双源CT在主动脉瓣置换术前左心功能评价中的应用

目的:以磁共振成像(MRI)为金标准,用双源CT(DSCT)定量评价左心功能,探讨DSCT在主动脉瓣置换术前左心功能评价中的应用价值.方法:选取临床诊断主动脉瓣病变欲行主动脉瓣置换术的患者21例,全部病例均行DSCT和MRI心功能分析检查.由有经验的2位放射科医生独立进行,结果以均数士标准差表示.两种仪器间测量值应用配对样本t检验及相关分析检验,同一仪器测量值的差异相互关系用组内相关系数描述,P ＜0.05为有统计学意义.结果:DSCT和MRI两种方法测量的心功能指标差异无统计学意义,舒张末期容积(EDV)、收缩末期容积(ESV)、每搏输出量(SV)、左室射血分数(EF)相关性高,r值(EDV)=0.93,r值(ESV)=0.94,r值(SV)=0.89,r值(EF)=0.85.EDV均值:DSCT＞ MRI;ESV均值:DSCT＞ MRI;SV均值:DSCT＞ MRI; EF均值:DSCT＞ MRI.同一仪器三次测量值的差异相互关系(ICC值):MRI测量的EDV、ESV、SV、EF值的ICC值在0.8～1之间;DSCT测量的EDV、ESV、SV、EF值的ICC值在0.6～0.75之间.结论:DSCT在左心室收缩功能定量评价方面准确、可靠,重复性好,并可在不增加放射剂量的前提下,一次DSCT冠状动脉造影检查同时评估冠状动脉狭窄情况和左心室收缩功能,能够为临床主动脉瓣置换术前评估及制订手术方案提供更多重要的参考信息.     

Evaluation of cardiac resynchronization therapy in drug-resistant dilated-phase hypertrophic cardiomyopathy by means of Tc-99m sestamibi ECG-gated SPECT

This case describes a 65-year-old male with drug-resistant heart failure. Cardiac resynchronization therapy was performed. We evaluated cardiac function with volume curve differentiation software (VCDiff) from QGS data with Tc-99m sestamibi. Left ventricular parameters during atrial-right ventricular pacing were left ventricular ejection fraction (LVEF) 30%, end-diastolic volume (EDV) 156 ml, end-systolic volume (ESV) 108 ml and peak filling rate 1.12 (EDV/sec). And during dual chamber pacing, those were LVEF 35%, EDV 145 ml and ESV 95 ml and PFR 1.58 (EDV/sec). And during atrial-left ventricular pacing, those were LVEF 36%, EDV 152 ml, ESV 97 ml and peak filling rate (PFR) 1.35 (EDV/sec). Cardiac resynchronization therapy may improve cardiac function as well as dyssynchrony, which could be evaluated non-invasively and accurately by ECG-gated SPECT.     

Global left-ventricular function assessment using dual-source multidetector CT: effect of improved temporal resolution on ventricular volume measurement

The purpose was to compare global left-ventricular (LV) function parameters measured with cine MRI with results from multiphase dual-source CT (DSCT) using 10 and 20 reconstruction phases. Twenty-eight patients with suspected or known CAD underwent DSCT coronary angiography. LV end-diastolic (EDV), end-systolic (ESV) and stroke volumes (SV), and ejection fraction (EF) were determined using LV segmentation and selection of specific phases from DSCT image sets reconstructed either at 5% or 10% steps through the R-R interval. Cine MRI served as the reference investigation. Threshold-based 3D-segmentation was feasible in all DSCT data sets. EDV and ESV were underestimated by DSCT, but showed excellent correlation (Pearson's correlation coefficient 0.95/0.97) to values obtained with MRI. Using data from 5% DSCT image reconstructions instead of 10% phase reconstructions, the position of the ED and ES phase was changed in 16 of 28 patients; ESVs were to found to be slightly smaller, whereas EDV were slightly larger, resulting in a systematic overestimation of LV EF by 1.9% (p = 0.56). Threshold-based 3D segmentation enables accurate and reliable DSCT determination of global LV function with excellent correlation to cine MRI. Minor differences in LV EF indicate that both modalities are virtually interchangeable, even if the number of reconstructed phases is limited to 10% phase reconstructions.     

