难治性颞叶癫痫的临床研究:传统MRI及弥散加权成像的应用价值

目的:探讨发作间期传统磁共振成像及弥散加权成像的对颞叶癫痫的定侧价值及其对患者术后疗效的预测能力.方法:27例准备手术的难治性颞叶癫痫患者及19例健康对照者行常规MRI及DWI检查.测量并分析颞叶癫痫患者及对照组双侧海马的ADC值.影像所见与术后切除的脑组织病理结果相对照.结果:颞叶癫痫患者手术侧海马的ADC值显著高于对侧及健康对照者的同侧海马.利用右/左侧海马ADC比值定侧与手术侧一致的患者为21例(77.8%),而常规MRI定侧与手术侧一致的患者为18例(66.7%),两者没有显著的统计学差异(P>0.05).利用右/左侧海马的ADC比值能够定侧与不能定侧的两组癫痫患者术后疗效没有显著性差异(P>0.05).结论:常规MRI是一种术前发现海马硬化的敏感方法.海马右/左侧ADC比值确定颞叶癫痫发作侧的准确性很高,但对患者术后癫痫控制情况的预测能力欠佳.     

常规MRI及MRI肩关节造影在肩袖撕裂中的应用

目的:探讨常规MRI及MRI肩关节造影在肩袖撕裂诊断中的价值。方法:226例肩关节损伤的患者,分别行常规MRI及MRI肩关节造影检查,以近期肩关节镜检查为金标准,对比2种检查方法的敏感性及特异性。结果:常规MRI对肩袖撕裂诊断的敏感性为70.8%(17/24),特异性100%(2/2),准确性65.4%(17/26);MRI肩关节造影对肩袖撕裂的敏感性为95.8%(23/24),特异性100%(2/2),准确性88.5%(23/26)。两者的诊断敏感性差异有统计学意义(P=0.016)。结论:MRI肩关节造影可以显著提高肩袖撕裂诊断的敏感性。     

MRI、MRS联合PSA鉴别前列腺癌和前列腺增生的价值

目的 探讨MRI、磁共振波谱(MRS)联合血清前列腺特异抗原(PSA)诊断前列腺癌(PCa)和良性前列腺增生(BPH)的价值. 资料与方法 经穿刺活检、手术病理或随访证实的31例PCa和41例BPH患者行常规MRI,其中26例行MRS扫描,58例获PSA数据.MRI上观察前列腺的形态、病变位置、信号特点及肿瘤侵犯范围.MRS上测量胆碱+肌酸(Cho+Cre)/枸椽酸盐(Cit)比值(CC/C). 结果 31例PCa,21例位于周围带(PZ),2例位于中央腺体(CG),8例同时累及PZ和CG,T2WI表现为结节状或片状低信号;8例包膜完整,23例突破包膜.41例BPH,39例位于CG,2例位于PZ;T2WI 18例表现为弥漫性混杂信号,23例表现为大小不等的圆形或结节状高信号(17例)或低信号(6例).26例行MRS检查,12例PCa的CC/C比值为2.34±1.21,14例BPH的CC/C比值为0.79±0.25,两组间差异有统计学意义(t=4.327,P＜0.001).58例获得PSA数据,29例PCa的PSA范围为3.22～2262 ng/ml,其中＞10 ng/ml者27例,＜10 ng/ml者2例;29例BPH的PSA范围为1.16～111 ng/ml,其中＞10 ng/ml者14例,＜10 ng/ml者15例.MRI、MRS诊断PCa的敏感性、特异性和准确性均在70%以上,MRI、MRS二者联合其敏感性、特异性、准确性分别为83.3%、92.9%、88.5%,联合PSA后则分别达到100%、92.9%、96.2%. 结论 MRI、MRS 和PSA3种检查方法的联合运用明显提高了鉴别PCa和BPH的诊断准确率.     

