含软骨基质型肉瘤的MR钆喷替酸葡甲胺增强和扩散加权成像特点

Objective To study the Gadolinium-enhanced MRI and diffusion weighted imaging (DWI) characteristics of the chondroid matrix-forming sarcomas.Methods Contrast-enhanced MRI and DWI were performed in 14 eases of chondroid matrix-forming sarcomas (10 chondrosarcomas,4 chondroblastic esteosarcomas) and 13 cases of other types of osteosarcomas.DWI was obtained with a single-shot echo-planar imaging (EPI) sequence using a 1.5 T MR imager with two different b values of 0 and 700 s/mm2.The apparent diffusion coefficient (ADC) values were obtained in GE Functiontool software.The contrast-enhancement pattern was evaluated and the ADC values of ehondroid matrix-forming sarcomas was compared with that of other types of asteosarcoma.Independent sample t-test was performed to evaluate the difference of ADC values between the group of chondroid matrix-forming sarcoma and the group of other types of osteosarcoma.In addition, nonparametrie test was used to assess the difference of ADC values between the chondrosareoma and the chondroblastic osteosarcoma.P value less than 0.05 was considered to represent a statistical significance.Results For 14 eases of ehondroid matrix-forming sarcomas, peripheral enhancement was found in all cases, septonodular enhancement was identified in 12 cases.While 13 eases of other types of osteosarcowas demonstrated heterogeneous enhancement.The mean ADC value of chondroid matrix-forming sarcomas [(2.56 ±0.35) × 10 -3 mm2/s] was significantly higher than that of other types of osteosarcoma [( 1.16±0.20) × 10-3 mm2/s] (t = 12.704,P <0.O1 ).There was no significant difference in the ADC value between the chondrosarcoma and the chondroblastie osteesarcama(Z =0.507 ,P =0.959).Conclusion Contrast-enhanced MRI and DWI can improve differentiation between chondroid matrix-forming sarcomas and other types of osteosarcomas.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

Objective To investigate the value of MR DWI in comparing inflammatory with metastastic lymph node in animal models of lymph disease.Methods Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination.Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups.Results Thirty-four inflammatory lymph nodes and 18 metastastic lymph nodes were observed .The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively.There was no significant statistical difference between the sizes of the two groups (t=2.624, P 0.05).Mean ADC value of lymph nodes was (1.19±0.31)×10-3mm2/s and (1.31±0.27)×10-3mm2/s in the benign and malignant groups, respectively.There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449,P 0.05).Conclusion DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

Objective To investigate the value of MR DWI in comparing inflammatory with metastastic lymph node in animal models of lymph disease.Methods Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination.Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups.Results Thirty-four inflammatory lymph nodes and 18 metastastic lymph nodes were observed .The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively.There was no significant statistical difference between the sizes of the two groups (t=2.624, P 0.05).Mean ADC value of lymph nodes was (1.19±0.31)×10-3mm2/s and (1.31±0.27)×10-3mm2/s in the benign and malignant groups, respectively.There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449,P 0.05).Conclusion DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

Objective To investigate the value of MR DWI in comparing inflammatory with metastastic lymph node in animal models of lymph disease.Methods Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination.Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups.Results Thirty-four inflammatory lymph nodes and 18 metastastic lymph nodes were observed .The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively.There was no significant statistical difference between the sizes of the two groups (t=2.624, P 0.05).Mean ADC value of lymph nodes was (1.19±0.31)×10-3mm2/s and (1.31±0.27)×10-3mm2/s in the benign and malignant groups, respectively.There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449,P 0.05).Conclusion DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

Objective To investigate the value of MR DWI in comparing inflammatory with metastastic lymph node in animal models of lymph disease.Methods Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination.Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups.Results Thirty-four inflammatory lymph nodes and 18 metastastic lymph nodes were observed .The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively.There was no significant statistical difference between the sizes of the two groups (t=2.624, P 0.05).Mean ADC value of lymph nodes was (1.19±0.31)×10-3mm2/s and (1.31±0.27)×10-3mm2/s in the benign and malignant groups, respectively.There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449,P 0.05).Conclusion DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

Objective To investigate the value of MR DWI in comparing inflammatory with metastastic lymph node in animal models of lymph disease.Methods Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination.Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups.Results Thirty-four inflammatory lymph nodes and 18 metastastic lymph nodes were observed .The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively.There was no significant statistical difference between the sizes of the two groups (t=2.624, P 0.05).Mean ADC value of lymph nodes was (1.19±0.31)×10-3mm2/s and (1.31±0.27)×10-3mm2/s in the benign and malignant groups, respectively.There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449,P 0.05).Conclusion DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

