3．0TMR动脉自旋标记与动态磁敏感对比增强灌注技术在脑胶质瘤术前分级中的对照研究

目的：对照研究动脉自旋标记（arterial spin labeling,ASL）与动态磁敏感对比增强（dynamic susceptibility contrast—enhanced．DSC）灌注成像技术在脑胶质瘤中的灌注特点．探讨ASL在脑胶质瘤术前分级中的临床应用价值。方法：使用3．0TMR成像系统对23例脑胶质瘤患者（术后病理证实高级别胶质瘤17例,低级别胶质瘤6例）术前行常规扫描外,加扫ASL及DSC灌注检查。测量肿瘤实质部分最大肿瘤血流量（maximal tumor blood flow,TBFmax）以及对侧白质、对侧灰质、对侧半球的血流量（cerebral blood flow,CBF）。结果：23例脑胶质瘤患者。两种灌注方法均获得了一致的灌注结果,TBF max／对侧白质CBF、TBFmax／对侧灰质CBF及TBFmax／对侧半球CBF的各比值在ASL和DSC两种技术之间的差异无明显统计学意义（P〉0．05）,但在高、低级别胶质瘤之间的差异均有统计学意义（P〈0．05）。在ASL法中,TBFmax／对侧白质CBF、TBFmax／对侧灰质CBF及TBFmax／对侧半球CBF分别取阈值为3．06、0．46和1．31时,其敏感性分别为i00％、88．2％和100％．特异性分别为83．3％、83．3％和100％。结论：ASL在评估脑胶质瘤血流灌注方面与DSC之间有相似的敏感性,具有可重复性高、完全无创性等优点,同时有助于术前对脑胶质瘤进行分级评判。     

三维动脉自旋标记技术在胶质瘤术后复发诊断中的价值

目的:探讨三维动脉自旋标记技术(3D-ASL)对胶质瘤术后复发的诊断价值。方法 :回顾性分析15例经第2次手术切除或活检病理证实的胶质瘤复发患者的临床及影像资料;术后每3个月(第3、6、9个月)复查MRI增强扫描及3D-ASL检查,追踪测量病变强化区域范围大小、病变及正常对照区脑血流量(CBF)值、相对脑血流量(r CBF)值,采用方差分析灌注参数变化以评价肿瘤变化趋势;3名医师分别对MRI增强扫描、3D-ASL图像及两者联合图像进行肿瘤复发的判断。结果:15例中,第2次术后第3、6、9个月出现异常强化病灶分别为5、11、13例;3D-ASL呈相对高灌注分别为8、12、13例,病变区域平均CBF值分别为(68.46±17.01)、(76.45±17.50)、(80.21±18.11)mL/(100 g·min),平均r CBF值为1.92±0.44、2.28±0.46、2.51±0.51,经方差检验分析发现术后第3个月与第6个月、第3个月与第9个月CBF值差异均有统计学意义(均P0.05),第3个月与第9个月r CBF值比较,差异有统计学意义(P0.05)。常规MRI增强扫描与3D-ASL对胶质瘤术后第6个月复发的诊断准确率差异有统计学意义(P0.05)。结论:胶质瘤术后复发病灶在3D-ASL随访过程中呈相对高灌注表现,且CBF、r CBF值随着病程进展出现灌注增加的趋势。较常规MRI增强扫描,动态观测CBF、r CBF变化结合MRI增强扫描有利于提高胶质瘤复发的诊断准确率。     

