MR扩散加权成像对急性脑梗死的诊断价值

目的 :评价磁共振扩散加权成像 (MRDWI)及ADC图对急性脑梗死的诊断价值。方法 :对 18例疑有急性脑梗死患者行MRDWI检查并分析其ADC图 ,并与CT及常规MRI进行比较。结果 :常规MRI、DWI及ADC图显示所有 18例脑梗死患者的 42个急性梗死病灶 ,而常规MRI只显示了其中 19个病灶。 18例患者中有 3例于MRI检查前行CT扫描 ,仅1例提示急性脑梗死 ,且为大脑中动脉供血区大面积脑梗死。结论 :MRDWI对于急性脑梗死的诊断明显优于CT及常规MRI,并且能够鉴别急性、亚急性和慢性脑梗死     

DWI对急性脑梗死病情及预后的评估价值

目的 :探讨DWI对急性脑梗死病情及预后的评估价值。方法 :选择92例急性脑梗死患者,根据脑梗死面积分为大面积梗死组、中小面积梗死组和腔隙性梗死组;根据脑梗死数量分为单发性梗死组、多发性梗死组;根据脑梗死部位分为幕上梗死组、幕下梗死组、幕上幕下梗死组。采用神经功能缺损评分评价患者的疗效及预后。结果:大面积梗死组的疗效显著低于中小面积梗死组和腔隙性梗死组,死亡率和神经功能缺损评分显著高于中小面积梗死组和腔隙性梗死组,差异有统计学意义(均P0.05);中小面积梗死组和腔隙性梗死组的疗效、死亡率和神经功能缺损评分比较,差异均无统计学意义(均P0.05)。多发性梗死组的疗效显著低于单发性梗死组,死亡率和神经功能缺损评分显著高于单发性梗死组,差异均有统计学意义(均P0.05)。幕上幕下梗死组的疗效显著低于幕上梗死组和幕下梗死组,死亡率和神经功能缺损评分显著高于幕上梗死组和幕下梗死组,差异均有统计学意义(均P0.05);幕上梗死组和幕下梗死组的死亡率和神经功能缺损评分比较,差异均无统计学意义(均P0.05)。结论:急性脑梗死患者的疗效及预后与DWI的脑梗死面积、数量及部位有关,DWI表现可指导急性脑梗死患者的疗效及预后。     

1H MRS与eADC值在急性脑梗死中的研究

目的:单体素氢质子磁共振波谱与扩散加权成像的指数表观弥散系数相结合分析急性脑梗死的脑内主要代谢物变化特点。方法:47例临床诊断为急性脑梗死的患者(发病6h后至48h内),以指数表观弥散系数(eADC)升高区及对侧分别为感兴趣区测定1H MRS,观察脑梗死病灶内化合物含量,进一步分析急性脑梗死的主要代谢物变化特点。结果:27例急性腔隙性脑梗死患者中eADC值明显升高区氮—乙酰天冬氨酸(NAA)降低,eADC值升高在50%以上的病例中乳酸检出率增高,且有显著性差异;20例急性非腔隙性脑梗死患者中eADC值明显升高区氮-乙酰天冬氨酸(NAA)降低,eADC值升高在50%以上的病例中乳酸检出率明显增高,没有显著性差异。结论:在脑梗死中联合应用1H MRS与DWI的eADC值能无创性的评价脑梗死局部代谢和形态的动态演变过程,eADC值升高,Lac升高,NAA下降是反映缺血的敏感指标;当eADC值升高超过50%时,1H MRS所能测到Lac敏感性提高,为临床诊断治疗提供依据。     