MRI心功能参数对陈旧性心肌梗死左心室重塑的评估价值

目的：观察陈旧性心肌梗死后心室形态和心功能参数的变化,探讨MRI测量心功能参数对心室重塑的评估价值。方法：纳入33例陈旧性心肌梗死患者为病变组,12例健康志愿者为对照组。病变组及对照组成员均行MRI检查。MRI测量参数包括：舒张末期客积（EDV）、收缩末期容积（ESV）、每搏输出量（SV）、左心室射血分数（LVEF）、射血率峰值（PER）、充盈率峰值（PFR）。同时测量梗死心肌面积所占的百分比,以24％为分界值,分为无重塑组（≤24％）和重塑组（〉24％）,分析各组间的心功能参数的差异,进行受试者操作特征（ROC）曲线分析,筛选能独立评估心室重塑的心功能指标。结果：病变组的EDV、ESV、SV均高于对照组,病变组的LVEF、PER和PFR低于对照组。ESV随EDV的增加而增加（P〈0．001）,PER、PFR及LVEF均随EDV的增加而下降（P〈0．05）,而SV与各参数均无相关性。PFR、EDV和ESV的ROC分析曲线下面积分别为0．725、0．741、0．764,分界值分别为2．27EDV／sec、140．23ml和79．12ml（P值分别为0．036、0．021和0．032）。结论：MRI可以从收缩和舒张功能的不同角度全面地评估心功能变化。MRI心功能指标对评估心室重塑有重要作用。PFR、EDV、ESV可以作为独立因子评估心室重塑,其中以PFR的评估效能更高。     

Measurement of ventricular volumes and function: a comparison of gated PET and cardiovascular magnetic resonance.

The aim of this study was to compare cardiac volume and function assessment using PET with the reference technique of cardiovascular magnetic resonance (CMR). METHODS: Left ventricular (LV) and right ventricular (RV) end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fractions (EF) were measured in 9 patients using both CMR and PET with inhaled C(15)O. RESULTS: Correlation between the techniques was generally reasonable (r values ranged from 0.63 to 0.99). Best agreement was seen for ESV (LV and RV). With PET, there was a tendency to underestimate LV EF and EDV, and RV EDV and SV. Agreement was worst for LV SV. Percentage difference between CMR and PET measurements ranged from -2% to 15%; Bland-Altman limits of agreement ranged from 24% to 75%. CONCLUSION: Although small systematic differences exist, the agreement between PET and CMR suggests useful information regarding function, and volumes may be obtained from a standard PET protocol.     

Accuracy of different reconstruction intervals to quantify left ventricular function and mass in cardiac computed tomography examinations

PURPOSE: To compare the accuracy of cardiac dual-source CT (DSCT) reconstructions obtained at 5% and 10% of the cardiac cycle and MRI for quantifying global left ventricular (LV) function and mass in heart transplant recipients. MATERIAL AND METHODS: We prospectively included 23 heart transplant recipients (21 male, mean age 60±11.7 years) who underwent cardiac DSCT and MRI examinations. We compared LV parameters on cardiac DSCT reconstructions obtained at 5% (0%-95%) and 10% (0%-90%) intervals of the cardiac cycle and on double-oblique short-axis MR images. We determined ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and myocardial mass using commercially available semiautomated segmentation analysis software for DSCT datasets and conventional manual contour tracing for MR studies. RESULTS: Using different reconstruction intervals to quantify LV parameters at DSCT resulted in non-significant differences (P>.05). Compared to MRI, DSCT slightly overestimated LV-EDV, ESV, and mass when both 5% (11.5±25.1ml, 6.8±10.9ml, and 28.3±21.6g, respectively) and 10% (mean difference 15.3±26.3ml, 7.4±11.5ml, and 29.3±18.7g, respectively) reconstruction intervals were used. DSCT and MRI estimates of EF and SV were not significantly different. CONCLUSION: In heart transplant recipients, DSCT allows reliable quantification of LV function and mass compared with MRI, even using 10% interval reconstructions.     