三维动脉自旋标记灌注成像在星形细胞瘤术前分级中的应用

目的：探讨三维动脉自旋标记（3D-ASL）灌注成像对星形细胞瘤术前分级的价值及其定量参数与肿瘤分级的相关性。方法：回顾性分析经组织病理学证实的10例低级别星形细胞瘤开口13例高级别星形细胞瘤的3D-ASL图像,应用兴趣区（ROIs）法获得肿瘤实体部分的平均最大相对脑血流量（CBF）。结果：ASI。法测量的高级别和低级别星形细胞瘤的平均最大CBF中位数（四分位数间距）分别为98．05（73．23,16l.51）和59．13（39．67,97．72）mL／（100g·min）,两组间差异有统计学意义（P=0．013）。当分别以镜像区域（M）、对侧正常灰质（GM）和对侧正常白质（WM）做为参照进行肿瘤CBF的标准化时,ASL法获得的3个标准化肿瘤血流量（nTBF）在高级别与低级别星形细胞瘤间差异均有统计学意义（P值分别为0．003、0．001和0．026）,两组的3个nTBF中位数分别为2．19（1．76,5．26）与1．21（0．84,1．80）、2．57（1．76,4．05）与1．25（0．75,1．59）、2．46（1．61,3．57）与1．08（0．76,2．10）。ASL法测量的CBF和nTBF（包括3个值,分别以M、GM和wM作为参照）与肿瘤级别均呈显著正相关,相关系数r值分别为0．529（P=0．009）、0．635（P=0．001）、0．727（P〈0．001）和0．476（P=0．022）。结论：313-ASL可以很好地鉴别高级别与低级别星形细胞瘤,将成为能进行星形细胞瘤术前分级的一种新的无创性影像学方法,由于无需注射对比剂,对于肾功能不全的患者和治疗后随访有重要意义。     

MR动脉质子自旋标记与动态磁敏感对比增强灌注技术在脑胶质瘤分级中的价值

目的 探讨动脉质子自旋标记（ASL）与动态磁敏感对比增强（DSC）灌注技术用于脑胶质瘤分级的可行性。方法 经病理证实的28例脑胶质瘤患者，按世界卫生组织2000年规定的胶质瘤分级标准分为高级15例，低级13例。使用3．0TMR扫描仪进行Q2TIPS的ASL检查和静脉团注钆喷替酸葡甲胺（Gd-DTPA）的DSC灌注检查。所得数据经两独立样本秩和检验分析，P〈0．05为差异有统计学意义；并用直线回归的方法分析两种灌注方法的相关性。结果 ASL法测得的脑胶质瘤血流量（TBF）／对侧脑白质相对血流量（CBF）：高、低级别胶质瘤分别为（5．5±1．8）、（2．1±1．4），DSC法测得的值分别为（4．3±1．0）、（2．0±1．1），差异均有统计学意义（Z值分别为-3．824、-3．939，P〈0．01）；ASL法测得的TBF／对侧半球CBF值，高、低级别胶质瘤分别为（2．2±0．8）、（0．8±0．5），DSC法测得的值分别为（2．1±0．8）、（1．0±0．6），差异均有统计学意义（Z值分别为-3．987、-3．386，P〈0．01）；ASL法测得的TBF／对侧灰质CBF值，高、低级别胶质瘤分别为（1．7±0．6）、（0．7±0．5），DSC法测得值分别为（1．6±0．5）、（0．8±0．4），差异均有统计学意义（Z值分别为-3．894、-3．754，P〈0．01）。两种方法测得的上述比值均密切相关（r分别为0．91、0．93、0．91，P〈0．01）。结论 ASL可用于胶质瘤微血管灌注的评估，有助于区分低级别和高级别脑胶质瘤。     

磁共振DWI和PWI在胶质瘤术前分级中的应用研究

目的：通过磁共振扩散加权成像（DWI）和灌注加权成像（PWi）研究肿瘤实性区域的组织扩散和微血管生成情况,探讨DWI和PWI在胶质瘤术前分级中的应用价值。方法：回顾性分析手术病理证实的脑胶质瘤患者常规MRI、DWI和PWI检查资料,按照2000年WHO脑肿瘤分级标准,低级别胶质瘤（Ⅰ～Ⅱ级）22例,高级别胶质瘤（Ⅲ～Ⅳ级）17例。所有病例均术前行DWI扫描,而同时行PWI扫描的有30例,其中低级别胶质瘤和高级别胶质瘤各15例。在工作站构建ADC图和rCBV图,分别测量肿瘤实性区域和相应部位正常参照区域的ADC值和rCBV值,尽可能把ADC值ROI与rCBV值ROI一致,观察高级别胶质瘤组和低级别组肿瘤实性区域ADC值和CBV值与正常对照的相互关系,并着重观察两组肿瘤各自与正常参照区域的相对（肿瘤／参照）ADC（rADC）值和相对CBV（rCBV）值之间的关系以及rADC与rCBV之间的相关性。低级别和高级别胶质瘤之间肿瘤实性区域各项比值的比较均采用两样本t检验。P〈0．05为有统计学差异,P〈0．01时有显著性差异。rADC和rCBV之间采用spearman检验以观察两组间有无相关性。结果：高级别胶质瘤组肿瘤实性区域ADC值（1．27±0．20,×10^-3mm^2／s）较正常对照区（1．10±0．15,×10^-3mm^2／s）稍高,两者之间具有统计学差异（P〈0．05）;而低级别胶质瘤组肿瘤实性区域ADC值（1．84±0．29,×10^-3mm^2／s）明显高于正常对照区（1．00±0．08,×10^-3mm^2／s）,具有显著性差异（P〈0．01）。高级别胶质瘤组rADC值（1．18±0．18）明显低于低级别组（1．82±0．30）,而前者rCBV值（4．14±0．85）明显高于后者（2．51±0．59）,两组之间均具有显著性差异（P〈0．01）。同时,rADC值和rCBV值之间表现为强相关性（r=-0．67,P〈0．01）。结论：高级别胶质瘤与低级别胶质瘤瘤体实性区域rADC值和rC     

