硝酸甘油介入^99mTc—MIBI心肌显像定量测定心肌梗死面积及心肌存活的实验研究

目的为了比较犬心肌梗死(MI)模型的静息心肌显像、潘生丁介入心肌显像、硝酸甘油(NTG)介入心肌显像所测定MI面积及存活心肌与病理性MI面积.方法选择12条杂种犬建立MI模型,给予NTG1.0mg后行心肌显像.次日将犬随机分为两组一组进行常规静息显像,另一组进行潘生丁介入显像,采用靶心图测定MI面积,并与病理性MI面积进行对比研究.结果犬病理性MI面积为(17.80±3.07)%,NTG介入显像、静息显像、潘生丁介入显像测定MI面积分别为(19.98±3.16)%、(25.53±3.91)%、(31.82±2.82)%.其中NTG介入显像测定MI面积与病理性MI面积大小最为接近(P＞0.05),并有很好相关性(r=0.91).静息显像有(21.52±4.8)%、潘生丁显像有(37.80±4.5)%的梗死心肌在使用NTG后得到恢复.结论利用NTG介入显像后可以降低静息显像、潘生丁介入显像所测得的MI面积与实际MI面积的误差,并可提高两者存活心肌的检出率.     

硝酸甘油介入~(99m)Tc-MIBI心肌显像定量测定心肌梗死面积及心肌存活的实验研究

目的　为了比较犬心肌梗死 (MI)模型的静息心肌显像、潘生丁介入心肌显像、硝酸甘油 (NTG)介入心肌显像所测定MI面积及存活心肌与病理性MI面积。方法　选择 12条杂种犬建立MI模型 ,给予NTG1.0mg后行心肌显像。次日将犬随机分为两组 :一组进行常规静息显像 ,另一组进行潘生丁介入显像 ,采用靶心图测定MI面积 ,并与病理性MI面积进行对比研究。结果　犬病理性MI面积为 ( 17.80± 3 .0 7) % ,NTG介入显像、静息显像、潘生丁介入显像测定MI面积分别为 ( 19.98± 3 .16 ) %、( 2 5 .5 3± 3 .91) %、( 31.82± 2 .82 ) %。其中NTG介入显像测定MI面积与病理性MI面积大小最为接近 (P >0 .0 5 ) ,并有很好相关性 (r =0 .91)。静息显像有 ( 2 1.5 2± 4.8) %、潘生丁显像有 ( 37.80± 4.5 ) %的梗死心肌在使用NTG后得到恢复。结论　利用NTG介入显像后可以降低静息显像、潘生丁介入显像所测得的MI面积与实际MI面积的误差 ,并可提高两者存活心肌的检出率。     

硝酸甘油介入99mTc-MIBI心肌显像与病理测定心梗面积的对比研究

目的　观察硝酸甘油介入99mTc MIBI心肌显像测定心肌梗死 (心梗 )面积的应用价值。方法　 12只犬制成心梗动物模型 ,给予 1 0mg硝酸甘油后行心肌显像。次日将动物随机分为两组 ,分别行常规静息显像和潘生丁介入显像。利用计算机测定心梗面积 ,并与动物病理测定的心梗面积进行比较。结果　硝酸甘油介入显像、静息显像和潘生丁介入显像测定的心梗面积均大于病理测定的心梗面积 ,其中硝酸甘油介入显像测定的心梗面积与病理测定的心梗面积最为接近 ,并具有良好的相关性。结论　利用硝酸甘油介入99mTc MIBI心肌显像降低了静息显像、潘生丁介入显像所测定的心梗面积与实际心梗面积的误差 ,可作为临床上估算心梗面积的首选无创性方法     

应用冠脉血流显像技术检测猪心外膜和心肌内冠脉血流特征的实验研究

目的：应用冠脉血流显像技术检测猪的冠脉血流，初步探讨心外膜和心肌内冠脉的时相性灌注特点及其在冠脉扩张状态下的变化。方法：5条实验小型猪，在麻醉状态下应用超声冠脉血流显像技术探测不同节段心外膜冠脉和左室心肌内的冠脉血流信号，记录其血流频谱曲线。观察心外膜及心肌内冠脉的时相灌注特点，测定冠脉血流速度，计算右冠脉和前降支的舒张期／收缩期峰值血流速度比值。观察静脉推注潘生丁（0．56mg/kg）后前降支和心肌内冠脉血流信号及其频谱曲线特点的变化。结果：所有动物均可检测较清晰的心外膜和心肌内冠脉血流信号；心外膜冠脉为全心动周期前向灌注，右 冠脉的收缩期血流速度明显高于前降支；心肌内冠脉的时相灌注特点为收缩期出现低速的逆向血流；静 注潘生丁使心外膜与心肌内冠脉的血流均明显增强，但灌注模式未变。结论：彩色多普勒冠脉血流显像技术为研究冠脉血流的时相性灌注特点提供了很好的无创性检测手段。     

