不同MR快扫序列对胰腺肿瘤的诊断价值

目的明确各种MR快扫序列对胰腺肿瘤的诊断价值,确定最佳扫描序列组合.方法对40名临床怀疑胰腺占位患者行MR检查,扫描序列包括:FS FLASH T1WI、TSE T2WI、True-FISPT2WI、MRCP及多时相动态增强3-D FLASH T1WI.测量正常胰腺与病灶的信号强度,计算胰腺-肿瘤的CNR,对各序列图像质量进行评分.最后,将各序列MRI的诊断和评价结果与手术病理相对照.结果胰腺-肿瘤的CNR:多时相动态增强3-D FLASH T1WI中,以胰腺实质期的胰腺-肿瘤CNR最高(9.7),其同期所获得的图像质量也最好(3.54±0.64),均优于平扫各序列(P＜0.05).对胰腺肿瘤的评价:动态增强3-D FLASH T1WI在检出胰腺癌及评价癌肿胰周血管受累、邻近器官受侵及转移灶方面均为最优(P＜0.05);MRCP对胰腺癌导致的胰胆管受侵最敏感,其次是True-FISP T2WI.综合各扫描序列的敏感性和准确性均优于任何单一的平扫、水成像或动态增强扫描序列.结论胰腺肿瘤的MR检查,多种扫描序列各有优缺点,联合应用能发挥最大潜力.理想的检查组合应包括:平扫屏气FS-FLASH T1WI、TSE T2WI、高分辨力的厚层及薄层MRCP、屏气的三维梯度回波序列多时相动态增强扫描.     

不同MR快扫序列对胰腺肿瘤的诊断价值

目的明确各种MR快扫序列对胰腺肿瘤的诊断价值,确定最佳扫描序列组合.方法对40名临床怀疑胰腺占位患者行MR检查,扫描序列包括FS FLASH T1WI、TSE T2WI、True-FISPT2WI、MRCP及多时相动态增强3-D FLASH T1WI.测量正常胰腺与病灶的信号强度,计算胰腺-肿瘤的CNR,对各序列图像质量进行评分.最后,将各序列MRI的诊断和评价结果与手术病理相对照.结果胰腺-肿瘤的CNR多时相动态增强3-D FLASH T1WI中,以胰腺实质期的胰腺-肿瘤CNR最高(9.7),其同期所获得的图像质量也最好(3.54±0.64),均优于平扫各序列(P＜0.05).对胰腺肿瘤的评价动态增强3-D FLASH T1WI在检出胰腺癌及评价癌肿胰周血管受累、邻近器官受侵及转移灶方面均为最优(P＜0.05);MRCP对胰腺癌导致的胰胆管受侵最敏感,其次是True-FISP T2WI.综合各扫描序列的敏感性和准确性均优于任何单一的平扫、水成像或动态增强扫描序列.结论胰腺肿瘤的MR检查,多种扫描序列各有优缺点,联合应用能发挥最大潜力.理想的检查组合应包括平扫屏气FS-FLASH T1WI、TSE T2WI、高分辨力的厚层及薄层MRCP、屏气的三维梯度回波序列多时相动态增强扫描.     

人胰腺癌细胞株PANC1裸鼠原位模型的建立及磁共振监测

目的 建立一种稳定的人胰腺癌裸小鼠原位移植瘤模型,并探讨无创的磁共振(MRI)对其监测的应用价值.方法 人胰腺癌细胞株PANC1体外常规传代后建立裸鼠皮下种植瘤模型,将皮下种植瘤制成细胞悬液,植入20只BALB/C-nn裸鼠的胰腺包膜下构建人胰腺癌原位移植模型;通过MRI检查监测模型的成瘤率、成瘤时间、肿瘤生长速度、肿瘤形态、信号变化等特征,于第7周末取肿瘤组织行病理学检查.结果 接种后15 d,7只(35%)荷瘤鼠在MRI上显示成瘤,至接种后27 d,成瘤率为100%.肿瘤信号与邻近组织相比,90%(18/20)病灶T1WI呈均匀稍低信号,10%(2/20)呈等信号;75%(15/20)在T2WI呈均匀高信号.移植后2、3、4、5、6、7周经MRI测量的移植瘤体积分别为(12.6±2.4)mm3、(94.3±11.2)mm3、(175.9±82.5)mm3、(395.8±126.6)mm3、(1290.2±167.2)mm3、(1583.4±87.4)mm3.病理学检查确诊为胰腺低分化腺癌,并保持原发瘤的生物学特征.结论 人胰腺癌细胞株PANC1移植瘤制成的细胞悬液种植裸小鼠胰腺包膜下制备胰腺癌模型符合人胰腺癌的特征,且易于无创监测,为临床研究提供了一个有效、稳定的体内实验体系.     