PWI鉴别诊断单发脑转移瘤和高级别胶质瘤的价值分析

目的探讨磁共振灌注加权成像(PWI)在单发脑转移瘤和高级别胶质瘤鉴别诊断中的价值。方法选择在本院治疗的255例单发脑转移瘤和104例高级别胶质瘤为研究对象(共359例,经病理组织活检确诊),术前均常规进行核磁共振扫描以及PWI检查,详细测量肿瘤区、瘤旁区、肿瘤周围水肿区(瘤周区)以及健侧无肿瘤的正常脑组织CBV(脑血容量)值,得出肿瘤区、瘤旁区、瘤周区相对无肿瘤的正常脑组织的rCBV(相对脑血容量)值,记录患者PWI特征。结果 255例单发脑转移瘤,104例高级别胶质瘤PWI显示:1)在肿瘤区,单发脑转移瘤的rCBV值(4. 85±2. 17),比高级别胶质瘤rCBV值(6. 32±2. 59)低,两者比较无统计学意义(P 0. 05),但均高于健侧正常脑组织的rCBV(2. 15±0. 42),差异具有统计学意义(P 0. 05); 2)转移瘤瘤旁区的rCBV值(1. 31±0. 25)低于高级别胶质瘤瘤旁区rCBV值是(3. 01±0. 56),差异具有统计学意义(P 0. 05); 3)在肿瘤周围水肿区内,单发脑转移瘤的rCBV值(1. 11±0. 31),比高级别胶质瘤的rCBV值低(1. 58±0. 29);差异均有统计学意义(P 0. 05); 4)单发转移瘤的PWI在对比剂首过后,信号恢复较高级别胶质瘤明显慢。结论对单发脑转移瘤与高级别胶质瘤采用PWI的检查手段,计算瘤周区的rCBV值,显示其血流灌注特性,有助于两者的鉴别诊断。     

DWI与动脉自旋标记成像在胶质瘤术前诊断中的应用价值

目的 :探讨DWI及动脉自旋标记法(arterial spin labeling,ASL)在胶质瘤术前分级中的应用价值。方法:选取28例经手术病理证实的脑肿瘤患者,其中高级别胶质瘤(high grade glioma,HGG)18例,低级别胶质瘤(low grade glioma,LGG)10例。所有患者均行DWI及ASL扫描,比较不同级别胶质瘤ADC值及脑血流量(CBF)值的差异。结果:HGG肿瘤实质区CBF值大于LGG;HGG肿瘤实质区ADC值小于LGG;且不同级别胶质瘤ADC值与CBF值有显著相关性(r=-0.759,P=0.002)。结论 :DWI及ASL可于术前安全无创地评估脑胶质瘤级别,有助于临床制订治疗方案。     

3.0T氢质子磁共振波谱成像在胶质瘤术前分级及术后随访中的应用

目的分析3.0T MRS成像在脑胶质瘤术前分级及术后随访中的应用价值。方法对61例临床及常规磁共振成像考虑胶质瘤者行2D-MRS检查并与3D-ASL比较,观察各代谢物成分及比值,术前对胶质瘤级别进行前瞻性判断,对照术后结果进行回顾性分析及随访。结果肿瘤实质部分NAA下降、Cho升高,高级别胶质瘤Cho/NAA为5.3±2.2、Cho/Cr为3.5±1.5,低级别Cho/NAA为1.6±0.3、Cho/Cr为1.8±0.5,差异有统计学意义(P﹤0.05)。术后6月内随访,12例复发,7例并发放射性脑病中4例复发。结论磁共振波谱成像可在术前准确判断胶质瘤级别、术后敏感监测肿瘤复发。与3D-ASL比较,MRS对瘤周水肿肿瘤细胞的浸润及术后放疗后肿瘤复发识别优于3D-ASL。     

