【作者】 赵秋枫；

【导师】 耿道颖；

【作者基本信息】 复旦大学 ， 影像医学与核医学， 2009， 博士

【摘要】 第一部分：臂丛神经MRI正常表现及检查方案目的：分析MRI不同成像序列对显示正常臂丛结构的价值，并进一步确定臂丛神经的最佳MRI检查方案。材料和方法：使用1.5T MRI扫描仪对20名正常志愿者行常规及MR新技术检查。常规扫描包括横轴位SE-T1WI、FSE-T2WI、STIR，冠状面SE-T1WI、FSE-T2WI，矢状面FSE-T2WI。MRI新技术包括：3D-FIESTA-c序列、冠状面薄层无间隔STIR及3D-FSPGR序列。观察上述序列图像对臂丛神经结构的显示情况，计算冠状面T1WI、T2WI及STIR序列图像的对比噪声比及对臂丛神经节后各部分的显示评分，获得臂丛神经最优MRI扫描方案。结果：常规序列横断面图像上，显示神经根自椎间孔处穿出，行于前中斜角肌间，与锁骨下动脉及腋动脉伴行；冠状面图像上，显示为由C5-T1神经孔旁起始的条索状结构；矢状面上表现为结节状结构，行于前中斜角肌间，围绕锁骨下动脉；T1WI、T2WI上臂丛神经呈等信号，STIR上呈高信号。T1WI、T2WI、STIR序列图像对比噪声比分别为：4.96±0.31、6.07±0.18、23.09±1.20，STIR图像对比噪声比明显高于常规组(P=0.000)；对节后段C5，6神经根及上干的显示评分STIR序列明显高于常舰序列，对C7-T1神经根、中、下干及臂丛神经锁骨后、锁骨下段各序列均可连续显示。3D-FIESTA-c序列可清晰显示椎管内臂丛神经前后根，为脑脊液高信号环绕下的等信号丝状结构。3D-FSPGR图像可清晰显示臂丛神经与邻近组织结构的关系。结论：常规横断面T1WI、T2WI、STIR，矢状面T2WI扫描，结合MRI新序列3D-FIESTA-c横断面及冠状面扫描、冠状面薄层无间隔STIR及3D-FSPGR扫描，可全面、清晰地显示臂丛神经，作为显示臂丛神经病变的常规检查方案。第二部分：臂丛神经损伤的MRI诊断及应用目的探讨臂丛神经损伤的MRI表现及其诊断价值。材料与方法70例临床诊断为臂丛神经损伤的患者于手术前行MR检查。采用1.5 T MRI扫描仪，行两侧臂丛神经MRI扫描。59例患者行锁骨上手术探查及术中EMG检查，11例未手术患者经临床随访，将手术探察所见、EMG及随访结果与MRI结果比较，探讨臂丛神经损伤的MRI表现及分型。结果47例节前患者计入统计的196对受损神经中MRI共检出176对，诊断的准确度、敏感度及特异度分别为89.1％、89.8％、84.8％。臂丛神经节前损伤的直接征象包括：(1)椎管内神经根消失或离断161对(82.1％)，(2)脊神经前后根增粗、迂曲、走行僵硬无法连续追踪至椎间孔处20对(10.2％)；间接征象包括：(1)椎管内脑脊液囊性聚集，假性脊膜膨出96对(49.0％)，(2)神经根袖形态异常54对(27.6％)，(3)脊髓变形、移位，79节段(40.3％)(4)椎间孔区纤维疤痕形成11对(5.6％)，(5)脊髓信号异常5例(10.6％)(6)脊柱旁肌信号异常42例(89.4％)。MRI臂丛神经节后损伤的表现包括：(1)神经走行自然，结构及信号与正常侧一致，2例。(2)神经连续、走行自然、增粗，STIR上信号增高，17例(3)神经连续、走行僵硬、增粗、结构紊乱，STIR上呈中等稍高信号，19例(4)神经连续性消失、中断，断端分离，2例(5)神经断裂，断端见假性神经瘤形成，T1WI等信号，STIR等稍高混杂信号，2例(6)神经连续、轻度增粗、STIR上信号增高，并见腋动脉起始处假性动脉瘤压迫臂丛神经1例。臂丛神经损伤MRI表现分为六型：正常表现型(A)、神经变性水肿型(B)、神经疤痕纤维化型(C)、神经断裂型(D)、神经根性撕脱伤(E)、混合型(F)。结论MRI可很好的显示椎管内外臂丛神经结构，对臂丛神经损伤可做出准确的定性及定位诊断，为早期、准确地诊断臂丛神经损伤提供可靠参考，有利于外科医生手术方案的制定和改善患者的预后。第三部分：臂丛神经损伤后失神经支配肌肉MRI表现及半定量研究目的探讨臂丛神经损伤后完全性失神经支配肌肉不同时期MRI表现、ADC值及萎缩程度的变化。材料和方法对臂丛神经损伤致冈下肌完全失神经支配的31例患者行MRI扫描。所有患者均行常规扫描序列扫描，包括：横断面T1WI，T2WI及STIR。对8例急性／亚急性期患者加扫横断面EPI-DWI。所有MRI检查均在肌电图检查及手术前进行。使用随机附带软件测量ADC值，测量两侧冈下肌的面积，计算S患／S健及ADC患／ADC健，．统计患侧与对侧肌肉ADC的差异，S患／S健及ADC患／ADC健与臂丛损伤时间的关系。结果臂丛神经损伤后完全性失神经支配肌肉常规MRI表现为：急性期和亚急性期，STIR上呈高信号，T2WI无异常或条片状高信号，T1WI无异常；慢性期，T1WI信号增高伴肌肉体积缩小。S患／S健与肌肉失神经支配时间呈负相关，失神经后2个月内下降较快。肌肉去神经支配后ADC值较对侧升高，且ADC患／ADC健与受损时间呈正相关。结论MRI可清晰显示不同时期臂丛神经损伤后失神经支配肌肉的信号特点；失神经支配肌肉急性期、亚急性期ADC值升高，反应细胞外空间水含量增大；慢性期，通过肌肉面积测量，可监测失神经支配肌肉的萎缩程度。第四部分：常见臂丛神经非损伤性病变的MRI诊断目的：探讨MRI在常见臂丛神经非损伤性病变诊断中的价值。材料和方法：回顾性分析30例累及臂丛神经的非外伤性患者，其中包括神经纤维瘤病累及臂丛神经2例，神经鞘瘤10例，转移瘤侵犯臂丛神经3例，放射性臂丛神经炎3例，MMN累及臂丛神经1例，下干型TOS11例。24例经手术病理证实，2例经组织活检证实，1例转移瘤、2例神经纤维瘤病及1例MMN累及臂丛神经经临床证实。所有患者均行MRI臂丛神经平扫检查，其中8例同时行Gd-DTPA增强检查，1例患者并行CT检查。主要观察病变的MRI特征及与臂丛神经的关系。结果：2例神经纤维瘤病累及臂丛，肿瘤沿臂丛神经走行生长，呈梭形、串珠状，并见累及椎管内臂丛神经根，T1WI呈等稍低信号，T2WI不均匀高信号，增强后不均匀强化。10例神经鞘瘤中2例位于相应椎间孔区，2例贯穿椎管内外生长；6例位于椎管外臂丛神经节后段，表现为偏向神经一侧生长的梭形肿块，边界清晰，T1WI呈低信号或不均匀高信号，T2WI呈不均匀高信号，其中3例可见有囊变，增强后不均匀强化。3例转移瘤中2例表现为臂丛神经周围的多发肿块影，1例表现为肿瘤组织弥漫浸润臂丛神经及周围组织。3例放射性神经炎表现为臂丛神经弥漫性增粗，信号增高，臂丛神经周围结构清晰，无肿块形成。1例MMN累及臂丛神经表现为臂丛神经增粗、信号增高。11例下干型TOS的患者，表现为C8、T1及下干的弓形抬高，神经增粗、信号增高，8例伴锁骨下动脉抬高，1例显示为颈肋末端占位压迫臂丛神经。结论：MRI可清晰显示常见累及臂丛神经的非损伤性病变，准确显示病变位置、累及范围及与邻近组织结构的关系，为临床准确诊断及治疗臂丛神经病变提供可靠信息。更多还原