应用冠脉血流显像技术评价高脂血症患者的冠脉血流储备

目的　应用冠脉血流显像技术结合潘生丁药物负荷试验对单纯高脂血症患者的冠脉血流储备（ＣＦＲ） 进行评价,探讨血脂对ＣＦＲ的影响。方法　研究对象分为单纯高脂血症组（Ａ 组,３０ 例） 和正常对照组（Ｂ 组,１５ 例）,应用冠脉血流显像技术检测每位受试者静息时的冠脉血流频谱及静脉推注潘生丁（０－５６ｍｇ／ｋｇ） 后的冠脉血流频谱,分别用最大充血状态下与静息时的冠脉峰值血流速度（ＣＰＶ） 比值及速度时间积分（ＶＴＩ） ×心率（ＨＲ） 比值来计算ＣＦＲ。结果　静息时,两组的ＣＰＶ 及ＶＴＩ×ＨＲ 无明显差别（Ｐ＞ ０－０５）。潘生丁负荷后两组的冠脉血流速度均明显加快,但Ａ组的ＣＰＶ 及ＶＴＩ×ＨＲ 增加程度低于Ｂ 组。两组的ＣＦＲ 值有显著性差别,Ａ 组明显低于Ｂ 组（ Ｐ＜０－０１） 。相关性分析显示ＣＦＲ与ＴＣ、ＬＤＬＣ呈显著负相关（Ｐ＜ ０－０５） 。结论　应用冠脉血流显像新技术结合潘生丁药物负荷试验无创性检测ＣＦＲ,可以早期发现高脂血症患者的冠脉储备功能异常,为指导治疗与评估各种降脂措施的疗效提供重要依据     

99Tcm-ECD SPECT显像潘生丁负荷试验评价痴呆病人脑血管储备功能初步研究

目的探讨和评价潘生丁试验99Tcm-ECD rCBF显像在痴呆诊断中的临床价值.方法首先行基础状态rCBF显像,在36～48小时之后行潘生丁介入后显像.对重建的影像进行肉眼和定量分析.Alzheimer痴呆(AD)组和血管性痴呆(VD)组分别为36例和66例,正常对照组18例.结果 VD和AD组显示双侧颞叶和/或顶叶血流低灌注病灶的发生率存在明显差异,血流灌注类型之间存在明显的差异(P<0.05);脑血管储备功能损害(或丧失)和保留的发生率亦存在明显差异.结论潘生丁介入rCBF显像定量分析可以避免肉眼分析的人为影响因素;它在AD和VD的病人鉴别诊断中,具有重要的临床价值.     

冠心病SPECT灌注显像检查的护理

利用单光子核素药物＾９９ＭＴＣ－ＭＩＢＩ进行心肌血流灌注显像，诊断冠心（ＣＡＤ）总结２１例ＣＡＤ患者，１１例健康体检者，８例心肌梗塞患者心脏ＥＣＴ显像检查的护理操作与放射性防护，并探讨了运动试验静脉主射潘生丁后出现副作用的应急护理。     

符合电路SPECT心肌灌注／代谢显像诊断冠心病的初步研究

目的 研究符合电路SPECT心肌灌注／代谢显像诊断冠心病的临床价值。方法 28例冠心病患者,男26例,女2例分别行心肌血流灌注和心肌代谢显像,全部28例均行冠状动脉造影,25例行心电图运动平板试验。结果 以冠脉造影为金标准,心肌灌注显像、心肌灌注／代谢显像和心电图运动平板试验诊断冠心病的准确率分别为82．14％,89．28％和72％（P＜0．05和P＜0．01）。结论 符合电路SPEFCT心肌灌注／代谢显像,在冠心病的诊断中具有一定的应用价值,且优于静息心肌血流灌注显像和心电图运动平板。     

药物负荷心肌灌注显像进展

核素心肌灌注显像负荷试验对冠心病诊断和评价具有重要价值,其中运动试验应用广泛,但对因老年及其他残疾或合并症而无法或不能充分运动的患者,药物负荷试验是一种有效的替代方法.用于心肌灌注显像负荷试验的药物可分为两大类:冠脉扩张剂和正性肌力药.前者主要有潘生丁、腺苷(或ATP);后者主要有多巴酚丁胺、阿布他明(Arbutamine).本文就药物负荷心肌灌注显像方面的研究进展作一综述.     

