磁共振成像与血管内超声识别兔腹主动脉易损斑块的对比研究

目的:探讨磁共振成像(MRI)和血管内超声(IVUS)识别兔腹主动脉易损斑块(VP)的价值.方法:20只雄性新西兰大白兔给以球囊拉伤腹主动脉加高脂饮食8周,建立兔腹主动脉VP模型.15只兔成功建立VP模型后分别进行MRI扫描和IVUS检查、病理组织学检查.结果:MRI和IVUS识别兔动脉粥样硬化VP的敏感性分别为83.8%和89.2%,特异性为90.6%和90.6%.MRI对VP检测阳性率结果与IVUS比较,差异无统计学意义(χ2＝0.10,P>0.05).结论:MRI与IVUS相似,对识别兔腹主动脉VP有较好的价值.     

核磁共振成像对兔腹主动脉易损斑块的诊断价值

目的探讨核磁共振成像(MRI)对兔腹主动脉易损斑块(VP)的诊断价值。方法 20只雄性新西兰大白兔给以球囊拉伤腹主动脉+高脂饮食8周,建立兔腹主动脉VP模型。15只兔成功建立VP模型后分别进行MRI扫描和病理组织学检查。结果与病理切片相对应的90组MRI图像,发现斑块52处,其中VP36处,纤维性斑块16处;与病理组织学比较,MRI识别兔动脉粥样硬化易损斑块的敏感性和特异性分别为83.8%和90.6%。结论 MRI对识别兔腹主动脉易损斑块有较好的价值。     

血管内超声评价兔腹主动脉易损斑块模型

目的应用血管内超声（IVUS）评价兔腹主动脉易损斑块（VP）模型建立情况。方法10只雄性新西兰大白兔高脂喂养4周后,经球囊扩张损伤腹主动脉,再高脂喂养8周后行IVUS检查。结果IVUS结果显示8只兔子有6只成功建立了vP模型。结论球囊扩张＋高脂饮食方法可成功建立兔腹主动脉vP模型,IVUS是评价斑块情况的简便方法。     

磁共振成像评价兔早期动脉粥样硬化斑块的表现与病理学的相关性

目的探讨磁共振成像(MRI)在识别兔动脉粥样硬化斑块中的诊断价值。方法 16只新西兰白兔,随机设置模型组8只,正常组8只,在建模后1、2、3、4个月分别行高分辨MRI。通过测量腹主动脉管壁厚度和面积、管腔面积、管壁信号增强程度等指标,观察腹主动脉壁的重构过程,并对模型最终的斑块成分进行MRI和组织病理结果对照研究。结果 MRI显示,模型组腹主动脉管壁厚度和面积逐渐增加,且与同期正常组相比差异均有统计学意义(P0.05);模型组腹主动脉管腔进行性扩张,管壁强化程度较对照组增加明显,但演变过程不明显。另外,MRI对兔腹主动脉脂质斑块及纤维斑块的检出率与病理学对比无统计学差异(P0.05)。结论高分辨MRI可以无创性地观察动脉粥样硬化动物模型腹主动脉管壁重构的演变过程,有助于对动脉硬化斑块的预后和药物干预进行探索。     

