【作者】 舒红格；

【导师】 漆剑频；

【作者基本信息】 华中科技大学 ， 影像医学与核医学， 2009， 博士

【摘要】 第一部分相位图用于脑铁沉积测量的研究目的：探讨相位图用于脑铁沉积测量的可行性。方法：选取30名健康成年志愿者作为研究对象，男20名，女10名，平均年龄36岁(20-65岁)，所有志愿者均经GE HD 1.5T磁共振扫描仪进行常规MR平扫和SWI检查，经工作站Functool软件后处理在相位校正图上分别测量双侧黑质、红核、苍白球、壳核、尾状核和丘脑的相位校正值CP。并将对照组所得CP值与相应部位脑组织所含铁量进行直线回归分析。结果：黑质、红核、苍白球在相位校正图和SWI重建图上均呈对称的均匀低信号，所显示核团边界清晰，与周围脑组织信号强度对比明显，壳核和尾状核的信号也较低，平均CP值分别为-0.1554、-0.1272、-0.1119、-0.0807和-0.1034，与脑白质内的校正相位值差异有显著性意义(P＜0.01)。CP值与铁含量呈负线性相关(R=-2.81，p=0.048＜0.05)，y=-0.0058x-0.0152(y为局部组织CP值，x为局部脑组织所含铁量)。结论：相位图可以清晰显示脑铁沉积的分布特点；1.5T磁共振条件下，CP值与脑铁含量呈负线性相关；在相位校正图上测量所得CP值可用以量化分析脑组织铁含量。第二部磁敏感成像在颅内钙化灶和铁沉积鉴别中的运用目的：对比研究颅内钙化和铁沉积在磁敏感成像(SWI)序列中的信号特点，并评价SWI技术在颅内病变诊断中的应用。方法：分别收集13例颅内钙化患者和20例健康志愿者的头部MR资料(包括常规T1WI，T2WI，SWI)。所有钙化灶均经过头颅CT检查证实，CT值＞90 HU。将20例健康志愿者纳入铁沉积的研究组。SWI采用高分辨率的3D-SPGR(3D spoiled gradient echo)序列，同时得到幅度图和相位图，图像在工作站经Functool软件处理。对13例颅内钙化患者共计56个钙化灶和20例志愿者的黑质SWI上的信号特点进行分析对比。在校正相位图上分别测量钙化灶、对照组的黑质和正常脑白质的校正相位(CP)值，并进行统计分析。结果：55(98.2％，55／56)个钙化灶在SWI上得到良好显示，在校正相位图上表现为高信号或以高信号为主的混杂信号，在SWI重建图上表现为均匀的极低信号。40个黑质代表铁沉积，在SWI重建图和校正相位图上均表现为均匀的极低信号。钙化灶和正常的脑白质校正相位值CP分别为+0.734±0.073，0.002±0.007，差异有显著性意义(R=8.6305，P＜0.01)。黑质校正相位值为-0.092±0.016，与脑白质内的校正相位值差异有显著性意义(R=-5.3293，P＜0.01)。结论：SWI对铁和钙沉积的检出有高敏感性；利用钙化和铁沉积在相位校正图上的信号差异可以对两者进行鉴别。第三部分帕金森病脑铁沉积的定量研究目的：研究帕金森病(Parkinson’s disease，PD)的发病和进展与脑铁沉积的关系。方法：PD患者30名作为研究组，男22名，女8名，平均年龄57.7岁(38-74岁)，按Hoehn- Yahr分级量表将双侧症状患者20名作为PD组1(中晚期)，单侧症状PD患者10名作为PD组2(早期)。选取年龄和性别匹配的健康志愿者30个作为对照组。所有对象均进行常规MR头部平扫和SWI检查。经后处理在相位校正图上分别测量双侧黑质、红核、苍白球、壳核、尾状核和丘脑的相位校正值CP。并将所获得数据进行统计分析。结果：PD组1、PD组2与对照组在以下核团(黑质、红核、苍白球和壳核)的CP值有统计差异(p＜0.05)，但是在丘脑和尾状核无统计差异(p＞0.05)。PD组1和PD组2各兴趣区CP值之间无统计差异(p＞0.05)。PD组2的症状同侧和对侧之间CP值无统计差异。结论：1) CP值与脑铁含量呈负线性相关联。2)铁含量的增加与PD的发病有关，但与病情的严重程度无关。3)在PD的亚临床期就有铁异常沉积。4) PD铁异常沉积的部位包括黑质、红核、苍白球和壳核，丘脑和尾状核的铁沉积变化不明显。第四部分帕金森病的DTI研究目的：研究帕金森病(PD)锥体外系和部分功能区的DTI改变状况，探讨PD早期诊断的线索及DTI参数与PD的关系。方法：PD患者30名作为研究组，男22名，女8名，平均年龄57.7岁(38-74岁)，按Hoehn-Yahr分级量表将双侧症状患者20名作为PD组1(中晚期)，单侧症状PD患者10名作为PD组2(早期)。选取年龄和性别匹配的健康志愿者30个作为对照组。所有对象均进行常规MR头部平扫和DTI检查。经后处理得到FA图和ADC图，用手动描绘法测量各兴趣区的FA值和ADC值，兴趣区包括双侧的黑质、红核、苍白球、壳核、尾状核、丘脑、胼胝体膝部、胼胝体压部、扣带回、额叶白质和中央前回。并将所获得数据进行统计分析。结果：PD组的黑质、尾状核和丘脑的FA值较对照组明显减低(P＜0.05)，PD组1黑质的FA值较PD组2双侧的FA值明显减低(p＜0.05)，PD组2的症状对侧和同侧黑质FA值之间有明显统计差异(p＜0.05)，PD组1和组2的胼胝体压部的FA值较对照组明显减低(p＜0.05)，PD组1的中央前回的FA值较对照组和PD组2明显减低(p＜0.05)，PD组1的扣带回的FA值较对照组减低(p＜0.05)；PD组余兴趣区的FA值和对照组之间无明显统计差异(p＞0.05)，PD组1和2之间也无明显统计学差异；PD组兴趣区的ADC值和对照组之间无明显统计差异(p＞0.05)，PD组1和2之间以及PD组2症状对侧和同侧之间也无明显统计学差异(p＞0.05)，但是随着病情级别的增加，ADC值呈增高趋势。结论：DTI特别是黑质、尾状核、丘脑和胼胝体压部的FA值有助于PD的早期诊断；黑质FA值的变化与PD分级负相关；中晚期PD患者的扣带回和中央前回的FA值减低；DTI为PD的在体研究提供更多与病理机制和临床表现有关的大量有用信息；第五部分帕金森病的脑基底节区MRS研究目的：研究分析帕金森病基底节区代谢变化，探讨磁共振质子波谱分析对帕金森病的临床应用价值。方法：对15例PD患者和8例健康志愿者对照进行双侧基底节区质子波谱检查，其中10例PD患者和8例志愿者均行双侧豆状核单体素质子波谱检查，5例PD患者行双侧基底节区2D-多体素质子波谱检查，并对所得结果进行分析统计。结果：PD患者豆状核的NAA／Cr的比值小于正常对照组(p＜0.05)，Cho／Cr与正常对照组无明显统计差异。2D-多体素MRS检查中PD患者双侧的NAA／Cr不对称，较重症状对侧的壳核和丘脑的NAA／Cr低于同侧。结论：质子波谱分析是研究PD患者基底节神经元是否遭受破环的一种无创性技术，2D-多体素MRS适宜于PD的检查，NAA／Cr比值的变化反应了PD的病理改变。更多还原

