磁共振增强血管成像对主动脉缩窄术后再狭窄评估

【摘要】目的：使用MRI增强血管成像序列（MRA）对主动脉缩窄（CoA）术后再狭窄患者进行检查,评估主动脉弓形变和血流动力改变的关系。方法：39例CoA术后再狭窄患儿经超声心动图测量主动脉弓跨狭窄处流速（FR）和压差（PG）明确诊断。所有患儿行MRA检查,测量升主动脉、主动脉弓、再狭窄及狭窄后扩张段及降主动脉横膈水平直径,计算升主动脉/降主动脉（A/d）、主动脉弓/降主动脉（Ar/d）、再狭窄/降主动脉（R/d）、狭窄后扩张段/降主动脉（D/d）比值。结果：根据R/d将患儿分为轻、中、重度狭窄3组,三组患儿A/d、Ar/d、D/d、FR及PG值均无统计学差异。R/d与FR、PG存在中等程度负相关（FR：r=-0.34,P=0.04;PG：r=-0.40,P=0.01）。38.46%患儿存在主动脉弓成角畸形,该组患儿D/d明显增高(t=-2.90,P=0.01),Ar/d减低（t=2.90,P=0.01）。35.90%合并主动脉弓发育不良,这组患者FR及PG值偏高（FR：t=-2.03,P=0.05;PG：t=-1.97,P=0.05）。结论：CoA术后再狭窄程度与局部血流动力改变相关,部分患者合并主动脉成角、主动脉发育不良,导致血流动力异常更为明显,需要更紧密的关注。     

健康成年人左心室形态和功能的磁共振成像研究

目的:探讨磁共振成像测量左心室形态及功能的方法和准确性。方法:应用磁共振成像仪对40例健康成年人进行图像扫描及后处理分析,分别用短轴位、长轴位、四腔心位测量左心室室壁和室间隔的厚度、心腔大小,屏气电影法测量计算左心室容积和功能。结果:左心室室壁和室间隔的厚度、心腔大小的测量值、舒张末期容积、收缩末期容积及心肌重量男性均大于女性,差异有显著性意义(P<0.05);但左心室短径的收缩末期径线男女无显著性差异(P>0.05);左心室心肌重量与身高的比值、射血分数与年龄无关;经身高的调整,各测量值仍是男性大于女性(P<0.02);经体表面积的调整,心室容积(包括舒张末期和收缩末期)、心肌重量的测量值男性大于女性(P<0.05),女性左心室心腔大小与体表面积的比值增加,而且舒张末期横径与体表面积的比值女性大于男性(P<0.05)。结论:左心室的室壁厚度、心腔的大小、心室的功能,均与性别、个体大小有关,磁共振成像能准确测量左心室的室壁厚度、心腔的大小,且能计算心室功能,是一种临床实用价值很高的技术。     

容积CT主动脉根部结构及其动态变化的影像学研究

目的应用容积CT全心动周期成像技术探讨正常主动脉根部解剖结构及其动态变化规律。资料与方法 2011年3月至8月间共50名来本院体检的正常成人,行单容积全心动周期CT心脏成像,所得影像资料经多期重组及相应后处理心功能分析软件处理,测量主动脉窦管交界以远2 cm、1 cm处主动脉内径(A2、A1),窦管交界部内径(B),主动脉窦内径(S),主动脉瓣环内径(O),左、右冠状动脉开口至同侧窦底垂直距离(L、R),并分析其在左室收缩末期和舒张末期之间、同期轴位前后径与左右径之间的变化规律,测量左室射血分数(LVEF),左室心肌质量(LV mass)及主动脉瓣开放面积、主动脉瓣环面积等参数。结果 (1)两名测量者对主动脉根部各径线测量结果一致性良好(r=0.765～0.803,P>0.05);(2)主动脉窦管交界以远2 cm处内径(A2)在左室收缩末期和舒张末期间差异有统计学意义(t=3.100、2.622,P<0.05);轴位测量窦管交界水平(S)同期相主动脉前后径(a-p)与左右径(r-l)测量值差异无统计学意义(t=0.418、-0.030,P>0.05);正常左右冠状动脉开口至同侧窦底收缩末期及舒张末期距离分别为(15.36±2.13)mm、(15.46±2.29)mm和(13.31±3.01)mm、(13.64±2.59)mm,且在全心动周期内变化差异无统计学意义(t=-0.274、-1.169,P>0.05);高度差均数为1.827 mm;(3)左室平均射血分数(67.00±4.40)%,平均左心室心肌质量(129.01±28.90)g,平均主动脉瓣口开放面积(323.64±78.94)mm2,平均主动脉瓣环面积(462.09±76.23)mm2,平均主动脉窦面积(916.36±209.93)mm2。结论应用容积CT全心动周期采集模式可以分析主动脉根部细微结构及其动态变化规律,并测量左心室功能,在主动脉根部病变诊治领域有着良好的应用前景。     

