0.35T磁共振心脏成像技术及其应用

目的 :探索低场磁共振成像系统心脏成像的可行性、技术和方法。方法 :将高场心脏成像序列和技术进行调整和优化 ,用于 0 .3 5T磁共振成像系统 ,进行心脏结构和功能的显示。结果 :在硬件、软件优化设计的低场磁共振成像系统获得的显示心脏结构和功能的图像 ,可满足临床诊断的需求。结论 :低场磁共振成像系统进行心脏检查 ,包括冠状动脉成像和心肌灌注成像等 ,值得进一步探索和期待。     

内耳迷路造影：磁共振3D快速成像技术及图像分析

随着磁共振技术在临床上的普及应用和内耳疾病在临床治疗上的进步，有关迷路解剖形态及病变的研究，越来越引起人们的注意。磁共振成像具有无辐射、多层面、多序列成像的优点，特别是MR水成像技术，因能直接显示迷路的立体解剖形态。而得到临床医师的青睐。内耳迷路的MRI及3D水成像图像，不仅可用以观察内耳解剖结构及评价内耳发育情况，对各种耳部病变亦有诊断价值。还可用来做电子耳蜗植入前的术前筛查和其它相关的术前评价。     

兔VX2瘤磁共振成像技术的探讨

目的:探讨临床型磁共振成像仪用于动物实验成像扫描参数的优化。材料和方法:利用1.5T磁共振成像仪对不同部位接种的52只兔VX2肿瘤模型进行常规自旋回波(T1WI,T2WI)及梯度回波扫描,并进行Gd-DTPA和铁剂增强扫描,比较各种序列图像质量并比较不同部位肿瘤/组织对比信噪比。结果:T2WI和增强扫描可以提供较好的肿瘤病灶的组织对比显示。结论:选择适当的成像参数可以在临床型磁共振成像仪上获得较好的动物图像。     

低场磁共振在人工耳蜗植入术前评估中的应用初探

目的 探讨低场磁共振在人工耳蜗植入术前评估中的应用价值.资料与方法 使用GE Signa Excite0.35 T永磁磁共振系统对拟行人工耳蜗植入术的24例患儿行常规MRI检查排除脑内病变,内耳三维稳态进动快速成像(3D-FIESTA)扫描,并对原始图像进行后处理,重组为二维或三维图像.结果 14例28耳良好地显示内耳及迷路的形态结构.内耳发育畸形5例7耳,内听道发育畸形3例5耳,大前庭导水管综合征2例3耳,合并脑白质病变3例.结论 低场磁共振能够清晰地显示内耳的解剖结构,在人工耳蜗植入术前评估中具有重要价值,可以帮助临床选择适合的植入耳,减少手术风险.     

探讨MR内耳水成像技术的应用

目的回顾性分析35例怀疑内耳病变患者的内耳MRI水成像特点,探讨磁共振内耳水成像技术的临床应用价值。方法利用西门子公司1.5T超导型扫描机,采用三维快速自旋回波序列(3D-TSE),对35例疑有内耳疾病患者作内耳水成像检查,所有患者均先行常规MR扫描,并行最大信号强度投影MIP及MPR后处理。结果均能满意显示两侧内耳的解剖结构:前庭、耳蜗、半规管、内听道。结论内耳水成像是一种有效且无创的显示双侧内耳膜迷路及内听道精细解剖结构的检查方法,它不仅可以显示内耳膜迷路、内听道的立体解剖结构,而且能够清晰显示其通畅程度,这样就可以帮助临床分析病情,同时为内耳外科手术,尤其是电子耳蜗植入等手术提供重要信息,并在一定程度上可排除一些绝对或相对禁忌症,大大提高手术的准确性。     

3T MRI在内耳诊断中的应用

目的:探讨3T磁共振内耳水成像在内耳病变中的应用价值。方法:分析35例3TMRI内耳水成像影像资料。使用快速三维梯度回波序列(3D-FIESTA),采集内耳所在区域内水信号,送图像工作站进行图像三维重建。结果:3D-FIESTA能满意显示内听道及内耳膜迷路的精细解剖结构,最大强度投影(MIP)重建可获得内耳膜迷路立体图像,多平面容积重建技术(MPVR)能三维立体观察膜迷路结构的解剖关系。结论:MR膜迷路成像可为内耳结构提供可靠的影像学解剖依据,具有一定的临床应用价值。     