磁共振波谱分析在儿童难治性癫痫中的应用价值

目的：评价磁共振波谱分析在儿童难治性癫痫灶诊断中的应用价值。方法：本组35例患儿中男21例、女14例,均行常规脑电图检查及长程视频脑电图监测,其中17例术中行皮层脑电图和深部电极脑电图监测。MRI及MRS检查采用1.5T超导MR扫描仪,先行常规T1WI、T2WI扫描,MRS检查采用多体素波谱采集序列,兴趣区为双侧海马头体部及海马外侧颞叶组织,原始数据经Function Tool软件后处理进行波谱分析。结果：35例中MRS表现无明显异常者6例;双侧海马硬化5例,MRS示双侧海马NAA峰值降低;单侧海马硬化9例,MRS示患侧NAA峰降低;软化灶10例,MRS示局部NAA峰消失;颞叶胶质增生5例,MRS示患侧NAA峰减低,Cr和Cho峰值升高。本组手术治疗17例中MRS定位于左侧海马10例、右侧海马7例,与术中深部电极脑电图监测结果一致。结论：MRS是目前唯一无创性检测活体器官内生化代谢物质的分析方法,不仅能早期诊断海马硬化,而且可进一步提高术前癫痫灶定位的准确性。     

难治性颞叶癫痫的分子影像学研究与病理对照

目的:对照难治性颞叶癫痫(TLE)手术病理资料,探讨联合单光子发射计算机断层(SPECT)和质子磁共振波谱(1 H-MRS)两种分子影像学技术对TLE定位的临床价值。方法:选择29例经手术病理证实的单侧TLE。所有患者术前均行SPECT发作间期脑血流(CBF)灌注显像、常规磁共振(MRI)扫描和1 H-MRS成像。将两种分子影像学技术,发作间期CBF灌注显像和1 H-MRS,对TLE的定位表现与病理结果进行对比分析。结果:病理改变最常见的是海马硬化和皮质发育不良,共27例(93.10%),此两种改变伴随出现于16例中(55.17%)。对于双重病理TLE,MRI、SPECT定位阳性率均为100%(16/16),MRS为87.50%(14/16)。对于单纯性海马硬化,MRI为阴性,SPECT仅为14.29%(1/7),而MRS高达57.14%(4/7)。对于单纯性皮质发育不全,MRS为阴性,MRI为50.00%(2/4),而SPECT高达75.00%(3/4)。联合应用SPECT和MRS对TLE定位率高达86.20%(25/29),尤其是对MRI阴性的患者,两种技术联合能发现54.55%(6/11)TLE的致痫灶。结论:联合SPECT发作间期脑血流灌注显像和1 H-MRS两种分子影像学技术能为难治性TLE提供更为全面和准确的定位诊断信息,可进一步提高定位MRI阴性TLE患者致痫灶的比例。     

膝关节半月板后根部撕裂的MRI评价

目的 探讨MRI对膝关节半月板后根部撕裂的价值.方法 回顾分析经关节镜证实的30例半月板后根部撕裂患者(17例累及内侧半月板,13例累及外侧半月板)的MRI表现,分析MRI对半月板后根部撕裂的诊断敏感度,MRI对内侧、外侧半月板后根部撕裂的检出比例比较采用Fisher确切概率法检验.结果 30例半月板后根部撕裂患者中,MRI正确诊断26例(包括17例内侧半月板后根部撕裂和9例外侧半月板后根部撕裂),诊断敏感度为86.7%(26/30).半月板后根部撕裂的MRI表现主要为后根部形态失常,代之以异常高信号影.MRI对内侧半月板后根部撕裂的检出比例(17/17)明显高于外侧(9/13)(P=0.026).内侧半月板后根部撕裂合并半月板脱位的发生比例(15/17)明显高于外侧(6/13)(P=0.020),但并发前交叉韧带损伤的发生比例(5/17)则明显低于外侧(11/13)(P=0.004).结论 MRI是诊断半月板后根部撕裂及伴发损伤的较好方法.     

氢质子磁共振波谱在海马硬化术前评定中的价值

目的　评价氢质子磁共振波谱 ( 1HMRS)在海马硬化术前评定中的价值。资料与方法　应用 3.0T磁共振扫描仪对 10例手术及病理证实为海马硬化的患者术前分别进行单体素MRS和化学位移成像 (CSI)检查。定量分析单体素MRS的N 乙酰天门冬氨酸 (NAA) / (肌酸 胆碱复合物 ) (Cr Cho)、NAA/Cr、Cho/Cr比值的差异。CSI观察NAA代谢图像上双侧海马信号强度的差别 ,并定量测量NAA值。结果　患侧的NAA/ (Cr Cho)、NAA/Cr比值均低于对侧 (P <0 .0 1,P <0 .0 5 )。以NAA/ (Cr Cho)比值为判定指标 ,8例 ( 8/ 10 )可以正确定侧。代谢浓度图显示患侧NAA的信号强度低于对侧 ,患侧NAA值明显低于对侧 (P <0 .0 1)。结论　MRS能够在体无创定量地反映出海马硬化的生化代谢异常 ,是术前评价海马硬化的一种非常有用的辅助检查方法     