心脏疾患PET显像检查的护理探讨

利用正电子核素药物＾１３Ｎ－ＮＨ３，＾１８Ｆ－ＦＤＧ进行心肌血流灌注ＰＥＴ显像和心肌代谢ＰＥＴ显像，进行ＣＡＤ的早期诊断和心肌存活性判断。总结了１５例ＣＡＤ患者；１０例健康查体者；５例心肌梗塞患者心脏ＰＥＴ显像检查的护理操作与放射护护。并探讨了静注潘生丁后出现副作用的应急护理。     

Myocardial density analysis utilizing automated myocardial defect analysis software on resting 320-detector MDCT

Cardiac CT myocardial perfusion is an emerging tool utilizing differences in myocardial density of ischemic compared to normal myocardium. We sought to document the contrast enhanced density profile of myocardial segments subtended by severely stenotic coronary arteries on rest (non stress) cardiac CT imaging, and compare the density with identical segments without ischemic disease. 100 cardiac CT studies were identified resulting in 25 normal patients, 37 with severe left anterior descending artery stenosis, 14 with severe left circumflex artery stenosis, and 24 with severe right coronary artery stenosis. The studies were reviewed on a workstation with dedicated myocardial analysis software. Left anterior descending artery ischemic segments (apical anterior and apical septal) measured 82.2 (±3) and 102 (±3) Hounsfield unit (HU) respectively comparing with non-ischemic segments 89 (±4) and 109 (±4) HU respectively (both P values 0.16). Left circumflex artery segments (basal anterolateral and mid anterolateral) demonstrated 80 (±4) and 76 (±4) HU respectively compared to non-ischemic segments, 89 (±4) and 87 (±4) HU (P value 0.13 and 0.07 respectively). Right coronary artery ischemic segments (basal inferoseptal and basal inferior) measured 104 (±3) and 105 (±3) HU respectively and these compared with non-ischemic segments, 102 (±4) and 105 (±4) HU respectively (P Value 0.69 and 0.94 respectively). Comparison of ischemic myocardial segments with non-ischemic segments demonstrated no significant difference in myocardial density. In prospectively acquired resting 320 multi detector CT, the myocardium subtended by severely stenotic vessels demonstrates no significant density difference compared with those supplied by vessels with no stenosis, confirming that myocardial ischaemia cannot be reliably detected on rest coronary computed tomography angiography by qualitative nor quantitative assessment.     

BOLD cardiovascular magnetic resonance at 3.0 tesla in myocardial ischemia

Background

The purpose of this study was to determine the ability of Blood Oxygen Level Dependent (BOLD) cardiovascular magnetic resonance (CMR) to detect stress-inducible myocardial ischemic reactions in the presence of angiographically significant coronary artery disease (CAD).

Methods

Forty-six patients (34 men; age 65 ± 9 years,) with suspected or known coronary artery disease underwent CMR at 3Tesla prior to clinically indicated invasive coronary angiography. BOLD CMR was performed in 3 short axis slices of the heart at rest and during adenosine stress (140 μg/kg/min) followed by late gadolinium enhancement (LGE) imaging. In all 16 standard myocardial segments, T2* values were derived at rest and under adenosine stress. Quantitative coronary angiography served as the standard of reference and defined normal myocardial segments (i.e. all 16 segments in patients without any CAD), ischemic segments (i.e. supplied by a coronary artery with ≥50% luminal narrowing) and non-ischemic segments (i.e. supplied by a non-significantly stenosed coronary artery in patients with significant CAD).

Results

Coronary angiography demonstrated significant CAD in 23 patients. BOLD CMR at rest revealed significantly lower T2* values for ischemic segments (26.7 ± 11.6 ms) compared to normal (31.9 ± 11.9 ms; p < 0.0001) and non-ischemic segments (31.2 ± 12.2 ms; p = 0.0003). Under adenosine stress T2* values increased significantly in normal segments only (37.2 ± 14.7 ms; p < 0.0001).

