Single and biplane TrueFISP cardiovascular magnetic resonance for rapid evaluation of left ventricular volumes and ejection fraction.

INTRODUCTION: Cardiovascular magnetic resonance (CMR) allows very accurate, but time-consuming, volume assessment by the short-axis slice summation technique. The single and biplane methods of volume assessment are used less, partly because FLASH cine imaging provides poor blood-myocardium contrast in long-axis views. TrueFISP gives excellent blood-myocardium contrast, even in patients with heart failure. We hypothesized that the single plane and biplane methods of volume assessment in TrueFISP images might provide an acceptable degree of accuracy and be quicker than the short axis method, and that single and biplane left ventricular volume assessment would be more accurate with TrueFISP than with FLASH in patients with impaired ventricular function. METHODS: Short- and long-axis CMR images were obtained by FLASH and TrueFISP with a 1.5-T scanner. We determined the accuracy of both single and biplane long-axis methods for left ventricular volume and ejection fraction (EF) measurements compared with the conventional short-axis method in 10 heart failure patients using both FLASH and TrueFISP and in 9 healthy subjects using TrueFISP. RESULTS: No difference in volumes and EF was found between the single plane method, the biplane method, and the short-axis method using TrueFISP for image acquisition, in both patients and healthy subjects. The same was true of the results obtained by FLASH in the patients with heart failure. CONCLUSIONS: The single and biplane methods, regardless of whether TrueFISP or FLASH is used, are a reasonable and rapid alternative to the conventional short-axis approach for left ventricular volume and EF assessment in patients with heart failure and impaired ventricular function.     

Determination of normal gender-specific left atrial dimensions by cardiovascular magnetic resonance imaging.

BACKGROUND: Because cardiovascular magnetic resonance imaging (CMR) is becoming increasingly available in clinical practice, there is a need to establish normal values for left atrial dimensions as determined by this method to allow accurate assessment of cardiac dimensions and to provide standardization for follow up studies. For clinical purpose measurements of the left atrial end diastolic diameter (LAEDD) are most appropriate to assess left atrial size. We aimed to establish normal values for LAEDD using CMR and a fast gradient-echo sequence with steady-state free precession (SSFP). METHODS: A total of 111 healthy subjects (52 women and 59 men, mean age 51.5 +/- 14.5 years) were examined by CMR. Images were acquired using SSFP in the horizontal (HLA) and vertical (VLA) long axis planes and the left ventricular outflow tract plane (LVOT) to measure the LAEDD. RESULTS: Age between men and women was not different (p = 0.7050). CMR yielded the following normal ranges for LAEDD: HLA 4.5 +/- 0.4 cm for men and 4.2 +/- 0.5 for women, VLA 4.5 +/- 0.5 cm for men and 4.2 +/- 0.4 for women, and LVOT 2.8 +/- 0.3 cm for men and 2.8 +/- 0.4 for women. LAEDD were significantly larger in HLA and VLA than in LVOT (p < or = 0.0001). There was no significant difference in the measurements between HLA and VLA (p = 0.4617). Gender-related differences for LAEDD were found in HLA (p = 0.0087) and VLA (p = 0.0015) but not in LVOT (p = 0.5281). LAEDD were not found to be age-related (p > or = 0.0994). CONCLUSIONS: LAEDD differ significantly according to the image plane. We provide reference values for CMR using prospective triggering in the evaluation of left atrial diameters to identify patients with enlarged left atria and for follow-up studies.     

Reference left atrial dimensions and volumes by steady state free precession cardiovascular magnetic resonance

Background

Left atrial (LA) size is related to cardiovascular morbidity and mortality. Cardiovascular magnetic resonance (CMR) provides high quality images of the left atrium with high temporal resolution steady state free precession (SSFP) cine sequences. We used SSFP cines to define normal ranges for LA volumes and dimensions relative to gender, age and body surface area (BSA), and examine the relative value of 2D atrial imaging techniques in patients.For definition of normal ranges of LA volume we studied 120 healthy subjects after careful exclusion of cardiovascular abnormality (60 men, 60 women; 20 subjects per age decile from 20 to 80 years). Data were generated from 3-dimensional modeling, including tracking of the atrioventricular ring motion and time-volume curves analysis. For definition of the best 2D images-derived predictors of LA enlargement, we studied 120 patients (60 men, 60 women; age range 20 to 80 years) with a clinical indication for CMR.

