Brain single-photon emission CT studies using 99mTc-HMPAO and 99mTc-ECD early after recanalization by local intraarterial thrombolysis in patients with acute embolic middle cerebral artery occlusion

BACKGROUND AND PURPOSE: The brain distribution of 9mTc-hexamethylpropyleneamine oxime (HMPAO) correlates with regional brain perfusion, whereas 99mTc-ethyl cysteinate dimer (ECD) reflects not only perfusion but also the metabolic status of brain tissue. We compared 99mTc-ECD single-photon emission CT (SPECT) with 99mTc-HMPAO SPECT early after recanalization by local intraarterial thrombolysis (LIT) in patients with acute embolic middle cerebral artery occlusion. We also assessed the predictive value of 99mTc-HMPAO and 99mTc-ECD SPECT for the development of ischemic brain damage. METHODS: 99mTc-HMPAO and consecutive 99mTc-ECD SPECT studies were performed in 15 patients within 3 hours of LIT. The two SPECT studies were obtained independently using a subtraction technique. SPECT evaluation was performed using semiquantitative region-of-interest analysis. Noninfarction, infarction, and hemorrhage were identified by follow-up CT or MR imaging. RESULTS: Forty-five lesions were identified (21 noninfarctions, 19 infarctions, and five hemorrhages). Regardless of 99mTc-HMPAO SPECT findings, lesions showing isoactivity (count rate densities of 0.9 to 1.1 as compared with the contralateral side) on 99mTc-ECD SPECT were salvaged. Lesions with hypoactivity (values < 0.9) on 99mTc-ECD SPECT developed irreversible brain damage. Hemorrhage appeared in lesions with both hyperactivity (values > 1.1) on 99mTc-HMPAO SPECT and hypoactivity on 99mTc-ECD SPECT. CONCLUSION: The brain distribution of 99mTc-ECD in a reperfused area identified by 99mTc-HMPAO SPECT early after recanalization of acute ischemic stroke is dependent on cerebral tissue viability. By combining 99mTc-ECD and 99mTc-HMPAO SPECT, performed within the first few hours of LIT, it is possible to identify patients at risk for hemorrhagic transformation reliably.     

急性脑梗塞动脉内溶栓治疗时间窗选择与疗效分析

目的探讨急性脑梗塞动脉内溶栓治疗时间及梗塞部位等因素对疗效的影响。方法288例脑梗塞患者均在CT检查及血管造影基础上接受选择性动脉溶栓治疗,其中在6h以内溶栓者76例,6~24h溶栓者212例。统计2组患者的血管再通率和90d后预后情况。结果脑血管造影发现血管闭塞245例,其中颈内动脉系统闭塞173例,椎基底动脉(VBA)闭塞72例;溶栓后再通分别为112例、38例。治疗后90d恢复良好者180例,预后差108例。颅内出血2例。不同治疗时间2组患者治疗后90d预后良好率分别为80.35%和71.43%,血管再通率分别为67.86%和59.26%,血管再通中位时间分别为68min和73min。结论动脉溶栓治疗脑梗塞,动脉内溶栓时间窗与多种因素密切相关。     

动脉内接触性溶栓治疗急性脑梗死时间窗选择与疗效分析

目的 探讨动脉内接触性溶栓治疗急性脑梗死的时间窗选择与疗效的关系.资料与方法 245例脑梗死均在CT检查及血管造影基础上接受选择性动脉内接触性溶栓治疗,其中在发病后6 h以内溶栓者56例,6～24 h溶栓者189例.分析两组患者的血管再通率和90天预后.结果 脑血管造影发现颈内动脉(ICA)系统闭塞173例,椎基底动脉(VBA)系统闭塞72例;溶栓后ICA系统再通113例,VBA系统再通37例.治疗后90天预后好者180例,预后差者65例.溶栓后颅内出血12例.6 h内组和6～24 h组患者血管内溶栓治疗后90天预后良好率分别为80.35 %(45/56)和71.43 %(135/189),血管再通率分别为66.07%(37/56)和59.79%(113/189),血管再通中位时间分别为67 min和73 min.结论 动脉内接触性溶栓可以明显改善脑梗死患者的预后,仅以发病时间不超过6 h作为动脉内溶栓治疗标准不够全面,应当根据病情适当放宽动脉内溶栓的时间窗.     