MRI在自身免疫性胰腺炎和胰腺癌鉴别诊断中的价值研究

目的探讨MRI在自身免疫性胰腺炎(AIP)和胰腺癌(PC)鉴别诊断中的价值。方法选取2009年1月~2016年12月期间我院收治的23例AIP患者(AIP组),另选取同期69例PC患者(PC组),对比两组MRI特征,包括T1加权成像、T2加权成像、磁共振胰胆管成像(MRCP)、弥散加权成像(DWI)和动态增强扫描,观察病变累及部位、范围、信号及动态强化方式等。结果 AIP组与PC组的MRI征象在病变累及范围、平扫信号价值、动脉期强化特点、胰管改变、假包膜的MRI征象上的差异有统计学意义(P0.05),动脉期"雪花样"不均匀低强化、假包膜是AIP的显著特征。自身免疫性胰腺炎病变累及范围以弥漫性为主,T1WI信号强度以降低为主,T2WI信号强度以升高为主,平扫信号分布多均匀,动脉期无强化,伴不同程度胆管和胰管改变,有假包膜征象。结论AIP和PC在MRI影像征象上有着明显的不同点,MRI多序列联合应用有助于全面反映AIP的病理学和生物学特性,提高临床诊断的准确性。     

胼胝体区脑胶质瘤34例MRI诊断及手术病理对照研究

目的　探讨胼胝体区胶质瘤的MRI表现 ,提高对该类肿瘤的诊断和鉴别诊断能力。方法　对 34例胼胝体区胶质瘤行MR平扫及增强扫描 ,并与手术及病理结果做对照分析。结果　胼胝体胶质瘤表现为胼胝体长T1长T2 异常信号 ,信号强度均匀或不均匀 ,有明显占位效应 ,注射Gd DTPA后增强扫描 ,根据肿瘤病理类型的不同可出现明显强化、轻度强化或不强化。胼胝体区肿瘤侵及双侧或单侧脑叶时 ,可出现“蝴蝶征”或“半蝴蝶征” ,此二种征象是诊断胼胝体区胶质瘤的重要征象。结论　胼胝体区胶质瘤是颅内特殊部位的肿瘤 ,MRI对该类肿瘤的诊断和鉴别诊断具有重要临床价值     

节细胞神经瘤的CT、MRI影像特征分析

目的探讨节细胞神经瘤（GN）的CT、MRI影像学特点。方法回顾性分析14例经手术病理证实的GN患者的CT、MRI影像资料。结果本组中11例行CT扫描,其中7例行增强扫描;6例行MRI平扫及增强扫描。CT平扫9例病灶密度均匀,2例密度欠均匀,3例可见少许小点状钙化灶;增强扫描动脉期1例无明显强化,6例轻度强化,2例静脉期可见渐进性强化。MRI平扫T1WI病灶呈较均匀等或低信号,T2WI呈明显不均匀高信号,3例可见漩涡状征象;增强扫描1例轻度强化,2例无强化,2例明显强化。结论GN的CT影像特点是密度较低的实性肿块,瘤内散在点状及沙粒样钙化,病灶呈渐进性强化;MRI影像学特点是T1WI呈均匀或稍不均匀的等低信号,T2WI呈不均匀的等高信号,还可发现旋涡状征像。     