3D-ASL技术在高级别脑胶质瘤术后复发诊断与鉴别诊断中的应用

目的探讨3D-ASL技术在高级别脑胶质瘤术后复发诊断与鉴别诊断中价值。方法选取52例高级别脑胶质瘤术后放疗后在MRI随访出现术区异常强化病灶的患者,其中经过二次手术或随访确诊肿瘤复发者34例为A组,确诊放射性脑损伤者18例为B组。2组患者均行常规MRI平扫、增强及3D-ASL检查;测量3D-ASL血流灌注图像中的病灶实质部分最大血流量值(CBFmax)和对侧镜像区、对侧白质、灰质的CBFmax值,所得数值标准化后做统计学分析。分别通过常规MRI和常规MRI联合3D-ASL技术做出诊断,将2种方法的诊断符合率行统计学比较。结果平均最大相对脑血流量(r CBFmax)比值在两组患者之间的差异有统计学意义;联合应用3DASL技术对胶质瘤复发的诊断正确率有明显提高,两种诊断方法差异有统计学意义。结论 3D-ASL技术安全无创,无需注射造影剂,可以用于胶质瘤复发与放射损伤的鉴别,常规MRI联合3D-ASL有助于提高胶质瘤复发的诊断正确率。     

3D-ASL与DSC对星形细胞瘤血流灌注评估的相关性研究

【摘要】目的：探讨星形细胞瘤动脉自旋标记（3D-ASL）与动态磁敏感对比增强（DSC）对脑血流量（CBF）评估的相关性。方法：70例经病理证实的星形细胞瘤患者［毛细胞型星形细胞瘤（Ⅰ级）4例,弥漫性星形细胞瘤（Ⅱ级）28例,间变性星形细胞瘤（Ⅲ级）22例,胶质母细胞瘤（Ⅳ级）16例］行常规MR平扫、3D-ASL、DSC及增强T1WI检查,分别测量肿瘤实性区最大CBF、近瘤周区及镜像区CBF,计算肿瘤实性区及近瘤周区rCBF;评估两种灌注方法rCBF的相关性。结果：70例星形细胞瘤3D-ASL和DSC法实性区rCBF（采用中位数与四分位数间距表示,下同）分别为3.069、2.151和3.7943、3.825,相关系数r=0.944;两者近瘤周区rCBF分别为0.913、0.576和1.095、0.783,r=0.732。高级别胶质瘤（HGG）组（38例）3D-ASL和DSC法实性区rCBF分别为3.662、2.054和4.179、3.468,r=0.918;两者近瘤周区rCBF分别为1.171、0.760和0.974、0.703,r=0.757。低级别胶质瘤（LGG）组（32例）3D-ASL和DSC实性区rCBF分别为2.109、2.205和2.591、3.988,r=0.931;两者近瘤周区rCBF分别为0.781、0.438和0.965、0.944,r=0.840。结论：3D-ASL与DSC法测量星形细胞瘤实性及近瘤周区rCBF值均有较好的相关性,且LGG组相关性更好,提示3D-ASL对星形细胞瘤CBF的评估具有可行性。     