DWI在散发性脑炎与急性脑梗死鉴别诊断价值

目的　探讨磁共振弥散加权成像在散发性脑炎与急性脑梗死的鉴别诊断中的应用价值。方法　回顾性分析 23例经临床诊断的散发性脑炎,包括 14例病毒性脑炎和 9例脱髓鞘性脑炎的磁共振弥散加权表现,并与 30例急性脑梗死进行比较。结果　病毒性脑炎和脱髓鞘性脑炎病灶表现局灶性或大片异常信号,T1WI呈稍低信号,T2WI及FLAIR呈高信号。除 1例超急性脑梗死未能显示梗死灶外, 29例脑梗死病灶T1WI呈稍低信号,T2WI及FLAIR呈高信号。脑炎与梗死病灶在DWI均呈稍高或高信号。ADC值测量, 30例梗死灶ADC值为(0. 46±0. 13)×10-3 mm2 /s。7例病毒性脑炎和 9例脱髓鞘性脑炎ADC值分别为(0. 98±0. 18)×10-3 mm2 /s和(0. 89±0. 07)×10-3 mm2 /s,病毒性脑炎与脱髓鞘性脑炎病灶ADC值差异无统计学意义 (Ρ>0. 05),但明显高于脑梗死(Ρ<0. 01)和镜面对侧正常区(Ρ<0. 05)。有 4例病毒性脑炎病灶在不同区域弥散增加和受限并存,ADC值表现高低不一,最高者达 0. 96×10-3 mm2 /s,最低者达 0. 31×10-3 mm2 /s;另有 3例全部病灶ADC值表现降低,分别为 0. 44×10-3 mm2 /s、0. 51×10-3 mm2 /s和 0. 58×10-3 mm2 /s。结论　磁共振弥散加权成像对脑炎与急性脑梗死鉴别诊断具有重要临床价值。     

表观扩散系数在中脑脚间区扩散高信号与急性脑梗死中的鉴别诊断价值

目的 探讨表观扩散系数(ADC)在中脑脚间区扩散高信号与急性脑梗死鉴别诊断中的价值.方法 回顾性分析经临床证实的中脑脚间区急性脑梗死31例(病例组)、健康受检者31例(对照组,中脑脚间区在DWI上呈高信号).均行常规MRI及DWI.由两名医师先采用双盲法独立对图像进行评估,并采用组内相关系数(ICC)值分析两名医师测量ADC值的一致性.计算两名医师测量ADC值的平均值,并采用独立样本t检验比较病例组与对照组ADC值的差异.以临床结果为金标准,绘制ADC值诊断中脑脚间区急性脑梗死的ROC曲线,判断最佳诊断界值点,计算ADC值诊断中脑脚间区急性脑梗死的敏感性、特异性和准确性.结果 两名医师测量ADC值的一致性好(ICC =0.926,P＜0.001).对照组ADC值为(635.69 ±54.16) ×10-6mm2/s(95％可信区间为615.83～655.56×10-6mmn2/s),病例组ADC值为(472.08±87.65)×10-6mm2/s(95％可信区间为439.93 ～ 504.23×10-6mm2/s),差异有统计学意义(t=8.842,P=0.000).ADC值诊断中脑脚间区急性脑梗死的ROC曲线下面积为0.935,最佳诊断界值为546×10-6mm2/s,诊断中脑脚间区急性脑梗死的敏感性为87.1％(27/31),特异性为93.5％(29/31),准确性为90.3％ (56/62).结论 ADC值有助于中脑脚间区扩散高信号与急性脑梗死的鉴别.     

MR扩散加权成像在腹部淋巴结的临床应用

目的:探讨MRDWI显示腹部淋巴结的可行性及其在良恶性淋巴结鉴别诊断中的价值。方法:回顾性分析20例肝癌并腹部淋巴结转移(肝门、门腔间隙和腹腔干、腹主动脉旁区域淋巴结)患者和15例乙型肝炎并肝门淋巴结肿大患者的MRI资料。对比分析T2WI和DWI对显示直径>1.0cm淋巴结的能力。在表观扩散系数(ADC)图上测量肝炎组与肝癌组淋巴结的ADC值并比较其差异。结果:肝炎组和肝癌组中T2WI显示的淋巴结DWI均可显示,淋巴结在DWI上信号强度较T2WI高。肝炎组淋巴结平均ADC值(3.92±0.28)×10-3mm2/s;肝癌组淋巴结平均ADC值(3.19±0.39)×10-3mm2/s,低于肝炎组淋巴结,两组间差异有统计学意义(P<0.001)。结论:MRDWI显示腹部淋巴结的敏感性和特异性高,可作为腹部淋巴结检查及良恶性淋巴结鉴别诊断的一种辅助手段。     

