中国汉族正常成人颞叶体积的高分辨率MRI测量

Objective To explore the morphological features of temporal lobe of healthy Chinese Han adults on the high-resolution MRI and provide morphological data of temporal lobe for the construction of database for Chinese Standard Brain.Methods This is a clinical multi-center study.Three hundred healthy Chinese volunteers (male 150, and female 150) recruited from 15 hospitals were divided equally into five groups according to their age, i.e., 18-30 ( Group A ), 31-40 ( Group B ), 41-50 ( Group C ), 51-60(Group D), 61-70( Group E).All subjects were scanned using T1WI 3D MPRAGE sequence and volumes of standardized temporal lobe were collected.The bilateral volumes of standardized temporal lobe were compared by variance analysis between male and female subjects and among five age groups.Results The mean volumes of left and right temporal lobe were (97 126±15 703) mm3 and (97 015±15 545) mm3 respectively for men, and (95 123±14 564) mm3 and (96 423±13 407) mm3 for women.The difference temporal lobe volume between male and female wasn't significant on the same side (F = 1.336, 0.127 ,P =0.249, 0.722).The left temporal lobe volumes of Group A-E were (93 873±13 351 ), (95 566±11 964), (10 1890±14 511 ), (93 972±14 050) and (95 636±19 864)mm3 respectively, and those on the right side were (93 409±10 984), (98 158±16 392), (102 079±15 112), (95 448±11 123 ) and (94 658±16 928) mm3.There were significant differences among 5 groups between left and right temporal lobe volume( F = 2.940, 3.514, P = 0.021, 0.008 ).Further pairwise comparison revealed that left and right temporal lobe volume in Group C is higher than those of Group A and D(P<0.05), while there were no significant differences between the other groups ( P > 0.05 ).Conclusion High-resolution MRI could offer detailed images and precise morphological data of temporal lobe, which provides morphological data of temporal lobe for the construction of database for Chinese Standard Brain.     

中国汉族正常成人颞叶体积的高分辨率MRI测量

Objective To explore the morphological features of temporal lobe of healthy Chinese Han adults on the high-resolution MRI and provide morphological data of temporal lobe for the construction of database for Chinese Standard Brain.Methods This is a clinical multi-center study.Three hundred healthy Chinese volunteers (male 150, and female 150) recruited from 15 hospitals were divided equally into five groups according to their age, i.e., 18-30 ( Group A ), 31-40 ( Group B ), 41-50 ( Group C ), 51-60(Group D), 61-70( Group E).All subjects were scanned using T1WI 3D MPRAGE sequence and volumes of standardized temporal lobe were collected.The bilateral volumes of standardized temporal lobe were compared by variance analysis between male and female subjects and among five age groups.Results The mean volumes of left and right temporal lobe were (97 126±15 703) mm3 and (97 015±15 545) mm3 respectively for men, and (95 123±14 564) mm3 and (96 423±13 407) mm3 for women.The difference temporal lobe volume between male and female wasn't significant on the same side (F = 1.336, 0.127 ,P =0.249, 0.722).The left temporal lobe volumes of Group A-E were (93 873±13 351 ), (95 566±11 964), (10 1890±14 511 ), (93 972±14 050) and (95 636±19 864)mm3 respectively, and those on the right side were (93 409±10 984), (98 158±16 392), (102 079±15 112), (95 448±11 123 ) and (94 658±16 928) mm3.There were significant differences among 5 groups between left and right temporal lobe volume( F = 2.940, 3.514, P = 0.021, 0.008 ).Further pairwise comparison revealed that left and right temporal lobe volume in Group C is higher than those of Group A and D(P<0.05), while there were no significant differences between the other groups ( P > 0.05 ).Conclusion High-resolution MRI could offer detailed images and precise morphological data of temporal lobe, which provides morphological data of temporal lobe for the construction of database for Chinese Standard Brain.     