Results

In the healthy subjects, age was associated with LA 4-chamber transverse and 3-chamber anteroposterior diameters, but not with LA volume. Gender was an independent predictor of most absolute LA dimensions and volume, but following normalization to BSA, some associations became non-significant. CMR normal ranges were modeled and are tabled for clinical use with normalization, where appropriate, for BSA and gender and display of parameter variation with age. The best 2D predictors of LA volume were the 2-chamber area and 3-chamber area (both r = 0.90, p < 0.001).

Conclusions

These CMR data show that LA dimensions and volume in healthy, individuals vary significantly by BSA, with lesser effects of age and gender.     

Assessment of right ventricular volumes and function using cardiovascular magnetic resonance cine imaging after atrial redirection surgery for complete transposition of the great arteries

Cardiovascular magnetic resonance (CMR) imaging is the reference standard for measurement of right ventricular (RV) volumes and function. To date, no study has compared methods of data acquisition and analysis by CMR for adults with a systemic RV. Our objective was to evaluate RV size and function using axial and short axis views in adults post atrial switch (Mustard) surgery. A total of 34 adults (20 male, mean age at CMR 32 ± 6 years) were identified at our centre. Volumes, RV end-diastolic (EDV) and end-systolic (ESV) were measured in short axis and axial orientations by two independent experienced readers, blinded to clinical and CMR data. Intra and interobserver measurements in each view were compared using Bland–Altman plots and intraclass correlation coefficients (ICC). Although mean volumes were larger in the axial as compared with the short axis view [RVEDV 247 ± 67 vs. 233 ± 54 ml (p = 0.002) and RVESV 148 ± 54 vs. 136 ± 50 ml (p = 0.001)], mean RV ejection fractions (EF) were similar [41 ± 9 % vs. 43 ± 12 % (p = 0.13)]. Bland–Altman plots demonstrated better agreement for axial measures of RVEDV and right ventricular ejection fraction (RVEF) within and between observers. Similarly, ICC values were stronger for axial as compared with short axis volumes and function—intraobserver RVEDV 0.99 (0.98–0.99) versus 0.96 (0.92–0.98) and RVEF 0.96 (0.93–0.98) versus 0.90 (0.82–0.95); interobserver RVEDV 0.97 (0.94–0.98) versus 0.90 (0.73–0.95) and RVEF 0.85 (0.53–0.94) versus 0.82 (0.67–0.90). Axially derived measurements of RV volumes and function have better agreement and reproducibility as compared with short axis values; whereas axial volumes tend to be larger, RVEF is not significantly different between the two methods.     

Relationship between left atrial appendage emptying and left atrial function using cardiac magnetic resonance in patients with atrial fibrillation: comparison with transesophageal echocardiography

To compare cardiac magnetic resonance (CMR) quantifications of left atrium (LA) function and left atrial appendage (LAA) emptying depending on the presence of LA spontaneous echogenic contrast (LA-SEC) on transesophageal echocardiography (TEE) in patients with atrial fibrillation (AF). A total of 48 patients with AF underwent sequential CMR examination and TEE in preparation for catheter ablation. The CMR protocol included cine and velocity encoding (VENC) sequences for evaluation of both LA function and LAA emptying. The peak blood velocity of LAA just before left ventricle systole was defined as the LAA emptying velocity (LAA-EV). Depending on the presence of LA-SEC on TEE, patients were divided into two groups, the SEC group (n?=?15) and the non-SEC group (n?=?33). Mean LAA-EV was significantly greater in the non-SEC group than in the SEC group (54.5?±?24.8 ml/s vs. 26.0?±?22.6 ml/s, P?<?0.01). LAA-EV had a significant positive relationship (P?<?0.05) with LAA backflow velocity, as assessed using TEE. Use of an optimal LAA-EV cutoff value of 35 ml/s to predict LA-SEC yielded a sensitivity of 80.0?%, a specificity of 75.7?%, and positive and negative predictive values of 58.8 and 83.9?%, respectively. Using VENC-CMR, LAA-EV is associated with LA function and can be useful for predicting LA-SEC in patients with AF.     