椎基底动脉扩张延长症的多层螺旋CT血管成像表现及应用价值

目的 探讨多层螺旋CT血管成像(MSCTA)在椎基底动脉扩张延长症(VBD)中的应用价值及临床意义.方法 对33例VBD患者的影像资料进行回顾性分析,并与对照组(40例)比较后循环血管狭窄性病变和脑梗死的发生率.结果 33例扩张的椎基底动脉直径4.8～14.3 mm,迂曲的基底动脉和椎动脉颅内段长度分别为30.3～41.7 mm 和23.9～42.2 mm,33例中发现大脑后动脉及椎动脉狭窄或闭塞11例,后循环供血区腔隙性脑梗死15例,大面积脑梗死3例;对照组40例中,椎动脉及大脑后动脉闭塞各1例,椎基底动脉和(或)大脑后动脉狭窄22例,后循环供血区腔隙性脑梗死7例,大面积脑梗死3例,2组间后循环供血区腔隙性脑梗死发生率差异有统计学意义(P＜0.05).结论 VBD可能是后循环供血区腔隙性脑梗死的重要危险因素;MSCTA结合原始图像可以清晰显示VBD及其颅内伴随病变.     

表观弥散系数在高级别胶质瘤与急性期脑梗死鉴别诊断中的应用

目的探讨表观弥散系数(ADC值)在高级别胶质瘤与急性期脑梗死鉴别诊断中的应用。方法回顾性分析经手术和病理证实的18例高级别胶质瘤及正规及时溶栓治疗的28例急性期脑梗死的常规磁共振表现和弥散加权成像(DWI)表现,对照分析高级别胶质瘤实性部分、急性期脑梗死灶中心部分及对侧正常脑组织ADC值。结果 18例高级别胶质瘤患者共发现20个病灶,其中11例病灶内合并有出血、坏死和囊变,肿瘤实质部分呈稍高信号,囊变坏死区呈明显低信号,肿瘤实质部分平均ADC值为(0.92±0.12)×10-3mm2/s,对侧相应正常部位平均ADC值为(0.79±0.09)×10-3mm2/s,差异有统计学意义(P<0.05),急性期脑梗死在DWI上表现为高或稍高信号,其ADC值明显低于对侧相应区域,平均ADC值为(0.69±0.10)×10-3mm2/s,高级别胶质瘤实性部分与急性期脑梗死平均ADC值差异有统计学意义(P<0.05)。结论 DWI表现及ADC值对高级别胶质瘤与急性期脑梗死磁共振鉴别诊断具有重要价值。     

扩散加权成像在诊断脑积水所致急慢性颅内压升高中的评估

目的:探讨磁共振扩散加权成像(DWI)在评估脑积水中能否提供更多脑室周围白质的信息。方法:分析的16例(11例患者具有急性颅内压增高症状,另5例没有临床症状)MRI资料中15例有脑积水表现,其中交通性脑积水4例,阻塞性脑积水11例。1例有症状者后来症状逐渐消失。研究皮层下白质及其周围的表面扩散系数(ADC),并将有症状病例的ADC值与无症状组的ADC值进行比较。结果:11例有症状的脑积水患者中,6例脑室周围水肿区的ADC值比皮层下白质明显增高,另5例脑室周围没有间质性水肿者,其ADC值也明显升高(两组均含交通性和阻塞性脑积水)。而5例没有症…     

Diffusion tensor imaging in the differential diagnosis of low-grade cerebral glioma,cerebral infarction and viral encephalitis

目的:探讨磁共振扩散张量成像在鉴别低级别脑胶质瘤、脑梗死和病毒性脑炎中的应用价值.方法:22例低级别脑胶质瘤、26例急性或亚急性期脑梗死和18例病毒性脑炎患者在治疗或手术前行常规MRI和DTI检查.脑低级别胶质瘤患者均经手术病理证实,病毒性脑炎和脑梗死患者均经临床治疗及随访证实.测量并计算3组病灶的表现扩散系数(ADC)值和相对表现扩散系数(rADC)值、各向异性分数(FA)值和相对各向异性分数(rFA)值,并进行统计学分析.结果:脑低级别胶质瘤组平均ADC、rADC、FA和rFA值分别为(1.55±0.08)×10-3mm2/s、1.68±0.25、0.17±0.03和0.42±0.08,脑梗死组分别为(0.54±0.12)×10-3mm2/s、0.64±0.12、0.14±0.03和0.30±0.05,病毒性脑炎组分别为(0.84±0.07)×10-3mm2/s、1.07±0.05、0.17±0.02和0.43±0.09.三组病例的平均ADC值及rADC值间的差异有高度统计学意义(P＜0.01),脑低级别胶质瘤与脑梗死的FA值和rFA值之间、病毒性脑炎与脑梗死的FA值和rFA值之间差异有高度统计学意义(P＜0.01),脑低级别胶质瘤与病毒性脑炎的FA值和rFA值之间差异无统计学意义(P＞0.05).结论:综合利用DTI的ADC值、rADC值、FA值及rFA值,对鉴别脑低级别胶质瘤、脑梗死和病毒性脑炎具有较高的指导价值.     