【Abstract】 Part 1: MR imaging of normal brachial plexus and thescan protocolObjective: To investigate the value of different MRI sequences inmanifesting the structure of normal brachial plexus, and determine the best MRI scanprotocol of brachial plexus. Materials and Methods: A total of 40 brachial plexus (20healthy volunteers) were examined with routine and new MR sequences. The routineMR sequences contain: axial SE T1WI、FSE T2WI、STIR, coronal SE T1WI and FSET2WI,sagittal FSE T2WI.And the new MR sequences contain:3D-FIESTA-c、coronalcontiguous thin slice STIR and 3D-FSPGR.The manifesting of normal brachial plexusin these sequences were observed. Nerve soft tissue contrast-to-noise-ratios (CNRs)and the display scores of brachial plexus were calculated and compared amongcoronal SE T1WI、FSE T2WI and STIR sequences. The comprehensive MRI scanprotocol to illustrate the preganglionic and postganglionic bundles of brachial plexusas well as the surrounding structures was designed. Results: On axial images, thenerve roots of cervical cord from C5 to T1 appeared as linear structure exiting fromthe intervertebral foramen and passing between the anterior and middle scalenemuscles in the sections of intervertebral foramen; in the sections of clavicle, underclavicle and axillary fossa, the divisions, cords and branches surrounded flow void ofthe subclavian artery. On coronal images, the roots appeared as linear structuresexiting from C5-T1 intervertebral foramen and collecting to infraclavicula andaxillary fission sagittal images, it appeared as oven or round structure wrapped by fattissue, in the intervertebral foramina and then surrounding the subclavian and axillaryartery. The brachial plexus was isointense on T1WI and T2WI, hyperintense on STIRimages compared with the signal intensity of normal muscle. CNRs of coronal SET1WI、FSE T2WI and STIR sequences was 2.04±0.97,2.11±1.01,23.68±5.93,respectively. CNRs of STIR was significantly higher than the other two sequences (P=0.000). The display scores of C5、C6 roots and the upper trunk on coronal STIRsequences were significantly higher than the other two sequences. The C7 root、middle and lower trunks、retroclavicular and infraclavicular segments can be continuously displayed on all the three squences..The 3D Fiesta-c images showedhigh contrast among cerebrospinal fluid, nerve roots and bone tissue; the nerve rootsappeared smoothly with low signal intensity and delineated well within the highsignal CSF. The anatomical details could be distinguished well in 3D FSPGR images,although the nerves were not so eye-catching. Conclusions: The brachial plexus MRIscan protocol, containing axial T1WI、T2WI、STIR, sagittal T2WI, 3D-FIESTA-c、coronal contiguous thin slice STIR and 3D-FSPGR,can illustrate well thepreganglionic and postganglionic bundles as well as the surrounding structures. Thiscomprehensive bpMRI protocol can be used as the routine scan modal to brachialplexus plexopathies.Part 2:MR imaging of brachial plexus injury【Abstract】Objective: To evaluate MRI in diagnosing brachial plexus injury.Materials and Methods:70 cases with brachial plexus injury underwent bpMRscanning before operation.MR imaging was obtained by GE Signa EXCITE 1.5 Tscanner.59 patients had carried out exploration of the supraclavicular plexus andelectrophysiology exam. 11 patients who had not surgery were followed-up. The MRIappearances and subtypes of brachial plexus injury were discussed. Results: Amongthe 196 pairs of injured roots,MR imaging detected 176 pairs. The accuracy,sensitivity and specificity of MRI in diagnosing preganglionic brachial plexus injurywere 89.1%、89.8%、84.8%, respectively...The direct signs of brachial