中国汉族正常成人颞叶体积的高分辨率MRI测量

目的 研究中国汉族正常成人颞叶MRI形态特征,为建立中国标准脑提供颞叶形态学测量数据.方法 采用全国多中心临床研究形式,选取18～70岁健康志愿者300名,按照年龄18～30、31～40、41～50、51～60、61～70岁进行分组,分别定义为A、B、C、D、E组,每组男、女各30名.所有受试者均行3D磁化强度预备梯度回波序列T1WI采集颞叶体积,并对不同性别和年龄段标准化后的左、右侧颞叶体积分别进行方差分析.结果 男性左、右侧颞叶体积分别为(97 126±15 703)、(97 015±15 545)mm3,女性左、右侧颞叶体积分别为(95 123±14 564)、(96 423±13 407)mm3,左、右侧颞叶体积在性别上差异无统计学意义(F值分别为1.336、0.127,P值分别为0.249、0.722).5组左侧颞叶体积分别为(93 873±13 351)、(95 566±11 964)、(101 890±14 511)、(93 972±14 050)、(95 636±19 864)mm3,右侧颞叶体积分别为(93 409±10 984)、(98 158±16 392)、(102 079±15 112)、(95 448±11 123)、(94 658±16 928)mm3,5组间左、右侧颞叶体积差异有统计学意义(F值分别为2.940、3.514,P值分别为0.021、0.008).进一步两两间比较,C组左、右侧颞叶体积高于A、D组(p值均<0.05),其余各组间差异无统计学意义(P值均>0.05).结论 高分辨率MRI能提供较为精确的颞叶图像和测量数据,为建立中国标准脑提供了科学数据.     

Partial volume effects in volume localized phased-array proton spectroscopy of the temporal lobe

MRS techniques can aide in confirming the location of seizure foci in temporal lobe epilepsy. N-acetyl aspartate (NAA). creatine plus phosphocreatine. choline-containing compounds, and lactate arc most often the clinically relevant metabolites in these studies. We examined the importance of partial volume effects from tissue heterogeneity in temporal lobe spectroscopy on the metabolite ratios. Our study shows that localized spectroscopy, using three different voxel slzes. centered on the anterior body of the hippocampus. produces significantly different values for the NAA to the creatine ratio. The spectroscopy was performed at 1.5 T wing the PRESS pulse sequence and a phased-array coil system specifically designed for the temporal lobe. The data exhibits a clear trend of increasing NM to creatine ratios with increasing voxel size. This trend demonstrates that partial volume effects can contribute to variation of NAA to creatine ratios in healthy subjects.     

中国汉族成人额叶体积的高分辨率MRI测量

目的 测量中国汉族正常成人大脑额叶体积,为建立中国成人数字标准脑提供基础数据.方法 采用全国多中心临床研究形式,选取18～70岁健康志愿者200名,按照年龄18～30、31～40、41～50、51～60、61～70岁进行分组,每组男、女各20名.所有受试者均行3D磁化强度预备梯度回波序列T1WI采集额叶体积,通过人工勾画ROI法分别测量志愿者左、右侧额叶体积,并对测量数据进行统计学分析.男、女性别间比较采用独立样本t检验;左、右侧别间比较采用配对样本t检验;年龄与额叶体积进行相关与回归分析.结果 200名志愿者大脑额叶总体积为(563±73)cm3.100名男性左、右侧额叶体积值分别为(288±42)、(292±41)cm3;100名女性左、右侧额叶体积值分别为(273±30)、(274±30)cm3.大脑额叶总体积男、女性别间差异有统计学意义(t=3.334,P<0.05).男性左、右侧额叶体积差异有统计学意义(t=-3.09,P<0.05),女性左、右侧额叶体积差异无统计学意义(t=-1.304,P>0.05).男性及女性大脑额叶总体积均与年龄呈负相关(r值分别为-0.586、-0.498,P值均<0.01).结论 健康国人男性额叶总体积大于女性.男性右侧额叶体积大于左侧,而女性双侧额叶体积差异无统计学意义.随着年龄的增长,男性及女性的额叶总体积均呈现逐渐缩小的趋势,男性额叶缩小的趋势比女性明显.     