血管外质子信号增强颈髓功能成像序列参数优化

目的通过优化成像参数,获得一种较高质量的利用血管外质子信号增强的颈髓功能成像。方法采用GRE-echoplan序列中的一种新的血管外质子信号增强(SEEP)磁共振功能成像技术,按TR、TE时间的相关关系,通过固定TR改变TE,同时通过选择使用呼吸门控或心电门控,是否加饱和带等不同参数下获得颈髓功能成像,比较上述不同参数下颈髓fMRI成像的影像质量,包括信噪比、显示激活区部位是否清晰、确定,是否可重复。结果采用SEEP成像技术能实现颈髓功能成像,TR 1065s与TE 45s时能获得较高质量的颈髓功能成像,使用心电门控较不使用心电门控图像质量明显提高,加前饱和带可减少呼吸与吞咽所致的伪影,呼吸门控对图像质量无明显影响。结论 GRE-echo plan序列的SEEP成像技术经优化技术参数后能获得较高质量的颈髓功能成像。     

3D-SPACE序列在面神经内耳道段成像中的初步研究

目的探讨可变翻转角的三维快速自旋回波序列(3D-SPACE)在面神经内耳道段成像中的应用价值。方法使用1.5T磁共振,对16例志愿者行颅底3D-SPACE横断位扫描,并重建面神经长轴位和斜矢状位图像,观察各方向上面神经的图像质量。结果 16例共32侧面神经内耳道段及其周围血管均清晰显示,显示率100%;面神经及周围血管在图像上显示为低信号,脑脊液显示为高信号,脂肪显示为中等信号。图像锐利,对比良好,空间分辨率高。结论 3D-SPACE序列能清晰显示面神经内耳道段,可作为面神经MRI的常规序列。     

Radial 3D VIBE在儿童自由呼吸下腹部平扫获得T_1WI的临床应用

目的探讨Radial 3D VIBE在儿童自由呼吸下腹部平扫获得T1加权图像的临床应用。方法选取我院2015年1月~2015年8月行腹部磁共振检查患者100例,T1加权图像均采用常规梯度回波序列和Radial 3D VIBE序列分别扫描。结果对两种扫描序列定性分析,结果表明Radial 3D VIBE序列得的信噪比和对比噪声比均显著高于常规序列,图像质量明显提高,能够清晰显示病变部位。与常规序列相比,Radial 3D VIBE序列出现呼吸运动伪影显著低于常规序列,P0.05。结论 Radial 3D VIBE序列可提高磁共振成像分辨率,有效减少呼吸运动伪影,提高图像质量。     

低场强磁共振扫描诊断原发性输尿管癌(附11例报告)

目的:探讨低场磁共振扫描对原发性输尿管癌的诊断价值。方法:常规行肾区SE序列T1WI、T2WI横断面扫描及泌尿系磁共振水成像(MRU),再对病变区域行FSE T2WI薄层横轴位或冠状面扫描及脂肪抑制(STIR)序列扫描。结果:11例MRU均能显示输尿管不同程度梗阻征象,轴位扫描于梗阻部位显示异常软组织信号。结论:应用低场磁共振机行泌尿系水成像加梗阻区域T2WI薄层扫描及脂肪抑制序列扫描对原发性输尿管癌具有较高的术前诊断价值,尤其对IVU检查不显影或不适于行逆行肾盂造影者更显其独特的作用。     

MR三维稳态进动快速成像序列在内耳扫描中的初步应用研究

目的探讨三维稳态进动快速成像（3D—FIESTA）列在内耳及内听道扫描中的技术及临床应用。资料与方法使用GE Signa HD MR1．5T超导磁共振仪，3D-FIESTA序列，对43名健康志愿者及1例单侧先天性耳聋者行内耳扫描，并行最大强度投影（MIP）、多平面重组（MPR）及表面容积重组（VR）后处理。结果44例共88个部位均能良好地显示内耳及内听道的形态结构。结论3D-FIESTA序列对内耳及内听道的结构显示清晰，具有较高的临床应用价值。     

Congenital malformations of the inner ear and the vestibulocochlear nerve in children with sensorineural hearing loss: evaluation with CT and MRI