海马硬化MR质子波谱分析与MRI的对比研究

目的　评价MR质子波谱分析 (1HMRS)和MRI对海马硬化的诊断价值。方法　对 8例病理证实的海马硬化病人和 8例健康志愿者分别进行1HMRS和MRI海马体积定量研究。通过计算峰下面积 ,对代谢产物氮 乙酰天门冬氨酸 (NAA)、肌酸 (Cr)及胆碱复合物 (Cho)的浓度进行定量并观察NAA/Cr、NAA/ (Cr Cho)及Cho/Cr各参数的变化 ,同时用右侧海马体积和左侧海马体积差值(DHF)的方法分析形态学的异常。结果　病变组病侧NAA/Cr、NAA/ (Cr Cho)及Cho/Cr值分别为0 5 5、1 77及 1 38,对照组分别为 0 77、1 38及 1 0 6。海马硬化病人NAA/Cr和NAA/ (Cr Cho)值下降 ,统计学上差异有显著性意义 (t值分别为 2 15和 4 83,P值均 <0 0 5 ) ,Cho/Cr值升高 ,统计学上差异有显著性意义 (t值为 2 34 ,P <0 0 5 )。根据NAA/ (Cr Cho)值的不对称降低可对 6例病人进行定侧诊断 ,其中错误 1例 ;根据DHF值的变化可诊断海马萎缩 2例。所有病例均经手术病理证实为海马硬化 ,病变程度与NAA/ (Cr Cho)值的降低相一致。NAA/ (Cr Cho)减低与癫痫发作次数无相关性 (r=- 0 134 ,P >0 0 5 )。结论　1HMRS能够早期发现海马硬化。1HMRS和MRI互相补充有利于海马硬化的术前诊断。     

高分辨MRI对直肠癌T分期和环周切缘的评估

目的 探讨体外相位阵列线圈高分辨MRI对直肠癌术前T分期和环周切缘判定的价值. 资料与方法 原发性直肠癌患者30例和术后离体直肠癌标本10例,全部行体外相位阵列线圈高分辨MRI检查,将影像学所见与手术病理对照观察. 结果 高分辨MRI对直肠癌T分期判定的整体准确度为86.7%(26/30),对T1～2期诊断的敏感度和特异度分别为66.7%(6/9)和95.2%(20/21),对T3期诊断的敏感度和特异度分别为100.0%(15/15)和73.3%(11/15),对T4期诊断的敏感度和特异度分别为83.3%(5/6)和87.5%(21/24).高分辨MRI对环周切缘判定的敏感度为92.3%(12/13),特异度为82.2%(15/17),准确度为90.0%(3/30). 结论 体外相位阵列线圈高分辨MRI技术可较准确地显示直肠癌的T分期,识别癌结节在直肠系膜内的沉积并预测环周切缘的受累与否,有助于术前选择放、化疗和计划手术方案以确保对病灶的完整切除,降低复发率.     

视网膜脱离的MRI诊断价值

目的:探讨视网膜脱离的MRI表现及诊断价值。方法:回顾性分析经手术和临床证实的16例(17只眼)视网膜脱离患者的MRI图像特征。结果:部分性脱离11例(12只眼),完全性脱离5例;脱落部位以累及视乳头双侧者较多见(9/17),发生于单侧者多位于颞侧(6/8);脱落的形态多呈"v"字形(8/17)和月牙形(6/17),其次不规则弧形(3/17);病变信号强度T1WI以等或稍高信号为主(16/17),仅1例呈稍低信号,T2WI信号均高于玻璃体信号;合并玻璃体出血、混浊5例,脉络膜黑色素瘤1例,脉络膜脱离1例。结论:视网膜脱离的MRI表现较具特征性,MRI对视网膜脱离的诊断具有重要价值。     