Conclusions

Rest and stress BOLD CMR at 3Tesla proved feasible and differentiated between ischemic, non-ischemic, and normal myocardial segments in a clinical patient population. BOLD CMR during vasodilator stress identified patients with significant CAD.     

心肌灌注显像CT衰减校正伪影产生的初步研究

目的：研究心肌灌注显像（MPI）经CT衰减校正（CTAC）后伪影的产生及其对临床诊断的影响。方法：回顾性分析按Bayesian理论,冠心病患病率〈5％的48例受检者所行的72例次MPI（负荷41例次,静息31例次）,图像在未行CTAC时显示正常者进行研究。将左心室心肌划分为20个节段,半定量分析（0分＝放射性分布正常;1分＝放射性分布轻度减低;2分＝放射性分布中度降低;3分＝放射性分布重度减低;4分＝放射性分布缺损）各心肌节段在CTAC后放射性分布变化情况。结果：72例次MPI中,16例次（22．2％）的75个心肌节段（均在左心室心尖、前壁、前间壁区域）在CTAC后出现了放射性分布不同程度的减低。75个受累节段中分别有51、21和3个节段评分增加了1、2和3分,平均每个心肌节段评分增加了1．3分。41例次负荷MPI和31例次静息MPI中,分别有9例次（21．9％）的39个心肌节段、7例次（22．6％）的36个心肌节段在CTAC后出现了放射性分布减低,负荷与静息MPI相比,CTAC后发生心肌节段放射性分布减低的概率（χ^2＝2．84,P〉0．05）与程度（μ=0．54,P〉0．05）均无显著统计学差异。10例负荷／静息MPI都满足纳入标准而纳入研究者中,4例的负荷／静息MPI在CTAC后,出现了相同部位（尖前壁、尖下壁）、相同程度（评分均增加了2分）的灌注降低;3例出现了同一部位,但不同程度的灌注减低;另有3例出现了不同部位心肌节段的灌注减低。CTAC后出现心肌节段灌注减低者与未出现者相比年龄、性别构成无统计学差异。结论：分析SPECT／CT心肌灌注图像时,应同时分析CTAC前后的灌注图像。对于只在CTAC后出现的灌注缺损,需要考虑可能存在CT与SPECT图像配位不准。     

Relationship between dobutamine response of dyssynergic myocardium and angiographically documented blood supply.

OBJECTIVE: Because hibernation is considered a down-regulation of contractile function in response to reduced regional myocardial perfusion, hibernating myocardium is expected to be supplied by a critically stenosed or even occluded coronary artery. Thus, high-dose dobutamine has been postulated to cause ischemia and reworsening of myocardial function (biphasic response), whereas myocardium that demonstrates sustained improvement with high-dose dobutamine should not be supplied by a significantly stenosed vessel. This study evaluates the type of dobutamine response-biphasic versus sustained improvement-of dyssynergic myocardium in relation to its angiographically documented blood supply. METHODS: In 38 patients (5 women; mean age 60 +/- 9 years) with chronic coronary artery disease and impaired left ventricular ejection fraction (相似文献   

Extracellular volume fraction mapping in the myocardium, part 2: initial clinical experience

Background

The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium.

Methods

3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis.

Results

The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 ± 7.8%) than non-ischemic segments (-9.6 ± 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86.

Conclusions

Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.     

Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR

Background

The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium.

Methods

3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis.

Results

The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 ± 7.8%) than non-ischemic segments (-9.6 ± 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86.

Conclusions

Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.     

