MRI STIR技术在诊断脊柱转移瘤中的应用价值

目的: 探讨STIR技术在MRI诊断脊柱转移瘤中的应用价值.材料和方法: 回顾性对照分析42例脊柱转移瘤之常规T1WI、T2WI及STIR序列的表现.结果: 42例共累及196个椎体.71个椎体T1WI呈低信号,T2WI呈高信号,11个椎体T1WI、T2WI均呈低信号,114个椎体T1WI或T2WI呈混杂信号,病灶STIR序列均呈异常高信号.105个椎体形态无明显改变,91个椎体伴有后缘膨隆或压缩性骨折,11例继发椎管狭窄,14例伴椎旁软组织肿块,STIR序列能清晰显示以上所有异常.结论: STIR序列易于发现脊柱转移灶,可较准确地判断肿瘤的侵袭范围及程度,并有助于转移瘤的鉴别诊断.     

GRE-T2*WI、FSE-T2WI、STIR序列在脊柱转移瘤MRI的应用比较

目的：比较3种MRI扫描序列在脊柱转移瘤的应用,探讨各种方法的序列设计特点、信号特点及适用性。方法：50例证实为脊柱转移瘤的患均进行矢状GRE—T2^*WI、FSE—T2WI、STIR序列扫描,并与矢状T1WI图像对照,比较3种序列对椎体、附件骨质破坏,脊髓受压、受侵,椎间盘、椎旁软组织肿块的显示情况。结果：GRE—T2WI和STIR序列显示脊柱转移瘤椎体、附件骨质破坏较优;FSE—T2WI显示脊髓受压、受侵的情况较优;软组织肿块的显示基本一致。结论：矢状GRE-T2^*WI可作为脊柱转移瘤常规扫描序列的首选,FSE—T2WI如有脊髓受压、受侵时可作为常规扫描序列;STIR是常规扫描的补充。     

磁共振不同序列对颅内海绵状血管瘤的诊断价值

目的 探讨磁共振成像不同序列对颅内海绵状血管瘤诊断的临床应用价值.方法 应用磁共振梯度回波FLASH T2WI及自旋回波序列SE T1 WI、T2 WI对36例颅内海绵状血管瘤病人进行扫描,分析MRI不同扫描序列图像特征.结果 36例病人中SE T1 WI发现海绵状血管瘤病灶31个,SE T2 WI发现病灶36个,FLASH T2 WI发现病灶38个.结论 在显示颅内海绵状血管瘤方面,MR梯度回波FLASH T2 WI较SE序列更为优越.     

不同MR扫描序列在SPIO增强大鼠肝癌模型的对比研究

目的：比较多种扫描序列超顺磁氧化铁（SPIO）增强扫描对显示大鼠肝癌病灶的能力，找出最佳扫描方案。TSE T2WI、SE双回波的T2WI＋PDWI、GRE T1WI、T2^＊WI，分析增强前后大鼠肝癌病灶的强化特征，并进行病理学检查对照分析。结果：注射SPIO对比剂后，所有扫描序列均显示肝脏的信号强度较增强前有不同程度的下降，肝癌病灶CNR均分别高于平扫。增强后GRE T2^＊WI中病灶的CNR明显高于其它序列，但增强后TSE T2WI和常规SE T2WI在显示病变的SNR、CNR方面没有显著性差异。结论：SPIO增强后检测肝癌病灶的各种序列中，以GRE T2^*WI最为敏感，其次是双回波的T2WI＋PDWI序列。     

脊柱转移瘤的MRI诊断

目的探讨MRI对脊柱转移瘤的诊断价值。方法对62例经手术证实的脊柱转移瘤均行平扫和增强扫描，分别采用SE序列T1WI，T2WI及STIR序列。结果62例中，单椎体受累12例，多椎体受累50例。单纯附件受累1例，并椎旁软组织肿块9例，椎管受累11例，合并椎体压缩性骨折7例。结论MRI是脊柱转移瘤的高敏感性检查方法，有助于临床确定治疗方案和评价预后。     