急性脑静脉闭塞脑损伤治疗时间窗初探:DWI与病理学对照实验研究

目的:探讨急性脑静脉闭塞模型脑实质损伤治疗时间窗的存在及其意义.方法:选择新西兰大白兔28只随机分为2组(实验组24只,对照组4只),实验组动物经一侧颈内静脉注入醋酸纤维素聚合物(CAP),分别于术后1、3、6、12、24和48 h行T1WI、T2WI和扩散加权成像(DWI)检查.各时间点MR扫描后取兔脑组织做胶质纤维酸性蛋白(GFAP)表达的免疫组化研究及电镜观察.结果:DWI、T2WI、GFAP的表达和电镜检查均能显示急性脑静脉闭塞模型脑实质损伤及其变化.DWI在术后1 h即能显示脑实质病变(ADC值下降),术后3 h DWI和T2WI均能显示病变;术后6 h前,DWI上有扩散异常的脑组织容积明显大于T2WI上异常高信号区的容积(t=13.69,P＜0.01);术后12、24和48 h病变区ADC值逐渐回升,T2WI上病变容积与DWI上的扩散异常区的容积比较,差异无显著性意义(t值分别为1.467、0.996和2.017,P＞0.05).术后1 h病变区GFAP阳性细胞增多,染色加深,胞体增大,突起增粗增长,术后3～6 h变化更明显,病理学改变以血管源性水肿为主,12 h后出现脑组织大量坏死.对照组未见上述各种异常表现.结论:DWI可准确评价急性脑静脉闭塞模型脑实质损伤程度,结合GFAP的表达,在探讨急性脑静脉闭塞脑损伤的治疗时间窗的存在及其意义中具有重要价值,在其发生发展过程中确实存在潜在的治疗时间窗.     

Hypoxic-ischemic brain injury in the neonatal rat model: relationship between lesion size at early MR imaging and irreversible infarction

BACKGROUND AND PURPOSE: By using a neonatal rat hypoxia-ischemia (HI) model, we studied the relationship between lesion volume-measured by diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) at an early time point-and irreversible infarct volume. We also evaluated the optimal apparent diffusion coefficient (ADC) threshold that provides the best correlation with irreversible infarct size. MATERIALS AND METHODS: Twenty-three neonatal rats underwent right common carotid artery ligation and hypoxia. MR imaging was performed 1-2 hours post-HI by using DWI and T2WI and at day 4 post-HI by using T2WI. Lesion volumes relative to whole brain (%LV) were measured on ADC maps by using different relative ADC thresholds 60%-80% of mean contralateral ADC and T2WI. Pearson correlation and multiple linear regression analysis were used to study the relationships between ln(%LV) at MR imaging and %LV at histopathology. RESULTS: At 1-2 hours post-HI, all lesion volume measurements on DWI were significantly correlated with the infarct volume on histopathology, with the best correlation attained at the 80% ADC threshold (r = 0.738; P < .001). The estimated regression formula was %LV on histopathology = 20.60 + 3.33 ln(%LV on 80% ADC threshold) (adjusted R(2) = 0.523; P < .001). Lesion volume at 1-2 hours post-HI tended to underestimate the final infarct volume. CONCLUSION: Early post-HI MR imaging by using DWI correlates moderately well with the size of irreversible infarct, especially when measured by using a relative ADC threshold of 80% mean contralateral ADC.     

扩散加权成像在急性脑缺血性中风诊断中的价值

目的　评价扩散加权成像 (DWI)技术在急性脑缺血性中风 (AIS)急诊MR检查中的价值和对急诊MR诊断质量的影响。资料与方法　回顾分析 86例AIS急诊MR检查资料 ,将距症状发作 1 0h内进行急诊MR检查者定为A组 ,1 0h后急诊MR检查者定为B组。利用双盲法 ,对DWI和TSET2 WI、FLAIRT2 WI、SET1 WI所见作对照分析。结果　A组 ,TSET2 WI+FLAIRT2 WI+SET1 WI对AIS新梗死灶显示能力为DWI的 32 .98% ,两者具有显著性差异(P <0 .0 1 )。B组 ,TSET2 WI+FLAIRT2 WI+SET1 WI与DWI具有相同的显示能力。AIS新梗死灶DWI呈高信号 ,ADC图呈低信号。结论　DWI能早期、超早期诊断AIS ,降低错、漏诊率 ,提高AIS常规急诊MR诊断质量     