A novel technique using biplane cine magnetic resonance imaging to evaluate left ventricular volume in children

The purpose of the study is to determine the feasibility of a novel simplified technique using cine magnetic resonance imaging (MRI) to assess left ventricular (LV) volume and ejection fraction (EF) validated by comparison with biplane LV angiography. Previous MRI studies to assess LV volumes have used multiple axial planes, which are compromised by partial volume effects and are time consuming to acquire and analyze. Accordingly, we developed a simplified imaging approach using biplane cine MRI and imaging planes aligned with the intrinsic cardiac axes of the LV. We studied 20 children (aged 4 months to 10 years) with various heart diseases. The accuracy of cine MRI was compared with that of LV angiography in all patients. LV volumes were calculated using Simpson's rule algorithm, for both MRI and LV angiography. LV volumes determined from MRI were slightly underestimated but correlated reasonably well with angiographic volumes (LVEDV: Y = 0.88X + 1.58, r = 0.99, LVESV: Y = 0.73X + 1.03, r = 0.98). Most importantly, even in patients who had abnormal ventricular curvature such as in tetralogy of Fallot, MRI determined LV volumes correlated well with angiographic values. The MR study was completed within 35 min in all patients. In conclusion, simplified biplane cine MRI, using the intrinsic LV axis planes, permits noninvasive assessment of LV volumes in views comparable to standard angiographic projections and appears practical for clinical use in childhood heart disease since the scan and analysis times are relatively short.     

二维斑点追踪显像评价阵发性房颤患者左心房功能

目的 应用二维斑点追踪显像(STI)技术评价阵发性房颤(PAF)患者左心房功能变化。 方法 分别对30例PAF患者(PAF组)和30名正常人(对照组)进行常规超声心动图检查,测定左心房内径(LAD)、舒张早期二尖瓣跨瓣血流速度(E)、舒张晚期二尖瓣跨瓣血流速度(A)、E/A、肺静脉收缩峰值流速(PVs)、肺静脉舒张峰值流速(PVd)、肺静脉收缩峰值流速/舒张峰值流速(S/D)、心房收缩期流入肺静脉血流流速(PVa),计算左心房最大容积(LAVmax)、左心房最小容积(LAVmin)、左心房收缩前容积(LAVp)、左心房被动射血分数(LAPEF)和左心房主动射血分数(LAAEF);应用STI技术获取左心房各壁各节段的应变率曲线,分别测量左心室收缩期左心房峰值应变率(SRs)、左心室舒张早期左心房峰值应变率(SRe)和左心室舒张晚期左心房峰值应变率(SRa),计算其平均值(mSRs、mSRe、mSRa)。 结果 与对照组比较,PAF组LAD、LAVmax、LAVp、LAVmin增大(P<0.05),LAAEF、LAPEF减低(P<0.05);E升高、A减低、E/A升高(P<0.05),PVs、PVd减低,S/D减低(P<0.05);PAF组左心房各壁各节段SRs、SRe和SRa降低,差异有统计学意义(P<0.05)。PAF组中,SRs与SRe及SRa之间无相关性(P>0.05),mSRa与LAAEF之间呈正相关(r=0.78,P<0.01);对照组中,SRs分别与SRe及SRa呈负相关(r分别为-0.347、-0.384,P<0.05)。 结论 PAF患者左心房各壁应变率峰值减低,左心房辅泵功能、管道功能和储蓄功能相互代偿作用减弱或消失。     

应变成像技术评价心房颤动患者左心房功能

目的 探讨应变成像技术评价心房颤动(房颤)患者左心房功能的价值.方法 对20例正常人、24例阵发性房颤患者与17例持续性房颤患者进行常规超声心动图及应变成像检查,于心尖四腔观测定房间隔和左心房侧壁中段及上段的应变峰值(ε),比较三组间测量结果.结果 在正常组,心房上段的ε明显高于中段,且具有较好的稳定性和重复性;同一水平房间隔的应变峰值(εs)和左心房侧壁的应变峰值(εl)差异无统计学意义,心房上段εs、εl的平均值(εm)可作为评价左心房功能的参数.房颤组的εm明显低于正常组;与阵发性房颤组相比,持续性房颤组的εm更低;而对于左心房前后径尚属于正常范围的阵发性房颤组,其εm也已明显低于正常组.结论 应变成像技术能够无创、简单而迅速地评价心房功能,εm是评价心房功能有效而敏感的参数.     