脊柱转移瘤的MR不同序列诊断价值比较

目的 MR脊柱转移瘤不同序列诊断价值进行比较.方法 回顾性分析54例脊柱转移瘤在各序列信号及检出数.结果 54例患者平扫（包括714椎体）及强化扫描16例（包括190个椎体）,①各序列受累椎体数目的计数资料的χ^2检验中,T1 WI与T2 WI、T2 WI与STIR、T：WI与增强扫描的分别配对对比的χ^2检验中,P＜0.01,差异有统计学意义;T1WI与增强扫描、STIR与增强扫描分别配对对比的χ^2检验中,P＞0.05,差异无统计学意义;②T1 WI、T2 WI、STIR信号测量的计量资料统计的t检验中,T2 WI的SD、SCR的P＞0.05,差异无统计学意义.T1 WI、STIR及增强扫描的SD、SCR的P＜0.01,差异有统计学意义.结论 T1WI与STIR是诊断脊柱转移瘤的平扫的黄金序列.     

磁敏感加权成像对颅内多发海绵状血管瘤的诊断价值

目的:探讨磁共振磁敏感加权成像序列(SWI)对脑内多发海绵状血管瘤的诊断价值。方法:前瞻性地采用磁共振SWI序列及快速自旋回波序列TSE-T1WI、T2WI对6例颅内多发海绵状血管瘤患者进行扫描,分析MRI不同扫描序列图像区别。结果:6例患者中TSE T1WI发现海绵状血管瘤病灶23个,TSE T2WI发现病灶92个,SWI发现病灶192个。结论:在显示颅内多发海绵状血管瘤方面,SWI较TSE序列有明显优势,特别是对于小病灶的检出。     

GRE OP和SE T1加权像在腰椎间盘突出症中的检查对比

目的比较梯度回波反相位T1加权(GRE OP T1WI)和自旋回波T1加权(SE T1WI)在腰椎间盘突出症中的应用效果。方法50例腰椎间盘突出症患者进行GRE OP T1WI和SE T1WI扫描。分别观察正常椎体、椎间盘、脑脊液、脊髓、腰椎附件在GREOP T1WI的表现,并对GRE OP T1WI和SE T1WI序列对突出椎间盘的信号和显示的清晰度进行比较。结果GRE OP T1WI所有椎间盘的信号均高于SE T1WI,GRE OP T1WI对椎间盘突出的显示比SE T1WI更清晰。结论GRE OP T1WI比SE T1WI更清晰快速地显示椎间盘突出症。     

FLASH序列T1加权成像在脊柱转移性肿瘤的应用价值

目的　评价FLASH序列T1 WI对脊柱转移性肿瘤的检出能力及其限度。方法　 5 9例病人 (2 79个病灶 )接受脊柱FLASH-T1 WI序列磁共振扫描 ,评价其图像信噪比 (SNR) ,脊椎—肌肉对比噪声比 (S -MCNR) ,病灶对比噪声比 (CNR)及病变检出率 ,并与SE -T1 WI ,TSE -T2 WI作比较。结果　FLASH -T1 WI的SNR低于SE -T1 WI、TSE -T2 WI ,两者Ρ <0 .0 0 1;其病灶CNR明显高于后两者 ,两者Ρ <0 .0 0 1;其S -MCNR高于SE -T1 WI ,Ρ <0 .0 0 1,近似于TSE -T2 WI,Ρ值 >0 .5。FLASH -T1 WI病变检出率 (98.6% )略高于SE -T1 WI(95 .3 % ) ,0 .0 2 5 <Ρ <0 .0 5 ;明显高于TSE -T2 WI(63 .4% ) ,Ρ <0 .0 0 5。椎体内局灶性黄骨髓 ,良性椎体压缩性骨折 ,脊柱结核在FLASH -T1 WI像上均表现为高信号。结论　与SE -T1 WI、TSE -T2 WI作比较 ,FLASH -T1 WI对脊柱转移性肿瘤有较高的病灶对比 ,能提高其检出率。其具有较高的敏感性 ,但特异性差。     