Objective To investigate the value of MR DWI in comparing inflammatory with metastastic lymph node in animal models of lymph disease.Methods Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination.Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups.Results Thirty-four inflammatory lymph nodes and 18 metastastic lymph nodes were observed .The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively.There was no significant statistical difference between the sizes of the two groups (t=2.624, P 0.05).Mean ADC value of lymph nodes was (1.19±0.31)×10-3mm2/s and (1.31±0.27)×10-3mm2/s in the benign and malignant groups, respectively.There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449,P 0.05).Conclusion DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

Objective To investigate the value of MR DWI in comparing inflammatory with metastastic lymph node in animal models of lymph disease.Methods Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination.Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups.Results Thirty-four inflammatory lymph nodes and 18 metastastic lymph nodes were observed .The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively.There was no significant statistical difference between the sizes of the two groups (t=2.624, P 0.05).Mean ADC value of lymph nodes was (1.19±0.31)×10-3mm2/s and (1.31±0.27)×10-3mm2/s in the benign and malignant groups, respectively.There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449,P 0.05).Conclusion DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

Objective To investigate the value of MR DWI in comparing inflammatory with metastastic lymph node in animal models of lymph disease.Methods Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination.Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups.Results Thirty-four inflammatory lymph nodes and 18 metastastic lymph nodes were observed .The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively.There was no significant statistical difference between the sizes of the two groups (t=2.624, P 0.05).Mean ADC value of lymph nodes was (1.19±0.31)×10-3mm2/s and (1.31±0.27)×10-3mm2/s in the benign and malignant groups, respectively.There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449,P 0.05).Conclusion DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy.     

扩散加权成像鉴别兔炎性及转移性淋巴结肿大的实验研究

Objective To investigate the value of MR DWI in comparing inflammatory with metastastic lymph node in animal models of lymph disease.Methods Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination.Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups.Results Thirty-four inflammatory lymph nodes and 18 metastastic lymph nodes were observed .The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively.There was no significant statistical difference between the sizes of the two groups (t=2.624, P 0.05).Mean ADC value of lymph nodes was (1.19±0.31)×10-3mm2/s and (1.31±0.27)×10-3mm2/s in the benign and malignant groups, respectively.There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449,P 0.05).Conclusion DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy.     

Management of breast magnetic resonance imaging-detected lesions

Breast magnetic resonance imaging (MRI) has become an essential component of breast imaging. Whether it is used as a problem-solving tool or a screening test or for staging patients with breast cancer, it detects many lesions in the breast. The challenge for the radiologist is to distinguish significant from insignificant lesions and to direct their management. A brief summary of the terminology according to the American College of Radiologists lexicon will be provided. This review article will cover the differential diagnosis of enhancing lesions, including masses and nonmass enhancement, from benign and malignant causes. Some of the specific morphologic and kinetic features that help to differentiate benign from malignant lesions will be illustrated, and positive predictive values of these features will be reviewed. The various methods of investigating enhancing lesions of the breast will be discussed, including second-look ultrasound, ultrasound-guided biopsy, stereotactic biopsy, and MRI-guided biopsy. A practical approach to the management of MRI-detected lesions will include timing of follow-up, when to biopsy and when to ignore enhancing lesions in the breast.     

自闭症的常规MRI和1H-MRS表现

目的 探讨常规MR成像和1H MR波谱(MRS)在自闭症诊断中的价值.资料与方法 回顾性分析12例自闭症患者的全脑常规MR扫描及其中8例患者额叶和海马的多体素2D 1H MR波谱扫描表现.结果 常规MR扫描发现3例患者的顶叶白质在FLAIR上出现斑片状高信号.1H MRS分析发现5例患者额叶的NAA/Cho明显下降(NAA/Cho<1),其中1例患者的左侧额叶出现Lac峰;另外有2例患者海马的NAA/Cho出现下降(NAA/Cho<1).结论 常规MR成像和1H MRS可发现部分自闭症患者脑组织异常.     