小鼠腹主动脉斑块模型建立的两种方法及超高场强磁共振成像的应用价值

目的 探讨建立腹主动脉粥样硬化斑块模型的方法及超高场强磁共振成像(MRI)在活体监测及量化小鼠腹主动脉粥样硬化斑块中的应用价值.方法 高脂饮食法小鼠腹主动脉粥样硬化斑块模型的建立及磁共振检测(高脂饮食组):选择3批10～12月龄apoE-/-小鼠13只、WT鼠3只高脂饮食喂养,分别于喂养前、喂养3个月、喂养6个月3个时期进行小鼠腹主动脉7.0 T磁共振活体扫描.血管紧张素Ⅱ(AngⅡ)灌注法小鼠腹主动脉粥样硬化斑块模型的建立及磁共振检测(AngⅡ灌注组):选用10只6月龄apoE-/-小鼠,分为AngⅡ1000 ng·kg-1·min-1组3只、AngⅡ500 ng·kg-1·min-1组3只(以上两组均在背部埋置AngⅡ缓释泵14 d)和对照组为4只(埋置生理盐水缓释泵),分别于灌注前后行磁共振扫描,选用FLASH T1WI黑血及MSME-T2WI-PDWI双回波序列.高脂饮食组依次在各时期扫描后分别处死3、5、5只小鼠,AngⅡ灌注组于装泵后14 d行磁共振扫描,然后处死本组小鼠,取处死小鼠的肾动脉段腹主动脉制作病理切片,进行苏木素-伊红(HE)染色、Masson胶原纤维(CME)染色.每只小鼠选5～7层肾动脉段腹主动脉病理图像及多对比MRI图像,分别测量外腔面积(VOA)、内腔面积(LA),计算管肇面积(VWA)并进行MRI与病理测量结果的相关性分析.结果 两种方法建立的小鼠模型,其腹主动脉MRI与病理切片均可见不稳定斑块形成.高脂饮食组随着高脂饮食时间的延长,斑块进展,VWA不断增加,3个时期VWA方差分析F=29.94(P<0.05),斑块信号于PDWI、T2WI逐渐增加,且不均匀.高脂饮食组MRI测量的斑块面积与病理测量的斑块面积有较高的-致性(高脂喂养前、喂养3和6个月3个时期r值分别为0.84、0.95、0.90).病理切片中斑块成分与磁共振显示信号一致,均表现为脂质成分增加,纤维成分减少.AngⅡ1000 ng·kg-1·min-1组AngⅡ灌注后斑块面积与灌注前比较差异有统计学意义(P=0.017),分别为(2.65±0.48)mm2和(1.21±0.21)mm2,部分小鼠可见夹层动脉瘤形成.AngⅡ500 ng·kg-1·min-1组灌注后斑块面积也比灌注前有所进展,面积分别为(1.01±0.17)mm2和(0.85±0.11)mm2,MRI测量的斑块面积与病理测量的斑块面积有较高的一致性(r值为0.93).结论 AngⅡ灌注显著加快动脉粥样硬化进展并促进腹主动脉夹层动脉瘤形成,长期高脂饮食亦可形成晚期斑块.超高场强MRI多种序列黑血技术的综合应用能显示小鼠腹主动脉粥样硬化斑块的进展,其检测分析斑块大小结果与病理表现基本一致,对斑块成分的判定亦有一定价值.     

磁共振动态增强扫描成像检测动脉粥样硬化斑块的临床应用价值

目的 探讨磁共振动态增强扫描成像(Dynamic Contrast Enhanced MRI,DCE-MRI)对动脉粥样硬化斑块检测临床应用价值.方法 应用DCE-MRI检测兔早期及成熟期动脉粥样硬化斑块,影像表现与HE染色病理切片、CD31免疫组化染色结果对照.结果 DCE-MRI对于早期动脉粥样硬化斑块的检测的准确率为83%,敏感度为76%,明显高于MRI T1WI/T2WI平扫(P＜0.05).MRI动态增强扫描斑块的强化与斑块内CD31表达具有一定的相关性.结论 MRI动态增强扫描可以作为临床早期检测动脉粥样硬化及评价动脉粥样硬化斑块易损性的无创性的影像学检查方法.     