Combined intraarterial/intravenous thrombolysis for acute ischemic stroke

BACKGROUND AND PURPOSE: The intravenous use of recombinant tissue-type plasminogen activator (rTPA) in acute ischemic stroke has been investigated in three large trials. Limited series have reflected outcome after local intraarterial thrombolysis (LIT) in the cerebral territory. The purpose of this study was to evaluate the safety and efficacy of combined intraarterial/intravenous thrombolysis using rTPA (actilyse) for acute ischemic stroke. METHODS: Forty-five patients with acute onset of severe hemispheric stroke and without signs of major cerebral infarction on early CT scans were randomized by order of admission. Twelve patients were treated with 50 mg actilyse (maximal dose, 0.7 mg/kg); three had occlusion of the internal carotid artery and nine had occlusion of the middle cerebral artery. Thrombolysis was started by LIT and continued intravenously within 6 hours of stroke onset. Outcome, assessed after 1 and 12 months according to the modified Rankin scale (MRS), was considered good (MRS score, 0-3) for patients who were functionally independent and poor (MRS score, 4-5) for those who were dependent or had died. RESULTS: In the thrombolysis group, outcome was good in eight patients at 1 month and in 10 patients at 12 months; in the control group, outcome was good in seven (21%) and 11 (33%) patients, respectively. Of the eight patients with a good outcome after thrombolysis, four had complete and one had partial recanalization. In the control group, the rate of intracerebral hemorrhage was 6%. Mortality at 1 month in the thrombolysis and control groups was 17% and 48%, respectively. CONCLUSIONS: Combined intraarterial/intravenous thrombolysis with low-dose rTPA may be a safe and effective treatment for acute ischemic stroke within 6 hours in carefully selected patients.     

Evaluation of reperfusion and recovery of brain function before and after intracarotid arterial urokinase therapy in acute cerebral infarction with brain SPECT.

PURPOSE: Perfusion defects can be demonstrated reliably at an early stage with regional cerebral blood flow studies using SPECT. The administration of thrombolytic therapy in ischemic stroke is targeted at restoring cerebral perfusion immediately, leading to salvage of ischemic penumbra, smaller infarct size, and improved clinical outcome. This study considered the role of brain perfusion SPECT in the evaluation of reperfusion and brain function recovery of the infarcted area after early recanalization (less than 6 hours) of the occluded artery using intracarotid arterial urokinase therapy (ICAU). METHODS: Intracranial artery occlusion was confirmed in seven patients using emergency carotid angiography performed within the initial 6-hour period. Intracarotid arterial urokinase (500,000 to 800,000 units) was administered into the occluded arterial system (the left middle cerebral artery in four and the right middle cerebral artery in three patients). CT scanning was performed when the patients arrived in the emergency department and was repeated 24 to 48 hours after ICAU and at 7 days or earlier if clinically indicated. All patients had two SPECT studies, the first before urokinase administration and the second 24 or 48 hours later. RESULTS: Complete recanalization of the occluded vessels was seen in one patient after ICAU, effective partial recanalization was achieved in four patients, and minimal recanalization occurred in the other two. Before ICAU, Tc-99m HMPAO brain SPECT showed decreased uptake of the infarcted area in all patients, whereas the follow-up brain SPECT performed 24 or 48 hours after ICAU revealed improvement in the uptake of the recanalized area on qualitative and semiquantitative assessments using an asymmetry index, suggestive of brain function recovery and clinical improvement. Hemorrhagic transformation adjacent to the reperfused regions occurred in two patients with partial recanalization of the left middle cerebral artery. CONCLUSIONS: Reperfusion of the recanalized area and brain function recovery could be achieved if the occluded artery is recanalized within the initial 6-hour period using ICAU, and this was documented using brain perfusion SPECT without a delay in the therapeutic time window. Because the number of patients we studied was limited, further study is necessary to evaluate the effect of ICAU and to determine its prognostic significance.     