急性胆红素脑病常规MRI及1H-MR波谱表现

Objective To investigate the characterized imaging in conventional MRI, get information about the metabolites in basal ganglia from proton MR Spectroscopy(1H-MRS) of acute bilirubin encephalopathy(ABE) and find out the relationship between those changes and bilirubin levels. Methods Twenty-eight patients with acute bilirubin encephalopathy and 15 normal neonates underwent MR and 1H-MRS examinations T1 WI, T2WI and DWI were collected via conventional MRI scanning of all neonates. All patients underwent multi-voxels scanning and 15 of them had single voxel scanning. 1H-MRS used point resolved spectroscopy (PRESS) both in multi-voxels and single voxel scanning. The data of them were acquired from the ROIs placed in basal ganglia and globus pallidus, respectively. The metabolites including NAA choline, Lactate, glutamate and glutamine, myoinositol and creatine were quantitatively analyzed to compare them between the control group and the case group. Equality of variance between patient data and normal values were tested by using the two-tailed t test. The case group was divided into three groups of 342.0 μmol/L < TSB ≤ 427. 5 μmol/L,427.5 μmol/L < TSB ≤ 513.0 μmol/L, TSB > 513.0 μmol/L including 8,9,11 patients, respectively. Analysis of variance was used for statistics. Results Conventional magnetic resonance imaging showed symmetrical high signal of T1WI in globus pallidus of 23 patients. The case group and the control group were significantly different. Single voxel 1H-MRS revealed that the relative concentrations of Glx/Gr and mI/Cr in the control group were 0.95±0.23, 0.57±0.20, respectively, While those in case group were 1.45±0.37, 0.74±0.23, respectively. There were significant differences between two groups (t =2. 13,4. 40,P =0.04,0.00 respectively). Multi-voxels scanning 1H-MRS revealed that Glx / Cr were 0.51±0.36 in case group and 0.29±0.18 in control group. There was also a significant difference between two groups (t =2.17,P =0.03). And the values of Cho/Cr, NAA/Cr and Lac/Cr were not significantly different. The results were same in multi-voxels 1H-MRS. Total bilirubin level and the concentration of metabolites in the brain do not have obvious correlation. Conclusions ABE has a characteristic signature which is symmetrical high signal of T1 WI in globus pallidus on conventional MBI; The values of mI/Cr and Glx/Cr remarkably increase as detected by 1H-MRS, which is generally in agreement with what has been known about bilirubin pathology.     

常规MRI和1H-MRS在职业性锰暴露致中枢神经损害中的应用价值

Objective MRI and MR hydrogen proton spectroscopy (1H-MRS) were used to detect the abnormal signal and alteration of metabolites, in order to explore the efficacy of these method in evaluating the damages of central nervous system (CNS) induced by occupational manganese exposure.Methods Eighteen workers exposed to manganese without any manganism symptoms, 12 workers with slightly chronic manganese poisoning, and 19 healthy workers were scanned using routine MRI sequence and 1H-MRS.The blood manganese concentration was also collected for each subject.On cerebral axial T1 WI,the signal intensities of ipsilateral globus pallidus and frontal white matter were measured in the visually brightest area (try to select the signal homogeneous region), and the globus pallidus index (PI) was then calculated.The 1H-MRS data was calculated to get the values of the peak height of N-acetylaspartate (NAA), choline (Cho), inositol (mI) and creatine (Cr) and the ratios of NAA/Cr, Cho/Cr, and mL/Cr were also calculated.One way ANOVA was used to compare the values of PI, NAA/Cr, Cho/Cr, mI/Cr and MnB among the three groups, and the correlations between PI and the time span of manganese exposure or blood manganese concentration were analyzed by Pearson correlation analysis.Eight workers exposed to manganese were followed up one year, and their PI , NAA/Cr before and after follow-up were compared by t test.Results Fourteen of 18 cases exposed to manganese without any manganism symptoms showed symmetrically high intensity signal on T1 WI, while the T2 WI were normal.No high signal intensity was observed on T1WI in any of the healthy workers or manganese poisoning workers.We found that the average PI in manganese exposed group (1.16 ±0.09) was significantly higher (F =24.79 ,P =0.O00)than those of the poisoning ( 1.05 ± 0.07 ) and control groups ( 1.01 ± 0.05 ).The blood manganese concentration in manganese exposed group, the poisoning group and the control group were (0.051 ±0.024), (0.047 ±0.018 ), ( 0.043 ± 0.020 ) μg/ml respectively, which was not significantly different ( F = O.623, P =0.541 ) and did not exceed the upper limit of normal reference value ( < 0.10 μg/ml ).There was a significantly correlation between PI and the time span of manganese exposure ( r = 0.67, P = 0.002 ),however, there was no correlation between PI and blood manganese concentration ( r = 0.20, P = 0.427 ).Furthermore, the NAA/Cr ratio decreased variously in the manganese poisoning group ( 1.22 ± 0.07 ) which was significantly lower( F = 4.120, P = 0.023 ) than those of the poisoning( 1.33 ± 0.13 ) and control groups ( 1.31 ±0.13).No statistical significanees were found in the ratios of Cho/Cr and mI/Cr among these three groups(P>0.05).No obvious changes of the PI and NAA/Cr were found in the 8 manganese exposed workers after 1 year follow-up.Conclusion Manganese exposure could lead to the high intensity signal on T1 WI, therefore the increased PI may be the biomarkers of central nerve system damages caused by the occupational manganese exposure.     