颈动脉粥样硬化患者磁共振成像分析对颈动脉支架置入术的指导价值及与超声的对比

目的探讨颈动脉粥样硬化患者磁共振成像(MRI)分析对颈动脉支架置入术的指导价值及与超声的对比结果。方法回顾性分析72例(142支血管)因颈动脉粥样硬化而接受介入治疗患者术前超声、MRI及数字减影血管造影(DSA)检查结果,比较MRI和超声对颈动脉管腔狭窄的诊断能力。结果 72例颈动脉粥样硬化患者中,有142支颈动脉存在不同程度的狭窄。其中轻度狭窄的血管83支,中度狭窄的血管24支,重度狭窄35支。斑块内脂质成分图像显示:可见大范围的T1WI、T2WI等信号,PDWI等级稍高的信号区,在TOF和MP-RAGE尚未显示异常高信号,增强后无强化。纤维帽图像显示:完整的纤维帽在TOF上表现为光滑的暗带,在CE-T1WI上表现为光滑的弧形高信号。斑块内出血图像显示:T1WI、TOF及MP-RAGE上表现为高信号,其中MP-RAGE更明显。斑块溃疡图像显示:TOF和CE-T1WI上显示纤维帽不连续,明显纤维帽破溃并与管腔相通形成溃疡。斑块钙化:各扫描系列均表现为低信号。MRI与DSA检测结果相比较,MRI的灵敏度为93.33%,特异度为92.68%,kappa值为0.839;超声与DSA检测结果相比较,超声的灵敏度为90.00%,特异度为93.90%,kappa值为0.802;MRI检测颈动脉粥样硬化斑块数明显高于超声检测结果(P0.05)。结论高分辨的MRI相对超声而言,准确识别和量化分析斑块内各种成分,准确评估斑块的稳定性,为支架置入术前判断斑块稳定性及确定手术时机提供参考。     

消瘀片消退兔腹主动脉粥样斑块作用的研究

目的 观察消瘀片对兔腹主动脉粥样斑块的消退作用。方法 采用高脂饮食８ｗ加主动脉内膜剥脱术帛成兔腹主动脉粥样硬化模型,通过血管腔内超声技术、光镜和电镜,检查口服消瘀片１６ｗ后兔腹主动脉粥样斑块的消长变化。结果 血管腔内超声检查显示,粥样硬化组管壁呈弥漫性增厚,腔内有环形或半月状粥样斑块低回声区,用消瘀片治疗后,管壁增厚不明显,仅可见散在或短弧形粥样斑块回声区,粥样斑块厚度和斑块面积与粥样硬化组相比明     

血管内膜表面温度差对识别兔腹主动脉易损斑块的价值

目的 评价血管内膜表面温度差在判定兔腹主动脉易损斑块中的价值.方法 雄性新西兰大白兔20只,给予球囊拉伤腹主动脉加高脂饮食喂养16周,建立兔腹主动脉易损斑块模型.存活的大白兔通过中国斑点蝰蛇毒和组胺触发,诱发斑块破裂以及血栓形成.行兔腹主动脉斑块和周围组织的表面温度差测定.结果 16只实验兔顺利完成模型建立,在这些模型上共发现斑块24处.共进行54次斑块表面温度测量.14只兔有17处光学显微镜下观察切片符合易损斑块的特征,共进行了37次表面温度测量;6只有7处符合纤维性斑块特征,进行了17次表面温度测量;4处为非斑块区,共进行9次测量.易损斑块的表面温度差水平为0.94±0.25℃,而纤维斑块的水平为0.15±0.14℃,非斑块区的水平为0.10±0.08℃.易损斑块的表面温度差较纤维斑块和非斑块区明显增高,有统计学差异(P＜0.01).血管内膜表面温度差大于0.3℃识别兔动脉粥样硬化易损斑块的敏感性和特异性分别为86.5％和85.2％.结论 血管内膜表面温度差的测定有助于识别易损斑块.     

冠状动脉易损斑块评价方法研究进展

冠状动脉粥样硬化是冠心病最主要的病因,易损斑块是冠状动脉粥样硬化的主要表现形式。早期识别冠状动脉易损斑块对于预防急性心血管事件的发生具有重要意义。现就冠状动脉易损斑块评价方法如血管内超声(IVUS)、光学相干断层成像(OCT)、冠状动脉多层CT(MSCT)、MRI、炎症指标等研究进展做一综述。     