Diastolic or systolic left and right ventricular impairment at moderate doses of anthracycline?

A prospective study was carried out to assess the early and later alterations in left and right ventricular diastolic and systolic function after the termination of anthracycline therapy. In 33 women without cardiac disease who were treated by anthracycline therapy, cardiac function was evaluated by radionuclide angiography before the treatment (T₀) and 1 month (T₁) and 12 months (T₁₂) after the end of the treatment. Cardiac function was assessed by radionuclide measurement throughout treatment. Analysis of ejection fraction (EF), peak ejection rate (PER), time to PER (TPER), peak filling rate (PFR) and time to PFR (TPFR) was performed before and after treatment. To normalise radionuclide measurements of the ventricular diastolic function, the ratio of the PFR and the EF and the ratio of the PFR and the PER were calculated. No patient developed symptomatic congestive cardiac failure. One-way analysis of variance showed a significant decrease in the three parameters (EF, PER, PFR) over time only for the left ventricle (LV); no significant alterations appeared for the right ventricle (RV). The EF of the LV decreased from 59%±5% at T_o to 57%±6% at T₁ and 56%±5% at T₁₂. The PER of the LV fell from 3.03±0.40 end-diastolic volume per second (EDV/s) at T₀ to 2.79±0.47 at T₁ and 2.78±0.43 at T₁₂. The PFR of the LV dropped from 2.99±0.43 EDV/s at T₀ to 2.62±0.44 at T₁ and 2.56±0.42 at T₁₂. For the normalised ratios, no differences were observed. Significant differences were found for EF, PER and PFR between T₀ and T₁, and between T₀ and T₁₂, but no difference was found between T₁ and T₁₂. This report shows simultaneous impairment of the systolic and diastolic LV radionuclide parameters at 1 and 12 months after anthracycline therapy without alteration in the RV function.     

回顾性心电门控多层螺旋CT对急性肺栓塞右心室功能障碍及溶栓前后右心室功能变化的评价

目的 应用ECG门控MSCT前瞻性对中心型急性肺动脉栓塞(APE)患者右心功能障碍及静脉溶栓前后右心功能变化进行评价.方法 96名可疑APE患者进行了ECG门控MSCT胸痛三联检查,25例确诊为中心型肺栓塞.行胸痛三联检查无心肺疾患且性别、年龄匹配的25例作为对照组.APE患者于静脉溶栓后复查MSCT,评价右心功能恢复情况.测量参数包括横断面舒张期的右心室(RV)及左心室(LV)短轴最大内径,RV及LV舒张末期容积(EDV)、收缩末期容积(ESV)、射血分数(EF)、主肺动脉/主动脉直径比.应用单因素方差分析,如果有统计学意义,则采用两两组间q检验.结果 对照组的右心室EDV、ESV、EF值、收缩末期RV/LV容积比、横断面RV/LV内径比及主肺动脉/主动脉直径比分别为(15O.5±24.1)ml、(71.5±18.5)ml、(53.5±4.2)%、1.08±0.04、1.01±0.04及0.99±0.02,中心型APE患者溶栓前以上各值分别为(190.3±16.2)ml、(128.1±13.2)ml、(32.7±3.6)%、2.00±0.26、1.30±0.09及1.34±0.11,溶栓后分别为(159.2±21.5)ml、(80.7±9.4)ml、(49.2±5.9)%、1.22±0.25、1.02±0.02及1.02±0.11.中心型APE患者与对照组比较,右心室ESV(q=6.28,P<0.01)及EDV均增大(q=7.59,P<0.01),EF减小(q=4.82,P<0.01),收缩末期RV/LV容积比增大(q=6.04,P<0.01),横断面RV/LV内径比(q=4.43,P<0.01)及主肺动脉/主动脉直径比增大(q=4.36,P<0.01),左心室EDV减小.中心型APE患者静脉溶栓后,与溶栓前比较,右心室ESV(q=5.03,P<0.01)及EDV减小(q=6.11,P<0.01),EF增加(q=6.29,P<0.01),收缩末期RV/LV容积比减小(q=4.74,P<0.01),横断面RV/LV内径比(q=3.83,P<0.01)及主肺动脉/主动脉直径比减小(q=3.46,P<0.01),左心室EDV增大(q=4.01,P<0.01).结论 回顾性ECG门控MSCT胸痛三联检查可同时检测APE和测量左右心功能,排除其他胸痛疾病,评价溶栓疗效.     