电影磁共振成像和超声心动图评价右心室功能的对比研究

目的 :了解BalancedFFE电影磁共振成像进行右心室功能分析的价值和限度。方法 :分别用BalancedFFE电影磁共振和二维超声、实时三维超声心动图对 2 5例健康志愿者进行右心室舒张末期容积、收缩末期容积 ,每搏输出量以及射血分数等功能指标的测定 ,并比较其测量值。结果 :BalancedFFE电影磁共振测量 2 5例健康志愿者右心室舒张末期容积为 (10 1.3 2± 6.77)ml ,收缩末期容积为 (5 4.3 7± 6.41)ml ,每搏输出量 (5 2 .47± 2 .98)ml ,射血分数为 (65 .44± 5 .17) % ,与实时三维超声心动图测量值相关性良好 (r值在 0 .74～ 0 .98)。结论 :BalancedFFE电影磁共振能够准确测量右心室容积变化情况 ,对右心室功能评价具有很高价值。     

心电门控64排CT评价肾下型腹主动脉瘤弹性的初步研究

目的 探讨心电门控技术64排CT评价肾下型腹主动脉瘤主动脉弹性的临床价值.方法 26例受检者分为腹主动脉瘤组13例,正常对照者组13例,均行腹主动脉CTA检查.两组间受检者性别及年龄完全匹配.所有受检者均采用64排螺旋CT、回顾性心电门控技术和分段数据采集方式.获得的原始数据分别在0％～95％R-R间期、间隔5％重组图像,然后在肾动脉水平(renal)和肾动脉下(infrarenal)采用MATLAB图像分割软件,分别测量各重建期相主动脉的横断面积.完成CT扫描后由专人常规测量受检者血压.最后通过公式计算主动脉弹性D值和脉搏波波速(PWV).结果 腹主动脉瘤组Drenal值和Dinfra值分别为(1.21 ±0.40)×10-5Pa-1、(0.68±0.36)×10-5Pa-1,对应的PWV值分别为(9.19±1.59) m/s、(13.37 ±4.84) m/s.正常对照组Drenal值和Dinfra值分别为(1.92±0.27)×10-5Pa-1、(1.24 ±0.37)×10-5pa-1,对应的PWV值分别为(7.07±0.52) m/s和(9.15±2.04) m/s.腹主动脉瘤组及对照组内Drenal值、Dinfra值差异有统计学意义(t值分别为5.668、7.966,P值均＜0.05),其Drenal值均大于Dinfra值.腹主动脉瘤组与对照组间Drenal值比较差异有统计学意义(t值为-5.852,P值＜0.05),两组间Dinfra值的差异亦有统计学意义(t值为-4.417,P值＜0.05),腹主动脉瘤组均小于对照组,D值对应的PWV值比较也有一致的结果.Bland-Altman一致性检验显示心电门控64排CT所测得腹主动脉弹性值观察者间、观察者内相关性良好,一致性较高.结论 心电门控64排CT可以定量评价肾下型腹主动脉瘤的弹性变化.肾下型腹主动脉瘤弹性较正常腹主动脉下降,而且正常瘤体近端主动脉的弹性也下降.     