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。     

高分辨磁共振成像评价颈动脉粥样硬化斑块成分

目的探讨高分辨MRI不同序列检查评价缺血性脑血管病患者颈动脉粥样硬化斑块成分的临床意义。方法选择64例缺血性脑血管病患者,其中短暂性脑缺血发作(TIA)患者18例,脑梗死患者46例。采用头颈联合线圈,行高分辨MRI检查,先后选用三维时间飞跃法、T_1WI、T_2WI和质子加权成像4种不同序列,分析斑块成分。结果 64例患者中,有完整厚纤维帽25例(39.1%)、完整薄纤维帽20例(31.2%)、破损纤维帽19例(29.7%),脂质池和坏死核心53例(82.8%),斑块内钙化44例(68.8%),斑块内出血31例(48.4%),斑块内纤维化33例(51.6%),脑梗死患者与TIA患者各类斑块成分所占比例比较,差异均无统计学意义(P>0.05)。结论高分辨MRI不同序列检查对颈动脉斑块的检测有助于分析斑块的成分特征,确定斑决的稳定性。     

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.     

超小超顺磁性氧化铁增强磁共振对兔动脉粥样硬化斑块成分的评估

目的:探讨超小超顺磁性氧化铁(USPIO)增强磁共振(MR)评估动脉粥样硬化(AS)斑块成分及易损性的价值。方法:将35只雄性新西兰大白兔随机分为2组,25只给予高脂饮食诱导AS,10只给予正常饮食作为对照组。所有扫描均在1.5TMR扫描仪上进行,采用Cardiac线圈。扫描序列包括:T1WISE,T2WIFSE,T2*WIGRE。所有动物于喂养10周开始扫描,完成平扫、USPIO增强24h扫描,1周后处死不同喂养阶段模型兔及同期对照组动物,每2周重复1次。USPIO使用剂量为0.05mmolFe/kg体重,MR所见与病理相对照。结果:除5只模型兔喂养中途死亡外,其余动物均完成全程扫描。所有模型兔大体标本均肉眼可见AS样改变。MR对10周模型兔病灶检出率40.0%,随病灶发展检出率明显提高。USPIO增强MR能更好识别斑块内各种成分,光镜及电镜检查示斑块内巨噬细胞可吞噬USPIO。结论:MR能动态监测AS病变并检出早期病灶;US-PIO增强MR对识别斑块成分具有独特价值,对判断斑块易损性具有较好价值。     

Detecting and assessing macrophages in vivo to evaluate atherosclerosis noninvasively using molecular MRI

We investigated the ability of targeted immunomicelles to detect and assess macrophages in atherosclerotic plaque using MRI in vivo. There is a large clinical need for a noninvasive tool to assess atherosclerosis from a molecular and cellular standpoint. Macrophages play a central role in atherosclerosis and are associated with plaques vulnerable to rupture. Therefore, macrophage scavenger receptor (MSR) was chosen as a target for molecular MRI. MSR-targeted immunomicelles, micelles, and gadolinium-diethyltriaminepentaacetic acid (DTPA) were tested in ApoE-/- and WT mice by using in vivo MRI. Confocal laser-scanning microscopy colocalization, macrophage immunostaining and MRI correlation, competitive inhibition, and various other analyses were performed. In vivo MRI revealed that at 24 h postinjection, immunomicelles provided a 79% increase in signal intensity of atherosclerotic aortas in ApoE-/- mice compared with only 34% using untargeted micelles and no enhancement using gadolinium-DTPA. Confocal laser-scanning microscopy revealed colocalization between fluorescent immunomicelles and macrophages in plaques. There was a strong correlation between macrophage content in atherosclerotic plaques and the matched in vivo MRI results as measured by the percent normalized enhancement ratio. Monoclonal antibodies to MSR were able to significantly hinder immunomicelles from providing contrast enhancement of atherosclerotic vessels in vivo. Immunomicelles provided excellent validated in vivo enhancement of atherosclerotic plaques. The enhancement seen is related to the macrophage content of the atherosclerotic vessel areas imaged. Immunomicelles may aid in the detection of high macrophage content associated with plaques vulnerable to rupture.     

