Evaluation of ischemic heart disease with cardiac magnetic resonance and computed tomography

Ischemic heart disease is the most common cardiac problem encountered by physicians in their daily practice. In the last few years, computed tomography and magnetic resonance have emerged as robust imaging modalities with great potential for the comprehensive evaluation of patients with this disorder. This article reviews current evidence of the applications where these techniques have demonstrated their usefulness and provides guidance for their use in the clinical management of coronary artery disease.     

屏气快速稳态进动序列心脏磁共振成像评价右心室功能的初步研究

目的用屏气快速稳态进动（FIESTA）序列心脏磁共振（MRI）电影成像方法测量右心室容积及功能,评价其重复性及左右心室功能的相关性.方法 16例心脏病患者及10例健康志愿者共26例实验者入组,用多次屏气节段采集FIESTA心脏MRI电影获得覆盖心室的短轴像;两名观察者分别独立地测定2次所有入选者的心室容积及功能,包括射血分数（EF）、舒张末期容积（EDV）、收缩末期容积（ESV）、每搏输出量（SV）;评价①右心室功能在观察者内部及观察者间的重复性;②左右心室SV的相关性.结果①观察者内部的右心室参数具有较高可重复性：ESV（r=0.995）,EDV（r=0.998）,EF（r=0.982）,SV（r=0.995）（均P＜0.001）;②观察者间的右心室参数亦具有较高可重复性：ESV（r=0.893）,EDV（r=0.941）,EF（r=0.711）,SV（r=0.867）（均P＜0.001）;③左右心室SV显著相关（r=0.983,P＜0.001）;④右心室SV与身高相关（r=0.471,P＜0.05）.结论屏气FIESTA心脏MRI成像方法检测右心室功能参数具有较好的可重复性,该方法得出的左右心室功能有较高的一致性.     

Isolated noncompaction of the ventricular myocardium: ultrafast computed tomography and magnetic resonance imaging

This study was undertaken to evaluate the feasibility of ultrafast computed tomography (CT) and magnetic resonance imaging (MRI) for anatomical and pathophysiological diagnosis of isolated noncompaction of the left ventricular myocardium (INVM) compared with other imaging modalities including thallium myocardial imaging. Six patients, three sets of siblings, ranging in age from 13 to 18 years, were included in this study. Two-dimensional echocardiograms revealed numerous prominent trabeculations and deep intertrabecular recesses in one or more ventricular wall segments in all cases. Thallium-201 myocardial imaging disclosed a hypoperfusion area corresponding to the zones where noncompacted ventricular myocardium was localized. Ultrafast CT showed early defects of varying degrees and rate enhancement of the noncompacted ventricular myocardium, implying fibrosis in this area. MRI disclosed inner zones of noncompacted myocardium distinguishable from thin outer zones of compacted myocardium. T2-weighted imaging revealed high intensity areas at the apex of the left ventricle, suggesting disturbed microcirculation due to fibrosis, thrombus formation, and hypokinesis. Cine MRI revealed hypokinesis of the noncompacted ventricular wall during the cardiac cycle. In conclusion, ultrafast CT and MRI provide high-resolution imaging of noncompacted myocardium, and also pathophysiological details regarding this rare disease.     

冠状动脉 CT 成像对女性冠心病评估的临床价值

冠心病是严重危害人类健康的主要心血管疾病之一。与男性相比,女性冠心病患者因其特殊的病理生理特点,在症状识别、采取治疗措施以及预后等方面均存在不同程度差异,因此,加强对女性冠心病的早期识别和干预尤为重要。与其他常用无创检查相比,冠状动脉 CT 成像在女性冠心病的危险分层和预后中具有重要价值,对女性冠心病的评估具有潜在优势,其临床应用价值逐渐提高。     

Focal hepatic lesions: Detection by dynamic and delayed computed tomography versus short TE/TR spin echo and fast field echo magnetic resonance imaging

Eighteen patients with focal hepatic lesions were evaluated with two computed tomographic (CT) techniques including dynamic sequential bolus contrast CT and delayed contrast CT, and 3 magnetic resonance (MR) techniques including a spin echo pulse sequence with TE/TR of 21/310 msec and 2 fast field echo sequences using a TE/TR of 15/300 msec and 80° flip angle (T1-weighted) and TE/TR of 15/500 msec and 10–20° flip angle (T2-weighted). We concluded that CT, using delayed contrast and dynamic sequential bolus contrast techniques, was consistently superior to the 3 MR pulse sequences used on our imagers in terms of number of lesions detected, lesion-to-liver contrast, and quality of scan.     