双向Glenn分流术后上腔静脉-肺动脉吻合口形态和血流的MRI与超声心动图对比测量分析

目的 对比研究MRI与超声心动图(UCG)评估双向Glenn分流术(BGS)后上腔静脉-肺动脉吻合口(腔-肺吻合口)形态和血流的差异.方法 应用3.0T相位对比(PC) -MRI对22例BGS术后患者上、下腔静脉进行血流测量,应用对比增强(CE) -MRI显示腔-肺吻合口及其邻近血管形态,用Report Card软件计算腔-肺吻合口宽度、峰值流速、压差,采用UCG进行对比测量分析.MRI测量上、下腔静脉血流参数,以及MRI和UCG测量腔-肺吻合口宽度、峰值流速和压差值采用配对样本t检验和Pearson相关分析.结果 上腔静脉血流量[(1.002±0.208) L/min]显著低于下腔静脉血流量[(1.794±0.392) L/min](t=- 15.148,P＜0.01),上腔静脉反流分数[(26.54±12.82)％]显著高于下腔静脉反流分数[(17.44±10.17)％](t=11.060,P＜0.01);CE-MRI能清楚显示腔-肺吻合口及其邻近血管狭窄、血栓形成等形态异常改变,UCG未显示上述形态异常改变.MRI测量腔-肺吻合口宽度[(12.46±3.43) mm]显著大于UCG[ (11.04±2.63) mm](t=4.048,P＜0.01),测量峰值流速[ (47.77±10.44) cm/s]显著小于UCG[(52.19±9.63) cm/s](t=-2.237,P＜0.05),测量压差[(0.95±0.42)mm Hg(1 mm Hg =0.133 kPa)]与UCG[( 1.12±0.38) mm Hg]差异无统计学意义(t=-2.010,P＞0.05);二者测量腔-肺吻合口宽度、峰值流速及压差呈显著正相关(r值分别为0.858、0.489、0.427,P值均＜0.05).结论 3.0 T MRI测量腔-肺吻合口宽度、峰值流速及压差与UCG具有较好相关性,但MR1显示腔-肺吻合口宽度及形态异常显著优于UCG.     

心电门控大螺距联合自动管电压选择技术在胸腹主动脉CTA中的应用研究

目的:探讨心电门控大螺距联合自动管电压选择(CARE k V)技术在胸腹主动脉CTA检查中的临床价值。方法:对临床疑似胸腹主动脉病变患者行CTA检查,研究组使用第2代双源CT的心电门控大螺距联合CARE k V技术,对比剂及生理盐水的用量、注射流率根据实际管电压值设定;对照组为同期使用64排CT行CTA检查的患者,对比剂用量(90±5)m L,注射流率5.0 m L/s。辐射剂量统计使用设备自带的数据。扫描图像上传至工作站行血管重建,图像评价由2名主治医师独立完成。结果:2组主动脉根部平均CT值差异无统计学意义(P0.05);2组在CTDIvol、DLP、ED、SNR、图像质量评分差异均有统计学意义(均P0.05)。与对照组比较,研究组接受的辐射剂量显著降低,图像质量评分更高(均P0.05)。研究组对比剂用量(68.81±2.34)m L,对照组为(90±5)m L,研究组用量为对照组的63%~82%,差异有统计学意义(P0.01)。研究组注射流率(4.88±0.23)m L/s,对照组为5 m L/s两者差异有统计学意义(P0.05)。结论:心电门控大螺距联合CARE k V技术在提高胸腹主动脉CTA图像质量的同时,降低了辐射剂量、对比剂用量和注射流率,缩短了扫描时间。     