肝脏神经内分泌癌的CT及MRI特征

目的探讨肝脏神经内分泌癌(HNEC)的CT及MRI特征,以期提高其诊断水平。方法回顾性分析经病理免疫组织化学证实的37例HNEC患者的影像资料,分析其表现特点。结果原发性HNEC常为单发,CT表现肿瘤平扫为低密度或混杂低密度占位,肿瘤合并出血时其内见斑片状稍高密度,增强扫描呈渐进性强化,肿瘤实性部分门脉及平衡期CT值略高于动脉期;磁共振DWI多呈均匀或厚壁样稍高信号,T2WI呈稍高信号,部分病变内见高信号囊变区,T1WI呈稍低信号,部分病变呈稍高信号,增强扫描呈中度均匀强化或边缘强化,部分病变内可见粗大供血动脉,门脉及延迟期呈等或稍低信号,部分病变可见完整或不完整假包膜,肿瘤周围门脉及肝静脉受压移位,但无癌栓形成。转移性HNEC常为多发、体积较大,CT平扫呈稍低或低密度,增强扫描动脉期病变多呈边缘轻中度强化或不均匀强化,门脉及平衡期相对肝实质呈等或稍低密度;磁共振检查DWI多呈环形高信号,T2WI呈稍高信号, T1WI呈稍低信号,大部分病变内见囊变坏死区,增强扫描动脉期不均匀强化或环形强化,门脉及延迟期多数可见偏心靶环征,部分门脉血管内可见癌栓。结论 HNEC可分为原发性和转移性,其影像学表现具有一定的特征性,结合临床资料及免疫组织化学有助于病变的诊断。     

鞍旁海绵状血管瘤的MRI诊断价值

目的分析经手术和病理证实的蝶鞍旁海绵状血管瘤MRI影像表现,探讨其诊断和鉴别诊断。方法 5例均经手术、病理证实,均行MR平扫和增强扫描,4例行MR扩散加权成像(DWI),1例行1HMRS单体素检查。结果蝶鞍旁海绵状血管瘤体积大小不一,可同时伸入到鞍内。MR-T1 WI呈等或稍低于脑灰质信号,T2 WI呈类似脑脊液高信号。增强扫描病变呈非常显著强化,可不均匀。DWI呈等或稍低信号,但表观扩散系数(ADC)值明显高于正常脑实质。1HMRS表现为NAA峰、Cr峰和Cho峰消失,可出现Lip峰。结论蝶鞍旁海绵状血管瘤MRI平扫鉴别诊断困难,信号与脑脊液容易较近,特别小的海绵状血管瘤易漏诊;增强扫描非常显著强化,ADC值明显升高而DWI接近等信号,1HMRS检查无NAA峰、Cr峰和Cho峰,MRI检查可以对蝶鞍旁海绵状血管瘤作出定性、定位诊断。     

MR多参数成像评估慢性胰腺炎临床分级的价值

目的 探讨应用多种MRI技术评估慢性胰腺炎(CP)临床分级的价值.方法 纳入经病理和临床随访证实的65例CP患者,按M-annheim分级分为轻度组(14例)、中度组(37例)和进展组(14例),并以20例健康志愿者作为对照.在上腹部常规T1WI及T2WI抑脂扫描后,进行胰腺MRCP检查及胰腺动态MR检查.测量T1WI、T2WI加权扫描的胰腺实质信号及肝脏信号,获取它们的比值(rT1、rT2),根据MRCP测量主胰管最大直径(MPD),并对胰腺病变进行评估、分类;测量动态MR增强时胰腺实质信号值,并计算强化率;ROC分析MRI表现与CP临床分级的相关性.结果 正常、轻度、中度和进展组rT1分别为0.98±0.27、0.84±0.12、0.81±0.16和0.75±0.24,中度、进展组较正常组明显降低(P<0.01);rT2分别为1.28±0.30、1.46±0.44、1.46±0.55和1.76±0.72,各组间无统计学差异;MPD为(2.0±0.6)mm、(5.4±2.4)mm、(6.5±3.3)mm和(8.1±4.1)mm,各组间差异显著(P值均<0.01).轻度、中度和进展组的剑桥重度分级分别有4例(29%)、33例(90%)和13例(93%),差异显著(P<0.01);胰管结石分别有2例(14%)、11例(30%)和5例(36%),胰腺假性囊肿分别有0例、6例(16%)和3例(21%),胰腺萎缩分别有4例(29%)、22例(60%)和10例(71%),各组间均无统计学差异.正常、轻度、中度和进展组的胰腺动态增强扫描实质期与动脉期胰腺信号强化率比值(P/A)分别为0.88±0.08、1.10±0.08、1.37±0.15和1.48±0.53,各组间差异显著(P<0.05).rT1值、剑桥分级、胰管直径及P/A比值与临床分级均有相关性(r值分别为0.34、0.41、0.62、-0.43).ROC分析显示,MPD>2.5 mm、rT1<0.8、P/A>0.8诊断CP均有较好的敏感性和特异性,三者结合时诊断CP的特异性可提高到95%.结论 应用磁共振的T1WI、MRCP及动态增强检查能准确、良好地评估CP的严重程度,其中MRCP的敏感性及特异性最高,其次是动态增强检查与T1平扫.     