血管内超声检验兔动脉粥样硬化斑块的研究

目的建立兔动脉粥样硬化模型,通过血管内超声（intravascularultrasound,IVUS）检查粥样硬化斑块．评价IVUS在粥样硬化斑块诊断的临床价值。方法选取20只健康的新西兰大白兔,按简单随机化方法分为两组,每组10只。一组单纯喂养高脂饲料;另一组除喂养高脂饲料外,4周时行腹主动脉内膜损伤术。12周后行IVUS检查,标记斑块远端、近端图像。观察病变处内中膜厚度．并通过病理检查评价IVUS效果。通过病理切片．生物病理图像分析系统处理,分别测量两组兔斑块厚度,并与IVUS结果相比较．同时比较不同方法观察到的斑块性质。结果高脂饲料加内膜损伤组（8只）12周时斑块厚度明显高于纯高脂组（8只）,差异有统计学意义[（521．286±124．732）μm vs.（240．029±73．528）μm,P〈0．05]。IVUS显示所有兔子（16只）的斑块厚度为（412．7±165．8）μm,病理为（360．2±98．1）μm,两者比较差异无统计学意义（P〉0．05）;对于斑块性质的判断,两者比较差异也无统计学意义（P〉0．05）。结论采用动脉内膜损伤加高脂饮食的方式来制作动脉粥样硬化斑块的模型是可行的、实用的。IVUS对血管斑块性质的界定及厚度的测量结果可靠。     

Vasa vasorum imaging: A new window to the clinical detection of vulnerable atherosclerotic plaques

Complications of vulnerable atherosclerotic plaques (rupture, luminal and mural thrombosis, intraplaque hemorrhage, rapid progression to stenosis, spasm, and so forth) lead to heart attacks and strokes. It remains difficult to identify what plaques are vulnerable to these complications. Despite recent developments such as thermography, spectroscopy, and magnetic resonance imaging, none of them is approved for clinical use. Intravascular ultrasound (IVUS), a relatively old yet widely available clinical tool for guiding intracoronary procedures, is increasingly used for characterization of atherosclerotic plaques. However, inability of IVUS in measuring plaque activity limits its value in detection of vulnerable plaques. In this review, we present new information suggesting that microbubble contrast-enhanced IVUS can measure activity and inflammation within atherosclerotic plaques by imaging vasa vasorum density. An increasing body of evidence indicates that vasa vasorum density may be a strong marker for plaque vulnerability. We suggest that a combination of structural assessment (cap thickness, lipid core, calcification, etc) and vasa vasorum density imaging by IVUS can serve as the most powerful clinically available tool for characterization of vulnerable plaques. Due to space limitations, all IVUS images and movies are posted on the website of the Ultimate IVUS Collaborative Project: http://www.ultimateivus.com     

人胰腺癌原位移植模型MRI增强扫描特征及病理对照研究

目的 探讨人胰腺癌原位移植瘤模型的MRI影像学表现及其病理基础.方法 应用3.0T磁共振成像仪及临床型乳腺线圈对30只胰腺癌裸鼠原位模型行冠状位及横断位TSE-T1 WI/T2 WI平扫,经腹腔注射钆喷酸葡胺(Gd-DTPA)行连续动态增强扫描,测量平扫和增强扫描各时相肿瘤信号强度,计算强化率,分析MR图像特征并与病理对照.结果 30只裸鼠荷瘤接种成功率为100%,组织学检查符合胰腺低分化腺癌.与邻近组织信号相比,90%(27/30)肿瘤T1 WI呈均匀稍低信号,10%(3/30)信号欠均匀;80%(24/30)肿瘤T2 WI呈不均匀高信号、内见斑片状更高或等信号区,20%(6/30)呈均匀等高信号.平扫肿瘤信号强度为228.35±11.71,增强扫描后1.5、3、6,9、12 min的肿瘤信号强度分别为258.20±11.17、301.75±17.09、358.65±25.13、480.05±19.01、558.35±40.49,均明显高于平扫(P值均<0.01);各时相强化率分别为0.13±0.04、0.35±0.11、0.56±0.10、1.10±0.10、1.45±0.18,各时相间差异均有统计学意义(P值均<0.01).MR强化明显区为供血丰富的肿瘤生长活跃区域,中央无强化区为坏死组织和(或)肿瘤细胞致密且毛细血管较少区域.结论 经腹腔注射对比剂后可获得清晰的移植瘤MRI图像,与病理检查结果具有很好的一致性.