急性期缺血性脑梗塞的动脉内溶栓治疗

目的：报道和评价动脉内溶栓对急性期缺血性脑梗塞的治疗效果。方法：选择从１９９８年５月以来临床诊断的急性期缺血性脑梗塞患者９例（男８例,女１例）,行动脉内溶栓治疗,年龄在４７～８０岁之间,溶栓方法为将８０ＩＵ位尿激酶溶于８０ｍｌ５生理盐水内,在１ｈ以内经导管缓慢注入,病人病情在入院时、灌注后２４ｈ、１周、３月内由神经科医生以欧洲中风评分法（ＥＳＳ）综合评价。结果：溶栓治疗后３例血管得以再通,所有病人     

Outcome of stroke patients without angiographically revealed arterial occlusion within four hours of symptom onset

BACKGROUND AND PURPOSE: Follow-up imaging data from stroke patients without angiographically apparent arterial occlusions at symptom onset are lacking. We reviewed our Emergency Management of Stroke (EMS) trial experience to determine the clinical and imaging outcomes of patients with ischemic stroke who showed no arterial occlusion on angiograms obtained within 4 hours of symptom onset. METHODS: All patients in this report were participants in the EMS trial that was designed to address the safety and potential efficacy of combined IV and intraarterial thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) in patients with acute ischemic stroke. RESULTS: Thirty-five patients were randomized to receive either IV rt-PA (n = 17) or placebo (n = 18), followed by cerebral angiography. No symptomatic arterial occlusion was evident in 10 (29%) of the 34 patients. Eight (80%) of 10 patients without angiographically apparent clot within 4 hours of symptom onset had a new cerebral infarction confirmed on follow-up brain imaging. The median 72-hour infarction volume was 2.4 cc (range, 1-30 cc). Four of the 10 "no-clot" patients had a favorable 3-month outcome as assessed by Barthel Index (score, 95 or 100) and modified Rankin Scale (score, 0 or 1). The six remaining patients had 3-month Rankin Scale scores of 1 (Barthel of 90), 2, 3, 4, or 5. CONCLUSION: Acute ischemic stroke patients with a neurologic deficit but a negative angiogram during the first 4 hours after symptom onset usually develop image-documented cerebral infarction, and approximately half suffer from long-term functional disability. The two most likely explanations for negative angiograms are very early irreversible ischemic damage despite recanalization or ongoing ischemia secondary to clot in non-visible penetrating arterioles or in the microvasculature.     

Dual-energy CT Immediately after Endovascular Stroke Intervention: Prognostic Implications

Purpose

Posttreatment intracerebral hemorrhage (ICH) after recanalization therapy of acute ischemic stroke increases morbidity and mortality. Dual-energy (DE) computed tomography (CT) allows differentiation of blood–brain barrier disruption (BBBD) and ICH. We evaluated the incidence of ICH and BBBD immediately after endovascular recanalization therapy, the correlation between BBBD and final infarction or ICH size, and the prognostic value of postinterventional BBBD.

Methods

Imaging data sets (pretreatment CT, posttreatment DE-CT, and follow-up imaging by CT and/or magnetic resonance imaging) of 60 consecutive patients after endovascular recanalization therapy of acute ischemic stroke were retrospectively analyzed. After material differentiation, areas of increase attenuation in posttreatment DE-CT were correlated to ICH and infarction in follow-up imaging.

Results

Areas of hyperattenuation were observed in 80.0 % (48 of 60) of all posttreatment CT. In 10.4 % (5 of 48) of these, hyperattenuating areas matched the hyperdensities on virtual nonenhanced CT and were rated as hemorrhage. The remaining 89.6 % (43 of 48) of scans with hyperattenuating areas demonstrated hyperdensities exclusively on iodine-only images and were rated as BBBD. All suspected ICH on DE-CT were proven in follow-up imaging. There were no false-positive or false-negative findings of ICH in DE-CT. In 98.3 % (59 of 60) of cases, at least small ischemic infarctions were identified in follow-up imaging. No correlation between the extent of BBBD and the final infarct size and/or early ICH size was found.