PURPOSE: The purpose of this work was to study the diagnostic value of CT and MRI in children with sensorineural hearing loss and to analyze anatomic abnormalities of the inner ear and the vestibulocochlear nerve in this patient group. METHOD: We evaluated 42 inner ears in 21 children with congenital deafness who had congenital inner ear malformations and who were candidates for cochlear implants. All patients were studied with high resolution MR and helical CT examinations. The MR study included a T2-weighted 3D fast SE sequence. We describe and tabulate the anatomic abnormalities. Special attention was given to abnormalities of the vestibulocochlear nerve. The field of view in the plane according to the length axis of the internal auditory canal (IAC) was 4 cm. Additional continuous parasagittal reformations perpendicular to the length axis of the IAC were studied with a field of view of 3 cm. RESULTS: CT and MRI allowed accurate identification of malformations of the inner ear in children with congenital deafness. We identified 99 malformations, with a majority of patients demonstrating multiple abnormalities. Common imaging findings were Mondini abnormality and Mondini variants (12/42) and fusion of the lateral or superior semicircular canal with the vestibule (12/42). MRI demonstrated in 9 of 21 patients a rudimentary or absent vestibulocochlear nerve in the auditory canal. CONCLUSION: CT and MRI are important modalities to analyze the inner ear in children who are candidates for cochlear implants. MRI with an extremely small field of view should be used to study possible abnormalities of the vestibulocochlear nerves. This may alter clinical care and allow cochlear implant placement in patients whose electrodiagnostic studies suggest that the implant should not be performed. The detailed analysis of abnormalities of the inner ear might establish prognostic factors.     

Computed tomography and magnetic resonance tomography of the normal temporal bone

The normal anatomy of the temporal bone and the inner ear will be described in detail on high resolution computed tomography (HRCT) and magnetic resonance images. The imaging technique of computer tomography--either single detector or multi detector CT--is normally obtained in an axial plane without the intravenous application of contrast material. The images are reconstructed in a high resolution bone window level setting. The coronal images are reconstructed either if used single detector or multi detector CT. Only in some cases a scan in the coronal plane is directly obtained using a single detector CT. MR imaging of temporal bone is usually performed in a head coil. Axial high resolution 3D-T2-weighted sequences either in fast spin echo technique or gradient echo technique--for example CISS-sequence--are obtained, then an axial high resolution T1-weighted sequence before and after the application of gadopentate dimiglumine is performed. HRCT excellently demonstrates the osseous structures of the temporal bone as well as of the inner ear, while MRI excellently depicts soft tissue structures especially those of the inner ear. Due to the susceptibility artifacts MRI is not very suitable for imaging the external auditory canal or the middle ear or the pneumatic system. In conclusion HRCT is so far excellent to delineate the osseous structures of the temporal bone and inner ear while MRI excellently depicts the soft tissue structures of the inner ear, the internal auditory canal and the cerebellopontine angle. Reissner's membrane, the cochlear duct, and the organ of Corti cannot be visualized even using high-resolution MRI. HRCT and MRI are therefore used as complementary methods for imaging the temporal bone.     

MSCT及MRI在耳部疾病诊断中的临床应用价值

目的:研究多层螺旋CT(MSCT)及磁共振成像(MRI)在耳部疾病诊断中的临床应用价值。方法:对23例(46耳)疑是耳部疾病患者行MSCT及MRI检查,利用图像重建技术对耳系统及其周围的血管、神经进行显示。结果:MSCT技术清楚显示骨迷路及听骨链的细微结构;MRI技术清楚显示膜迷路及内耳周围的血管与神经,并清楚显示各结构之间的关系。在本组病例中,检出听骨链关节融合2例,听骨链炎性溶解、破坏2例,内耳附近血管形态、走行异常1例,耳蜗及半规管发育异常2例;炎症7例;其余未见异常。结论:MSCT与MRI技术能清楚显示耳部超微结构及其周围的血管与神经,MSCT与MRI检查技术对耳部疾病的诊断具有重要临床应用价值。     