球囊扩张成形术在小儿食管狭窄中的应用

目的 总结球囊扩张成形术在小儿食管狭窄治疗中的应用,评价其安全性、有效性和影响疗效的因素.方法 回顾性分析30例小儿食管狭窄行球囊扩张成形术的临床资料,其中先天性食管闭锁术后吻合口狭窄20例,先天性食管下段狭窄5例,误服强碱食管腐蚀伤后狭窄5例.按扩张次数将患儿分为3组,A组18例,行1次球囊扩张,均为先天性食管闭锁术后吻合口狭窄患儿;B组7例,行2～3次球囊扩张,主要为先天性食管狭窄和先天性食管闭锁术后吻合口狭窄患儿;C组5例,行4～6次球囊扩张,为食管化学性烧灼伤患儿.扩张前行上消化道造影检查,明确病灶部位及狭窄程度,分别使用不同规格球囊进行扩张;扩张后复查造影进行对照分析了解扩张效果,分析各组间病因、食管狭窄长度和狭窄食管直径对扩张效果的影响.结果 30例患儿共接受62次扩张,平均每例扩张2.1次(1～6次).27例患儿扩张后呕吐症状明显改善,体重明显增加;3例化学性烧灼伤患儿疗效不佳,转而进行手术治疗,全部患儿未发生穿孔、呕血或黑便等并发症.A、B、C3组患儿食管扩张前狭窄段平均直径分别为:4.0 mm(3.0 ～ 5.0),4.3 mm(2.5 ～ 6.0)和4.4 mm(4.0～5.0),平均狭窄段长度分别为(1.18±0.59)cm,(1.53±0.49)cm和(7.50±2.89)cm.3组扩张成功率分别为18/18、7/7和2/5.C组患儿食管狭窄段长度显著大于其他两组,P＜ 0.05.C组患儿扩张有效率显著低于A、B组(P＜ 0.01).结论 球囊扩张成形术治疗小儿食管狭窄操作简便,安全有效,可以有效地解除患儿的食管狭窄症状,是治疗小儿食管狭窄的首选方法.食管闭锁术后吻合口狭窄和先天性食管狭窄患儿扩张有效率高;化学性烧灼伤患儿需要反复多次扩张和再手术.     

Cheatham-Platinum覆膜支架治疗主动脉缩窄11例

目的 探讨Cheatham-Platinum腹膜支架(CCPS)临床治疗主动脉缩窄(CoA)的有效性和安全性.方法 回顾分析采用CCPS支架治疗的11例CoA患者临床资料.结果 11例患者均成功植入CCPS支架1枚,缩窄病变得以明显扩张,缩窄处直径由术前(4.76±0.89) mm扩张至术后即刻(12.86±0.90) mm(t=24.86,P＜0.001),平均跨缩窄收缩压压差由术前(38.55±10.02) mmHg下降至术后即刻(9.82±6.60) mmHg(t=10.8,P＜0.001);术后随访3～79个月,平均(31.91±27.58)个月,患者症状明显缓解,活动耐量明显改善,无内漏、急性主动脉壁损伤、再缩窄或狭窄、穿刺部位血管损伤或死亡.结论 CCPS植入治疗CoA具有良好的近、中期效果,可有效避免主动脉壁损伤等并发症发生.     