Comparison of electron beam computed tomography with magnetic resonance imaging in assessment of right ventricular volumes and function

OBJECTIVE: Intraindividual comparison of right ventricular volumes and function using electron beam computed tomography (EBT) and magnetic resonance imaging (MRI). METHODS: Twenty-seven patients with a known cardiac history were referred for evaluation of ventricular function parameters. The following standardized protocols were used: contrast-enhanced multislice mode EBT and gradient echo sequence MRI. Right ventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) were calculated using a slice summation method. Interobserver variability was calculated. RESULTS: The correlation between the 2 methods was: r = 0.901 for EDV, r = 0.938 for ESV, r = 0.823 for SV, and r = 0.953 for EF. Electron beam computed tomography overestimated EDV and ESV slightly when compared with MRI (P < 0.05). No significant differences (P > 0.05) were found between SV and EF. Mean values determined by EBT and MRI were as follows: 168.6 +/- 62.3 mL and 153.7 +/- 59.1 mL for EDV, 104.7 +/- 60.4 mL and 95.1 +/- 54.8 mL for ESV, 63.2 +/- 19.3 mL and 58.7 +/- 19.8 mL for SV, and 40.2% +/- 14.1% and 40.2% +/- 13.6% for EF, respectively. Interobserver variability ranged between 1.0% and 3.2%. CONCLUSION: Electron beam computed tomography shows good agreement with a close correlation and an acceptable interobserver variability for right ventricular volumes and global function, with a small but significant overestimation of EDV and ESV when compared with MRI.     

Dual-source cardiac CT imaging with improved temporal resolution: Impact on image quality and analysis of left ventricular function

In a newly developed dual-source computed tomography system (DSCT) the relation of heart rate and image quality and the possible advantages of the system's superior temporal resolution in the evaluation of left ventricular parameters as compared to results of cardiac magnetic resonance imaging (MRI) were assessed. Coronary CT angiography was performed using a DSCT (Somatom Defintion, Siemens Medical Solutions, Forchheim, Germany) in 21 patients (mean age 62+/-8; 15 male, 6 female). Image quality of the coronary arteries, the heart valves, and the left ventricular myocardium was assessed using a three-point grading scale. Ten of these patients also underwent cardiac MRI for the assessment of left ventricular function, using a SSFP (steady-state free precession) sequence. Left ventricular ejection fractions (LV-EF), the end-systolic volumes (ESV), and the end-diastolic volumes (EDV) were measured employing MRI and DSCT datasets. The image quality ratings for the coronary arteries at the optimal reconstruction interval were diagnostic even in patients with high heart rates (1.42+/-0.49). Analysis of global LV function using DSCT quantified from CTA datasets showed a good correlation with results of cardiac MRI [EF: r=0.75 (p=0.01); ESV: r=0.72 (p=0.19); EDV: r=0.71 (p=0.02)]. The dual-source CT system offers robust image quality of the coronary arteries, independent of the heart rate, and provides combined diagnostic imaging of coronary arteries, the heart valves, the myocardium, and the global left ventricular function.     