High-grade and low-grade gliomas: differentiation by using perfusion MR imaging

AIM: Relative cerebral blood volume (rCBV) is a commonly used perfusion magnetic resonance imaging (MRI) technique for the evaluation of tumour grade. Relative cerebral blood flow (rCBF) has been less studied. The goal of our study was to determine the usefulness of these parameters in evaluating the histopathological grade of the cerebral gliomas. METHODS: This study involved 33 patients (22 high-grade and 11 low-grade glioma cases). MRI was performed for all tumours by using a first-passage gadopentetate dimeglumine T2*-weighted gradient-echo single-shot echo-planar sequence followed by conventional MRI. The rCBV and rCBF were calculated by deconvolution of an arterial input function. The rCBV and rCBF ratios of the lesions were obtained by dividing the values obtained from the normal white matter of the contralateral hemisphere. For statistical analysis Mann-Whitney testing was carried out. A p value of less than 0.05 indicated a statistically significant difference. Receiver operating characteristic curve (ROC) analysis was performed to assess the relationship between the rCBV and rCBF ratios and grade of gliomas. Their cut-off value permitting discrimination was calculated. The correlation between rCBV and CBF ratios and glioma grade was assessed using Pearson correlation analysis. RESULTS: In high-grade gliomas, rCBV and rCBF ratios were measured as 6.50+/-4.29 and 3.32+/-1.87 (mean+/-SD), respectively. In low-grade gliomas, rCBV and rCBF ratios were 1.69+/-0.51 and 1.16+/-0.38, respectively. The rCBV and rCBF ratios for high-grade gliomas were statistically different from those of low-grade gliomas (p < 0.001). The rCBV and CBF ratios were significantly matched with respect to grade, but difference between the two areas was not significant (ROC analysis, p > 0.05). The cut-off value was taken as 1.98 in the rCBV ratio and 1.25 in the rCBF ratio. There was a strong correlation between the rCBV and CBF ratios (Pearson correlation = 0.830, p < 0.05). CONCLUSION: Perfusion MRI is useful in the preoperative assessment of the histopathologicalal grade of gliomas; the rCBF ratio in addition to the rCBV ratio can be incorporated in MR perfusion analysis for the evaluation.     

Grading of CNS neoplasms using continuous arterial spin labeled perfusion MR imaging at 3 Tesla

PURPOSE: To differentiate glioma grade based on blood flow measured using continuous arterial spin labeled (CASL) perfusion MRI, implemented at 3 Tesla for improved signal-to-noise ratio (SNR) and spin labeling effect. MATERIALS AND METHODS: CASL perfusion images were obtained preoperatively in 26 patients with brain neoplasms (19 high-grade gliomas (HGGs; WHO grades 3 and 4) and seven low-grade gliomas (LGGs; WHO grades 1 and 2)). The mean and maximum tumor blood flow (TBF and TBFmax) were calculated in the neoplasm, including surrounding infiltrating tumor vs. edema. Measures normalized to global CBF (nTBF and nTBFmax) were also obtained. RESULTS: Normalized measures of TBFmax provided the best distinction between HGG and LGG groups (Wilcoxon rank sum test, P = 0.01). Seventeen of 19 HGGs showed nTBFmax > 1.0, and 15 of 19 showed nTBFmax > 1.3. Four of seven LGGs showed nTBFmax < 1.0, and six of seven showed nTBFmax < 1.3. Absolute TBFmax also differed significantly between the HGG and LGG groups (P = 0.04). TBFmax in 11 of 17 HGGs was >50 mL/100 g/min (mean +/- SD = 94.9 +/- 71.7 mL/100 g/min). All but one LGGs showed TBFmax < or = 50 mL/100 g/min (mean +/- SD = 42.8 +/- 22.0 mL/100 g/min). CONCLUSION: CASL perfusion MRI provides a quantitative, noninvasive alternative to dynamic susceptibility contrast perfusion MR methods for evaluating gliomas.     

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。     

Using relative cerebral blood flow and volume to evaluate the histopathologic grade of cerebral gliomas: preliminary results