磁共振特征追踪技术定量左心室应变评估急性STEMI患者微血管阻塞

目的 采用心脏磁共振特征追踪技术（CMR-FT）量化急性ST段抬高型心肌梗死（STEMI）患者急性期左心室心肌应变及心功能改变，探讨其检测心肌梗死伴微血管阻塞（MVO）的可行性。方法 收集78例急性STEMI患者（梗死组）和10名健康志愿者（对照组）的CMR动态电影序列图像及钆对比剂延迟强化成像（LGE）资料。采用CMR-FT分析电影序列图像左心室整体心肌应变[整体峰值径向应变（GPRS）、周向应变（GPCS）及纵向应变（GPLS）]、节段心肌应变[节段峰值径向应变（PRS）、周向应变（PCS）及纵向应变（PLS）]和左心室心功能[左心室射血分数（LVEF）、左心室舒张末期容积指数（LVEDVi）、左心室收缩末期容积指数（LVESVi）及心脏指数（CI）]。根据LGE评估是否存在MVO，将患者分为MVO组（n=50）和无MVO组（n=28），将其左心室心肌节段分为MVO节段组（n=173）和无MVO节段组（n=1 075）。根据左心室节段应变绘制ROC曲线，并计算AUC值。结果 梗死组左心室GPRS、GPCS、GPLS、PRS、PCS及PLS与对照组差异均有统计学意义（P均<0.001）；梗死组左心室LVEF、LVEDVi、LVESVi与对照组差异有统计学意义（P均<0.05）；MVO节段组左心室PRS、PCS、PLS与无MVO节段组差异均有统计学意义（P均<0.001）；PRS和PCS取24.65%和－14.05%时检测MVO的敏感性、特异性、AUC分别为89.0%、60.6%、0.816和75.7%、75.9%、0.818。结论 采用CMR-FT测量左心室心肌节段峰值应变可检测急性STEMI患者是否发生MVO，为临床对急性STEMI患者进行早期风险分层管理提供了无创、便捷的新方法。     

超声声学定量技术评价左心房功能的准确性——与电影磁共振的对比研究

目的　评价超声声学定量 (AQ )技术测量左心房功能的准确性。方法　使用AQ技术和电影磁共振 (Cine MRI)技术分别测量了 2 2例肥厚型心肌病 (hypertrophiccardiomyopathy ,HCM )患者的左心房功能。 结果根据AQ技术测得的左心房容积 -时间曲线及面积 -时间曲线得到的左心房功能各指标均同利用cine MRI技术测得的各相应指标有良好的相关性 ,根据容积 -时间曲线得到的左心房功能各指标相关性明显高于根据面积 -时间曲线得到的指标同cine MRI技术相应测量结果之间的相关性 (r =0 .74～ 0 .98,均 P <0 .0 0 1vsr =0 .5 7～ 0 .96,P <0 .0 0 6～ 0 .0 0 1)。结论　利用AQ技术测得的左心房容积 -时间曲线可准确可靠地对左心房功能进行评价     