【Abstract】 PartⅠPhase images in study of quantifying brain ironObjective: To explore whether the phase images has potential for quantifying brain iron invivo.Methods : Thirty healthy adult volunteers (20 males,10 females ) were studied with a GE1.5 T scanner. The subjects ranged from 20 to 65 years old ( mean = 36). All subjects wereimaged with SWI sequence. The correct phase shift value (CP) of substantia nigra (SN),red nucleus (RN),, globus pallidus (GP), putamen (PU), caudate (CA) and thalamus (TH)were measured on the corrected phase images. Regional CP values were compared withpublished brain iron concentration by linear correlation analysis.Results : The SN, RN and GP showed symmetrically homogeneous low intensity both inthe CP images and SWI reconstruction images. And their mean CP value were -0.1554,-0.1272, -0.1119, -0.0807 and -0.1034, Significant difference was demonstrated at the CPvalues of ROI and white matter (p＜0.01). There was negative linear correlation betweenCP value and brain iron store (R=-2.81, p=0.048＜0.05), y=-0.0058x-0.0152.Conclusions : The phase shift images could be used to detect minor iron concentrationdifferences in the brain. There was negative linear correlation between CP value and brainiron store in 1.5 T MR. The phase shift images may be useful for estimating the amount ofbrain iron in vivo. PartⅡApplication of MR Susceptibility Weighted Imaging inthe Differential Diagnosis of Intracranial Calcification and IronAccumulationObjective: To study the signal character of intracranial calcification and ironaccumulation by using MR SWI (susceptibility weighed imaging, SWI) technology, andevaluate the value of SWI sequence in diagnosis of intracranial lesions.Methods: The materials of 13 cases with intracranial calcification and 20 cases volunteerMRI(including routine T1Wi,T2Wi and SWI) were collected. All calcification areconfirmed by CT scan with their CT value beyond 90 HU . And the 20 volunteersrepresentiron accumulation group. 3D-SPGR(3D spoiled gradient echo) sequence is applied insusceptibility weighed imaging. Magnitude images and phase images are obtained. AndSWI reconstruction images will be obtained at the workstation AW4.2 . The MR signalcharacter of 56 calcification and that of substantia nigra in 20 volunteers werecompared..The CP(corrected phase ,CP) values of calcification ,substantia nigra andnormal alba are measured in corrected phase images. And statistical analysis is carried out.Results: All 55 (98.2%) calcification were well demonstrated in SWI sequence. Incorrected phase images, calcification showed high signal intensity or heterogeneously highsignal intensity, and hypointensity in SWI reconstruction images. 