MR各成像序列对脑弥漫性轴索损伤的诊断价值

目的比较MR各序列成像诊断脑弥漫性轴索损伤(DAI)的价值。方法对21例临床诊断DAI的患者行常规自旋回波(SE)T1WI、快速自旋回波(TSE)T2WI、流动衰减反转恢复序列(FLAIR)、扩散加权成像(DWI)和小角度激发快速梯度回波序列(FLASH)扫描,比较各序列脑内病灶的显示率,分析其信号特征。结果FLASH为显示DAI病灶最敏感的序列,能显示常规序列所不能显示的DAI小针尖样大小的出血灶。21例各序列脑内各部位DAI病灶平均检出数依次为:T1WI(0.78±0.58)个、T2WI(1.96±1.30)个、FLAIR(2.98±2.39)个、DWI(3.67±2.75)个、FLASH(6.24±5.46)个。FLASH的DAI病灶检出数最高,与SE T1WI、TSE T2WI的差异有统计学意义(q值分别为3.14、2.47,P值均<0.05)。结论FLASH序列能提高DAI病灶的检出数及早期诊断率,应作为MR诊断DAI的首选序列。     

GRE-T_2''WI、FSE-T_2WI、STIR序列在脊柱转移瘤MRI的应用比较

目的:比较3种MRI扫描序列在脊柱转移瘤的应用,探讨各种方法的序列设计特点、信号特点及适用性。方法:50例证实为脊柱转移瘤的患者均进行矢状GRET2WI、FSET2WI、STIR序列扫描,并与矢状T1WI图像对照,比较3种序列对椎体、附件骨质破坏,脊髓受压、受侵,椎间盘、椎旁软组织肿块的显示情况。结果:GRET2WI和STIR序列显示脊柱转移瘤椎体、附件骨质破坏较优;FSET2WI显示脊髓受压、受侵的情况较优;软组织肿块的显示基本一致。结论:矢状GRET2WI可作为脊柱转移瘤常规扫描序列的首选,FSET2WI如有脊髓受压、受侵时可作为常规扫描序列;STIR是常规扫描的补充。     

The value of T2*-weighted gradient-echo MRI for the diagnosis of cerebral venous sinus thrombosis

ObjectivesThe purpose of this study is to compare the various magnetic resonance imaging (MRI) sequences when they are used to visualize and evaluate cerebral venous thrombosis.MethodsEleven patients with cerebral venous thrombosis were retrospectively analyzed using computed tomography, MRI, magnetic resonance angiography (MRA), and conventional angiography. The MR sequence included T1-weighted spin echo (SE) imaging, obtained before and after administration of contrast medium, T2-weighted turbo spin echo (TSE), fluid-attenuated inversion recovery (FLAIR), T2*-weighted conventional gradient-echo (GRE), as well as three-dimensional (3D) venous time-of-flight MRA and conventional angiography.ResultsIn all of our patients, the venous sinus thromboses were most successfully detected during the T2*-weighted GRE sequence. The thrombosis was well visualized with the T1-weighted SE sequence in three of four patients in whom it was in the subacute stage. The T2*-weighted GRE sequence was superior to the T2-weighted TSE, T1-weighted SE, and FLAIR sequences in all patients. Enhanced 3D MR venography showed the thrombosed segment of the venous sinus and well correlated with the conventional angiographic findings.ConclusionsThe T2*-weighted conventional GRE sequences may be the best method for detecting of cerebral venous thrombosis. Therefore, it would seem to be beneficial to integrate a T2*-weighted conventional GRE sequence into the MR protocol to diagnose cerebral venous thrombosis.     

