauma , Head Injuries, Closed , Hypoxia, Brain , Hypoxia-Ischemia, Brain , Imidazoles , Myocardium , Neuroimaging , Permeability , Prognosis , Radiopharmaceuticals , Stroke , Tomography, Emission-Computed, Single-PhotonABSTRACT
The intra-arterial thrombolysis is one of the most effective approaches in salvaging brain ischemic penumbra and treating acute cerebral infarction.However,because of the limita- tions of short time windows for treatment,intracerebral hemorrhage after thrombolysis and reocclusion,more clinical studies are needed before this technique is widely developed and applied.
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Computed tomography perfusion imaging can accurately and promptly provide hemodynamic parameters of brain tissues after stroke,and it has a good correlation with the accepted hemodynamic measurement,the parameters got from xenon-computed tomography, functional magnetic resonance imaging and positron emission tomography.Therefore,CTP has been widely used in predicting the studies of ischemic penumbra after stroke.
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The ischemic penumbra is defined as functionally impaired but salvageable ischemic brain tissue surrounding an irreversibly damaged core. Therefore, rapid and precise identification of the penumbra is of considerable interest for decision-making in acute stroke treatment. The region with perfusion abnormality but no diffusion lesion (the so-called diffusion-perfusion mismatch) identifies tissue that is hypoperfused but that not yet experienced advanced bioenergetic failure and represents the penumbra. Thus, diffusion-perfusion mismatch are predicted to have the most lesion growth and may benefit most from any perfusion-altering therapies. The time window available for salvage of the penumbra in selected patients may be much longer than the traditional, presumed 3- to 6-hour window and that diffusion-perfusion MRI has the ability to identify these patients. Multimodal MRI allows therapeutic decisions to be based on individual patient pathophysiological information, allowing the time window to be extended in appropriate patients.
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Humans , Brain , Diffusion , Energy Metabolism , Magnetic Resonance Imaging , Perfusion , StrokeABSTRACT
BACKGROUND: In recent years, thrombolytic therapy has been used with success to reduce the infarction area in patients with acute cerebral infarction, It is very important to identify ischemic penumbra in the treatment of stroke. The aim of this study is detect ischemic penumbra and border between ischemic penumbra and infarction area using perfusion CT and diffusion-weighted MR images (DW-MRI) in patient 's with acute ischemic stroke. METHODS: Thirteen inpatients with acute ischemic stroke at the Department of Neurology at Chonnam University Hospital were selected for this study. They had the discrepancy of lesion between perfusion CT and DW-MRI. Perfusion CT was done on admission and DW-MRI within 24 hours after stroke in all patients. Ischemic penumbra was assessed by comparing the defect on perfusion CT with the infarction area on DW-MRI. Clinical outcome was measured with the NIHSS on day 1, 3, and 7. RESULTS: The subjects (perfusion defect on the perfusion CT> infarction area on DW-MRI) achieved significant improvement at NIHSS. There was a significant difference between infarct and non-infarct tissue for both rCBF and rCBV but not for MTT. It could be possible not to define the tissue outcome but to estimate it by this study. CONCLUSIONS: Perfusion CT with DW-MRI is a useful tool for the detection of ischemic penumbra which may be the main target of active treatment.
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Humans , Cerebral Infarction , Infarction , Inpatients , Neurology , Perfusion , Stroke , Thrombolytic TherapyABSTRACT
Objective To investigate the involvement of Bcl-2 and Bax mRNA expressions in mitochondrial toxin 3-nitropropionic acid(3-NPA)induced ischemic tolerance to focal cerebral ischemia in rats.Methods Rats were administrated 3-NPA intraperitoneally at dose of 20 mg/kg 3 days prior to a 2 h middle cerebral artery occlusion followed by 1 h,6 h,12 h,24 h and 48 h of reperfusion.The Bcl-2 and Bax mRNA expressions were measured by reverse transcriptase polymerase chain reaction and compared to the sham operation group and ischemic reperfusion group.Results Compared to the sham operation group,the ischemic reperfusion and 3-NPA pretreated groups exhibited an increase in Bcl-2 and Bax mRNA after reperfusion every time point of focal cerebral ischemia(all(P