二维斑点追踪成像技术评价慢性肺源性心脏病患者室收缩功能的应用研究

目的 应用二维斑点追踪成像(2D-STI)技术测量慢性肺源性心脏病(CPHD)患者右室收缩功能指标,探讨所测各参数与心脏磁共振成像(CMRI)所测右室射血分数(RVEF)的相关性,并评价2D-STI在监测右室收缩功能中的应用价值.方法 选取60例伴有三尖瓣反流的CPHD患者,测量三尖瓣反流峰值速度(Vmax),估测肺动脉收缩压(PASP).根据PASP严重程度分为轻度肺动脉高压(PH)组[30～ 50 mm Hg(1 mm Hg=0.133 kPa)]和中重度PH组(PASP＞50 mm Hg);另选30例健康志愿者作为对照组.对所有入选者行2D-STI及CMRI检查,2D-STI测量右室游离壁及室间隔(基底段、中间段、心尖段)纵向收缩峰值应变(LS)和纵向收缩峰值应变率(LSR),CMRI计算RVEF.将2D-STI所测参数与RVEF行相关分析.结果 轻度PH组右室游离壁及室间隔各节段LS均减低,右室游离壁心尖段及室间隔基底段LSR均减低,与对照组比较差异均有统计学意义(均P＜0.05);而右室游离壁基底段、中间段及室间隔中间段、心尖段LSR与对照组比较差异无统计学意义.中重度PH组右室游离壁及室间隔各节段LS、LSR均减低,与对照组、轻度PH组比较差异均有统计学意义(均P＜0.05).2D-STI所测各参数与CMRI所测RVEF呈正相关(P＜0.001).结论 2D-STI所测各参数与CMRI所测RVEF相关性良好,且能更准确地评估CPHD患者右室各节段的收缩功能,有望成为临床评价右室收缩功能的新方法.     

Beneficial effects of beta‐blockers on left ventricular function and cellular energy reserve in patients with heart failure

Beta‐blockers have been shown to improve left ventricular (LV) function in patients with heart failure. The aim of this study is to non‐invasively assess, by means of in vivo 31P‐magnetic resonance spectroscopy (31P‐MRS), the effects of beta‐blockers on LV cardiac phosphocreatine and adenosine triphosphate (PCr/ATP) ratio in patients with heart failure. Ten heart failure patients on full medical therapy were beta‐blocked by either carvedilol or bisoprolol. Before and after 3 months of treatment, exercise testing, 2D echocardiography, MRS, New York Heart Association (NYHA) class, ejection fraction (EF), maximal rate–pressure product and exercise metabolic equivalent system (METS) were evaluated. Relative concentrations of PCr and ATP were determined by cardiac 31P‐MRS. After beta‐blockade, NYHA class decreased (from 2.2 ± 0.54 to 1.9 ± 0.52, P = 0.05), whereas EF (from 33 ± 7 to 44 ± 6%, P = 0.0009) and METS (from 6.74 ± 2.12 to 8.03 ± 2.39, P = 0.01) increased. Accordingly, the mean cardiac PCr/ATP ratio increased by 33% (from 1.48 ± 0.22 to 1.81 ± 0.48, P = 0.03). Beta‐blockade‐induced symptomatic and functional improvement in patients with heart failure is associated to increased PCr/ATP ratio, indicating preservation of myocardial high‐energy phosphate levels.     

Evaluation of left ventricular volumes and ejection fraction by automated gated myocardial SPECT versus cardiovascular magnetic resonance

BACKGROUND: Electrocardiogram-gated myocardial single-photon emission computed tomography (SPECT) with (99m)Tc-tetrofosmin allows simultaneous evaluation of myocardial perfusion and function. In this study, left ventricular volumes, ejection fraction (LVEF), and left ventricular wall volume (LVWV) derived from gated SPECT were compared with measurements from cardiovascular magnetic resonance (CMR), performed within a few hours. METHODS: The study population included 55 patients with known or suspected coronary artery disease, including 13 patients with recent acute myocardial infarction. End-diastolic (EDV) and end-systolic (ESV) volumes, LVEF and LVWV were derived automatically from gated SPECT using commercially available software (QGS). In the CMR studies, manually delineated endocardial and epicardial borders on short-axis slices were used to calculate the volumes. RESULTS: Gated SPECT underestimated EDV by 35 +/- 14 ml (mean +/- SD) (P < 0.001), ESV by 10 +/- 13 ml (P < 0.001), and LVEF by 4 +/- 7 percentage points (P < 0.001). There were no systematic difference in EDV, ESV or LVEF between the methods. SPECT underestimated LVWV by 49 +/- 30 ml (P < 0.001), with a trend towards increasing underestimation by SPECT for larger wall volumes. CONCLUSION: These findings show that gated SPECT slightly underestimates EDV, ESV and LVEF compared with CMR. This underestimation is systematic, however, indicating that ventricular volumes derived from gated SPECT are robust enough to guide clinical management. Estimates of LVWV in patients with large wall volumes are less accurate.     