中国汉族成人额叶体积的高分辨率MRI测量

Objective To explore the normal range of the volume of frontal lobe in Chinese adults of the Han nationality and provide morphological data for the construction of database for Chinese Standard Brain. Methods This is a clinical multi-center study. Two hundred Chinese healthy volunteers (age range= 18 to 70) recruited from 16 hospitals were divided into 5 groups, i. e. , age range from 18 to 30, age range from 31 to 40, age range from 41 to 50, age range from 51 to 60, and age range from 61 to 70. Each group contained 20 males and 20 females. All of the volunteers were scanned by MR using T1 weighted threedimensional magnetization prepared rapid acquisition gradient echo sequence. We used the manual method to trace the region of interest and measured the left and right frontal lobe volumes separately. All the data were analyzed with SPSS (version 13.0). The sex differences in the frontal lobe volumes were analyzed by independent-samples t test, and the side differences were analyzed by paired-samples t test. Correlation and regression analysis was used between the age and the frontal lobe volumes. Results In 200 healthy Chinese Han volunteers, the total frontal lobe volumes was (563 ± 73) cm3. For male, the volumes of the left and the right frontal lobe were (288±42) cm3 and (292 ±41 ) cm3 ,respectively. The volumes of the left and right frontal lobe in 100 women were (273 ±30) cm3 and (274 ± 30) cm3 respectively. The differences of sex (t = 3. 334, P < 0. 05 ) and side ( t = - 3.09, P < 0. 05 ) in the total frontal lobe volumes reach significant. There was no significant differences in women ( t = - 1. 304, P > 0. 05 ). There were negative correlations between the frontal lobe volumes and age in men and women ( r = - 0. 586, - 0. 498, P <0. 01 ). Conclusions The total frontal lobe volume of men was larger than that of women. The volume of the right frontal lobe was larger than the left frontal lobe in men, and the asymmetries didn't exist in women.The total frontal lobe volumes were both shrinking with age in men and women, which was more rapid in men than in women.     

中国汉族成人额叶体积的高分辨率MRI测量

Objective To explore the normal range of the volume of frontal lobe in Chinese adults of the Han nationality and provide morphological data for the construction of database for Chinese Standard Brain. Methods This is a clinical multi-center study. Two hundred Chinese healthy volunteers (age range= 18 to 70) recruited from 16 hospitals were divided into 5 groups, i. e. , age range from 18 to 30, age range from 31 to 40, age range from 41 to 50, age range from 51 to 60, and age range from 61 to 70. Each group contained 20 males and 20 females. All of the volunteers were scanned by MR using T1 weighted threedimensional magnetization prepared rapid acquisition gradient echo sequence. We used the manual method to trace the region of interest and measured the left and right frontal lobe volumes separately. All the data were analyzed with SPSS (version 13.0). The sex differences in the frontal lobe volumes were analyzed by independent-samples t test, and the side differences were analyzed by paired-samples t test. Correlation and regression analysis was used between the age and the frontal lobe volumes. Results In 200 healthy Chinese Han volunteers, the total frontal lobe volumes was (563 ± 73) cm3. For male, the volumes of the left and the right frontal lobe were (288±42) cm3 and (292 ±41 ) cm3 ,respectively. The volumes of the left and right frontal lobe in 100 women were (273 ±30) cm3 and (274 ± 30) cm3 respectively. The differences of sex (t = 3. 334, P < 0. 05 ) and side ( t = - 3.09, P < 0. 05 ) in the total frontal lobe volumes reach significant. There was no significant differences in women ( t = - 1. 304, P > 0. 05 ). There were negative correlations between the frontal lobe volumes and age in men and women ( r = - 0. 586, - 0. 498, P <0. 01 ). Conclusions The total frontal lobe volume of men was larger than that of women. The volume of the right frontal lobe was larger than the left frontal lobe in men, and the asymmetries didn't exist in women.The total frontal lobe volumes were both shrinking with age in men and women, which was more rapid in men than in women.     

Developmental abnormalities of the medial temporal lobe in patients with temporal lobe epilepsy.