3.0T高分辨率MRI综合评估主动脉顺应性和肱动脉内皮功能的可行性研究

目的 探讨3.0T高分辨率MRI综合评估主动脉顺应性和外周肱动脉内皮功能的可行性.方法 选取32名健康志愿者,对每名志愿者在1～2h内重复行2次MR检查,检查项目包括胸主动脉脉搏波传导速度(PWV),升主动脉(AA)、近段胸降主动脉(DA)和远段降主动脉(DDA)的扩张度(AD),以及肱动脉内皮依赖性舒张功能(FMD).PWV扫描应用时间分辨率为4.7～7.8 ms的二维相位对比层间速率编码技术获得数据,利用时间分辨率为18.75 ～ 31.25 ms的MR电影技术评估AD和FMD.对前后2次扫描图像质量行整体评分并对前后一致性行Kappa检验,对于重复扫描所得的2次PWV、AD和FMD结果的可重复性行组内相关系数分析(ICC)分析;利用Bland-Altman plot分析图评价重复检查所得2次结果间的一致性.结果 32名志愿者64次检查均成功完成,每次检查均可在30 min左右完成.前后2次图像整体评分分别为(3.53±0.62)、(3.41±0.67)分,两次结果间一致性良好(Kappa值=0.776,P＜0.05).5个指标前后2次检查可重复性分析结果显示可重复性较高:PWV分别为(4.33 ±0.88)、(4.36±0.88) m/s,AA-AD分别为(8.60±3.11)×10-3、(8.59±3.10)× 10-3/mm Hg(1 mm Hg =0.133 kPa),DA-AD分别为(6.95±2.44)×10-3、(6.95±2.42)×10-3/mm Hg,DDA-AD分别为(10.54±2.91) ×10-3、( 10.55±2.90)×10-3/mm Hg,FMD分别为(24.94±12.55)％、(24.92±12.38)％(ICC值分别为0.95、0.97、0.99、0.98和0.94,P值均＜0.01).2次检查主动脉PWV、AA-AD、DA-AD、DDA-AD、肱动脉FMD的95％一致性限分别为-0.55 ～0.50、-0.11 ～0.12、-0.08 ～0.08、-0.23 ～0.21、-1.46～1.51,最大差值占最小平均值的比例分别为38.53％、9.65％、3.86％、5.68％、42.37％,均＜50％,各数值之间一致性良好.结论 3.0T高分辨MRI可在一次检查中完成主动脉PWV、AD和外周肱动脉FMD的综合功能性评价,且有良好的可重复性,具备临床使用的可行性.     

Analysis of pulse wave velocity in the thoracic aorta by flow-sensitive four-dimensional MRI: reproducibility and correlation with characteristics in patients with aortic atherosclerosis

Purpose:

To measure aortic pulse wave velocity (PWV) using flow‐sensitive four‐dimensional (4D) MRI and to evaluate test–retest reliability, inter‐ and intra‐observer variability in volunteers and correlation with characteristics in patients with aortic atherosclerosis.

Materials and Methods:

Flow‐sensitive 4D MRI was performed in 12 volunteers (24 ± 3 years) and 86 acute stroke patients (68 ± 9 years) with aortic atherosclerosis. Retrospectively positioned 28 ± 4 analysis planes along the entire aorta (inter‐slice‐distance = 10 mm) and frame wise lumen segmentation yielded flow‐time‐curves for each plane. Global aortic PWV was calculated from time‐shifts and distances between the upslope portions of all available flow‐time curves.

Results:

Inter‐ and intra‐observer variability of PWV measurements in volunteers (7% and 8%) was low while test–retest reliability (22%) was moderate. PWV in patients was significantly higher compared with volunteers (5.8 ± 2.9 versus 3.8 ± 0.8 m/s; P = 0.02). Among 17 patient characteristics considered, statistical analysis revealed significant (P < 0.05) but low correlation of PWV with age (r = 0.25), aortic valve insufficiency (r = 0.29), and pulse pressure (r = 0.28). Multivariate modeling indicated that aortic valve insufficiency and elevated pulse pressure were significantly associated with higher PWV (adjusted R² = 0.13).

Conclusion:

Flow‐sensitive 4D MRI allows for estimating aortic PWV with low observer dependence and moderate test–retest reliability. PWV in patients correlated with age, aortic valve insufficiency, and pulse pressure. J. Magn. Reson. Imaging 2012;35:1162‐1168. © 2012 Wiley Periodicals, Inc.     