Comparative sensitivity of computed tomography vs. magnetic resonance imaging for detecting acute posterior fossa infarct

Background

Posterior fossa strokes, particularly those related to basilar occlusion, pose a high risk for progression and poor neurological outcomes. The clinical history and examination are often not adequately sensitive or specific for detection.

Study Objectives

Because this population stands to benefit from acute interventions such as intravenous and intra-arterial tissue plasminogen activator, mechanical thrombectomy, and intensive monitoring for neurologic deterioration, this study examined the sensitivity of non-contrast head computed tomography (NCCT) for diagnosing posterior fossa strokes in the emergency department.

Methods

This study analyzed a prospectively collected database of acute ischemic stroke patients who underwent head NCCT within 30 h of symptom onset and who were subsequently found to have a posterior fossa infarct on brain magnetic resonance imaging (MRI) performed within 6 h of the NCCT.

Results

There were 67 patients identified who had restricted diffusion on MRI in the posterior fossa. The National Institutes of Health Stroke Scale (NIHSS) scores ranged from 0 to 36, median 3. Only 28 patients had evidence of infarction on the initial NCCT scan. The timing of NCCT scans ranged from 1.2 to 28.9 h after symptom onset. The sensitivity of NCCT was 41.8% (95% confidence interval 30.1–54.4). The longest period of time between symptom onset and a negative NCCT with a subsequent positive diffusion-weighted imaging MRI was 26.7 h.

Conclusions

Head NCCT imaging is frequently insensitive for detecting posterior fossa infarction. Temporal evolution of strokes in this distribution, coupled with beam-hardening artifact, may contribute to this limitation. When a posterior fossa stroke is suspected and the NCCT is non-diagnostic, MRI is the preferred imaging modality to exclude posterior fossa infarction.     

速度向量成像对冠心病患者左室扭转特征的评价

目的 探讨速度向量成像（VVI）技术在评价冠心病患者左室扭转方面的临床价值.方法 30例健康者为对照组,48例冠心病患者,根据冠状动脉造影的结果将冠心病患者分为缺血组20例和梗死组28例.采集受检者左室短轴（二尖瓣水平、心尖水平）二维图像,应用VVI软件测量左室扭转指标.结果 与对照组比较,缺血组扭转速度峰值（PtwV）减低（P〈0.05）,梗死组心尖旋转角度峰值（PAr）、左室扭转角度峰值（Ptw）、PtwV减低,任意两个节段达峰时间的差值（Tw-diff）增大,差异均有统计学意义（P〈0.05）;与缺血组比较,梗死组PtwV减低（P〈0.05）.Ptw与左室射血分数呈正相关（r=0.68,P〈0.05）.结论 VVI技术是研究冠心病患者心肌扭转特征的有效方法,左室扭转指标较常规超声心动图更能敏感地检出冠心病患者早期的心肌缺血改变.     