Dual-source-Computertomographie des Herzens

In a newly developed dual-source computed tomography system (DSCT) the relation of heart rate and image quality and the possible advantages of the system’s superior temporal resolution in the evaluation of left ventricular parameters as compared to results of cardiac magnetic resonance imaging (MRI) were assessed. Coronary CT angiography was performed using a DSCT (Somatom Defintion, Siemens Medical Solutions, Forchheim, Germany) in 21 patients (mean age 62±8; 15 male, 6 female). Image quality of the coronary arteries, the heart valves, and the left ventricular myocardium was assessed using a three-point grading scale. Ten of these patients also underwent cardiac MRI for the assessment of left ventricular function, using a SSFP (steady-state free precession) sequence. Left ventricular ejection fractions (LV-EF), the end-systolic volumes (ESV), and the end-diastolic volumes (EDV) were measured employing MRI and DSCT datasets. The image quality ratings for the coronary arteries at the optimal reconstruction interval were diagnostic even in patients with high heart rates (1.42±0.49). Analysis of global LV function using DSCT quantified from CTA datasets showed a good correlation with results of cardiac MRI [EF: r=0.75 (p=0.01); ESV: r=0.72 (p=0.19); EDV: r=0.71 (p=0.02)]. The dual-source CT system offers robust image quality of the coronary arteries, independent of the heart rate, and provides combined diagnostic imaging of coronary arteries, the heart valves, the myocardium, and the global left ventricular function.     

Sixteen-slice spiral CT versus MR imaging for the assessment of left ventricular function in acute myocardial infarction

The aim of this study was to assess global left ventricular (LV) function and regional wall motion using retrospectively ECG-gated 16-slice computed tomography (CT) in comparison with magnetic resonance imaging (MRI). Twenty-one patients (18 male, 65.5±8.6 years) with acute myocardial infarction underwent multislice spiral CT (MSCT) and MRI. From manually drawn endo- and epicardial contours, LV volumes including myocardial mass, peak filling rate (PFR), peak ejection rate (PER), time to PER (TPER) and time from end-systole to PFR (TPFR) were calculated. Regional wall motion was assessed from cine loops using a 16-segment model of the left ventricle. LV function was analyzed using the Bland–Altman method, Pearsons correlation coefficient, multivariate analysis and post hoc t tests. Regional wall motion was evaluated with weighted kappa-statistics. Multivariate analysis revealed significant differences for global LV function as determined by MSCT and MRI. Post hoc t-tests showed significant differences for end-diastolic volume (EDV), PFR and TPER (P<0.05), while there was a good agreement for the LV volumes with an ejection fraction of 46.9±8.4% for MSCT and 46.9±8.9% for MRI. PER, PFR, TPER and TPFR presented a poor correlation and a wide range of scattering between MSCT and MRI. Regional wall motion scores showed a good agreement with =0.791. Sixteen-slice spiral CT allows for reliable assessment of LV volumes, but is not yet suited for the evaluation of all functional parameters. Assessment of regional wall motion at rest is feasible.     

Clinical usefulness of a novel program “Heart Function View” for evaluating cardiac function from gated myocardial perfusion SPECT

Objective

To investigate clinical usefulness of a novel program “Heart Function View (HFV)” for evaluating left ventricular (LV) function from myocardial perfusion SPECT (MPS), we compared LV functional parameters (F(x)) calculated by HFV with those obtained by the other similar programs QGS and cardioGRAF or by ultrasound echocardiography (UCG) and examined their correlations with clinical markers of heart failure: plasma BNP concentrations (BNPs) and exercise capacity.

Methods

Studied patients (n = 60) underwent technetium-99m tetrofosmin quantitative gated MPS including treadmill exercise for examining heart disease. Myocardial stress images were acquired 30 min after the first tracer injection during maximal exercise. Three hours later, the second tracer was injected, and resting images were acquired. LV systolic F(x) [ejection fraction (EF), peak ejection rate (PER)] and diastolic F(x) [first third filling fraction (1/3FF), first third filling rate (1/3FR), peak filling rate (PFR), time to PFR (TPF)] were analyzed, and phase standard deviation (SD) and histogram bandwidth were obtained by phase analysis.