Conclusion

BBBD is a frequent finding after endovascular revascularization therapy. DE-CT allows for a reliable differentiation between frequent BBBD and rare ICH immediately after endovascular recanalization therapy.     

动、静脉结合r-tPA溶栓治疗早期脑梗死

目的 评价动、静脉结合r-tPA溶栓治疗急性脑梗死的方法和临床疗效.方法 共15例急性脑梗死患者,术前均行CT、MR 和DSA检查证实颅内动脉闭塞部位：M1段4例,M2段2例,M3、4段2例,A1、2段1例,颈内动脉2例, P1段1例,豆纹动脉1例,其他穿支2例.其中术前经DSA证实12例.溶栓治疗时间在发病后3～7 h,采用动脉内药物灌注和机械疏通相结合方法溶栓,另外经静脉术前和术后持续滴注r-tPA辅助.术后观察临床症状和影像表现.结果 15例患者溶栓治疗中微导管和溶栓导管均到位满意,DSA所示闭塞段血管均有效再通.术后CT检查发现片状渗血2例,异位脑梗死1例.术后肢体功能即刻明显改善6例.临床观察3个月,症状基本完全恢复6例,较好改善7例,2例无明显改善;生活能力完全自理13例,有效率达87%（13/15）,生活能部分自理者1例,失去生活自理能力 1例,无患者死亡.结论 动、静脉结合溶栓治疗急性颅内动脉栓塞是一种有效、安全的治疗方法;局部动脉内灌注和机械疏通有效结合以及术前各项影像学检查的综合分析,将有利于动脉溶栓治疗的进行.     

Clinical and imaging outcomes after stroke with normal angiograms

BACKGROUND AND PURPOSE: Information about the prognosis of patients with acute ischemic stroke and normal angiography is limited. We report clinical and imaging outcomes of patients seen within 6 hours of symptom onset who were considered candidates for thrombolysis. METHODS: Between November 1994 and December 1999, patients with stroke onset of less than 6 hours who were thrombolytic candidates underwent cerebral angiography. Patients with normal angiograms (defined as no sign of occlusive disease in the head or neck in the symptomatic artery) were included. Admission National Institutes of Health Stroke Scale (NIHSS) scores and discharge modified Rankin scores (mRS) were obtained. CT or MR images were obtained 24 hours or longer after symptom onset. Good outcome was defined as an mRS score < or =2. For analysis, follow-up CT or MR imaging findings were classified as showing cortical infarct, subcortical infarct > or =1.5 cm, subcortical infarct < or =1.5 cm, or no new infarct. The mechanism of the normal angiogram was assumed on the basis of these results. RESULTS: Twenty-one patients with stroke had normal angiograms. About 43% (9/21) of the patients had a favorable hospital discharge clinical outcome, and an additional 33% (7/21) had favorable clinical outcomes at subsequent follow-up. New infarct on follow-up imaging was seen in 71% (15/21). Discharge mRS scores were not correlated with admission NIHSS scores or the mechanism of the normal angiogram. CONCLUSION: Approximately 76% of acute stroke patients with normal angiograms have a favorable clinical outcome, and 71% have associated new infarctions. Given these outcomes, further study is needed before recommendations regarding thrombolytic treatment can be made in this population.     