恶性胶质瘤的二维氢质子磁共振波谱研究

研究脑恶性胶质瘤的二维氢质子磁共振波谱(2D1H -MRS)特征及其代谢物变化规律。材料和方法 :经病理学证实的恶性胶质瘤14例(男性8例 ,女性6例 ,年龄19～72岁) ,年龄相近正常对照组15例 ,使用1.5TMRI成像仪 ,PRESS序列 ,TR/TE=1000ms/144ms ,多体素相位矩阵 :16×16 ,FOV :24cm。完成扫描后用随机软件包FuncTool进行分析 ,观察正常对照组(作为外参照)、病例组病灶周边、病变区及对侧正常区(内参照)各主要代谢物变化情况。结果 :14例胶质瘤按WHO标准分类Ⅲ级6例 ,Ⅳ级8例 ,肿瘤实体区NAA/Cho、NAA/Cr、NAA/(Cho +Cr)分别为0.39±0.11 ,1.09±0.38 ,0.28±0.06 ,较正常参照区降低且具显著性差异(p<0.05) ;Cho/Cr和Lac/Cr分别为3.05±1.44 ,0.35±0.59 ,均较参照区升高 ,前者p<0.05 ,后者无统计学差异(p>0.05) ;结合多体素波谱图观察提示恶性胶质瘤Cho升高、NAA下降和出现异常Lac峰 ,同时可显示肿瘤周边区域的Cho升高等异常。结论 :Cho升高、NAA下降和出现异常Lac峰是恶性胶质瘤的主要波谱表现。2D 1H -MRS可检测胶质瘤MRI所示病灶以外区域的代谢异常 ,此对鉴别诊断、立体定向活检和制定治疗方案等有较高临床应用价值     

常规MRI和1H-MRS在职业性锰暴露致中枢神经损害中的应用价值

Objective MRI and MR hydrogen proton spectroscopy (1H-MRS) were used to detect the abnormal signal and alteration of metabolites, in order to explore the efficacy of these method in evaluating the damages of central nervous system (CNS) induced by occupational manganese exposure.Methods Eighteen workers exposed to manganese without any manganism symptoms, 12 workers with slightly chronic manganese poisoning, and 19 healthy workers were scanned using routine MRI sequence and 1H-MRS.The blood manganese concentration was also collected for each subject.On cerebral axial T1 WI,the signal intensities of ipsilateral globus pallidus and frontal white matter were measured in the visually brightest area (try to select the signal homogeneous region), and the globus pallidus index (PI) was then calculated.The 1H-MRS data was calculated to get the values of the peak height of N-acetylaspartate (NAA), choline (Cho), inositol (mI) and creatine (Cr) and the ratios of NAA/Cr, Cho/Cr, and mL/Cr were also calculated.One way ANOVA was used to compare the values of PI, NAA/Cr, Cho/Cr, mI/Cr and MnB among the three groups, and the correlations between PI and the time span of manganese exposure or blood manganese concentration were analyzed by Pearson correlation analysis.Eight workers exposed to manganese were followed up one year, and their PI , NAA/Cr before and after follow-up were compared by t test.Results Fourteen of 18 cases exposed to manganese without any manganism symptoms showed symmetrically high intensity signal on T1 WI, while the T2 WI were normal.No high signal intensity was observed on T1WI in any of the healthy workers or manganese poisoning workers.We found that the average PI in manganese exposed group (1.16 ±0.09) was significantly higher (F =24.79 ,P =0.O00)than those of the poisoning ( 1.05 ± 0.07 ) and control groups ( 1.01 ± 0.05 ).The blood manganese concentration in manganese exposed group, the poisoning group and the control group were (0.051 ±0.024), (0.047 ±0.018 ), ( 0.043 ± 0.020 ) μg/ml respectively, which was not significantly different ( F = O.623, P =0.541 ) and did not exceed the upper limit of normal reference value ( < 0.10 μg/ml ).There was a significantly correlation between PI and the time span of manganese exposure ( r = 0.67, P = 0.002 ),however, there was no correlation between PI and blood manganese concentration ( r = 0.20, P = 0.427 ).Furthermore, the NAA/Cr ratio decreased variously in the manganese poisoning group ( 1.22 ± 0.07 ) which was significantly lower( F = 4.120, P = 0.023 ) than those of the poisoning( 1.33 ± 0.13 ) and control groups ( 1.31 ±0.13).No statistical significanees were found in the ratios of Cho/Cr and mI/Cr among these three groups(P>0.05).No obvious changes of the PI and NAA/Cr were found in the 8 manganese exposed workers after 1 year follow-up.Conclusion Manganese exposure could lead to the high intensity signal on T1 WI, therefore the increased PI may be the biomarkers of central nerve system damages caused by the occupational manganese exposure.     