MRI evaluation of left ventricular hypertrophy in a canine model of aortic stenosis

The progression of ventricular myocardial mass in nine puppies with experimental left ventricular hypertrophy and three controls was observed over a period of 7 months using magnetic resonance imaging (MRI). Left ventricular hypertrophy was created by surgically induced aortic stenosis when the puppies were 1 month old. Quantification of the progression of the left ventricular mass due to aortic stenosis as compared to the controls of similar age was then performed during the subsequent 7 months. Cardiac gated spin-echo technique was used for the imaging of the heart. Novel edge detection techniques were applied for automated identification of the border of the myocardium for measurement. Methods for correction of partial volume effect were applied in the analysis of the data. Clear-cut differences in myocardial mass (P less than .001) and in radius-to-wall thickness ratio (r/h, P less than .02) between puppies with aortic stenosis and controls were observed. The differences in end-diastolic volume between the two groups, however, were significant during the initial phase of hypertrophic compensation (P less than .001) and insignificant (P greater than .05) during the long-term phase of hypertrophic compensation. The results demonstrated that MRI is applicable in serial assessment of myocardial hypertrophy.     

主动脉缩窄及主动脉弓离断的电子束CT诊断

目的：探讨电子束CT诊断先天性主动脉缩窄和主动脉弓离断的价值。材料和方法：共10例病人，年龄6—18岁，均经手术证实。对所有患儿行EBCT增强扫描，并对图像行三维重建。结果：10例病人术前均得到正确诊断，其中8例为主动脉缩窄，2例为主动脉弓离断。EBCT均显示了全部8例主动脉缩窄及其缩窄的程度、形态，并显示缩窄处与左锁骨下动脉的关系。其中6例（75％）为局限性狭窄，2例（25％）形成中-重度长管状狭窄。合并畸形有：3例合并动脉导管未闭，1例合并室间隔缺损，1例合并肺动脉狭窄，1例合并二尖瓣狭窄，2例同时合并动脉导管未闭和室间隔缺损。2例主动脉弓离断病例，均合并有动脉导管未闭、室间隔缺损和肺动脉狭窄。EBCT均显示升主动脉与降主动脉呈分离状。结论：EBCT作为一种无创性检查方法，对先天性主动脉病变的诊断有重要价值，并能同时显示合并的胸部大血管异常。     

静息态下冠状动脉狭窄对左室壁透壁心肌灌注影响的640层CT研究

目的确定静息态下透壁心肌灌注指数(TPR)的正常值,并探讨静息态下不同分支的冠状动脉狭窄与各冠状动脉分支的不同狭窄程度对左室壁不同节段TPR的影响。方法 274例患者行Toshiba 640层CT检查,包括冠状动脉CTA及左心室室壁CT灌注(CTP)检查。根据冠状动脉狭窄程度及17节段进行分组。计算正常组及不同冠状动脉狭窄程度组之间相应节段内TPR是否存在差异,以及冠状动脉狭窄程度与相应节段TPR的相关性。结果前降支及左旋支病变对于左室壁心肌灌注影响较为明显,前降支狭窄主要影响中间段前壁(r=-0.288)、心尖段前壁(r=-0.263)及中间段间隔壁(r=-0.196),左旋支主要影响基底部前侧壁(r=-0.241)、基底部后侧壁(r=-0.279)及心尖段侧壁(r=-0.201),而右冠状动脉病变影响较小,主要影响中间段后壁(r=-0.195);冠状动脉中、重度狭窄组对于左室壁心肌灌注影响程度较大(P<0.05),轻度狭窄影响较小;左室前壁心肌灌注最易受到冠状动脉狭窄影响;在静息状态下前降支供血区域组、左旋支供血区域组及右冠状动脉供血区域组正常心肌和重度狭窄心肌平均TPR值分别为1.14±0.09和1.07±0.13、1.13±0.11和1.06±0.14、1.15±0.14和1.10±0.12。结论不同冠状动脉分支狭窄分别可以影响不同节段的心肌透壁灌注;不同冠状动脉狭窄程度可以不同程度地影响心肌的TPR,二者具有相关性;静息状态下TPR正常值大于负荷状态下TPR。本研究提供了TPR静息态下的正常值。     