Der akute ischämische Schlaganfall

Stroke is the third most common cause of death after myocardial infarction and neoplasms in industrialized countries and the most common cause for permanent disability with impairment of an independent life style. In addition to the socioeconomic problems caused by a disabling stroke, it is to be expected that with an increasing average age of the population, the number of stroke patients will increase as well [4]. The need for effective and widely available therapies against this severe disease is highly evident. Diagnostic imaging is indispensable in order to apply these therapies efficiently and precisely. In addition to the established intravenous thrombolytic therapy with rt-PA within the first 3 h, a therapeutic benefit can also be achieved with thrombolysis inside the time-window 3-6 h, whereas the rate of symptomatic intracerebral hemorrhages increases. Local intraarterial fibrinolysis (LIF) within 6 h is effective and safe and may lead to considerable improvement despite an initially severe medical condition [13]. Besides LIF, interventional techniques for mechanical recanalization of intracranial vessel occlusions are becoming increasingly more established. According to international guidelines for the treatment of acute stroke, computed tomography (CT) is considered to be the most important technical diagnostic tool if available round-the-clock. Alternatively, magnetic resonance tomography (MRT) may primarily be performed if carried out without delay and if the imaging protocol contains a sequence suitable for exclusion of hemorrhages.     

Clinical experience with Tc-99m HM-PAO high resolution SPECT of the brain in patients with cerebrovascular accidents

In order to evaluate the diagnostic contribution of brain SPECT imaging with 99mTc-HMPAO in cerebrovascular disease, we examined 92 stroke cases (144 lesions), 2 hematoma cases and 30 cases with transient neurologic symptoms. Abnormal tracer distribution is visible as zones of either hypoactivity or hyperactivity (border zone hyperemia or luxury perfusion). Remote vascularization changes could also be found (crossed cerebellar diaschisis or ipsilateral cortical perfusion reduction in thalamic or capsula interna lesions). Both X-ray CT and blood flow SPECT have comparable sensitivity in the exploration of cerebral infarction, with detection in, respectively, 89.5% and 87.5% of the lesions. False negative scintitomographic images are frequently recorded in small lacunar infarcts within the basal ganglia and white matter (capsula interna). Some early infarcts and asymmetry of brain perfusion in patients with transient neurologic symptoms are frequently not detected by CT. An additional advantage of blood flow SPECT is its ability to visualize remote blood flow changes and the changing pattern of vascularization of ischemic lesions and their surrounding areas including hyperemia.     

Clinical experience with Tc-99m HM-PAO high resolution SPECT of the brain in patients with cerebrovascular accidents

In order to evaluate the diagnostic contribution of brain SPECT imaging with ^99mTc-HMPAO in cerebrovascular disease, we examined 92 stroke cases (144 lesions), 2 hematoma cases and 30 cases with transient neurologic symptoms. Abnormal tracer distribution is visible as zones of either hypoactivity or hyperactivity (border zone hyperemia or luxury perfusion). Remote vascularization changes could also be found (crossed cerebellar diaschisis or ipsilateral cortical perfusion reduction in thalamic or capsula interna lesions). Both X-ray CT and blood flow SPECT have comparable sensitivity in the exploration of cerebral infarction, with detection in, respectively, 89.5% and 87.5% of the lesions. False negative scintitomographic images are frequently recorded in small lacunar infarcts within the basal ganglia and white matter (capsula interna). Some early infarcts and asymmetry of brain perfusion in patients with transient neurologic symptoms are frequently not detected by CT. An additional advantage of blood flow SPECT is its ability to visualize remote blood flow changes and the changing pattern of vascularization of ischemic lesions and their surrounding areas including hyperemia.     

急性缺血性脑梗死动脉介入溶栓治疗临床疗效观察

目的 探讨急性缺血性脑梗死经动脉溶栓的治疗效果。方法 采用尿激酶(UK)对19例急性缺血性脑梗死病人行动脉溶栓治疗，并行临床疗效判定及DSA再通判定。结果 19例患者中临床总有效率为89．5％，DSA再通率为89．5％，有些病人即使闭塞血管未完全再通但临床症状和体征也有好转。1例溶栓中引发脑出血，在短时间内吸收。结论 动脉溶栓是安全、有效的方法，但需注意治疗的个体化和预防并发症。     

Safety and efficacy of delayed intraarterial urokinase therapy with mechanical clot disruption for thromboembolic stroke.