PURPOSETo evaluate MR temporal lobe malformations and their frequency in patients with temporal lobe epilepsy.METHODSTwo hundred twenty-two consecutive adult patients with temporal lobe epilepsy of varying severity were investigated with 1.0-T or 1.5-T MR units using three-dimensional T1-weighted acquisition protocol.RESULTSSixteen patients (7.2%) presented with malformations of the temporal lobe. Four patterns of malformations were encountered: (a) heterotopia (n = 1), lining the temporal horn of the lateral ventricle; (b) focal neocortical dysgenesis (n = 6), which consisted of cortical thickening, poor gray/white matter demarcation, abnormal gyration (n = 5), or limited schizencephaly (n = 1); (c) hippocampal malformations (n = 5), which presented as abnormal hippocampal formation associated with a cyst (n = 2), isolated malformation of the subiculum (n = 1), or bilateral hippocampal malformation (n = 2) consisting of an abnormal shape and a misplaced fimbria; (d) complex malformations of the temporal lobe, combining categories a, b, and c (n = 4). The age at onset, severity of the disease, and occurrence of generalized tonicoclonic seizures were not significantly different between patients with malformations and the entire population of patients with temporal lobe epilepsy.CONCLUSIONMR analysis of temporal lobe malformations allowed a precise determination of the extent of the malformations and the presence or absence of associated hippocampal disease, all of which are of great help in the preoperative evaluation of patients with intractable epilepsy.     

巨大颈内动脉海绵窦瘘一例

目的:评价T1加权三维磁化强度预备梯度回波序列(3D-MPRAGE)在儿童原发性颞叶癫痫(TLE)海马体积(HCV)测量中的作用,分析TLE病例HCV改变的可能影响因素。方法:对原发性颞叶癫痫儿童(病变组,24例)及健康对照组(NC组,24例)儿童分别行手动HCV测量。按年龄组(<6岁组、6～9岁组、9～13岁组)对两组数据进行统计学比较。结果:病变组和对照组在<6岁患儿中总HCV差异有统计学意义(P=0.02),在另两个年龄组中差异无统计学意义(6～9岁组P=0.9535,9～13岁组P=0.9822)。<6岁病变组左、右侧HCV差异有统计学意义(P=0.0018),而在6～9岁、9～13岁病变组及对照组3个年龄组内差异均无统计学意义。对照组2～13岁儿童HCV范围为(2020.25±26.89)～(2100.93±57.33)mm3。结论:3D-MPRAGE可清晰显示海马及相关脑组织结构,具有较高的应用价值。<6岁儿童原发性颞叶癫痫HCV改变可能与癫痫发作次数、持续时间、发作后距MRI检查时间等多种因素有关。正常儿童HCV范围的测定可作为评价海马病变的参考之一。     

Cerebral blood flow in temporal lobe epilepsy: a partial volume correction study

Purpose Previous studies in temporal lobe epilepsy (TLE) have shown that, owing to brain atrophy, positron emission tomography (PET) can overestimate deficits in measures of cerebral function such as glucose metabolism (CMR_glu) and neuroreceptor binding. The magnitude of this effect on cerebral blood flow (CBF) is unexplored. The aim of this study was to assess CBF deficits in TLE before and after magnetic resonance imaging-based partial volume correction (PVC). Methods Absolute values of CBF for 21 TLE patients and nine controls were computed before and after PVC. In TLE patients, quantitative CMR_glu measurements also were obtained. Results Before PVC, regional values of CBF were significantly (p<0.05) lower in TLE patients than in controls in all regions, except the fusiform gyrus contralateral to the epileptic focus. After PVC, statistical significance was maintained in only four regions: ipsilateral inferior temporal cortex, bilateral insula and contralateral amygdala. There was no significant difference between patients and controls in CBF asymmetry indices (AIs) in any region before or after PVC. In TLE patients, AIs for CBF were significantly smaller than for CMR_glu in middle and inferior temporal cortex, fusiform gyrus and hippocampus both before and after PVC. A significant positive relationship between disease duration and AIs for CMR_glu, but not CBF, was detected in hippocampus and amygdala, before but not after PVC. Conclusion PVC should be used for PET CBF measurements in patients with TLE. Reduced blood flow, in contrast to glucose metabolism, is mainly due to structural changes.     

MRI of temporal lobe pleomorphic xanthoastrocytoma.