脊髓梗死的磁共振诊断初探

目的:探讨脊髓梗死的MRI诊断,评价其诊断价值.方法:对临床怀疑脊髓梗死的7例病例进行MRI检查,包括常规矢状位T1WI、T2WI、SPIR和轴位T1WI、T2WI,其中6例病例有增强扫描,5例有扩散加权序列.结果:脊髓梗死诊断7例:颈段3例,胸腰段4例.MR信号强度与发病时间、病程进展有关:发病3天内脊髓略肿胀,T1WI略低信号,T2WI略高信号,扩散为高信号,无明显强化.3～14 d病灶呈T1WI低信号,T2WI高信号,可有不同程度强化,扩散为高信号.2周后扩散为混杂信号.缓解期,病变受损范围可减少1～2个节段.结论:MRI可显示脊髓梗死的病变范围及受累部位,与临床结合,可早期诊断.     

正常青少年膝关节软骨的低场MRI表现

目的：探讨正常青少年膝关节软骨的MRI表现。方法：使用GE 0．2T低场磁共振成像机，采用膝关节线圈，对膝关节行矢状面扫描，应用序列为梯度回波序列T2WI、自旋回波T1WI、自旋回波T2WI、脂肪抑制序列、质子密度序列。翻转角200。扫描野16cm。层厚4mm，间隔1mm。结果：膝关节矢状位MRI梯度回波序列T2WI。和质子密度序列中，股骨髁与胫骨平台的骺软骨MRI能显示出3层不同的信号强度。结论：MRI能准确地显示膝关节软骨的层次结构，为临床诊断膝关节疾病提供参考依据。     

Comparison of different magnetic resonance imaging sequences for assessment of fistula-in-ano

AIM: To assess agreement between different forms of T2 weighted imaging (T2WI), and post-contrast T1WI in the depiction of fistula tracts, inflammation, and internal openings with that of a reference test.METHODS: Thirty-nine consecutive prospective cases were enrolled. The following sequences were used for T2WI: 2D turbo-spin-echo (2D T2 TSE); 3D T2 TSE; short tau inversion recovery (STIR); 2D T2 TSE with fat saturation performed in all patients. T1WI were either a 3D T1-weighted prepared gradient echo sequence with fat saturation or a 2D T1 fat saturation [Spectral presaturation with inversion (SPIR)]. Agreement for each sequence for determination of fistula extension, internal openings, and the presence of active inflammation was assessed separately and blindly against a reference test comprised of follow-up, surgery, endoscopic ultrasound, and assessment by an independent experienced radiologist with access to all images.RESULTS: Fifty-six fistula tracts were found: 2 inter-sphincteric, 13 trans-sphincteric, and 24 with additional tracts. The best T2 weighted sequence for depiction of fistula tracts was 2D T2 TSE (Cohen’s kappa = 1.0), followed by 3D T2 TSE (0.88), T2 with fat saturation (0.54), and STIR (0.19). Internal openings were best seen on 2D T2 TSE (Cohen’s kappa = 0.88), followed by 3D T2 TSE (0.70), T2 with fat saturation (0.54), and STIR (0.31). Detection of inflammation showed Cohen’s kappa of 0.88 with 2D T2 TSE, 0.62 with 3D T2 TSE, 0.63 with STIR, and 0.54 with T2 with fat saturation. STIR, 3D T2 TSE, and T2 with fat saturation did not make any contributions compared to 2D T2 TSE. Post-contrast 3D T1 weighted prepared gradient echo sequence with fat saturation showed better agreement in the depiction of fistulae (Cohen’s kappa = 0.94), finding internal openings (Cohen’s kappa = 0.97), and evaluating inflammation (Cohen’s kappa = 0.94) compared to post-contrast 2D T1 fat saturation or SPIR where the corresponding figures were 0.71, 0.66, and 0.87, respectively. Comparing the best T1 and T2 sequences showed that, for best results, both sequences were necessary.CONCLUSION: 3D T1 weighted sequences were best for the depiction of internal openings and active inflammatory components, while 2D T2 TSE provided the best assessment of fistula extension.     