核磁共振成像在非典型脑膜瘤中的诊断价值

目的探讨核磁共振成像(MRI)对非典型脑膜瘤的诊断价值。方法回顾分析绵阳市中心医院2011年1月—2015年1月收治的非典型脑膜瘤患者18例,均行MRI平扫、液体衰减反转恢复序列(Fl AIR)、DWI及增强扫描,对患者的肿瘤位置、大小、形态、瘤周水肿、瘤内囊变坏死及出血、瘤体信号及强化特点进行观察分析。结果所有患者中,肿瘤位于大脑镰旁及矢状窦、大脑凸面10例,鞍旁5例,桥小脑角区3例;类圆形14例,不规则3例,分叶状1例;平扫:T1WI低信号10例,TIWI等信号6例,呈稍高信号2例;T2WI呈稍高信号10例,T2WI呈高信号5例,等高混杂信号3例;增强扫描:不均匀强化11例,中、轻度不均匀强化4例,均匀强化3例;12例可见脑膜尾征。结论非典型脑膜瘤MRI影像学表现不典型,需根据肿瘤部位、信号及强化等特点,提高其诊断准确率。     

原发性肝癌碘油栓塞后磁共振成像表现与病理的对照研究

目的分析原发陆肝癌（HCC）碘油栓塞（TACE）后的磁共振成像（MRI）表现及其病理学基础。方法23例TACE后于术切除的HCC患者，共31个病灶。手术前1周内行MRI检查，包括SE序列T1W1、FSET2W1和FMPSPGR多回合动态增强扫描。术后沿MRI扫描平面作5～10mm层厚肿瘤连续切面和HE染色病理大切片。行MRI影像病理对照研究。结果（1）MRI表现：SE序列上病灶信号多样，且多为不均匀的混杂信号。FMPSPGR平面扫描：3个为不均匀高信号，28个为等低信号。增强早期22个强化，9个无强化。增强晚期6个部分强化。（2）病理结果：2个病灶无明显坏死，6个100％凝固性坏死，其余23个有不同程度坏死。其它病理改变包括肿瘤内坏死伴出血（10个）．纤维间隔形成（5个）、纤维包膜（12个）、炎性细胞浸润（28个）、局限性粘液样变（2个）、玻璃样变（2个）．碘油沉积（6个）。（3）MRI表现与病理对照：T1W1高信号为凝固性坏死伴（或小伴）出血、肿瘤残存；等、低信号为凝固性坏死或肿瘤残存。T2W1高信号为肿瘤残存、凝固性坏死伴出血；等信号为凝固性坏死、少量肿瘤残存、纤维间隔；低信号为凝固性坏死、纤维间隔。增强早期强化为肿瘤残存，无强化为凝固性坏死．出血、纤维间隔或少量肿瘤残仔；增强晚期强化为肿瘤残存、纤维间隔，无强化为肿瘤残存、凝固性坏死、出血。MRI各种信号区均可见炎性细胞浸润。结论（1）由于碘油栓塞后肝癌病灶的不同病理改变导致SE序列上病灶信号多种多样。T2W1低信号有特异性，代表凝固性坏死。（2）多回合动态增强扫描判断肿瘤坏死和残存较SE序列更有优势，增强早期有强化区为肿瘤残存，包膜早期明显强化可提示包膜下残存。（3）MRI能较准确的显示TACE后HCC的肿瘤坏死和残存及评价肝TACE疗效。     

