Brain diffusivity in patients with neuropsychiatric systemic lupus erythematosus with new acute neurological symptoms

PURPOSE: To investigate the source of significant difference in apparent diffusion coefficient (ADC) between patients with acute symptoms of neuropsychiatric (NP) systematic lupus erythematosus (SLE) (NPSLE) and normal controls. MATERIALS AND METHODS: Diffusion-weighted echo-planar imaging was performed on 1.5-T scanners in 17 female and four male NPSLE patients with acute neurological symptoms (23-76 years, mean = 42.7 years), and in 21 aged-matched healthy controls (16 female, five male, 26-63 years, mean = 41.1 years). ADC histograms were calculated for whole brain, gray matter tissue, and white matter tissue. RESULTS: Of the 17 NPSLE patients, 13 (72%) had abnormal findings on MR imaging. The NPSLE patients had a mean ADC value of (1105.1 +/- 23.6) x 10(-6) mm(2)/second and the control had a mean ADC value of (1012.5 +/- 9.4) x 10(-6) mm(2)/second (P < or = 0.0012). Significant differences were also found in white matter (P < or = 0.0020) and gray matter (P < or = 0.0022). CONCLUSION: ADC histogram analysis demonstrated increased general diffusivity in the brain in NPSLE patients with acute symptoms compared with healthy normal controls. This finding suggests that in the brain parenchyma of NPSLE patients a loss of tissue integrity occurs facilitating motility of free-water protons.     

Quantitative assessment of the cervical spinal cord damage in neuromyelitis optica using diffusion tensor imaging at 3 Tesla

Purpose:

To investigate whether quantitative MRI measures of cervical spinal cord white matter (WM) using diffusion tensor imaging (DTI) in neuromyelitis optica (NMO) differed from controls and correlated with clinical disability.

Materials and Methods:

Ten referred patients and 12 healthy volunteers were imaged on a 3 Tesla scanner and patients were clinically assessed on the Expanded Disability Status Scale (EDSS). Two raters quantified DTI‐derived indices from all participants, including fractional anisotropy (FA), mean diffusivity (MD), parallel diffusivity (lambda[parallel]) and perpendicular diffusivity (lambda[perpendicular]) at C1–C6 for lateral and dorsal columns. After the inter‐rater reliability test, univariate correlations between DTI measures and disability were assessed using the Spearman's rho correlation coefficient. Multiple regression analysis was performed to investigate which DTI measures independently correlated with the clinical score.

Results:

Statistical test results indicated high reliability of all DTI measurements between two raters. NMO patients showed reduced FA, increased MD and lambda[perpendicular] compared with controls while lambda[parallel] did not show any significant difference. The former three DTI metrics also showed significant correlations with disability scores, and especially FA was found to be sensitive to mild NMO (EDSS ≤ 3)

Conclusion:

FA is a potentially useful quantitative biomarker of otherwise normal appearing WM damage in NMO. Such damage is associated with clinical disability. J. Magn. Reson. Imaging 2011;33:1312–1320. © 2011 Wiley‐Liss, Inc.     

大脑胶质瘤弥散张量磁共振成像定量研究

目的:应用弥散张量磁共振成像定量分析大脑胶质瘤的特点。方法:11例经病理证实的大脑胶质瘤患者,行弥散张量磁共振成像检查,在ADC图和FA图上分别测量肿瘤周围水肿区域、肿瘤强化区域、囊变区域、脑脊液及对侧正常大脑白质ADC值和FA值。结果:肿瘤周围水肿区域的ADC值和FA值与肿瘤囊变区域、脑脊液及对侧大脑白质相比较均有显著性差异(P<0.05),而与肿瘤强化区域相比较无显著性差异。肿瘤囊变区域的ADC值及FA值与脑脊液、对侧正常大脑白质相比较有显著性差异(P<0.05);肿瘤囊变区域与肿瘤强化区域相比较,ADC值无显著性差异,FA值却有显著性差异(P<0.05)。肿瘤强化区域的ADC值及FA值与对侧大脑白质相比较具有显著性差异(P<0.05)。高、低级别胶质瘤肿瘤周围水肿区域、肿瘤强化区域、肿瘤囊变区域的ADC值及FA值均无统计学显著差异。结论:磁共振弥散张量成像对定量分析大脑胶质瘤本身及其周围脑组织具有重要价值。     