plexuspreganglionic injury include:(1)lack or mutilation of nerve root, 161pairs(82.1%),(2)coarsening, bending、coursering stiff and can not be traced to theintervertebral foramen continuously,20 pairs(10.2 %);the indirect signsinclude:(1)cystoid cerebrospinal fluid concentrating in the vertebral canal,posttraumatic spinal meningocele,96 pairs(49.0 %),(2) abnormal shape of nervesleeve, 54 pairs(27.6%),(3)displacement and deformity of spinal cord, 79segments(40.3 %),(4)fibrae scar in intervertebral foramen region,11pairs(5.6 %)(5)abnormal signal in spinal cord,5 patients(10.6%)(6)abnormal signal ofparaspinal muscles,42 patients(89.4%).The signs of brachial plexus postganglionicinjury include: (1)natural courser of the nerve and the same structure and signalintensity with normal side,2 cases,(2)thickening of the nerve ,with continuity and natural courser, and high intensity on STIR, 17 cases(3) thickening of the nerve ,withcontinuity and stiff courser, and little lower signal intensity than the normal nerve onSTIR,19 cases,(4)losing of continuity completely, with isolated broken ends, 2cases(5)traumatic nerofibroma,appeared as isointensity on T1WI、mixture ofiso-and-hyperintensity on STIR,2 cases.(6)little thickening of the nerve ,withcontinuity, and pseudoaneurysm in the beginning of axillary artery compressed thebrachial plexus,1 ease. The MRI appearances of brachial plexus injury contained 6types: normal appearance(A)、neural degeneration and oedema(B)、neural scarificationand fibrosis(C)、neurotmesis(D)、root avulsion(E) and mixed type(F). Conclusion:MRI can distinctly manifest the nerves within and out of the vertebral canal, thus,help making a correct diagnosis in brachial plexus injuries, and making references forearly diagnosis.Part 3.MRI appearance and semi-quantitative researchof complete denervated muscle after brachial plexusinjury【Abstract】Objective: To approach MRI appearance、ADC value、and hypotrophydegree of complete denervated muscle after brachial plexus injury in different times.Materials and Methods:31 patients with complete denervated infraspinous muscleafter brachial plexus injury underwent MRI scan before EMG and operation all thepatients, had taken the routine scan sequences, containing axial T1WI、T2WI andSTIR. The axial EPI-DWI sequence were added to 8 acute/subacute patients. The areaof bilateral infraspinous muscle were measured, and the area ratio between denervatedand normal side were calculated. The ADC values of the muscle were measured bythe Functool software, and the ADC ratio between denervated and normal side werecalculated. The relationship between injury time and area ratio、injury time and ADCratio, and the differences of ADC values between two sides of infraspinatus werestatistical analyzed. Results: The MRI appearance of complete denervatedinfraspinous muscle after brachial plexus injury was: in acute and subacute stage,appearing hyperintensity on STIR, normal or patchy of hyperintensity shadow onT2WI and normal on T1WI;in chronic stage, appearing hyperintensity on T1WI with decreased volume. It was observed that the area ratio between denervated and normalside decayed over time and correlated negatively with time. The area ratio decreasedquickly within two months. There were significant differences in ADC value of themuscle between denervated and normal side (P=0.000). The ADC value of denervatedmuscle were higher than that of normal muscle. The ADC ratio between denervatedand normal side correlated positively with time. Conclusion: The MRI appearance ofcomplete denervated infraspinous muscle after brachial plexus injury have itscharacteristics. In acute and subacute stage, the denervated muscle had elevated ADCvalues. And MRI can be used as a tool of monitoring hypotrophy degree ofdenervated muscle.Part 4: MR imaging of common non-traumatic brachialplexopathies【Abstract】Objective: To establish MRI findings and diagnosis values in commonnon-traumatic brachial plexopathies. Materials and Methods:30 patients withnon-traumatic brachial plexopathies were retrospectively analysised.The patientsgroup contained 2 patients of neurofibromatosis involving brachial plexus,10 patientsof schwannoma,3 patients of metastases involving brachial plexus,3 patients ofradiation plexopathy,1 patient of multifocal motor neuropathy involving brachialplexus, and 11 patients of typical thoracic outlet syndrome.24 cases were proved bypathology after operation.2 cases underwent biopsy.1 case of metastases、2 cases ofneurofibromatosis and 1 cases of multifocal motor neuropathy were proved by clinicalinformations.All the patients had brachial plexus MRI plain scan,8 patients hadenhanced MR scan, and 1 patient also had CT plain scan. Thee MR characteristics ofthe lesions and relationship between them and brachial plexus were focusedobservations. Results: In 2 patients of neurofibromatosis, the tumors appeared asfusiform、bead-like mass, along the courser of brachial plexus, and iso-to littlehypointensity on T1WI、inhomogeneous hyperintensity on T2WI andinhomogeneously enhanced. Also the rootlets in vertebral canal were involved.Among 10 cases of schwannoma,2 cases located in intervertebral foramen region,2cases growed through vertebral canal ,6 cases located outside the spinal canal from the postganglionic part of brachial plexus. The schwannoma displayed as fusiformmass, eccentric to the original never with sharply defined edge, and hypointensity orinhomogeneous hyperintensity on T1WI、inhomogeneous hyperintensity on T2WIwith cystic necrosis in 3 cases, and inhomogeneously enhanced. Two of the 3 cases ofmetastases manifested as multiple masses besides brachial plexus, the other oneappeared as widespread lesion infiltrated brachial plexus and surrounding structures.The 3 cases of radiation plexopathy displayed as diffused thickened nerves, withincreased signal intensity、clear structure surrounding the plexus and no mass can befound. One cases of MMN showed thickened nerves with increased signal intensity. 11cases of typical thoracic outlet syndrome manifested as archformly raised C8、T1 andinferior trumk, with thickened nerves and increased signal intensity, meanwhile 8cases with raised subclavian artery. And one patient of TOS,MRI and CT imagesrevealed a mass in the end of cervical rib and compressed the local brachial plexus.Conclusion: MRI is an excellent tool in the evaluation of non-traumatic brachialplexus pathologies. Imaging helps in the accurate localization、involving scope of theabnormality, and picture the relationship among lesion and the surroundingstructures.bpMRI supplies reliable information for accurate diagnosing and treatingbrachial plexopathies.更多还原