应变率成像评价高血压和冠心病患者左室心肌功能

目的应用应变率成像（SRI）技术评价高血压和冠心病患者的左心室功能,探讨SRI评价左心室功能的临床价值。方法A组30例健康人群,B组23例原发性高血压病患者,C组19例冠心病合并原发性高血压患者,取心尖四腔、心尖两腔、心尖左室长轴切面的心肌应变率曲线,测定左室各室壁的收缩期、舒张早期、舒张晚期的峰值应变率（SRS、SRE、SRA）和收缩期峰值应变（εS）,计算其平均峰值应变率（mSRS、mSRE、mRSA）和平均峰值应变（mεS）;统计各组左室各壁出现的收缩后缩短（PSS）的节段数;观察左心室曲线M型应变率成像（CMM-SRI）图像特点,定量检测各节段收缩-舒张转换时间（TCEC）,冠状动脉造影确定缺血节段,比较各组左心室壁各节段TCEC的差异。结果与正常组（A组）相比,高血压病组（B组）患者和冠心病合并高血压组（C组）患者的mSRS、mSRE、mRSA和mε均有明显降低（P〈0.05）;与A组及B组相比,C组各节段PSS的检出率明显增多（P〈0.05）,而A、B两组各节段的PSS检出率的差异无显著性（P〉0.05）;与非缺血节段比较,缺血节段TCEC延长（P〈0.05）。结论应变率成像（SRI）技术为定量、准确评价高血压和冠心病左室心肌功能提供了新的方法。     

心房颤动对慢性心力衰竭伴左室射血分数≥0.50患者预后的临床研究

目的 探讨左室射血分数(LVEF)≥0.50的住院慢性心力衰竭(心衰)患者中心房颤动(房颤)的发生和分布类型,及房颤对此类心衰预后的影响.方法 调查患者417例次,按LVEF＜0.50与≥0.50分为两组,根据患者入院前是否有房颤病史分为阵发性房颤、持续性房颤及入院后新发房颤.随后观察并记录严重恶性事件发生情况及因慢性心衰而再人院次数及每两次住院的间隔时间.结果 LVEF＜0.50的慢性心衰更多见于男性,一年内心肌梗死的发病率较LVEF≥0.50者高[15.6%(34/218)比8.0%(16/199),P<0.01],且房颤使得患者脑卒中发生率较不伴房颤者明显增高(24.3%(27/111)比8.4%(9/107),P＜0.05),急性冠脉综合征、心血管死亡事件例数及死亡数也高于不伴房颤者;在LVEF≥0.50的慢性心衰患者中新发房颤数量较LVEF＜0.50者明显增多(51比30,P＜0.05),房颤可见伴发在近2/3的患者中,且再入院次数较不伴房颤者增加[(2.78±1.79)次比(2.00±1.35)次,P＜0.01],前两次入院间隔时间亦较不伴房颤者缩短[(117±107)d比(154±130)d,P＜0.05].结论 房颤更易发生在LVEF≥0.50的慢性心衰患者,导致更短的再入院间隔,强调治疗和管理这类房颤的重要性.     

64层螺旋CT量化冠状动脉钙化在冠心病中的诊断价值

目的 探讨64层螺旋CT(64-slice spiral computed tomography,64SCT)量化冠状动脉钙化(coronary artery calcification,CAC)对诊断冠心病(coronary heart disease,CHD)的价值.方法 对56例临床诊断及可疑冠心病患者,进行64SCT冠脉成像及其钙化的量化分析,并同期进行选择性经皮冠状动脉造影(coronary angiography,CAG)检查,CAG采用经典插管法,冠状动脉钙化积分(coronary artery calcification score,CACS)采用Agatston方法完成,64SCT结果与CAG结果做双盲对照研究;根据CAG结果将患者分为冠心病组34例(冠状动脉至少有1支血管狭窄≥50%)和非冠心病组22例;进一步将224支血管按狭窄程度分为A组(狭窄＜50%)、B组(狭窄50%～75%)和C组(狭窄＞75%),记录其CACS分别进行统计分析;按照年龄分为＜60岁组和≥60岁组,分别分析CAC率和CACS与年龄的关系.结果 64SCT冠状动脉三维成像对冠状动脉钙化显示清晰,对冠状动脉各分支显示良好,冠心病组的CACS与非冠心病组比较,差异有统计学意义(P＜0.01),且A组与B、C组比较CACS差异有统计学意义(P＜0.01),但B组、C组两组之间CACS差异无统计学意义(P＞0.05);随着年龄的增长,CAC率和CACS逐渐增高,＜60岁组与≥60岁组CAC率和CACS比较差异有统计学意义(P＜0.01);＜60岁组冠心病患者CAC率和CACS明显高于非冠心病组(P＜0.05),≥60岁组冠心病患者CAC率与非冠心病组比较差异无统计学意义(P＞0.05),但CACS差异有统计学意义(P＜0.01).结论 应用64SCT量化冠状动脉钙化,可以对可疑冠心病患者提供早期诊断依据,CACS与相应血管管腔狭窄的对照分析显示,CACS与冠状动脉狭窄程度之间有一定关系;年龄对CAC有影响.     