PURPOSETo evaluate safety and efficacy of delayed intraarterial urokinase therapy with mechanical disruption of clot to treat thromboembolic stroke.METHODSThirteen patients with cerebral thrombolic disease (10 carotid territory, 3 basilar territory) were treated with catheter-directed intraarterial urokinase therapy with mechanical disruption of the clots. All patients were excluded from a 6-hour multicenter thrombolytic trial by either time, recent surgery, age, seizure, or myocardial infarction. Time elapsed before treatment ranged from 3.5 to 48 hours (12 +/- 13 hours), with 200,000 to 900,000 U of urokinase used.RESULTSTen patients had successful vessel recanalization, confirmed by repeat angiography. Cases with distal branch vessel occlusions were less likely to recanalize. Asymptomatic hemorrhagic conversion occurred in 2 patients on repeat scans. Both acute neurologic and functional outcomes were assessed with significant improvement occurring in 9 (69%) of 13 patients at 48 hours (greater than four-point change on the National Institutes of Health scale) and in 100% of 3-month survivors. All patients who improved had normal initial CT scans.CONCLUSIONSIntraarterial cerebral thrombolysis with mechanical disruption of clot seems to be a useful therapy in selected stroke cases even after 6 hours.     

Use of self-expanding intracranial stents in the treatment of acute ischemic stroke

Conventional endovascular therapy for acute ischemic stroke includes intraarterial pharmacologic thrombolysis with tissue plasminogen activator (TPA) administration with or without mechanical thrombectomy with a variety of devices. The present report describes two cases of stroke refractory to TPA administration in which successful recanalization was accomplished by the use of a self-expanding intracranial stent. Stent-assisted recanalization may be a viable option for patients with acute ischemic stroke refractory to thrombolysis or thrombectomy.     

Snare retrieval of intracranial thrombus in patients with acute stroke

Intravenous or intraarterial thrombolysis of intracranial emboli is becoming an accepted clinical treatment modality for acute ischemic stroke, but not all emboli respond to the lytic drug regimens available today. If drug therapy fails, mechanical retrieval seems warranted. Four patients whose condition was resistant to intravenous and intraarterial thrombolytic drug treatment underwent at least partial clot removal with use of a snare, and almost immediate clinical improvement was noted. A fifth patient's clot was removed before lytic drugs were administered. All five patients, who presented with a sudden onset of stroke, were evaluated by arterial angiography; then, after a failed trial of intraarterial fibrinolytic drugs, they were treated by passing a 2- or 4-mm snare through a microcatheter. The snare wire was guided around the thrombus, gently brought back toward the microcatheter-but not into it-and the entire microcatheter and snare assembly was then removed. In four of the five cases, follow-up angiography performed immediately after the retrieval showed wider distal branches than normal. Follow-up computed tomography results were abnormal in all cases, showing hyperdense material in the territory that was previously ischemic. This hyperdensity subsided within 48 hours in all but one patient who developed small parenchymal hemorrhages; however, he remained asymptomatic. The snare device offers an additional or alternative therapy until completely effective thrombolytic agents become available. Although use of a snare is not ideal, device improvements should make the retrieval less technically challenging and more effective. There is a need for improved mechanical extraction devices, especially in light of the patient improvement that occurred. This experience also suggests that immediate removal of a mature clot could reduce the total time of brain ischemia more quickly than administration of thrombolytic drugs.     

Local intraarterial urokinase thrombolysis of acute ischemic stroke with or without intravenous abciximab: a pilot study

PURPOSE: One of the most important prognostic factors in the thrombolytic treatment of acute ischemic stroke is the time to recanalization. To shorten the recanalization time, an antiplatelet agent, abciximab (platelet glycoprotein receptor IIb/IIIa antagonist), was administered intravenously before the initiation of local intraarterial urokinase thrombolysis. The purpose of this study was to evaluate the effectiveness and safety of this combined therapy. MATERIALS AND METHODS: A total of 26 patients with acute ischemic stroke (National Institutes of Health Stroke Scale score >10) were enrolled in this study. In the earlier phase of this study, conventional local intraarterial urokinase thrombolysis was performed in 16 patients (urokinase group). In the later phase, combined use of intravenous abciximab and local intraarterial urokinase thrombolysis was performed in 10 patients (urokinase + abciximab group). Recanalization rate (Thrombolysis in Myocardial Infarction grade >or=2), total amount of urokinase used, incidence of symptomatic hemorrhage, and better functional outcome rate (modified Rankin scale 相似文献   