MDCT评价冠状动脉狭窄程度与升主动脉弹性的相关性

目的:采用64-MDCT评价冠状动脉狭窄程度与升主动脉弹性的相关性。方法:病变组搜集120例冠状动脉狭窄患者,所有患者同时行64排螺旋CT冠状动脉成像和常规造影,对每支血管病变按狭窄程度分组、评价,并计算Gensini积分。CTA原始数据间隔5%R-R间期在0%～95%R-R间期重组图像,然后在主动脉窦上方约25mm层面采用MATLAB图像分割软件,分别测量各重建期相主动脉的横断面积。受检者完成CT扫描前后由专人常规测量血压。弹性值D[Pa-1]的计算公式为:D=ΔA/(A0.ΔP),ΔA代表管腔最大与最小面积的差值,A0代表心动周期内最小管腔面积,ΔP代表脉压差。选取经CTA证实冠状动脉无狭窄的健康志愿者25例为对照组,在CT检查前后一周内采用M型超声测量升主动脉的直径变化,并将计算的弹性值与CTA测得的弹性值进行比较。结果:64-MDCT与超声测量的主动脉弹性值间有极好的一致性(组内相关系数ICC=0.98,P<0.001)。正常对照组与病变组间弹性D值及PWV差异均有统计学意义(P=0.000)。冠状动脉狭窄的Gensini积分与弹性D值呈显著负相关(r=-0.83,P<0.01),与脉搏波速度(PWV)呈显著正相关(r=0.83、P<0.01)。冠状动脉狭窄程度随主动脉弹性D值的增加而递减,随PWV值的增加而递增。冠状动脉不同狭窄程度组间D值、PWV值、Gensini积分的均值比较,差异均有统计学意义(FD=79.29,FPWV=119.11,FG=128.07,P=0.000)。logistic回归分析显示主动脉弹性D是冠心病的独立影响因子。结论:64-MDCT评价冠状动脉狭窄程度的同时,可以客观评价升主动脉的弹性,升主动脉弹性的定量评价有助于检测亚临床冠状动脉血管病变及预测冠心病。     

脉搏波速度预测冠状动脉疾病发生及其严重程度的价值

 目的 探讨脉搏波速度在冠状动脉疾病患者中临床应用的意义.方法 冠状动脉造影检查发现异常的冠状动脉疾病110例 ,按病变累及支数划分为单支病变组、双支病变组和多支病变组,以健康志愿者为对照组,分别进行PWV检测.结果 冠状动脉造影异常患者脉搏波速度较对照组显著增高, 且随冠脉病变支数增多呈上升趋势.结论 脉搏波速度增高可成为冠状动脉疾病发生及其病变严重程度的预测指标.     

Echocardiographic evaluation of left ventricular diastolic function in patients with aortic valve stenosis

Impairment of left ventricular diastolic function in aortic valve stenosis occurs very early and precedes the impairment of systolic function. Aim was to examine left ventricular diastolic function and its association with severity of myocardial hypertrophy and clinical picture. The paper comprised 78 patients with isolated aortic valve stenosis in whom were performed ultrasonography and catheterization. No significant differences in parameters of diastolic filling were observed in patients with mild hypertrophy and preserved systolic function compared to healthy subjects. In patients with moderate myocardial hypertrophy, left ventricular filling was decreased in an early diastole (Emax 51 +/- 5 cm/s, Evti 6.4 +/- 1.1 cm) and increased in late diastole (Amax 88 +/- 11 cm/s, Avti 11.4 +/- 1.8 cm), while deceleration time was prolonged (DT 171 +/- 32 ms). Pulmonary vein flow was decreased during diastole (Dmax 33 +/- 5 cm/s, Dvti 7.6 +/- 2 cm). Pseudonormalization of flow through mitral valve was observed in patients with pronounced hypertrophy of left ventricular wall (mass > 180 g/m2): increase of the velocity during the phase of fast left ventricular filling (Emax 72 +/- 13 cm/s, Evti 9.8 +/- 2.1 cm), decrease during atrial contraction (Amax 31 +/- 6 cm/s, Avti 3.7 +/- 0.4 cm), reduction in deceleration time (DT 116 +/- 11 ms), while pulmonary vein flow velocity was increased during the early diastole (Dmax 64 +/- 17 cm/s, Dvti 10.7 +/- 2.2 cm). Likewise, significant correlation between clinical picture and type of blood flow through mitral valve was observed.     