偏头痛患者磁共振弥散张量成像的初步探讨

 目的探讨偏头痛患者磁共振弥散张量中脑白质损害。方法对17例偏头痛患者和16名健康志愿者,进行磁共振弥散张量成像(diffusiontensorimaging,DTI)检查。分别测定两组受试者的双侧额叶皮层下白质、双侧侧脑室旁周围白质和双侧枕叶皮层下白质中感兴趣区(regionofinterests,ROIs)的“看似正常的白质”(normalappearingwhitematter,NAWM)表观扩散系数(apparentdiffusioncoefficient,ADC)和各向异性分数(fractionalanisotropy,FA),对两组数据进行比较分析。结果偏头痛组双侧侧脑室旁周围白质ADC值较对照组明显增高(P<0.05),双侧枕叶皮层下白质各向FA值较对照组明显降低(P<0.01)。结论DTI有助于早期发现偏头痛患者的脑白质损害。     

多发性硬化的正常表现脑白质的DTI定量

目的：应用磁共振弥散张量成像（DTI）技术，定量研究多发性硬化（MS）患者在常规磁共振上表现正常的脑白质（NAWM），以及探讨其相关的微观病理改变。材料和方法：采用3．0T磁共振仪，对34例Ms患者和25例性别年龄相匹配的正常志愿者均进行DTI检查。分别测量MS组和对照组的9个不同部位脑白质的平均弥散率（MD）和部分各向异性指数（FA值），这9个部位包括胼胝体膝部、体部、压部、内囊后肢、侧脑室旁白质、额叶白质、顶叶白质、枕叶白质以及小脑中脚。比较两组NAWM之间的MD和FA值是否存在差异。结果：MS组的NAWM的MD值均高于对照组（P〈0．05），以胼胝体体部、内囊、侧脑室旁及额叶白质、顶叶白质、枕叶白质更为显著（P〈0．01）；MS组的FA值与对照组比较，胼胝体体部、顶叶白质、额叶白质、枕叶白质及内囊、侧脑室旁发现明显降低（P〈0．05），以后4个部位更为显著（P〈0．01），而胼胝体膝部、压部和小脑结合臂有降低趋势，但无统计学意义。结论：应用DTI定量研究可以探测到多发性硬化的NAWM所出现的微观病理改变，表现为水分子的平均弥散幅度明显升高，以幕上明显，并且胼胝体体部、内囊后肢等白质纤维明显失去正常的方向性。DTI在对白质损伤程度的量化评估中具有重要的价值。     

Assessment of white matter damage in subacute sclerosing panencephalitis using quantitative diffusion tensor MR imaging

BACKGROUND AND PURPOSE: Subacute sclerosing panencephalitis (SSPE), a rare progressive degenerative disease, is caused by persistent infection with a defective measles virus. The correlation between the clinical staging and MR imaging is usually poor. The aim of the study was to investigate the role of diffusion tensor imaging (DTI) in the early detection of white matter damage in SSPE in the presence of normal findings on conventional imaging. METHODS: DTI was performed in 21 patients in stage II SSPE and 10 age/sex-matched healthy controls. Fractional anisotropy (FA) and mean diffusivity (MD) values were calculated in the periventricular white matter, corpus callosum, and posterior limb of the internal capsule in patients with normal and abnormal findings on conventional imaging as well as healthy controls. RESULTS: The patients were grouped into those with normal (n = 11) and abnormal (n = 10) findings on conventional imaging for the purpose of quantitative DTI analysis. Abnormal- and normal-appearing white matter on T2-weighted images showed significantly decreased FA values in all the regions compared with those in healthy controls. MD values were significantly increased in the periventricular white matter region of the frontal and parietooccipital lobe in patients with normal as well as abnormal findings on conventional imaging compared with those in healthy controls. CONCLUSION: DTI detects early white matter abnormalities that may have significant therapeutic implication, even in the presence of normal findings on conventional imaging, in patients with SSPE.     