Vascular occlusion sites determine differences in lesion growth from early apparent diffusion coefficient lesion to final infarct

BACKGROUND AND PURPOSE: Occlusion of major cerebral arteries is the primary source of tissue damage in ischemic stroke and the target of thrombolytic therapy. We hypothesized that large infarcts in more proximal vascular occlusions correspond with substantially increased ischemic lesions shown on initial apparent diffusion coefficient (ADC) maps. METHODS: Initial ADC lesions in 120 patients with acute ischemic stroke were analyzed within 6 hours of stroke onset. Patients were categorized on the basis of vascular occlusion, as shown on MR angiography. Lesion volumes were determined by using manual delineation (ADC(man)) and a threshold method for ADC values (<550 x 10(-9) mm(2)/s(-1), ADC(<550)). Infarct volumes were analyzed by using T2-weighted (n = 109) or CT (n = 11) images obtained on days 5-8. RESULTS: Median lesion volumes for ADC(<550), ADC(man), and infarcts, respectively, were as follows: proximal internal carotid artery (ICA)/middle cerebral artery (MCA) occlusions, 10, 23, and 32 cm(3); carotid-T occlusions, 11, 37, and 138 cm(3); MCA trunk occlusions, 11, 27, and 44 cm(3)); and MCA branch occlusions 8, 27, and 21 cm(3). Initial ADC lesion volumes were different only between the carotid T and the MCA branch (P < .05). On days 5-8, infarct volumes decreased from proximal to distal sites (P < .05), with the exception of MCA trunk versus proximal ICA/MCA occlusions. Recanalization rate in carotid-T occlusion was significantly lower than those of all other occlusion types. CONCLUSION: Initial ADC lesions can be small, even in patients with proximal vascular occlusions. These patients develop considerably large infarctions, suggesting a high potential for infarct growth. This growth might be averted with improved early recanalization of proximal vascular occlusions.     

Prediction of clinical outcome with baseline and 24-hour perfusion CT in acute middle cerebral artery territory ischemic stroke treated with intravenous recanalization therapy

Introduction We sought to determine whether Alberta Stroke Program Early CT Scores (ASPECTS) derived from baseline noncontrast CT (NCCT) and perfusion CT (CTP) imaging maps can predict clinical outcome after recanalization therapy in acute ischemic stroke of the middle cerebral artery (MCA) territory and whether changes in the ASPECTS from baseline to 24 h after recanalization therapy can help predict clinical outcome. Methods We retrospectively studied consecutive patients with acute ischemic stroke of the MCA territory treated with intravenous tissue plasminogen activator (t-PA) or abciximab within 6 h of symptom onset. We performed NCCT and CTP before and 24 h after intravenous t-PA or abciximab treatment and determined the ASPECTS and the changes in the ASPECTS from baseline to 24 h. A favorable outcome was defined as a modified Rankin scale score of 0 or 1 at 3 months. Results During the 18-month study period 44 patients were studied. In multivariate logistic regression analysis, the cerebral blood volume (CBV) ASPECTS (OR 1.80, 95% CI 1.10 to 2.93) at baseline and the increase in cerebral blood flow (CBF) ASPECTS (OR 1.68, 95% CI 1.13 to 2.50) from baseline to 24 h were associated with a favorable outcome. The cutoff values for a favorable outcome using receiver operating characteristic curves were 8 and 1, respectively. When the CBV ASPECTS at baseline was 8 or more, its positive predictive value was only 58.1%. When the CBV ASPECTS at baseline was 8 or more and the increase in CBF ASPECTS from baseline to 24 h was 1 or more, the positive predictive value was 100% and the negative predictive value was 74.2%. Conclusion The CBV ASPECTS derived from baseline CTP maps was found to be predictive of a favorable outcome, but its positive predictive value was suboptimal. The change in the CBF ASPECTS from baseline to 24 h after treatment was helpful in predicting outcome.