Functional MRI of the patellofemoral joint: comparison of ultrafast MRI,motion-triggered cine MRI and static MRI

In recent years ultrafast gradient echo sequences have been used in MRI that allow functional MRI studies of the joints during active motion in an acquisition time of seconds. To evaluate the feasibility and usefulness of ultrafast MRI (u), patellar tracking from 30° of flexion to knee extension (0°) was analysed and compared with motion-triggered cine MRI (m) and a static MRI technique (s). The different imaging methods were compared in respect of the patellofemoral relationship, the examination time and image quality. Eight healthy subjects and four patients (in total 18 joints) with patellar subluxation or luxation were examined. Significant differences between the static MRI series without quadriceps contraction and the functional MRI studies (motion-triggered cine MRI and ultrafast MRI) were found for the patellar tilt angle (PTA: P _m/s = 0.01; P _u/s < 0.01). In the dynamic joint studies there was no statistical difference of the regression coefficients between the motion-triggered cine MRI studies and the ultrafast MRI studies (P _m/u = 0.8). The findings of the functional MRI studies compared with the static MRI images were significantly different for the lateralisation of the patella, expressed by the lateral patellar displacement (LPD: P _m/s < 0.01; P _u/s = 0.01) and bisect offset (BSO: P _m/s = 0.01; P _u/s < 0.05). No significant differences in patellar lateralisation were found between motion-triggered cine MRI and ultrafast MRI (LPD: P _m/u = 0.89; BSO: P _m/u = 0.33). Ultrafast MRI was superior to motion-triggered cine MRI in terms of the reduction in imaging time and improvement of the image quality. Correspondence to: C. Muhle     

副脾典型及不典型MRI表现分析

目的探讨副脾典型及不典型MRI表现。方法回顾性分析29例患者共38个副脾的MRI平扫与增强扫描表现。结果副脾常见于脾门区(47.4%),单发多见(86.0%)。平扫36个副脾T1WI(同相位)及T2WI与脾脏相比呈等信号,2个副脾T2WI呈稍高信号。增强扫描动脉期15个副脾均匀强化d=(8.3±1.2)mm,2个副脾呈花斑状不均匀强化(d1=28.2mm,d2=16.4mm)。门静脉期及延迟期强化程度均与脾脏一致。与胰腺实质比较,增强扫描16个副脾各期呈稍高信号,1例50岁男性肝硬化脾功能亢进患者副脾各期强化程度均稍低于胰腺。结论副脾MRI表现通常具有特征性,少数情况下可表现不典型,需要注意鉴别。     

主动脉夹层几种磁共振影像的评价和比较

目的：评价和比较ＭＲＩＳＥ常规序列、电影（ｃｉｎｅ）ＭＲＩ及ＭＲ血管造影（ＭＲＡ）对主动脉夹层的诊断价值。材料和方法：对２５例主动脉夹层进行了３１人次ＭＲ检查。其中包括胸腹主动脉ＳＥ序列３１人次，胸主动脉ｃｉｎｅＭＲＩ２３人次及腹主动脉二维时间飞跃（２ＤＴＯＦ）ＭＲＡ２１人次。将ｃｉｎｅＭＲＩ及ＭＲＡ分别与其相应ＳＥ序列ＭＲ表现进行比较。结果：胸主动脉ｃｉｎｅＭＲＩ２３例与相应ＳＥ序列比较，两者所有病例均显示内膜片及真假两腔，但显示破口分别为１４和９例。显示头臂血管受累分别为７和２条。腹主动脉ＭＲＡ２１例与相应ＳＥ序列比较，两者均显示内膜片和真假两腔，但显示破口或再破口者分别为４和２例，腹主动脉分支血管受累分别为３９和１４条。结论：ＭＲ是诊断主动脉夹层的最佳影像学方法之一。在常规ＳＥ序列基础上，辅以ｃｉｎｅＭＲＩ和ＭＲＡ技术将大大提高ＭＲ总体观察夹层范围、内膜破口以及分支受累的能力，给临床提供更多的信息。     