扩散加权成像诊断超急性和急性脑梗塞的应用价值

目的:探讨DWI和ADC图诊断超急性和急性脑梗塞的价值.材料和方法:14例脑梗塞患者(超急性期6例,急性期8例)采用1.5T MR机进行扫描,对DWI、ADC图及常规T1WI、T2WI进行对比研究分析.结果:超急性和急性脑梗塞DWI均表现为高信号,ADC图均表现为低信号,DWI对病变显示达100%.6例超急性期脑梗塞患者仅DWI可显示病变而常规T1WI、T2WI无任何相应的异常发现.全部病灶ADC值均低于其相对应的正常脑组织.结论:DWI对急性脑梗塞诊断敏感、准确,且能对脑梗塞作定量分析.     

急性脑缺血表观扩散系数成像的实验研究

用改良的线栓法大脑中动脉阻塞模型,探讨急性脑缺血及再灌注的表现扩散系数成像特点。方法：２０只ＳＤ大白鼠,分为４组：Ａ组（８只）,非再通组,Ｂ、Ｃ、Ｄ组（各４只）,分别于ＭＣＡＯ３０ｍｉｎ、１ｈ、２ｈ后再通,于不同时间点作ＡＤＣ成像和Ｔ２ＷＩ,并测量感兴趣区的ＡＤＣ、相对ＡＤＣ（ｒＡＤＣ）。结果：ＭＣＡＯ后１５ｍｉｎ好出现缺血区ＡＤＣ下降,而Ｔ２ＷＩ最早在栓塞后２ｈ出现异常。６ｈ内缺血区,ＡＤＣ及ｒ     

MR功能成像对早期强直性脊柱炎骶髂关节的定量评估

目的：探讨联合应用T2*mapping T2*值和扩散加权成像(DWI)的表观扩散系数(ADC)值定量评估骶髂关节炎性活动性的可行性。方法将30例强直性脊柱炎(AS)根据病情严重程度按临床病情活动指数(BASDAI)评分,分为急性期 A组(17例)和慢性期B组(13例),另选健康志愿者C组(20例),行骶髂关节常规 MR扫描、T2*mapping及DWI,分别测量骶髂关节骨髓水肿区及相对正常区域的T2*值和 ADC值,并对3组间的均值差异和A、B组与BASDAI评分关系进行统计分析。结果 A组的T2*值和ADC值均大于B组和C组,差异有统计学意义(P<0.05);B组的T2*值和ADC值与C组对比,无统计学差异(P>0.05);A、B组T2*值和 ADC值与临床BASDAI评分呈正相关性(P<0.05)。结论联合应用T2*mapping 和DWI有助于 AS早期诊断并定量分析骶髂关节炎性活动性程度。     

Rodent stroke induced by photochemical occlusion of proximal middle cerebral artery: evolution monitored with MR imaging and histopathology

PURPOSE: To longitudinally investigate stroke in rats after photothrombotic occlusion of proximal middle cerebral artery (MCA) with magnetic resonance imaging (MRI) in correlation with histopathology. MATERIALS AND METHODS: Forty-two rats were subjected to photochemical MCA occlusion and MRI at 1.5T, and sacrificed in seven groups (n=6 each) at the following time points: 1, 3, 6 and 12h, and at day 1, 3 and 9. T2-weighted (T2WI) and diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) map was performed in all rats. Contrast-enhanced T1-weighted imaging (CE-T1WI) was compared to intravital staining with Evans blue in one group for assessing blood-brain barrier (BBB) integrity. The brain was stained histochemically with triphenyl tetrazolium chloride (TTC) and processed for pathological assessment. The evolutional changes of relative lesion volume, signal intensity (SI), and the BBB integrity on MRI with corresponding histopathology were evaluated. RESULTS: The ischemic lesion volume reached a maximum around 12h to day 1 as visualized successively by DWI, ADC map and T2WI, implicating the evolving pathology from cytotoxic edema through vasogenic edema to tissue death. The ADC of brain infarction underwent a significant reversion after 12h, reflecting the colliquative necrosis. On CE-T1WI, BBB leakage peaked at 6h and at day 3 with a transitional partial recovery around 24h. The infarct volume on T2WI, DWI and ADC map matched well with that on TTC staining at 12h and at day 1 (p>0.05). CONCLUSION: The evolution of the present photothrombotic stroke model in rats could be characterized by MRI. The obtained information may help longitudinal studies of cerebral ischemia and anti-stroke agents using the same model.     