OBJECTIVE: Relative cerebral blood flow has rarely been studied as part of the preoperative assessment of tumor grade, although relative cerebral blood volume is known to be useful for this assessment. The purpose of our study was to determine the usefulness of relative cerebral blood flow in assessing the histopathologic grade of cerebral gliomas. SUBJECTS AND METHODS: MR imaging was performed in 17 patients with proven cerebral gliomas (11 high-grade gliomas and six low-grade gliomas), using a first-pass gadopentetate dimeglumine-enhanced T2-weighted echoplanar perfusion sequence. The perfusion data were deconvoluted with an arterial input function, using singular value decomposition to obtain a color map of relative cerebral blood volume and flow; the relative cerebral blood volume and flow ratios were expressed relative to values measured in the contralateral white matter. The Wilcoxon's rank sum test was performed to test the difference between the mean of the relative cerebral blood volume (or flow) ratio in high-grade gliomas and that in low-grade gliomas. Receiver operating characteristic curve analysis was used to evaluate the association between the relative cerebral blood volume (or flow) ratio and the grade of the glioma, as well as to calculate the relative cerebral blood volume and flow ratio cutoff value permitting discrimination between high- and low-grade gliomas. The correlation between relative cerebral blood volume and flow ratios was evaluated using Spearman's rank correlation analysis. We also made a qualitative assessment regarding the match or mismatch of areas of maximal contrast enhancement with the areas of highest color perfusion maps. RESULTS: The mean of the relative cerebral blood volume ratio was 4.91 in the high-grade gliomas and 2.00 in the low-grade gliomas. The mean relative cerebral blood flow ratio was 4.82 in the high-grade gliomas and 1.83 in the low-grade gliomas. A significant difference in each relative cerebral blood volume and flow ratio was found between the high- and low-grade gliomas (Wilcoxon's rank sum test, p < 0.05). Both the relative cerebral blood volume and flow ratios strongly matched the grade of the glioma, but the difference between the two areas was not significant (receiver operating characteristic curve analysis, p > 0.05). The desired cutoff value was 2.93 in the relative cerebral blood volume ratio and 3.57 in the relative cerebral blood flow ratio. Additionally, there was a strong correlation between the relative cerebral blood volume and flow ratios (Spearman's rank correlation coefficient = 0.762; p < 0.05). There was frequent mismatch (33%) between the qualitative assessment of the contrast-enhanced T1-weighted MR images and the perfusion maps. CONCLUSION: First-pass gadopentetate dimeglumine-enhanced T2-weighted echoplanar perfusion MR imaging is useful for the preoperative assessment of tumor grade. A relative cerebral blood flow ratio, in addition to a relative cerebral blood volume ratio, can be a useful tool in the evaluation of the histopathologic grade of cerebral gliomas.     

128层螺旋CT全脑灌注对浸润性星形细胞瘤的分级评估

目的:评价128层螺旋CT全脑灌注(CTP)对浸润性星形细胞瘤分级定性诊断的价值。方法:选择我院90例脑肿瘤患者进行CTP检查,经手术和病理学证实为浸润性星形细胞瘤(Ⅱ~Ⅳ级)者46例纳入本研究对象。CTP采用SOMATOM Definition AS型128层螺旋CT机进行灌注扫描,应用后处理工作站对原始数据进行后处理,获得时间-密度曲线(TDC),测定肿瘤区和对侧正常组织的脑血流量(CBF)、脑血容量(CBV)、毛细血管表面通透性(PS)及对比剂达峰值时间(TTP),并对灌注参数进行统计学分析。结果:在所有病例中,全脑灌注图像平均视觉评价分数明显高于传统灌注图(P<0.01),且对病变定位更为精确。星形细胞肿瘤高级别组的CBF、CBV和PS值均显著高于低级别组(P<0.01),而TTP值的差异无统计学意义(P>0.05)。ROC曲线分析表明,CBF、CBV和PS值对鉴别高、低级别星形细胞肿瘤的ROC曲线下面积分别为0.925、0.897和0.954,采用CBF≥72.052ml/min/100g,CBV≥4.293ml/100g和PS≥6.337ml/min/100g作为分界点对鉴别高低级别星形细胞肿瘤的敏感性均为87.2%,特异性分别是83.5%、83.5%和93.0%。结论:128层螺旋CT全脑灌注有利于脑肿瘤的术前整体评估和精确定位;CTP参数CBF、CBV及PS值及TDC曲线对鉴别高、低级别星形细胞肿瘤具有较高的敏感性和特异性。     

256层螺旋CT全脑灌注联合CTA在急性脑梗死诊断中的价值

目的 探讨256层MSCT全脑CTP与CTA技术相结合在急性脑梗死中的应用价值,并评估脑梗死与供血动脉状况的关系.方法 对21例临床拟诊急性脑梗死患者行常规CT平扫、CTP和CTA检查,重建并分析CT平扫图像、CTP及CTA图像,所有病例在CTP检查后24h内进行MRI＋ DWI检查.结果 21例脑梗死患者CTA发现33条动脉不同程度狭窄及闭塞,其中包括轻度狭窄4例,中度狭窄13例,重度狭窄7例,闭塞9例.21例患者CTP发现32处梗死灶,脑梗死中心区及周边区rCBF下降、TTP延长的差异在统计学上有显著性意义.结论 256层螺旋CT全脑CTP联合CTA扫描方法简便,可对缺血后脑组织供血动脉状况及血流动力学改变进行有效评价.     