MRI检测活性心肌及其与冠状动脉造影、SPECT和PET对比研究

目的：分析MRI对冠心病患者心肌活性的诊断价值并与冠状动脉造影、SPECT和PET结果对比。方法：应用MRI对21例临床符合冠心病的患者进行检查，并将结果与冠状动脉造影、SPECT和PET检查结果对照。结果：MRI静息心肌灌注扫描检出的缺血节段比狭窄冠状动脉的供血节段少但无统计学差异（Z=-1.732，P=0．083）；比SPECT心肌灌注扫描检出的缺血节段多且有统计学差异（Z=-3．691，P=0．000）。SPECT心肌灌注扫描检出的缺血节段比狭窄冠状动脉的供血节段少且有统计学差异（Z=-3．029，P=0．002）。以正电子发射断层显像（PET）结果为标准，MR延迟扫描检测活性心肌的灵敏度为97．6％，特异度为98．4％，总符合率为98．2%，Kappa值为0．953。MR延迟扫描检出的活性心肌比PET检出的少但无统计学差异（Z=-0．209，P=0．835）。结论：MR心脏检查清晰显示心肌梗死的位置、程度和附壁血栓情况，并可对左室室壁运动进行直观显示。常规SPECT心肌灌注显像由于空间分辨率低明显低估心肌缺血范围。心肌PET显像空间分辨率低，无法显示心肌梗死的透壁程度，且不能直观显示室壁运动情况。     

应变率显像定量评价冠状动脉旁路移植术后左心室局部功能

目的 探讨应变率显像(SRI)技术在评价冠心病患者冠状动脉旁路移植术前后左心室局部功能变化中的应用价值.方法 对16例冠心病患者分别于冠状动脉旁路移植术前3 d、术后12 d及3个月行超声心动图检查,应用SRI技术对左室各壁基底段和中间段的局部心肌功能进行定量分析,共分析192个节段.根据术前二维超声心动图室壁运动情况将心肌节段分为运动正常组(152个节段)和运动异常组(40个节段).结果 术前运动正常组收缩期心肌峰值应变率(SRs)和舒张早期心肌峰值应变率(SRe)与运动异常组相比差异无统计学意义(P>0.05).运动异常组术后3个月的房缩期心肌峰值应变率(SRa)较术前3 d增高(P<0.05).运动正常组术后3个月与术前3 d相比,SRs、SRa及SRe均增高(分别P<0.05和0.01),术后3个月与术后12 d相比,SRs增高(P<0.05).结论 应用SRI技术能定量评价冠状动脉旁路移植术前后左室局部心肌功能的改变.     

Disturbed Endothelial Function of the Internal Thoracic Artery in Patients with Coronary Artery Disease

Objectives and Background The internal thoracic artery is an established arterial graft for myocardial revascularization. It never had been investigated, whether there are functional differences in this vessel between patients with or without coronary artery disease. Methods We investigated the left internal thoracic artery of 28 patients (15 with and 13 without coronary artery disease) with a duplex-system at rest and with a handgrip exercise. Results Concerning the measured flow velocities at rest there was only a significant difference between the diastolic mean and peak velocity between the two groups, the other investigated parameters demonstrate no significant difference. The peak diastolic and the mean diastolic velocity was less in patients with coronary artery disease during the handgrip-test. The flow reserve was decreased in patients with coronary artery disease (12.6±24.0% vs. 32.3±30.9%, P < 0.05). Conclusions We demonstrated, that patients with coronary artery disease have a higher peripheral resistance and a lower diastolic velocity of the internal thoracic artery during stress testing. This corresponds to a disturbed vasomotion and may be an early marker of arteriosclerosis.     

纵向、径向及周向二维应变评价冠心病患者左心室局部收缩功能异常

目的 应用二维应变超声心动图定量分析静息状态下冠心病患者局部心肌纵向、径向及周向的收缩期峰值应变,了解静息状态下冠状动脉狭窄对左室局部心肌收缩功能的影响.方法 26例冠心病患者和26例健康志愿者接受超声检查,获取心尖四腔观、二腔观及左心长轴观和左室短轴观(二尖瓣环、乳头肌和心尖水平)二维灰阶图像,分析各个心肌节段的纵向、径向和周向的收缩期峰值应变.按左室18节段划分法,将26例冠心病患者的共194个病变心肌节段按供血冠脉狭窄程度分为两组:A组为冠脉狭窄≤70%供血的心肌,B组为冠脉狭窄>70%供血的心肌.结果 A组共90个节段.其纵向收缩期峰值应变(SL)明显低于对照组(P<0.05),而径向收缩期峰值应变(SR)和周向收缩期峰值应变(SC)低于对照组,但差异无统计学意义(P>0.05);B组共104个节段,其SL、SR和SC均明显低于对照组(P<0.05),A组和B组之间SL、SC和SR的差异有统计学意义(P<0.05).结论 二维应变超声心动图能准确评价冠心病患者左室局部收缩功能异常,局部心肌SL、SR和SC的变化町反映冠脉狭窄严重程度.