Biomedical implants and devices: assessment of magnetic field interactions with a 3.0-Tesla MR system

PURPOSE: To evaluate magnetic field interactions for 109 different biomedical implants and devices in association with exposure to a 3.0-Tesla magnetic resonance (MR) system. MATERIALS AND METHODS: A total of 109 implants and devices (aneurysm clips, 32; clips, fasteners, and staples, 10; coils and stents, 10; heart valve prostheses and annuloplasty rings, 12; orthopedic implants, five; suture materials, 13; vascular access ports and accessories, 13; miscellaneous implants and devices, 14) were tested for magnetic field interactions at 3.0-Tesla using previously-described, standardized techniques to assess magnetic field translational attraction and torque. RESULTS: The deflection angles and torque measurements ranged, respectively, from 0 to 16 degrees and 0 to +2 for the aneurysm clips; 0 to 90 degrees and 0 to +4 for the clips, fasteners, and staples; 0 to 47 degrees and 0 to +4 for the coils and stents; 0 to 4 degrees and 0 to +1 for the heart valve prostheses and annuloplasty rings; 0 to 12 degrees and 0 to +2 for the orthopedic implants; 0 to 13 degrees and 0 to +2 for the suture materials; 0 to 52 degrees and 0 to +4 for the vascular access ports and accessories; and 0 to 28 degrees and 0 to +3 for the miscellaneous implants and devices. CONCLUSION: Of the 109 implants and devices assessed for magnetic field interactions at 3.0-Tesla, four (4%) are potentially unsafe based on deflection angle criteria. The implications of these results for patients undergoing MR procedures at 3.0-Tesla is discussed. Notably, these results are specific to the 3.0-Tesla MR system used for this evaluation.     

线粒体脑肌病综合影像表现

目的:探讨多种影像技术对线粒体脑肌病(ME)的诊断价值.方法:回顾性分析7例线粒体脑肌病患者的影像资料,其中7例行常规MRI扫描,3例行MRA扫描,4例行MRS扫描,1例行DSA检查,6例行CT平扫.结果:6例病变主要累及两侧大脑皮层和皮层下,1例主要表现为白质内改变,均表现为长T1、长T2改变;MRA示2例未见明显改变,1例示病变处血管分支明显增粗;4例MRS在病变处检出乳酸双峰,1例在脑脊液中检出乳酸双峰.1例行DSA检查示病灶内血管分支增粗,血运加快.6例行CT检查病灶均呈低密度改变.结论:影像检查尤其是MRI检查对ME的诊断提供了丰富的信息,当年青患者出现非典型性脑梗死表现,MRS检出乳酸双峰时要考虑到线粒体脑肌病的可能.     

肝细胞急性坏死与凋亡的磁共振波谱研究

 目的 建立大鼠肝细胞坏死和凋亡的动物模型,将不同时间点的MRS检测结果与病理学所见进行对照研究,以评估MRS检测及鉴别肝细胞凋亡和坏死的能力与价值.方法 72只S-D大鼠随机分成假手术对照组、右侧肝动脉与门静脉分支均结扎组(HA+PV组)和单独右侧门静脉分支结扎组(PV组),实验组各分成4个亚组,每个亚组6只,分别于术后3 h、12 h、24 h、72 h行普通MRI和单体素PRESS 35序列MRS,得到肝右叶与左叶各代谢物浓度,以及肝右叶内代谢物相对比值.结果 HA+PV及PV组术后3 h,少量肝细胞发生坏死与凋亡时,肝右叶Lip-Lac较左叶相比即有明显增高,随着凋亡与坏死细胞增多,Lip-Lac增高更加明显.术后12 h肝右叶Cho较左叶相比出现降低,也随时间延长逐渐明显;肝右叶Lip-Lac/Cho比值在HA+PV及PV组术后3 h均有增高,以PV 3 h组增高更显著.结论 凋亡与坏死组织在1H MRS中都有Lip-Lac增加,Cho降低.肝细胞凋亡后早期,Lip-Lac/Cho比值增高较坏死明显,采用Lip-Lac/Cho比值对鉴别早期肝细胞坏死与凋亡具有一定意义.