40 substantia nigrarepresenting iron accumulation showed extremely homogeneous low intensity both incorrected phase and SWI reconstruction images. The CP value of calcification is+0.734±0.073 ; The CP value of alba is +0.002±0.007 .There is significant differencebetween calcification and alba (t=8.6305,p＜0.01). There is significant differencebetween substantia nigra(-0.092±0.016) and alba (t=-5.3293,p＜0.01).Conclusion: SWI has high sensitivity in detection of iron accumulation and intracranial calcification. The signal difference in phase corrected images is valuable in differentialdiagnosis of intracranial calcification and iron accumulation.PartⅢThe quantitative study of iron stores in the brain ofParkinson’s diseaseObjective: To explore MR technology for the quantitative study of iron store inbrain. And to invest the relationship between PD’s pathogenesy and progress and ironstore in brain.Methods : 10 PD patients with unilateral symptoms and 20 PD patients with bi-lateralsymptoms were enrolled in PD group 1 and PD group 2. The 30 PD patients included 22males and 8 females .The average age was 57.7 years old (38-74). The PD group and thecontrol group which including 30 age and sex matched healthy volunteers were underwentthe routine MR plain scan and SWI scan. The phase correction value (CP) of substantianigra, red nucleus, globus pallidus, putamen, caudate and thalamus were measured inCP imaging. The statistical analysis was underwent.Result : There was negative linear correlation between CP value and iron store (R=-2.81,p=0.048＜0.05) . The CP value of substantia nigra , red nucleus, globus pallidus andputamenl were significantly lower in PD groups (p＜0.05). No significant difference wasdemonstrated at CP value of caudate and thalamus (p＞0.05). No significant differencewas demonstrated at CP value of all ROI between PD group 1 and PD group 2 (p＞0.05).And no significant difference was demonstrated at the CP value between the two sides ofthe PD group 2.Conclusions : 1) There was negative linear correlation between CP value and iron store. 2)Increasing of iron store concerned with PD’s pathogenesy, not with severity degree. 3) There has abnormal iron store before clinical period. 4) The site of pathologic iron storeinclude substantia nigra, red nucleus, globus pallidus, putamen, not including caudateand thalamus.PartⅣDTI study of Parkinson’s diseaseObjective: To investigate the diffusion tensor imaging (DTI) change on extracorticospinaltract and some domain in Parkinson’s disease (PD). To explore some clues for PD’s earlydiagnosis. And to explore the relationship between DTI and PD.Methods: 10 PD patients with unilateral symptoms and 20 PD patients with bi-lateralsymptoms were enrolled in PD group 1 and PD group 2. The 30 PD patients included 22males and 8 females .The average age