Results

LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF obtained from HFV were well correlated with those from QGS, cardioGRAF and UCG. A diastolic parameter Doppler E/e′ from UCG was significantly with PFR from HFV. There were good correlations between LVEDV, LVESV, LVEF, PER, PFR, 1/3FR, TPF and 1/3FF from HFV and those from cardioGRAF. LVEF, PER, 1/3FR, and PFR were significantly correlated with plasma BNP concentrations. In patients with non-ischemic heart disease (n = 42), phase SD and histogram bandwidth were correlated negatively with exercise capacity or PFR.

Conclusions

HFV-derived LVF(x) are correlated with LVF(x) from the other programs or UCG, or with the clinical markers of heart failure and are thus useful in the functional assessment for patients with heart disease.     

Quantification of left ventricular function and mass in heart transplant recipients using dual-source CT and MRI: initial clinical experience

The purpose of this study was to compare LV function and mass quantification derived from cardiac dual-source CT (DSCT) exams with those obtained by MRI in heart transplant recipients. Twelve heart transplant recipients who underwent cardiac DSCT and MRI examination were included. Double-oblique short-axis 8-mm slice thickness images were evaluated. Left ventricular ejection fraction, end-diastolic volume, end-systolic volume, stroke volume, cardiac output and myocardial mass were manually assessed for each patient by two blinded readers. A systematic overestimation of all left ventricular volumes by DSCT when compared with MRI was observed. Mean difference was 16.58 +/- 18.61 ml for EDV, 4.9 4 +/- 6.84 ml for ESV, 11.64 +/- 13.58 ml for SV and 5.73 +/- 1.14 l/min for CO. Slightly lower values for left ventricular ejection fraction with DSCT compared with MRI were observed (mean difference 0.34 +/- 3.18%, p = 0.754). Correlation between DSCT and MRI for left ventricular mass was excellent (rho = 0.972). Bland and Altman plots and CCC indicated good agreement between DSCT and MRI left ventricular function and mass measurements. The interobserver correlation was good. In conclusion, DSCT accurately estimates left ventricular ejection fraction, volumes and mass in heart transplant recipients.     

Stereological estimation of left-ventricular volumetric and functional parameters from multidetector-row computed tomography data

This study aims to optimize the stereological method for estimating left-ventricular (LV) parameters from retrospectively electrocardiography-gated 16-row MDCT and to compare stereological estimations with those by MRI. MDCT was performed in 17 consecutive patients with known or suspected coronary disease. Stereological measurements based on point counting were optimized by determining the appropriate distance between grid points. LV parameters were evaluated by standard CT analysis using a semi-automatic segmentation method. Two independent observers evaluated the reproducibility of the stereological method. End-diastolic volume (EDV) and end-systolic volume (ESV) estimations with a coefficient of error below 5% were obtained in a mean time of 2.3 +/- 0.5 min with a point spacing of 25 and 15 pixels, respectively. The intra- and interobserver variability for estimating LV parameters was 2.6-4.4 and 4.9-8.2%, respectively. MRI estimations were highly correlated with those by standard CT analysis (R > 0.82) and stereology (R > 0.84). Stereological method significantly overestimated EDV and ESV compared to MRI (EDV: P = 0.0011; ESV: P = 0.0013), whereas for stroke volume (SV) and ejection fraction (EF), no difference was observed (P > 0.05). For standard CT analysis and MRI, significant differences were found except for SV and EF (EDV: P = 0.0008; ESV: P = 0.0004; EF: P = 0.051; SV: P = 0.064). The time-efficient optimized stereological method enables the reproducible evaluation of LV function from MDCT.     