先天性感音神经性耳聋患儿的CT病因分析

目的：探讨先天性感音神经性聋儿患者的CT诊断价值及可能的病因分析。方法：收集120例先天性感音神经性耳聋患儿高分辨率CT图像,对内耳结构行MPR重组最佳显示层面,观察其形态结构、大小、位置有无异常。结果：120例患者中有21例（33耳）内耳发育畸形,其中共同腔畸形2例（3耳）,耳蜗发育不全3例（4耳）,耳蜗不完全分隔Ⅱ型9例（17耳）,半规管畸形7例（10耳）。结论：多层螺旋CT能准确显示先天性骨性内耳畸形的部位和程度,为先天性感音神经性聋儿的病因分析及临床制定正确的治疗方案提供重要的参考依据。     

Computed tomography and magnetic resonance imaging of congenital abnormalities of the temporal bone

Congenital abnormalities of the temporal bone are mostly accompanied by conductive or sensori-neural hearing loss. Before any therapeutic procedures are done high resolution CT (HRCT) and magnetic resonance imaging (MRI) should be performed to establish the correct diagnosis and to plan the potentially surgical intervention. HRCT best depicts osseous changes especially those of the external auditory canal and the middle ear containing the ossicles and the osseous structures of the temporal bone and the petrous bone containing the inner ear. MRI excellently shows soft tissue changes of the inner ear especially on the high resolution 3DT2-weighted sequences which give a superb contrast between the nerves and the cerebro-spinal fluid. Malformations of the external auditory canal consists of aplasia or hypoplasia and those of the middle ear range form extreme hypoplasia or aplasia to very mild deformations of the ossicles. Malformations of the inner ear also range form complete aplasia to very mild hypoplasia of the organs of the inner ear as well as malformations concerning the nerves in the internal auditory canal range from aplasia to hypoplasia. Malformations of the temporal bone can either occur isolated or in combination in which malformations of the external and middle ear may be accompanied by those of the inner ear. Furthermore, malformations of the temporal bone may also occur in otofacial, otocervical or otoskeletal syndromes. These syndromes may be accompanied by certain malformations of the temporal bone. HRCT and MRI are both excellent methods to depict congenital abnormalities of the temporal bone and of the inner ear and should be used as complementary methods because HRCT best depicts osseous changes and MRI superbly depicts soft tissue changes. Both methods are important to establish the correct diagnosis to plan the therapeutic procedures.     

MR imaging of the internal auditory canal and inner ear at 3T: comparison between 3D driven equilibrium and 3D balanced fast field echo sequences

OBJECTIVE: To compare the use of 3D driven equilibrium (DRIVE) imaging with 3D balanced fast field echo (bFFE) imaging in the assessment of the anatomic structures of the internal auditory canal (IAC) and inner ear at 3 Tesla (T). MATERIALS AND METHODS: Thirty ears of 15 subjects (7 men and 8 women; age range, 22-71 years; average age, 50 years) without evidence of ear problems were examined on a whole-body 3T MR scanner with both 3D DRIVE and 3D bFFE sequences by using an 8-channel sensitivity encoding (SENSE) head coil. Two neuroradiologists reviewed both MR images with particular attention to the visibility of the anatomic structures, including four branches of the cranial nerves within the IAC, anatomic structures of the cochlea, vestibule, and three semicircular canals. RESULTS: Although both techniques provided images of relatively good quality, the 3D DRIVE sequence was somewhat superior to the 3D bFFE sequence. The discrepancies were more prominent for the basal turn of the cochlea, vestibule, and all semicircular canals, and were thought to be attributed to the presence of greater magnetic susceptibility artifacts inherent to gradient-echo techniques such as bFFE. CONCLUSION: Because of higher image quality and less susceptibility artifacts, we highly recommend the employment of 3D DRIVE imaging as the MR imaging choice for the IAC and inner ear.     

磁共振内耳成像在先天性内耳发育畸形中的诊断应用

目的:探讨磁共振内耳成像在先天性内耳发育畸形中的临床应用价值。方法:18例先天性感音神经性耳聋患者行MRI扫描并进行后处理,主要方法包括多平面重组(MPR)、最大密度投影(MIP)及客积再现技术(VRT)。结果:18例34耳存在内耳畸形。1例2耳Michel畸型;2例3耳共同腔畸形;4例8耳Mondini畸型;8例16耳前庭导水管扩大;3例5耳显示内听道畸形。MRI MPR、MIP及VRT重组图像可以清晰地显示内耳畸形的部位和程度。结论:磁共振内耳成像能清楚、立体显示正常膜迷路和内听道内神经结构,对于内耳畸形的诊断及人工耳蜗植入术前评价有重要价值。