Altered diffusion tensor in multiple sclerosis normal-appearing brain tissue: cortical diffusion changes seem related to clinical deterioration

PURPOSE: To investigate normal-appearing white (NAWM) and cortical gray (NAGM) matter separately in multiple sclerosis (MS) in vivo using diffusion tensor imaging (DTI). MATERIALS AND METHODS: In 64 MS patients (12 primary progressive [PP], 38 relapsing remitting [RR], 14 secondary progressive [SP]) and 20 healthy controls, whole-brain apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps were acquired. A stimulated echo acquisition mode (STEAM) DTI sequence was used with minimal geometrical distortion in comparison to echo-planar imaging (EPI). NAWM and NAGM were identified using conventional magnetic resonance (MR) images, allowing a cautious assessment of FA in cortex. RESULTS: Histogram analyses showed significant global FA decreases and ADC increases in MS NAWM compared to control WM. MS cortical NAGM had no significant global ADC increase, but FA was decreased significantly. In regional analyses, nearly all NAWM regions-of-interest (ROIs) had significantly increased ADC compared to controls, but FA was not changed. In nearly all cortical NAGM ROIs, ADC was significantly increased and FA significantly reduced. In multiple linear regression analyses in RR/SPMS patients, NAGM-ADC histogram peak height was associated more strongly with clinical disability than T2 lesion load. CONCLUSION: Tissue damage occurs in both NAWM and cortical NAGM. The cortical damage appears to have more clinical impact than T2 lesions.     

Preferential occult injury of corpus callosum in multiple sclerosis measured by diffusion tensor imaging

PURPOSE: To investigate the feasibility of diffusion tensor imaging (DTI) assessment of microscopic fiber tract injury in the corpus callosum (CC) and other normal-appearing white matter (NAWM) in patients with early multiple sclerosis (MS). MATERIALS AND METHODS: DTI was performed in 12 healthy volunteers and 15 patients who have relatively short disease duration (mean = 2.7 years). Both fractional anisotropy (FA) and mean diffusivity (MD) were obtained in different regions of normal-appearing CC (NACC) and NAWM in frontal and occipital regions. RESULTS: The data showed significantly lower FA (P < 0.001) and higher MD (P < 0.04) for NACC regions, but not for frontal and occipital NAWM regions, in patients than in those in healthy volunteers after Bonferroni adjustment. The increase of MD in the entire NACC regions was correlated with the total cerebral lesion volume (r = 0.75, P = 0.001) in patients. CONCLUSION: The water diffusion changes indicate that in the early phase of disease there is a preferential occult injury of CC, which is likely due to the Wallerian degeneration from distant lesions.     

Diffusion tensor imaging of the auditory pathway in sensorineural hearing loss: changes in radial diffusivity and diffusion anisotropy

PURPOSE: To prospectively compare diffusion tensor imaging (DTI) measures of axial diffusivity (lambda parallel), radial diffusivity (lambda perpendicular), mean diffusivity (MD), and fractional anisotropy (FA) along the auditory pathway of patients with sensorineural hearing loss (SNHL) and normal controls. MATERIALS AND METHODS: In 37 individuals with SNHL and 10 healthy controls, two regions of interest (ROIs) positioned along the auditory pathway-the lateral lemniscus (LL) and the inferior colliculus (IC)-were investigated bilaterally using diffusion tensor imaging at 3 T. SNHL patients were divided into three groups: patients with bilateral hearing loss, patients with unilateral hearing loss, and patients with partial hearing loss. DTI measures (lambda parallel, lambda perpendicular, MD, FA) of both ROIs were determined in all subjects. RESULTS: The FA value was reduced and the lambda perpendicular was increased both at the lateral lemniscus and the inferior colliculus of patients with SNHL compared with controls. Similar changes were seen between the ipsilateral and contralateral LL and IC for patients of unilateral profound hearing loss. No changes were observed in any other parameters. CONCLUSION: In SNHL patients DTI showed a high radial diffusivity that consequently led to a decreased fractional anisotropy in the LL and the IC.     

Peroxisomal biogenesis disorder: comparison of conventional MR imaging with diffusion-weighted and diffusion-tensor imaging findings

BACKGROUND AND PURPOSE: Peroxisomal biogenesis disorders (PBDs) refer to a group of disorders of peroxisomal biogenesis causing neuronal migration disorder, delayed myelination, and demyelination. The aim of this study was to evaluate the added value of diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) compared with that of conventional T2-weighted imaging in assessing the extent of white matter damage in patients with PBDs. METHODS: Three patients (aged 12, 16, and 80 months) with PBD (type 1 protein targeting sequence [PTS1]) and three age-matched control subjects underwent MR imaging on a 1.5-T system. The protocol included axial T2-weighted, DWI, and DTI sequences. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) changes were calculated using regions of interest at several predefined white matter areas and compared with those of age-matched control subjects. Color-coded maps were obtained to visualize the range of FA values. RESULTS: On the T2-weighted images, one patient revealed severe hypomyelination throughout the brain; the two other patients showed focal abnormal high-signal-intensity areas. All patients had significantly decreased FA values in white matter areas that appeared abnormal on the T2-weighted images. In two of the three patients, significant FA reduction was also found in normal-appearing white matter. The ADC values of the patients were significantly increased compared with those of the age-matched controls. CONCLUSION: Although based on a small number of patients, our data suggest that DWI and DTI can be used to characterize and quantify white matter tract injury in patients with PBD-PTS1. Furthermore, our data suggest that these techniques have the potential to identify neurodegenerative changes not yet visible on T2-weighted images.     