was 57.7 years old (38-74). The PD group and thecontrol group which including 30 age and sex matched healthy volunteers were underwentthe routine MR plain scan and DTI scan .There would be FA imaging and ADC imagingafter postprocessing. And the FA values and ADC values of ROI (region of interest) weremeasured .The ROI included SN (substantia nigra)、NR (red nucleus)、GP (globuspallidus)、PUT (putamen)、CN (caudate nucleus)、thalamus、genu of corpus callosum、splenium of corpus callosum、callosal gyms、white matter of frontal lobe and anteriorcentra gyms. All data were analyzed.Results : The FA value of SN、CN and thalamus of PD group degraded obviouslycompared with control group (p＜0.05).The FA value of PD group 1 degraded comparedwith that of PD group 2. There was significant diference at SN’s FA value between thetwo sides of PD group 2. The FA value of splenium of corpus callosum of PD groups weresignificant lower than control group. The FA value of PD group 1 was lower compared withcontrol group and PD group2 at anterior central gyms and callosal gyms (p＜0.05). There was no significant diference among PD groups and contra group at other ROI’s FA value.And there was no significant diference between PD group 1 and PD group 2 at other ROI.There were no significant diference at ADC value among PD group 1、PD group 2 andcontrol group .But there was an increasing tendency at ADC value along with the progressof PD.Conclusions: The FA values of SN、CN、thalamus and splenium of corpus callosum offeredsome important informations for the early diagnosis of PD.There was negative correlationbetween the change of FA value at SN and PD grade.The FA values of callosal gyrus andanterior central gyms decreased at advanced stage of PD .DTI was useful to the study aboutPD’s pathomechanism and clinical manifestation in vivo.PartⅤMagnetic resonance spectroscopy study on basal gangliadomain of idiopathic Parkinson’s diseaseObjective : To analyze the metabolism change on basal ganglia of idiopathic Parkinson’sdisease. And to explore the clinical application of magnetic resonance spectroscopy (MRS)on Parkinson’s disease (PD).Methods : 15 PD patients and 8 healthy volunteers underwent MRS study on their basalganglia. Among them ,10 PD patients and the volunteers underwent single-voxel MRSstudy. And 5 PD patients underwent multi-voxel MRS study.Results : NAA/Cr radio on lenticular of PD patients were decrease .There was no statisticsdifference on Cho/Cr radio between the PD patients and volunteers. NAA/Cr radio of PDpatients was asymmetry in 2D multi-voxel MRS study.Conclusions: H-MRS was a useful technique in study the function and quantity of basalganglia neuron of PD. 2D multi-voxel MRS lend itself to the study of PD. The NAA/Cr radiochange was the reaction of the pathology change of PD.更多还原