磁共振成像技术识别兔腹主动脉易损斑块的实验研究

目的探讨磁共振成像(MRI)识别动脉粥样斑块性质的价值。方法制作兔腹主动脉易损斑块模型,对兔腹主动脉分别采用MRI扫描,血管内超声(IVUS)检查和病理学检查。结果成功建立兔腹主动脉易损斑块模型。MR图像T_1WI、T_2WI、PDWI序列中易损斑块呈高信号,FSE-PDWZ脂肪抑制信号消失,SE T_1WI增强扫描可见斑块略有强化;稳定斑块的影像学表现为斑块厚度增大,以等信号居多,增强扫描后斑块强化明显;与病理切片结果符合率较高,与IVUS的结果相近。结论MRI可以检测兔腹主动脉粥样斑块并进行定性分析。     

Role and limitation of FMPSPGR dynamic contrast scanning in the follow—up of patients with hepatocellular carcinoma treated by TACE

AIM：To evaluate the role and limitation of fast multiplanar spoiled gradient-recalled(FMPSPGR)MRdynamiccontrast scanning in the follow-up of patients with HCCtreated by transarterial chemoembolization(TACE).METHODS:Twenty-two patients with 24HCClesions confirmed by biopsy or surgical resection underwent MR imaging in 4-9wks after TACEwith a superconducting 1.5TMR scanner,including SE T1WI,T2WIand FMPSPGR dynamic contrast scanning.The signal intensities of all lesions on SET1WI,T2WIand the enhancement patterns on FMPSPGRdynamic contrast scanning were observed,and the comparison was made between MRI findings and pathological results in all the casese.RESULTS:Of the 24lesions,the signal intensities were various on SET1WIand T2WI.OnT1WI,13lesions appeared as hyperintense,4 lesions were isointense and the other 7lesions were hypointensese,Histologically.Hyperintense lesions showed on T1WI were viable tumor or hemorrhage;isointensities were coagulative necrosis or inflammatory infiltration;hypointensities were tumor,liquified necrosis,coagulative necrosis or inflammatory infiltration.OnT2WI,15lesions appeared as hyperintense,3lesions were isointense and the other 6lesions were hypointensese,Hyperintense lesions shower on T2WI were residuals of viable tumor,hemorrhage,liquefied necrosis or inflammatory infiltration;isointense lesions were residuals of viable tumor or inflammatory infiltration;hypointense lesions were coagulative necrosis.On FMPSPGR dynamic contrast scanning,18 of the 24lesions enhanced on early-phase dynamic scanning corresponding to residuals of viable tumor and the other 6lesions had no enhancement at this phase because complete necrosis were seen in the histologic examination.On delayed-phase dynamic scanning,6lesions had permanent enhancement appeared as inhomogeneous hyperintensity and both residuals of viable tumor and inflammatory infiltration were found by histologic examination,18 lesions were hypointense at this phase and 8of them coexisted with peripheral ring-like enhancement of the lesions resulting from viable tumors or inflammatory infiltration.CONCLUSION:FMPSPGR MR dynamic contrast scanning can reflect the pathologic changes of HCCtreated by TACE.Especially.early-phase dynamic scanning can evaluate accurately residuals of viable tumor and necrosis in HCClesions.FMPSPGR dynamic contrast scanning is useful in the follow-up of patients with HCC treated by TACEcombined with SET1WIand T2WI,but is is difficult to differentiate peripheral viable tumors from inflammatory infiltration.     

先天性支气管囊肿CT及MRI诊断价值

目的探讨先天性支气管源性囊肿(bronchogenic cysts, BC)的计算机断层扫描(computerized tomography, CT)及磁共振成像(magnetic resonance imaging, MRI)诊断。 方法回顾性分析经手术病理证实的23例BC患者的CT及MRI表现和临床资料。 结果纵隔内11例，其中前纵隔4例，中纵隔3例，后纵隔4例，均为单发，呈类圆形，边缘光滑，密度均匀；其中一例合并出血和感染，平扫表现为稍高密度影、CT值约为50～60 HU，增强扫描可见轻度强化；其余纵隔型BC均表现为平扫低密度影，CT值约为10～30 HU，增强扫描未见明显强化。肺内10例，均为单发类圆形或椭圆形病灶，其中3例为含气囊腔，7例为囊性低密度影，增强扫描未见明显强化。颅内2例，位于左侧额部，MRI表现为椭圆形T1WI低信号，T2WI高信号影，一例其后份可见片状T1WI、T2WI稍高信号影，增强扫描均未见强化。 结论支气管囊肿的CT及MRI表现有一定的相对特征性，结合临床综合分析可提高诊断正确率。     