Late structural alterations of cerebral white matter in long-term survivors of childhood leukemia

PURPOSE: To look for the presence and age-dependence of late structural alterations of otherwise normal-appearing cerebral gray and white matter after radiation and chemotherapy in adult survivors of acute lymphoblastic leukemia (ALL) during childhood. MATERIALS AND METHODS: In a group of 13 adult survivors 17-37 years old, who had been treated by total brain radiation (18-24 Gy) and chemotherapy 16-28 years ago, prospective MR examinations including diffusion tensor imaging (DTI) were performed. Evaluation included volumetry, calculation of mean diffusivity (MD) and fractional anisotropy (FA), and comparison of results to an age-matched control group. RESULTS: DTI showed significantly reduced FA values in the temporal lobes (difference of 0.069 units, P < 0.001), hippocampi (difference of 0.033 units, P < 0.001), and thalami (difference of 0.046 units, P = 0.001), which were accompanied by significant white matter volume loss (difference of 92 cm(3), P < 0.001). Significant elevations of MD were limited to the temporal white matter (difference of 42 x 10(-6) mm(2)/s, P = 0.005). Global and frontal white matter MD correlated negatively to increasing age of the survivors (P < 0.01). CONCLUSION: With regard to structural white matter alterations, adult long-term survivors of childhood ALL, who had received total brain radiation and chemotherapy, apparently show the same overall age dependence as controls. Follow-up studies are needed for confirmation.     

青年抑郁症患者胼胝体MR扩散张量成像研究

目的 研究青年抑郁症患者胼胝体可能存在的细微结构异常。资料与方法 对54例青年抑郁症患者（抑郁症组）和38名年龄和性别匹配的正常志愿者（对照组）进行扩散张量成像（DTI）检查,测量胼胝体膝部、体部和压部的表观扩散系数（ADC）值和各向异性分数（FA）,并对两组进行对比分析。结果 抑郁症组患者胼胝体膝部和体部的ADC值明显高于正常对照组,FA值明显低于对照组,P值均〈0．01;胼胝体压部的ADC值和FA值在两组间差异无统计学意义（P〉0．05）。抑郁症组内ADC、FA值的性别差异无统计学意义（P〉0．05）。结论 青年抑郁症患者胼胝体膝部和体部白质纤维束可能存在细微结构的改变。     

Diffusion tensor fractional anisotropy of the normal-appearing seven segments of the corpus callosum in healthy adults and relapsing-remitting multiple sclerosis patients

PURPOSE: To investigate the utility of whole-brain diffusion tensor imaging (DTI) in elucidating the pathogenesis of multiple sclerosis (MS) using the normal-appearing white matter (NAWM) of the corpus callosum (CC) as a marker of occult disease activity. MATERIALS AND METHODS: A high signal-to-noise ratio (SNR) and optimized entire brain DTI data were acquired in 26 clinically-definite relapsing and remitting multiple sclerosis (RRMS) patients and 32 age-matched healthy adult controls. The fractional anisotropy (FA) values of seven functionally distinct regions in the normal-appearing CC were compared between patients and controls. RESULTS: This study indicates that 1) there was a gender-independent FA heterogeneity of the functionally specialized CC segments in normal volunteers; 2) FA in the MS group was significantly decreased in the anterior (P=0.0039) and posterior (P=0.0018) midbody subdivisions of the CC, possibly due to a reduction of small-caliber axons; and 3) the FA of the genu of the CC was relatively intact in the MS patients compared to the healthy age-matched controls (P=0.644), while the splenium showed an insignificant trend of reduced FA values (P=0.248). The decrease in FA in any of the CC subdivisions did not correlate with disease duration (DD) or the expanded disability status scale (EDSS) score. CONCLUSION: The preliminary results are consistent with published histopathology and clinical studies on MS, but not with some published DTI reports. This study provides insights into the pathogenesis of MS, and the role played by compromised axonal integrity in this disease.     