Pleomorphic xanthoastrocytomas (PXA) are classically supratentorial, peripherally located, well-circumscribed, partially cystic neoplasms, which can enhance on CT following the administration of intravenous contrast agents. Focal calcification may also be seen. Although the CT appearance has been described, we report the MR findings in two cases of histologically documented temporal lobe PXA. The two well-circumscribed lesions were predominantly cystic and both contained a Gd-DTPA enhancing mural nodule. The latter was isointense with gray matter on T1-weighted images and hyperintense on T2-weighted scans. Minimal surrounding edema was present. Histologically, PXA may be confused with glioblastoma multiforme (GBM) due to the pronounced cellular pleomorphism. Because of their potentially more indolent behavior compared with GBM, it is important to recognize the gross morphologic characteristics of this rare tumor on MR. The MR pattern of a cystic lesion with enhancing mural nodule is characteristic of PXA, but not diagnostic, and other lower grade gliomas such as ganglioglioma and pilocytic astrocytoma need to be considered. The MR and CT appearance of PXA can provide critical information for the pathologist, especially when only a small amount of tissue is obtained for histologic evaluation.     

Morphological abnormalities of limbic lobe structures in partial temporal lobe epilepsy

PURPOSE: To evaluate lesions of the different structures of the Papez circuit in association with hippocampal sclerosis. MATERIAL: and methods. 13 patients (32.1+/-8.2 y.o.) suffering from partial, temporal lobe, drug-resistant epilepsy and 20 normal volunteers (31.8+/-7.7 y.o.) were evaluated by MRI on a 1.5 T scanner (Philips): axial T1w 3D Gradient Echo acquisitions, thickness: 1.5mm. Hippocampus and cingulate gyrus volume were calculated after semi-automated segmentation of intrasulcal gray matter using the "Surgiscope Scopeplan" Elekta((R)). The thickness of the posterior column of the fornix and the thickness of the mamillary bodies were also measured. RESULTS: We found 10 cases of ipsolateral hippocampal sclerosis, 6 cases of ipsolateral atrophy of the mamillary body and 4 cases of ipsolateral atrophy of the fornix. We did not find any atrophy of the cingulate gyrus. CONCLUSION: Hippocampal sclerosis can be associated with lesions of limbic lobe structures (fornix and mamillary body), excluding the cingulate gyrus.     

Correlation between PET and SISCOM in temporal lobe epilepsy.

The subtraction of interictal from ictal SPECT coregistered to 3-dimensional (3D) MRI (SISCOM) and (18)F-FDG PET are 2 techniques that are involved in the definition of the epileptogenic zone in refractory partial temporal lobe epilepsy (TLE). The aim of this study was compare, region by region, the functional patterns obtained by both strategies, SISCOM and PET, in patients with unilateral TLE. METHODS: Perfusion data using SISCOM and metabolic data using (18)F-FDG PET scans were acquired from 17 patients with unilateral TLE. The functional metabolism and perfusion maps were overlaid onto a 3D rendering of the patient's anatomic MRI scans. RESULTS: The functional patterns that were observed with PET and SISCOM were found mainly in the ipsilateral and contralateral temporal lobes, in the orbitofrontal and insular cortices. Despite the high rate of concordance, in some cases discrepancies could be observed between PET and SISCOM abnormalities: In the mesial regions, as in the anterior neocortex, PET abnormalities were found more frequently than SISCOM changes. SISCOM abnormalities were found more frequently in the posterior temporal neocortex. In the extratemporal cortex, SISCOM abnormalities were more widespread. CONCLUSION: The marked rate of concordance between PET and SISCOM abnormalities observed in relatively extensive regions shows that, in TLE, seizures were generated and spread in metabolically abnormal regions.     

MR imaging-based volume measurements of the hippocampal formation and anterior temporal lobe: validation studies

An experiment was designed to compare the accuracy and reproducibility of three different techniques for in vivo magnetic resonance (MR) imaging-based volume measurements of brain structures. These techniques were tracing, thresholding, and random marking. Anterior temporal lobe (ATL) and hippocampal formation (HF) volumes in 10 volunteers were measured from MR images, as were four cylinders of known volume. The upper limit of accuracy of in vivo volume measurements is estimated to be within 0.1 cm3 of true volume for the HF and 0.9 cm3 for the ATL with a combined tracing-thresholding technique. Intra- and interobserver variations were estimated from the pooled standard deviations of HF and ATL measurements. With the combined tracing-thresholding technique, the coefficient of variation for HF measurement was 1.9%; for the ATL measurement, it was 0.7%. The results indicate that MR-based volume measurements of these brain structures can be made with high precision and reproducibility.     