动态增强容积内插序列在肝脏占位性病变的临床应用价值

目的:评价MRI三维动态增强容积内插序列在肝脏局灶性病变的临床应用价值.方法:91例肝脏占位性病变患者进行常规MR T1WI和T2WI扫描后,采用三维扰相梯度序列行屏气全肝3期动态增强扫描并进行图像重组,观察病灶的增强特点,并对肝动脉的显示程度进行分级.结果:91例中原发性肝癌17例,肝血管瘤24例,肝转移性肿瘤16例,局灶性结节增生2例,肝脓肿11例,肝囊肿21例.肝动脉显示为2级86例94.5%,1级3例3.3%,0级2例2.2%.结论:MR 动态增强容积内插技术可以获得高质量的图像(尤其是动脉期),有利于肝脏局灶性病变的定性、定位诊断和指导临床治疗.     

MRI特异性对比剂铁羧葡胺对肝脏局灶性病变检出的比较研究

目的 通过比较MR平扫、应用对比剂钆喷替酸葡甲胺（Gd—DTPA）增强MRI及MRI特异性对比剂铁羧葡胺增强MRI对肝脏局灶性病变的检出，验证铁羧葡胺在病灶检出方面的优势。方法 2003年12月至2004年7月，选择怀疑为肝脏局灶性病变的病例59例，根据相对金标准判定共133个病灶。所有病例均先行梯度回波（GRE）T1WI、去脂快速自旋回波（FSE）序列T2WI、动态梯度回波Gd—DTPA增强MRI，48h后行铁羧葡胺动态GRE增强扫描及去脂FSE T2WI与GRE TW^＊W延迟扫描。统计各序列对局灶性病变检出的敏感性。结果 铁羧葡胺延迟增强去脂FSE T2W序列、动态GRE增强扫描、GRE T2^＊W延迟增强扫描检出病灶数分别为130、115、127个；平扫GRE T1WI序列、去脂FSE T2WI检出病灶分别为84和106个；Gd—DTPA动态GRE增强检出123个病灶。对于其中44个的微小病灶（〈1cm），铁羧葡胺延迟增强去脂FSE T2WI检出率达到932％（41/44），铁羧葡胺动态增强检出率为727％（32/44），铁羧葡胺延迟增强GRE T2^＊WI检出率为886％（39/44），Gd—DTPA动态增强检出率为795％（35/44），平扫去脂FSE T2WI检出率为545％（24/44），平扫GRE T1WI检出率为34.1％（15/44）。铁羧葡胺延迟增强去脂FSE T2WI及GRE T2WI显著提高了对于微小病灶（〈1cm）的检出率，与平扫MR（包括去脂FSE T2WI和GRE T1WI）及Gd—DTPA动态增强MR相比差异有统计学意义（P〈005）。结论 铁羧葡胺延迟增强去脂FSE T2WI及GRE T2^＊WI序列优势主要为提高肝微小病灶（〈10cm）的检出率。     

Magnetic resonance imaging of the metastatic vertebral tumor

Fourty two patients underwent MR studies for a variety of lesions in the vertebral body. A 0.15-T MR system was employed. Twenty five patients were found to have malignant metastatic lesions (group 1); 16 had non-neoplastic lesions (group 2). The ability to discriminate between group 1 and group 2 with MR imaging was evaluated. All malignant metastatic lesions appeared as low intensity areas on both T1-weighted spin echo image and inversion recovery image, but 44 to 53% of the non-neoplastic lesions appeared as low intensity areas, respectively. The diagnostic ability with signal intensity of the vertebral column was evaluated on various pulse sequences; sensitivity of inversion recovery and T1-weighted spin echo image was 100%, in contrast specificity of these pulse sequences was 47 to 56%, overall accuracy was the highest on T1-weighted spin echo image (86%). The signal intensity of intervertebral disk was also evaluated in both groups. The intervertebral disks adjacent to the all malignant metastatic lesions showed normal intensity on both T1-weighted spin echo image and inversion recovery image, but non-neoplastic lesions showed variable intensities on images with all pulse sequences. The diagnostic ability with the signal intensities of the vertebral column and intervertebral disk was higher than that of the vertebral columns alone. Consequently accuracy was the highest in that case of both intervertebral disk and bone marrow which were imaged on T1-weighted spin echo (93%). We concluded that this diagnostic method was useful in distinguishing malignant metastatic from non-neoplastic lesions.