Diffusion tensor imaging of tract involvement in children with pontine tumors

BACKGROUND AND PURPOSE: Conventional MR imaging permits subcategorization of brain stem tumors by location and focality; however, assessment of white matter tract involvement by tumor is limited. Diffusion tensor imaging (DTI) is a promising method for visualizing white matter tract tumor involvement supratentorially. We investigated the ability of DTI to visualize and quantify white matter tract involvement in pontine tumors. METHODS AND MATERIALS: DTI data (echo-planar, 1.5T) were retrospectively analyzed in 7 patients with pontine tumors (6 diffuse, 1 focal), 4 patient controls, and 5 normal volunteers. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were calculated from the diffusion tensor in 6 regions of interest: bilateral corticospinal tracts, transverse pontine fibers, and medial lemnisci. Relationships between FA and ADC values and results of the neurologic examinations were evaluated. RESULTS: The corticospinal tracts and transverse pontine fibers were affected more often than the medial lemnisci. The DTI parameters (FA and ADC) were significantly altered in all tracts of patients with pontine tumors (P < .05), compared with those values in the control groups. A marginally significant (P = .057) association was seen between the severity of cranial nerve deficit and decreased FA. CONCLUSION: DTI provided superior visualization and quantification of tumor involvement in motor, sensory, and transverse pontine tracts, compared with information provided by conventional MR imaging. Thus, DTI may be a sensitive measure of tract invasion. Further prospective studies are warranted to assess the ability of DTI to delineate tumor focality and improve risk stratification in children with pontine tumors.     

MRI abnormalities in normal-appearing brain tissue of treated adult PKU patients

PURPOSE: To detect possible subclinical pathological brain changes a study on adult phenylketonuria (PKU) patients by using quantitative MRI methods was performed, since neuropsychological and cognitive deficits in treated patients with PKU have not yet been shown to correlate clearly with the brain lesions identified by conventional MRI. MATERIALS AND METHODS: Eight subjects, four PKU patients with well-documented dietary treatment and four age- and sex-matched adult controls, underwent MRI, including a triple echo sequence and a diffusion tensor imaging sequence. Brain maps of T2 relaxation time (T2), relative proton density (PD), and fractional anisotropy (FA) as well as apparent diffusion coefficient (ADC) were derived for each subject. T2, PD, FA, and ADC were measured in 22 predefined regions of gray matter (GM) and white matter (WM) on the corresponding maps, and compared with those of four age-matched healthy adult controls. RESULTS: In addition to a prolonged T2 value measured in affected WM, as expected, we observed a significant shortening of the T2 relaxation time and reduction of ADC in normal-appearing brain tissue and an increased proton density in both GM and WM of the patients. No differences were observed in FA values between controls and patients. CONCLUSION: Repeatedly reduced T2 relaxation time, ADC, and increased proton density without changes in FA indicate a higher cell-packing density in normal-appearing brain without changes in the directedness of fibers. These structural changes may be related to neuropsychological and cognitive deficits in treated PKU patients.     

Diffusion tensor imaging in evaluation of human skeletal muscle injury

PURPOSE: To explore the capability and reliability of diffusion tensor magnetic resonance imaging (DTI) in the evaluation of human skeletal muscle injury. MATERIALS AND METHODS: DTI of four patients with gastrocnemius and soleus muscles injuries was compared to eight healthy controls. Imaging was performed using a GE 3.0T short-bore scanner. A diffusion-weighted 2D spin echo echo-planar imaging (EPI) pulse sequence optimized for skeletal muscle was used. From a series of axially acquired diffusion tensor images the diffusion tensor eigenparameters (eigenvalues and eigenvectors), fractional anisotropy (FA), and apparent diffusion coefficient (ADC) were calculated and compared for injured and healthy calf muscles. Two dimensional (2D) projection maps of the principal eigenvectors were plotted to visualize the healthy and pathologic muscle fiber architectures. RESULTS: Clear differences in FA and ADC were observed in injured skeletal muscle, compared to healthy controls. Mean control FA was 0.23 +/- 0.02 for medial and lateral gastrocnemius (mg and lg) muscles, and 0.20 +/- 0.02 for soleus (sol) muscles. In all patients FA values were reduced compared to controls, to as low as 0.08 +/- 0.02. The ADC in controls ranged from 1.41 to 1.31 x 10(-9) m(2)/second, while in patients this was consistently higher. The 2D projection maps revealed muscle fiber disorder in injured calves, while in healthy controls the 2D projection maps show a well organized (ordered) fiber structure. CONCLUSION: DTI is a suitable method to assess human calf muscle injury.     