电影磁共振图像评定运动员心脏形态与功能

本文对瑞典10名耐力运动员(耐力组,长跑7人,游泳3人),10名举重运动员(力量组)及10名健康无训练者(对照组)进行了心脏电影磁共振图像与最大吸氧量的测试。结果表明:1)从左室舒末容量、左室编末容量、心搏量、左室心肌重量、最大吸氧量、最大通气量等指标来看,无论是其绝对实测值,还是其按体表面积或体重校正计算的相对值,耐力组均非常显著地大于其它二组。力量组除了左室心肌重量及左室心肌重量/左室舒末容量比值略有增高外(P<0.05),其余各指标与对照组比较均无显著性差异。2)左室舒末容量、心搏量、左室心肌重量及最大通气量四指标均与最大吸氧量呈高度正相关关系,相关系数依次为0.88,0.85,0.81,0.76,各相关系数均有高度显著性(P<0.001)。3)本文各组的左室心肌重量的电影磁共振图像测定值低于以往多数类似研究对象的超声心动图测定值。文章指出,电影磁共振图像技术是评定左室心肌重量与左室容量十分准确可靠的无创性检查新方法。本文首先报道了运动员心脏电影磁共振部分指标正常测量值。     

中国人心脏房室腔内径及左右心室功能正常参数的MRI研究

目的 使用MRI测量中国正常成人心脏各房室腔内径及心功能参数.方法 共269名正常志愿者,无线矢量心电门控下,采用单次激发半傅立叶快速自旋回波与真实稳态自由进动序列,分别获得标准心脏各长轴及短轴切面二维体层及电影图像.由2名医师独立分析MRI,分别测量心脏各房室腔径线及心功能后处理分析,获得包括射血分数(EF)、舒张末容积(EDV)、收缩末容积( ESV)及心肌质量(CM)等心功能参数.男性与女性相对应参数做非配对的t检验.结果 所有志愿者均完成MR扫描,平均扫描时间(15 ±3) min.心脏各房室腔主要参数为:左心房前后径(2.87±0.77) cm,右心房径(垂直于房间隔,3.61 ±0.57)cm,左心室舒张末横径(4.97±0.52) cm,右心室舒张末横径(2.65±0.48) cm,心功能主要参数为:左心室EF (60.62±7.08)％、EDV( 128.27±32.16) ml、ESV(46.02±15.72) ml、CM( 82.97±24.03)g;右心室EF (47.73±6.50)％、EDV(115.37±26.71) ml、ESV(67.7±21.07) ml、CM(48.24±13.42)g.除左心室ESV(P =0.144)、EDV指数(P=0.714)、ESV指数(P =0.113)、心脏指数(P=0.199)及右心室EF值(P=0.296)和ESV指数(P =0.093)男女差异无统计学意义外,其余各指标性别间差异均有统计学意义(P＜0.01).结论 MRI以其高度的可重复性可获得正常中国人心脏形态与功能信息.     

Assessment of cardiac function and left ventricular regional wall motion by 99mTc multigated cardiac blood-pool emission computed tomography]

Forty-three patients underwent the analysis of left and right ventricular (LV and RV) volumes, and LV regional wall motion by multigated cardiac blood pool single photon emission computed tomography (SPECT) with 99mTc. To calculate the cardiac volume correctly, the optimal cutoff level in relation to background level was first obtained by a phantom study. Left ventricular end-diastolic, end-systolic volume (EDV and ESV) and ejection fraction (EF) calculated thus with SPECT were correlated well with the data obtained with left ventriculography (LVG) and magnetic resonance imaging (MRI), especially using horizontal long axial image. RV stroke volume (SV) without shunt or valvular diseases was also correlated well with that of LV when it was calculated using horizontal long axial image. However, SV ratio (LVSV/RVSV) was not necessarily ideal numerical 1. In addition LV wall motion was evaluated by multicontour systolic display and phase analysis in SPECT and gated planar images. The results obtained with SPECT were better correlated with those of LVG than gated planar images. It is concluded that multigated cardiac blood pool SPECT is a clinically useful method for an evaluation of cardiac function and left ventricular regional wall motion.     