心脏磁共振心肌灌注成像在冠心病患者冠状动脉病变及微循环梗阻中的临床应用价值

目的  探讨心脏磁共振（CMR）心肌灌注成像在冠心病冠状动脉病变及微循环梗阻（MVO）中的临床应用价值。方法  选取2020年1月~2022年12月我院收治的106例冠心病患者,均在经皮冠状动脉介入治疗前和治疗后行CMR心肌灌注成像。以冠状动脉造影诊断结果为金标准,对比经皮冠状动脉介入治疗前CMR心肌灌注成像中延迟强化透壁局部室壁异常运动及病变区与正常心肌区CMR心肌灌注成像参数。分析CMR心肌灌注成像对冠心病冠状动脉病变的诊断效能。经皮冠状动脉介入治疗后根据患者是否存在MVO将其分为MVO组（n=29）和无MVO组（n=77）,对比两组CMR心肌灌注成像参数,并采用ROC曲线分析CMR心肌灌注成像参数对MVO的诊断价值。结果  106例患者中的1802个心肌节段被纳入评价。CMR心肌灌注成像显示106例患者共有147个延迟强化的心肌节段（每个患者至少有1个心肌节段延迟强化）,其中68个透壁强化,79个非透壁强化。病变心肌首过灌注时间、首过灌注最大上升斜率（Slope_max）、心肌延迟强化信号值与正常心肌间对比有统计学差异（P < 0.05）。以冠状动脉造影结果为金标准,CMR心肌灌注成像对左前降支、右冠状动脉、左回旋支病变的诊断敏感度分别为94.12%、88.64%、88.89%,特异性分别为95.00%、96.55%、94.74%,准确度分别为94.66%、93.89%、93.13%。经皮冠状动脉介入治疗后有MVO者29例,无MVO者77例。MVO组中首过灌注时间、Slope_max、心肌延迟强化信号值与无MVO组的差异有统计学意义（P < 0.05）。ROC曲线显示,CMR心肌灌注成像参数中首过灌注时间、Slope_max、心肌延迟强化信号值对冠心病患者MVO诊断的曲线下面积分别为0.803、0.718、0.851,敏感度分别为82.76%、72.41%、86.21%,特异性分别为66.23%、68.83%、67.53%,准确度分别为70.75%、69.81%、72.64%。结论  CMR心肌灌注成像可显示冠心病心血管病变区域的变化,对诊断冠心病冠状动脉病变及MVO情况有较高的诊断价值。     

门控心肌显像在测定左心室射血分数中的应用

目的:应用单光子发射计算机体层摄影(SPECT)技术同时测定不同采集条件下左心室射血分数(LVEF)值,并与超声LVEF值比较,研究其一致性和相关性。方法:选择172例受试者,利用SPECT共行门控显像技术,用99mTc-MIBI作为示踪剂,同时将心动周期设定8和16等份,在一次采集中得到两种条件的LVEF值,并与1周时间所得超声LVEF值作比较,研究门控心肌显像在LVEF测定中的影响因素,以及与常规超声法有无相关性。结果:统计分析显示,心动周期分成8和16等份所得的LVEF值大小是不同的,后者LVEF值较大,但两种方法所得结果存在相关关系。另一方面,SPECT所得的LVEF值均较超声心动图(UCG)所得值大,但与UCG所得结果具有很好一致性。结论:门控心肌显像在心肌活力判断时,利用共行显像技术可同时得到LVEF等心功能参数,其LVEF大小与超声结果有很大相关性,但其值存在显著差异,其正常参考范围尚需进一步研究。     