DWI序列ADC值联合LAVA在肝脏恶性肿瘤诊断中的应用价值探讨

目的 探讨多b值扩散加权成像（DWI）序列表观扩散系数（ADC）联合肝脏三维容积快速多期动态增强技术（LAVA）在肝脏恶性肿瘤诊断中的应用价值。方法 本研究纳入80例肝脏占位性病变患者（共124个病灶）,其中血管瘤17例（27个病灶）和肝囊肿23例（31个病灶）,肝转移癌14例（23个病灶）和肝细胞癌26例（43个病灶）。进行T1WI和T2WI常规扫描、DWI（b值分别为0、50、100、150、200、250、300、500、750和1000 s/mm²）和LAVA检查。采用不同方法诊断,A法为T1WI和T2WI常规扫描和DWI诊断,B法为T1WI和T2WI常规扫描和LAVA诊断,C法为T1WI和T2WI常规扫描、DWI联合LAVA诊断,比较三种方法的诊断率。结果 31个（72.1%）肝细胞癌病灶表现为“快进快出”式强化,19个（82.6%）转移瘤病灶表现为边缘环形强化,21个（77.8%）血管瘤病灶表现为“填充式”强化,31个囊肿病灶无明显强化;良性肿瘤ADC10b、ADChigh、ADC3b值显著高于恶性肿瘤（P<0.05）,良性肿瘤ADCperf值显著低于恶性肿瘤（P<0.05）;A法、B法和C法对病灶的检出率均为100%,但诊断率存在统计学差异（P<0.05）,C法（92.7%）最高,B法（83.9%）次之,A法（71.8%）最低。结论 ADC10b、ADChigh、ADC3b和ADCperf值对肝脏良恶性病变诊断优势明显,LAVA能够清楚显示肝脏病变不同时期的血供特征, DWI和LAVA技术联合应用可提高肝癌的诊断率。     

Magnetic resonance imaging of haemorrhage within reperfused myocardial infarcts: possible interference with iron oxide-labelled cell tracking?

AIMS: Magnetic resonance imaging (MRI) has been proposed as a tool to track iron oxide-labelled cells within myocardial infarction (MI). However, infarct reperfusion aggravates microvascular obstruction (MO) and causes haemorrhage. We hypothesized that haemorrhagic MI causes magnetic susceptibility-induced signal voids that may interfere with iron oxide-labelled cell detection. METHODS AND RESULTS: Pigs (n = 23) underwent 2 h occlusion of the left circumflex artery. Cine, T2*-weighted, perfusion, and delayed enhancement MRI scans were performed at 1 and 5 weeks, followed by ex vivo high-resolution scanning. At 1 week, MO was observed in 17 out of 21 animals. Signal voids were observed on T2*-weighted scans in five out of eight animals, comprising 24 +/- 22% of the infarct area. A linear correlation was found between area of MO and signal voids (R2 = 0.87; P = 0.002). At 5 weeks, MO was observed in two out of 13 animals. Signal voids were identified in three out of seven animals. Ex vivo scanning showed signal voids on T2*-weighted scanning in all animals because of the presence of haemorrhage, as confirmed by histology. Signal voids interfered with the detection of iron oxide-labelled cells ex vivo (n = 21 injections). CONCLUSION: Haemorrhage in reperfused MI produces MRI signal voids, which may hamper tracking of iron oxide-labelled cells.     