3.0T磁敏感加权成像诊断脑梗死后脑出血的价值

目的：探讨3.0T磁敏感加权成像（SWI）对梗死后脑出血的诊断价值。方法：对50例急性脑梗死后疑有脑出血患者行CT检查,同时行MRI常规序列（T2WI、T1WI、DWI）扫描及SWI扫描,对检查结果进行统计学分析。结果：34例患者CT扫描证实为梗死后脑出血,SWI诊断脑出血34例,T2WI诊断19例,T1WI诊断21例,DWI诊断25例。SWI、T2WI、T1WI和DWI诊断梗死后脑出血的敏感度分别为100.0%、59.0%、61.4%和73.0%,特异度分别为100.0%、65.2%、68.0%和65.3%,阳性预测值分别为100.0%、68.1%、71.0%和75.4%,阴性预测值分别为100%、60.3%、57.2%和78.3%,约登指数（正确指数）分别为1.0、0.24、0.29和0.38。诊断试验秩和比法分析示SWI、T2WI、T1WI和DWI各序列的秩和比值（RSR）分别为1.0、0.3、0.5和0.7。结论：SWI诊断梗死后脑出血比MRI常规扫描序列具有更高的临床应用价值,可作为急性脑梗死及溶栓治疗后常规复查方法。     

急性脑梗塞磁共振弥散加权成像的演变特征

目的：研究临床急性脑梗塞病变在弥散加权（DW）MRI上的表现规律。材料和方法：用单次激发平面回波弥散加权MRI和MRI其他技术对47例脑梗塞患者和14例非脑梗塞患者进行了对比研究。分别测量梗塞灶ACD图、DWI和T2WI的信号强度，绘出时间-信号强度图。分别在DWI和T2WI上测量梗塞面积．比较两者的关系。结果：急性脑梗塞发病后局部ACD逐渐降低．至12h达到峰值．以后逐渐升高。弥散加权MRI对急性脑梗塞病变非常敏感和特异，发病3h内T2WI为阴性，DW－MRI全部显示了梗塞灶；发病24h内T2WI所显示的梗塞灶面积明显小于DWI。发病7天内梗塞灶在DWI上与正常脑信号比均＞2．0．非脑梗塞病变均＜2．0。结论：急性脑梗塞病变在DW．MRI上有特征性演变规律，DW．MRI能快速、敏感、准确地诊断急性脑梗塞     

Predicting final infarct size using acute and subacute multiparametric MRI measurements in patients with ischemic stroke

PURPOSE: To identify early MRI characteristics of ischemic stroke that predict final infarct size three months poststroke. MATERIALS AND METHODS: Multiparametric MRI (multispin echo T2-weighted [T2W] imaging, T1-weighted [T1W] imaging, and diffusion-weighted imaging [DWI]) was performed acutely (<24 hours), subacutely (three to five days), and at three months. MRI was processed using maps of apparent diffusion coefficient (ADC), T2, and a self-organizing data analysis (ISODATA) technique. Analyses began with testing for individual MRI parameter effects, followed by multivariable modeling with assessment of predictive ability (R(2)) on final infarct size. RESULTS: A total of 45 patients were studied, 15 of whom were treated with tissue plasminogen activator (tPA) before acute MRI. The acute DWI and DWI-ISODATA mismatch lesion size, and the interactions of ADC, T2, and T2W imaging lesion with tPA remained in the final multivariable model (R(2) = 70%). A large acute DWI lesion or DWI < ISODATA lesion independently predicted increase in the final infract size, with predictive ability 68%. Predictive ability increased (R(2) = 83%) when subacute MRI parameters were included along with acute DWI, DWI-ISODATA mismatch, and acute T2W image lesion size by tPA treatment interaction. Subacute DWI > acute DWI lesion size predicted an increased final infarct size (P < 0.01). CONCLUSION: Acute-phase DWI and DWI-ISODATA mismatch strongly predict the final infarct size. An acute-to-subacute DWI lesion size change further increases the predictive ability of the model.