Early anisotropy changes in the corpus callosum of patients with optic neuritis

INTRODUCTION: Optic neuritis (ON) and any other early manifestation of multiple sclerosis (MS) are referred to as clinically isolated syndrome (CIS) as long as MS is suspected. In this prospective study we aimed to determine whether diffusion tensor imaging (DTI) could quantify structural changes in patients with early MS. METHODS: A total of 24 patients and 15 control subjects were prospectively followed by clinical examinations and MRI. the main inclusion criterion was presentation with ON. Patients underwent serial MRI scans: MRI1 (baseline, n=24), MRI2 (mean 6.6 months, n=24), MRI3 (mean 13.0 months, n=14), MRI4 (mean 39.4 months, n=5). Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps were derived from DTI. Four regions of interest (ROIs) were defined in normal-appearing white matter (NAWM). RESULTS: In the temporal course FA decreased in the genu of the callosal body (GCC) from MRI1 to MRI4 (P=0.005) and in the splenium of the callosal body (SCC) (P=0.006). Patients already had lower FA values in the SCC (P<0.01) on MRI1 compared with the controls. Patients had lower FA values in the GCC (P<0.01) starting from MRI2. Patients with definite MS on follow-up (n=9) showed a correlation between FA in the SCC and time (r=-0.40, P=0.004), whereas patients without progression did not. CONCLUSIONS: Our findings suggest that the corpus callosum is an early site for development of anisotropy changes in MS patients with ON. There seems to be a primary FA decrease in all patients with ON that only deteriorates in the group developing definite MS.     

复发好转型多发性硬化表现正常脑白质DTI研究

目的:利用扩散张量成像(DTI)直方图分析,明确复发好转型多发性硬化(RRMS)患者表现正常脑白质(NAWM)的异常改变及DTI直方图指标与扩展残疾状态(EDSS)评分的相关性。方法:对29例RRMS患者和35例健康志愿者行常规MRI和DTI检查,分割提取NAWM后,绘制出NAWM的平均扩散率(MD)和部分各向异性(FA)直方图,并对其进行分析。结果:与健康志愿者比较,RRMS患者NAWM平均MD直方图右移、峰高降低;平均FA直方图左移、峰高增高。RRMS患者NAWM的平均MD、MD直方图峰位置和FA直方图峰高明显高于健康志愿者(P<0.001),而MD直方图峰高和平均FA明显低于健康志愿者(P<0.001)。在RRMS患者,所有NAWM的MD和FA直方图指标与EDSS评分均无相关性。结论:RRMS患者NAWM内存在明显扩散异常。     

轻型创伤性脑损伤脑白质纤维束扩散张量成像研究

目的：使用3.0T 磁共振扩散张量成像(DTI)技术观察轻型创伤性脑损伤(mTBI)患者脑白质纤维束的改变,探讨 DTI对 mTBI 的临床诊断价值。方法选取30例 mTBI 患者及30例健康对照者分别进行常规 CT、MRI 及 DTI 检查,分别测量 mTBI患者(急性期、亚急性期、伤后5周~3个月)和对照者的胼胝体膝部、压部、双侧内囊前后肢、扣带束、上纵束、下纵束的各向异性(FA)值、表观扩散系数(ADC)值,观察各测量值的变化规律。结果mTBI 患者部分脑白质纤维束区的 FA 值在急性期、亚急性期减低(P 均<0.05),伤后5周~3个月时仍低于对照者(P 均<0.05),但胼胝体膝部及压部的 FA 值在急性期不减低反而升高(P 均>0.05),此后呈逐渐减低趋势,并在外伤5周~3个月时略低于正常对照组,但差异无统计学意义(P 均>0.05)。急性期、亚急性期 mTBI 患者的 ADC 值低于正常对照组,并在外伤5周~3个月时接近或略高于对照组,但差异无统计学意义(P 均>0.05)。结论DTI 对 mTBI 敏感性较高,能够准确显示白质纤维束的损伤情况并使其可视化,DTI 对 mTBI 的诊断具有重要的临床价值。     

Correlation of diffusion tensor imaging findings and episodic memory impairment in temporal lobe epilepsy

Purpose

Our aim was to evaluate the utility of diffusion tensor imaging (DTI) in exploration of white matter tracts microstructure changes and clarify their relation to episodic memory in temporal lobe epilepsy (TLE).