Measurement of left ventricular volume after anterior myocardial infarction: comparison of magnetic resonance imaging,echocardiography, and radionuclide ventriculography

We have compared echocardiography (echo) and radionuclide ventriculography (RNV) with magnetic resonance imaging (MRI) for the measurement of left ventricular (LV) volume and ejection fraction. Seventy asymptomatic patients were studied up to 12 days after first Q wave anterior myocardial infarction and again after 6 months. Each patient had LV volume measured by all three techniques within 24 hours of each other on each occasion. LV end-systolic and end-diastolic volume index (LVESVI and LVEDVI) and LV ejection fraction (LVEF) were measured using the modified Simpson formula (echo), a counts-based method (RNV), and a multislice area summation method (MRI). Radionuclide volumes were measured both with and without correction for attenuation of isotope. Echocardiography overestimated LV volume compared with MRI. Mean (SD) differences (echo–MRI) were: LVEDVI + 10.6 ml/m² (16.8), LVESVI + 13.7 ml/m² (12.9), LVEF – 8.5% (11.2). RNV underestimated both volume and ejection fraction compared with MRI. Mean differences (RNV–MRI) were: LVEDVI –25.4 ml/m² (23.8), LVESVI – 5.0 ml/m² (18.6), LVEF – 13.8% (10.4). Variability in the difference between echo and MRI and between RNV and MRI was very similar for LVEF (coefficient of variation 23.9% echo, 22.2% RNV) but there was greater variability in the radionuclide than the echo measurements of absolute volume. Variability of the radionuclide measurements was reduced by not correcting for attenuation, and this finding may improve the radionuclide technique for serial measurements of percentage change in volume. Long-term inter-study reproducibility of MRI for LVEF (coefficient of reproducibility) was 10.9%, for echo it was 10.6%, and for RNV it was 14.6%. We conclude that measurements of LV volume depend on the method used and are not interchangeable. Echocardiography agrees more closely with MRI than RNV for the measurement of absolute volume, but the two techniques are similar for the measurement of LVEF.     

二维斑点追踪应变成像对冠心病患者左心室同步性的定量研究

目的 探讨二维斑点追踪应变成像技术评价冠心病患者左室同步性的临床价值.方法 42例急性心肌梗死患者、39例冠心病心肌缺血患者和32例对照者接受二维超声检查,用二维应变软件分析心尖长轴观、心尖两腔观和四腔观以及左室短轴观基底水平、乳头肌水平、心尖水平的图像,测量自心电图QRS波起点至左室在心尖长轴观上的收缩期纵向应变达峰时间(Tssl)及胸骨旁短轴观上的收缩期径向和环向应变达峰时间( Tssr,Tssc).计算左室各节段达峰时间标准差(Tssl-SD,Tssr-SD,Tssc-SD)及节段达峰时间最大差值(Tssl-Dif,Tssr-Dif,Tssc-Dif),以左室短轴观乳头肌水平前室间隔和后壁的径向应变的达峰时间之差(TAS-POST)≥130 ms作为左室收缩不同步标准,同时测量18个心肌节段纵向应变峰值与收缩末应变的差值之和作为纵向应变延迟指数(LSDI),LSDI≥25％作为左室不同步标准.结果 急性心肌梗死组同步性参数较对照组增加(P ＜0.001或P＜0.05);心肌缺血组同步性参数较对照组增高(P＜0.05); LSDI与TAS-POST呈正向线性相关(r=0.676,P＜0.05);急性心肌梗死组中,LSDI检测左室不同步敏感性高于TAs-POST(P＜0.05).结论 二维斑点追踪应变成像技术能准确评价左室不同步性,LSDI与TAS-POST可定量评价冠心病患者左室不同步性.