Assessment of ameloblastomas using MRI and dynamic contrast-enhanced MRI

We retrospectively evaluated magnetic resonance images (MRI) and dynamic contrast-enhanced MRI (DCE-MRI) of ameloblastomas. MRI and DCE-MRI were performed for 10 ameloblastomas. We obtained the following results from the MRI and DCE-MRI. (a) Ameloblastomas can be divided into solid and cystic portions on the basis of MR signal intensities. (b) Ameloblastomas show a predilection for intermediate signal intensity on T1WI, high signal intensity on T2WI, and well enhancement in the solid portion; they also show a homogeneous intermediate signal intensity on T1WI and homogeneous high signal intensity on T2WI, and no enhancement in the cystic portion. (c) The mural nodule or thick wall can be detected in ameloblastomas lesions. (d) CI curves of ameloblastomas show two patterns: the first pattern increases, reaches a plateau at 100-300 s, then sustains the plateau or decreases gradually to 600-900 s, while the other increases relatively rapidly, reaches a plateau at 90-120 s, then decreases relatively rapidly to 300 s, and decreases gradually thereafter. There was no difference in the CI curve patterns among primary and recurrent cases, a case with glandular odontogenic tumor in ameloblastoma or among histopathological types such as plexiform, follicular, mixed, desmoplastic, and unicystic type.     

Ovary: MRI characterisation and O-RADS MRI

Ultrasound has a high specificity for the diagnosis of a benign lesion in cases of classic appearing simple cyst, hemorrhagic cyst, endometrioma and dermoid. However, ultrasound can sometimes be limited for definitive characterisation and risk stratification of other types of lesions, including those with echogenic content that may appear solid, with or without blood flow. Frequently, MRI can be used to further characterise these types of lesions, due to its ability to distinguish solid tissue from non-tissue solid components such as fat, blood, or debris. Incorporating the MR imaging into the evaluation of adnexal lesions can improve diagnostic certainty and guide clinical management potentially avoiding inappropriate surgery for benign lesions and expediting appropriate treatment for malignant lesions, particularly in the females with sonographically indeterminate adnexal lesions.     

MRI of tracheobronchomegaly

Tracheobronchomegaly, a disorder of uncertain etiology, is manifested by the enlargement of the trachea and mainstem bronchi. While the diagnosis may be suggested on chest radiographs, bronchography in the past has been the definitive diagnostic modality. Recently, however, computed tomography has been used to confirm the diagnosis of TBM. We have now demonstrated TBM using MRI, and, in this patient, have shown it to be as good as CT.     

MRI of splenomegaly

Splenomegaly was evaluated by a 0.1 T MR system using multi-echo SE image. (TR = 1500 msec., TE = 40, 80 and 120 msec.) Calculated measurement of T2 relaxation time was obtained. Material consists of 32 cases including 14 liver cirrhosis, 3 chronic myelocytic leukemia, 1 malignant lymphoma and 14 normals. 1) T2 value of normal spleen measured 113.7 +/- 5.68 msec. 2) Splenomegaly due to congestion had the prolonged T2 value of 122.6 +/- 10.25 msec. 3) T2 value of splenomegaly with malignant cell infiltration such as leukemia and lymphoma were shorter than normal spleen. Good histological correlation was obtained in MRI findings of splenomegaly due to congestion and malignant cell infiltration.     

MRI of retinoblastoma

We review the role of MRI in retinoblastoma and simulating lesions. Retinoblastoma is the most common paediatric intra-ocular tumour. It may be endophytic, exophytic or a diffuse infiltrating tumour. MRI can detect intra-ocular, extra-ocular and intracranial extension of the tumour. MRI is essential for monitoring patients after treatment and detection of associated second malignancies. It helps to differentiating the tumour from simulating lesions with leukocoria.     

MRI of atherosclerosis

The emergence of high-resolution, rapid imaging methods has enabled MRI to noninvasively image the fine internal structure of atherosclerotic artery walls. This capability has, in turn, captured the interest of clinicians, who see it as an opportunity to assess disease severity based on the characteristics of atherosclerotic lesions themselves, rather than only their effects on the vessel lumen. MRI of atherosclerosis thus has the potential to be used in medical treatment decisions or to assess the effects of experimental treatment options. Given this potential, a number of research groups have been investigating MRI of atherosclerosis in an effort to establish the ability of MRI to determine atherosclerotic plaque burden, detect plaque composition, and ultimately identify vulnerable plaque before it leads to a clinical event. In this review, the current state of the art is summarized for the three primary vessel targets: the carotid artery, the aorta, and the coronary arteries.