In vivo measurement of local aortic pulse‐wave velocity in mice with MR microscopy at 17.6 tesla

Transgenic mouse models of human diseases have gained increasing importance in the pathophysiology of cardiovascular diseases (CVD). As an indirect measure of vascular stiffness, aortic pulse‐wave velocity (PWV) is an important predictor of cardiovascular risk. This study presents an MRI approach that uses a flow area method to estimate local aortic pulse‐wave velocity at different sites in the murine aorta. By simultaneously measuring the cross‐sectional area and the through‐plane velocity with a phase‐contrast CINE method, it was possible to measure average values for the PWV in the ascending and descending aorta within the range of 2.4–4.3 m/s for C57BL/6J mice (ages 2 and 8 months) and apoE‐knockout mice (age 8 months). Statistically significant differences of the mean values of the PWV of both groups could be determined. By repeating CINE measurements with a time delay of 1 ms between two subsequent data sets, an effective temporal resolution of 1000 frames/s (fps) could be achieved. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.     

Cardiac systolic rotation and contraction before and after valve replacement for aortic stenosis: a myocardial tagging study using MR imaging

OBJECTIVE: Aortic stenosis leads to the derangement of cardiac function and contraction mode because of chronic pressure overload that is relieved after surgical valve replacement. The purpose of this study was to determine the changes in left ventricular systolic rotation and contraction using MR tagging in patients with aortic stenosis before and after surgical valve replacement compared with age-matched healthy volunteers. MATERIALS AND METHODS: Twelve patients with aortic stenosis were examined with an electrocardiographically triggered two-dimensional tagging sequence at 1.5 T before and 12 months after surgical valve replacement for the evaluation of wall function of the apical, mid ventricular, and basal levels. Eight healthy volunteers in the same age group served as the control group. RESULTS: Before surgery, all patients showed a significant increase of apical rotation (22.2 degrees +/- 5.9 degrees vs 10.3 degrees +/- 2.5 degrees, p < 0.0001) and overall left ventricular torsion (25.1 degrees +/- 6.6 degrees vs 14.5 degrees +/- 3.7 degrees, p < 0.001); basal rotation was not significantly different (-2.9 degrees +/- 2.1 degrees vs -4.2 degrees +/- 1.9 degrees, p = not significant) compared with the volunteer group. Apical rotation and torsion were negatively correlated with left ventricular mass (r = -0.73, p < 0.01, and r = -0.61, p < 0.05, respectively) and end-diastolic volume (r = -0.73, p < 0.01 and r = -0.64, p < 0.03, respectively). One year after surgery, basal rotation was reduced in the patients with aortic stenosis compared with the patients in the control group (-1.9 degrees +/- 1.8 degrees, p < 0.01). In comparison with preoperative values, apical rotation (14.2 degrees +/- 3.6 degrees, p < 0.01) also decreased but was still elevated, and this resulted in a normalization of left ventricular torsion (16.1 degrees +/- 3.7 degrees, p < 0.01). CONCLUSION: Surgical valve replacement for aortic stenosis leads to normalization of the left ventricular torsion 1 year after surgery. Pressure overload before surgery is associated with an increase of systolic left ventricular wringing motion, possibly serving as a compensatory mechanism. This mechanism declines with increasing left ventricular hypertrophy and dilatation.