Gated SPECT findings revealing diastolic dysfunction in acute hypothyroidism

PURPOSE: The purpose of this study was to assess left ventricular (LV) function by gated SPECT in acute hypothyroidism. METHODS: Thirty-eight acute hypothyroid patients without any cardiac disease and 40 healthy controls underwent gated SPECT at rest. Fourteen patients had a second examination during thyroxine replacement therapy. Gated SPECT was performed using Tc-99m sestamibi with 16 frames per cardiac cycle. The LV end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), peak ejection rate (PER), peak filling rate (PFR), and time to peak filling (TTPF) were measured by quantitative gated SPECT (QGS). Systolic wall thickening/motion was determined in 5 myocardial segments. RESULTS: Hypothyroid patients exhibited a decrease in PFR (222 +/- 52 EDV/s) and prolongation of TTPF (194 +/- 32 msec) as compared with controls (247 +/- 41 EDV/s and 179 +/- 17 msec, respectively; P < 0.05). During thyroxine therapy, the mean values for EDV (74 +/- 21 mL) and PFR (265 +/- 64 EDV/s) increased significantly in 14 follow-up patients (pretreatment values 67 +/- 18 mL and 219 +/- 50 EDV/s, respectively; P < 0.05). A significant difference was detected in the mean TTPF between the thyroxine group and the controls (195 +/- 35 msec vs 179 +/- 17 msec; P < 0.05). No significant differences were found in wall thickening and motion values (P > 0.05). CONCLUSION: Gated SPECT findings revealed diastolic dysfunction as indicated by a decrease in PFR and a prolongation in TTPF in patients with acute hypothyroidism.     

Quantitative assessment of left ventricular function with dual-source CT in comparison to cardiac magnetic resonance imaging: initial findings

Cardiac magnetic resonance imaging and echocardiography are currently regarded as standard modalities for the quantification of left ventricular volumes and ejection fraction. With the recent introduction of dual-source computedtomography (DSCT), the increased temporal resolution of 83 ms should also improve the assessment of cardiac function in CT. The aim of this study was to evaluate the accuracy of DSCT in the assessment of left ventricular functional parameters with cardiac magnetic resonance imaging (MRI) as standard of reference. Fifteen patients (two female, 13 male; mean age 50.8 ± 19.2 years) underwent CT and MRI examinations on a DSCT (Somatom Definition; Siemens Medical Solutions, Forchheim, Germany) and a 3.0-Tesla MR scanner (Magnetom Trio; Siemens Medical Solutions), respectively. Multiphase axial CT images were analysed with a semiautomatic region growing algorithms (Syngo Circulation; Siemens Medical Solutions) by two independent blinded observers. In MRI, dynamic cine loops of short axis slices were evaluated with semiautomatic contour detection software (ARGUS; Siemens Medical Solutions) independently by two readers. End-systolic volume (ESV), end-diastolic volume (EDV), ejection fraction (EF) and stroke volume (SV) were determined for both modalities, and correlation coefficient, systematic error, limits of agreement and inter-observer variability were assessed. In DSCT, EDV and ESV were 135.8 ± 41.9 ml and 54.9 ± 29.6 ml, respectively, compared with 132.1 ± 40.8 ml EDV and 57.6 ± 27.3 ml ESV in MRI. Thus, EDV was overestimated by 3.7 ml (limits of agreement −46.1/+53.6), while ESV was underestimated by 2.6 ml (−36.6/+31.4). Mean EF was 61.6 ± 12.4% in DSCT and 57.9 ± 9.0% in MRI, resulting in an overestimation of EF by 3.8% with limits of agreement at −14.7 and +22.2%. Rank correlation rho values were 0.81 for EDV (P = 0.0024), 0.79 for ESV (P = 0.0031) and 0.64 for EF (P = 0.0168). The kappa value of inter-observer variability were amounted to 0.85 for EDV, ESV and EF. DSCT offers the possibility to quantify left ventricular function from coronary CT angiography datasets with sufficient diagnostic accuracy, adding to the value of the modality in a comprehensive cardiac assessment. The observed differences in the measured values may be due to different post-processing methods and physiological reactions to contrast material injection without beta-blocker medication. S. Busch and T. Johnson contributed equally to this study.