White matter abnormalities in the anterior temporal lobe suggest the side of the seizure foci in temporal lobe epilepsy

Introduction White matter abnormalities in the anterior temporal lobe (WAATL) are sometimes observed on magnetic resonance (MR) images of patients with temporal lobe epilepsy (TLE). Our purpose was to determine whether WAATL could indicate if the seizure foci are ipsilateral on electroencephalograms (EEG) in TLE patients.Methods We reviewed 112 consecutive patients with medically intractable TLE. We compared the side of seizure foci on EEG (preoperative and intraoperative) and MR images.Results Both loss of gray–white matter demarcation and increased signal intensity changes in the anterior white matter (positive WAATL) were observed in 54 of 112 patients (48.2%) with TLE. WAATL were present on the same side as the seizure foci on preoperative intracranial EEG with subdural electrodes (iEEG) and on intraoperative electrocorticography (ECG) in all the patients. In 47 patients, MR images showed WAATL and focal lesions that were possibly epileptogenic for TLE. In 2 of the 47 patients, the seizure foci on iEEG and ECG were contralateral to the focal lesion; in the remaining 45 patients, the seizure foci on surface EEG (sEEG) and ECG and the focal lesion were on the same side. In three patients, no focal lesions were seen but WAATL were present on the same side as the seizure foci on sEEG and ECG. In four patients, MR images showed focal lesions for which epileptogenicity was questionable, and WAATL on the same side as the seizure foci on EEG.Conclusion WAATL are clinically useful because they indicate the side of the seizure foci.     

MR in temporal lobe epilepsy: analysis with pathologic confirmation.

PURPOSEWe evaluated the MR findings in patients with temporal lobe epilepsy to determine the predictive value of MR imaging in assessing patient outcome.METHODSMR studies from 186 of 274 consecutive patients who underwent temporal lobectomy for intractable epilepsy were reviewed retrospectively. Images were interpreted by an experienced neuroradiologist, who was blinded to the side of seizure activity and to pathologic findings.RESULTSMR imaging exhibited 93% sensitivity and 83% specificity in detecting hippocampal/amygdalar abnormalities (n = 121), and 97% sensitivity and 97% specificity in detecting abnormalities in the rest of the temporal lobe (n = 60). Abnormal high signal of the hippocampus on T2-weighted images had a sensitivity of 93% and specificity of 74% in predicting mesial temporal sclerosis (n = 115). The presence of hippocampal atrophy on MR correlated with the duration of seizures. Sensitivity and specificity of MR imaging in detecting temporal lobe tumors (n = 42) were 83% and 97%, respectively, based on abnormal signal and mass effect. After surgery, 63% of patients were seizure free and 28% had a significant reduction of seizure frequency at an average of 24 months (range, 12 to 78 months) after surgery. Patients with a single lesion in the anterior temporal lobe or hippocampus/amygdala had a better outcome than patients with multiple lesions (n = 22). Interrater agreement varied from 0.4 to 0.93, with best agreement for tumors or abnormal hippocampal signal on T2-weighted images.CONCLUSIONMR imaging is highly sensitive in detecting and locating abnormalities in the temporal lobe and the hippocampus/amygdala in patients with temporal lobe epilepsy. Hippocampal atrophy appears to correspond to the duration of seizure disorder.     

Brain SPECT imaging in temporal lobe epilepsy

Summary Temporal lobe epilepsy is diagnosed by clinical symptoms and signs and by localization of an epileptogenic focus. A brain SPECT study of two patients with temporal lobe epilepsy, using^99mTc-HMPAO, was used to demonstrate a perfusion abnormality in the temporal lobe, while brain CT and MRI were non-contributory. The electroencephalogram, though abnormal, did not localize the diseased area. The potential role of the SPECT study in diagnosis and localization of temporal lobe epilepsy is discussed.