DTI对鉴别脑低级别胶质瘤、脑梗死和病毒性脑炎的价值

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组病灶的表观扩散系数(ADC)值和相对表观扩散系数(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)×10-3 mm2/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)×10-3 mm2/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)×10-3 mm2/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。     

脑胶质瘤^1HMRS与肿瘤细胞增殖活性的相关性研究

目的探讨脑胶质瘤^1HMRS表现与肿瘤增殖活性的相关性。方法术前行MRI和^1HMRS检查且经手术病理证实的脑胶质瘤患者33例,切除的肿瘤组织用链菌素一生物素．过氧化酶连接法（SP法）行Ki-67免疫组化标记。结果33例胶质瘤中,高级别星形细胞瘤（Ⅲ／Ⅳ级）的Cho／NAA、Cho／Cr比低级别星形细胞瘤（I／II级）明显升高（P=0．001）;Cho／NAA、Cho／Cr与Ki-67的表达呈明显正相关（r=0．455,P=0．038;r=0．633,P=0．012）。结论^1HMRS有助于术前预测胶质瘤的恶性度,反映肿瘤细胞增殖活性,间接判断胶质瘤的某些生物学行为及预后,制定个性化手术方案。     

发作间期SPECT对难治性颞叶癫痫的诊断价值

目的:探讨难治性颞叶癫痫(TLE)单光子发射计算机断层(SPECT)的影像特征及定位诊断价值.方法:选择35例经临床手术证实的难治性TLE,术前均行发作间期SPECT脑血流灌注显像和常规MRI扫描.以临床定位结果做对照,观察难治性TLE的SPECT影像改变,分析发作间期脑血流灌注显像定位诊断颞叶致痫灶的临床应用价值.结果:难治性颞叶癫痫SPECT的影像特征为致痫灶侧前颞叶内侧和/或外侧皮质的血流灌注减低,对侧前颞叶的内侧皮质可出现轻度的灌注减低.常合并与患侧同侧的一处或以上脑区的灌注减低.SPECT致痫灶定位诊断的阳性率达77.14％00(27/35),尤其能检出52.94％ (9/17) MRI阴性TLE的致痫灶.结论:发作间期SPECT脑血流灌注显像能丰富难治性TLE的定位诊断信息,提高定位MRI阴性TLE患者致痫灶的比例.     

Assesment of perfusion in glial tumors with arterial spin labeling; comparison with dynamic susceptibility contrast method

Purpose

Arterial spin labeling perfusion imaging (ASL-PI) is a non-invasive perfusion imaging method that can be used for evaluation and quantification of cerebral blood flow (CBF). Aim of our study was to evaluating the efficiency of ASL in histopathological grade estimation of glial tumors and comparing findings with dynamic susceptibility contrast perfusion imaging (DSC-PI) method.

Methods

This study involved 33 patients (20 high-grade and 13 low-grade gliomas). Multiphase multislice pulsed ASL MRI sequence and a first-passage gadopentetate dimeglumine T2*-weighted gradient-echo single-shot echo-planar sequence were acquired for all the patients. For each patient, perfusion relative signal intensity (rSI), CBF and relative CBF (rCBF) on ASL-PI and relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values on DSC-PI were determined. The relative signal intensity of each tumor was determined as the maximal SI within the tumor divided by SI within symetric region in the contralateral hemisphere on ASL-PI. rCBV and rCBF were calculated by deconvolution of an arterial input function. Relative values of the lesions were obtained by dividing the values to the normal appearing symmetric region on the contralateral hemisphere. For statistical analysis, Mann–Whitney ranksum test was carried out. Receiver operating characteristic curve (ROC) analysis was performed to assess the relationship between the rCBF-ASL, rSI-ASL, rCBV and rCBF ratios and grade of gliomas. Their cut-off values permitting best discrimination was calculated. The correlation between rCBV, rCBF, rSI-ASL and rCBF-ASL and glioma grade was assessed using Spearman correlation analysis.

Results

There was a statistically significant difference between low and high-grade tumors for all parameters. Correlation analyses revealed significant positive correlations between rCBV and rCBF-ASL (r = 0.81, p < 0.001). However correlation between rCBF and rCBF-ASL was weaker (r = 0.64, p < 0.001).

Conclusion

Arterial spin labeling is an employable imaging technique for evaluating tumor perfusion non-invasively and may be useful in differentiating high and low grade gliomas.