3.0T磁共振三维容积内插屏气检查在小肝癌诊断中的应用

目的 探讨3.0T磁共振(MRI)三维容积内插屏气检查(3D-VIBE)序列动态增强扫描对小肝癌的检出率,并评价其在小肝癌定性诊断中的价值.方法 回顾性分析经临床手术及病理学检查证实的61例小肝癌患者的影像学资料,用3.0T磁共振扫描仪进行平扫及3D-VIBE序列动态增强扫描.分析病灶在3D-VIBE序列动态增强扫描各个时相的信号特点及强化特征,评价各平扫及增强序列对病灶的检出率及定性诊断价值.结果 6l例患者手术共发现66个病灶,49个病灶见假包膜形成.T1加权成像(T1WI)发现病灶43个(65.15%),19个(38.78%)见假包膜.T2加权成像(T2WI)发现病灶53个(80.30%).3D-VIBE序列动态增强扫描共发现65个病灶(98.48%),35个(71.43%)见假包膜.3种不同序列对病灶检出率的差异具有统计学意义(X2=24.197,尸<0.05).平扫(T1WI+T2WI)与3D-VIBE序列动态增强扫描对病灶的定性准确率的差异也具有统计学意义(X2=66,P<0.05).结论 3.0T MRI 3D-VIBE序列动态增强扫描的扫描速度快,可清楚显示动脉期、门静脉期及实质期等各个时相的特点,这不仅有利于发现平扫所不能发现的小病灶,而且可以通过绘制时间一信号强度曲线协助诊断.对肝癌癌灶的检出及鉴别诊断具有重要价值.     

Characterization of focal hepatic lesions with SPIO—enhanced MRI

AIM: To evaluate the value of superparamagnetic iron oxide (SPIO) enhanced MRI in characterizing focal hepatic lesions. METHODS: Forty-three patients (32 men,11 women, mean age 51 years, age range 25-74 years) with previously identified focal hepatic lesions were enrolled into this study. All the patients underwent plain, Gd-DTPA enhanced MRI and the SPIO enhanced MRI 1-7 d later. The surgico-pathologic diagnosis was aestablished in 31 cases and the diagnosis in other 12 cases was made on the basis of clinical findings and biochemical tests. The signal changes of lesions were analyzed and the CNRs of lesion-to-liver were measured before and after SPIO enhancement. The data were analyzed by paired t test. RESULTS: Focal hepatic lesions included primary hepatocellular carcinoma (HCC,n=22), hemangioma (n=5), cyst (n=4), metastases (n=5), cirrhotic nodule (n=4), focal nodular hyperplasia (FNH, n=5) and other miscellaneous lesions (n=6). After SPIO enhancement HCC demonstrated iso- or slight hyperintensity on T1WI and moderate hyperintersity on T2WI, hemangioma showed moderate hyperintensity on T1WI and obvious hyperintensity on T2WI, the SI of cyst had no change either on T1WI or on T2WI, cirrhotic nodules revealed iso-intensity on T2WI, and the SI of FNH decreased significantly on T2WI. No specific manifestations were found in the other 6 miscellaneous lesions after SPIO enhancement. CONCLUSION: SPIO enhanced-MRI can improve the characterization confidence for diagnosis of focal hepatic lesions.     

慢性胰腺炎的猫模型制作及磁共振影像表现

目的 制备猫慢性胰腺炎(CP)模型,观察其MRI与MRCP的影像学表现.方法 32只猫按数字表法随机分为对照组及制模后3、5、7周组.采用胰管不全结扎法制备CP模型,术后3、5、7周行MRI平扫及MRCP检查,观察胰腺形态,测量胰管直径及感兴趣区(ROI)的T1信号强度值(Tls),计算同层胰腺及肝脏Tls比值.结果 制模的24只猫中存活19只,其中15只形成CP,病理证实轻、中、重度CP分别为7、5、3只,制模成功率为62.5％.在MRI上,猫的正常胰腺显示清晰,T1加权像信号强度高于肝脏,T2加权像信号强度低于肝脏;在MRCP图像上,4只正常猫显示主胰管,胰管最大径(0.79±0.18)mm,并可见胰管及胆总管共同开口于十二指肠降部.正常胰腺及轻、中、重度CP感兴趣区的rTls值分别为1.03±0.06、0.95±0.08、0.90±0.10、0.80±0.11,各CP组与正常对照组间差异均有统计学意义(t=2.18,P＜0.05;t =2.89,P＜0.05;t =4.63,P＜0.01);胰管最大径分别为(0.79±0.18)、(0.95±0.24)、(1.26±0.31)、(2.67±0.71)mm,中、重度CP组与正常对照组间差异均有统计学意义(P＜0.05或＜0.01).结论 胰管不全结扎可制备猫的CP模型.猫的胰腺解剖形态、CP的MRI及MRCP表现与人类相似.