Left atrial appendage function in patients with cardioembolic stroke in sinus rhythm and atrial fibrillation.

The purpose of this study was to determine the left atrial appendage (LAA) function in patients with stroke. The study group consisted of 61 patients with stroke and 37 control subjects. Patients with stroke were divided into 2 groups on the basis of the presence of atrial fibrillation (group 1) or sinus rhythm (group 2). Group 1 showed a significant reduction of LAA flow velocities (13.2 +/- 6.4 cm/s versus 27.5 +/- 8 cm/s, P <.05) and significant increase in LAA areas (minimum area: 360.5 +/- 204 mm(2) versus 217.7 +/- 113.9 mm(2), P =.004). Group 2 showed a decrease in LAA flow velocities (17.7 +/- 8.2 cm/s versus 27.5 +/- 8 cm/s, P <.05), but no significant change was found in LAA areas. No significant difference was found in other parameters related to LAA. These findings show that a decreased LAA flow velocity is a risk factor for stroke in patients in sinus rhythm without LAA enlargement. Left atrial appendage area was increased in size only in patients with atrial fibrillation.     

心房颤动状态下左心耳功能的超声应变率研究

目的应用应变率显像（SRI）分析持续性心房颤动（房颤）患者左心耳功能变化特点，探讨病理状态下左心耳机械运动的变化。方法分别选择29例持续性房颤患者和31例对照者，经食管超声心动图（TEE）获取左心耳超声图像，应用SRI技术对两组左心耳壁各节段应变率（SR）相关指标变化特点进行分析和比较。结果对照组中，左心耳壁顶部收缩期峰值应变率（SR）s和舒张期应变率（SRD）均高于其余节段（P〈O．01）。持续房颤组中，心耳顶部SRs仅高于间隔壁及侧壁中段（P〈0．05），心耳顶部SRD，仅高于间隔壁中段（P〈0．05）。持续房颤组各节段SRs和SRD较对照组均降低（P〈0．01）。对照组中，心耳顶部SRs与左心耳面积变化率和左心耳充盈速度呈正相关（r=0．724，0．637，P〈0．001）。结论左心耳顶部SRs决定了心耳整体的排空能力，房颤患者心耳壁的舒缩功能明显降低且失去有效协调运动。     

左心耳多模态磁共振成像研究进展

左心耳(left atrial appendage,LAA)是左心房的重要附属结构,对其结构和功能的评价在房颤治疗、相关介入手术中至关重要。多模态磁共振成像可以清晰地显示LAA结构并可定量测量其功能指标,其在评估LAA结构和功能方面的应用日益广泛。现将近年来多模态MRI在LAA扫描技术、LAA结构及功能的定量研究、LAA血栓检测及相关危险因素评价、LAA介入治疗的相关评估等方面予以综述。     

Assessment of left atrial volumes at 1.5 Tesla and 3 Tesla using FLASH and SSFP cine imaging.

PURPOSE: To investigate left atrial volumes and function and their variability in healthy volunteers using steady state free precession (SSFP) and fast low angle shot (FLASH) sequences at both 1.5 and 3 T using both the short-axis and biplane area-length methods. MATERIALS AND METHODS: Ten healthy volunteers underwent CMR at both 1.5 and 3 Tesla. The biplane area-length method utilized volumes from the horizontal and vertical long axis images. RESULTS: There were no significant differences between left atrial short-axis volumes or function between 1.5 and 3 T assessed using either FLASH or SSFP sequences. The biplane area-length method underestimated maximal left atrial volume using FLASH by 12 mL at 3 T (18%) and by 10 mL (14%) at 1.5 T (p = 0.003 and p = 0.05 respectively). Variability was larger for left atrial measurements using the biplane area-length method. CONCLUSION: Field strength had no effect on left atrial volume and function assessment using either FLASH or SSFP. The use of the short-axis method for the acquisition of left atrial parameters is more reproducible than the biplane area-length for serial measurements.     

Validation of a rapid semi-automated method to assess left atrial longitudinal phasic strains on cine cardiovascular magnetic resonance imaging

Background

Abnormal left atrial (LA) function is a marker of cardiac dysfunction and adverse cardiovascular outcome, but is difficult to assess, and hence not, routinely quantified. We aimed to determine the feasibility and effectiveness of a fast method to measure long-axis LA strain and strain rate (SR) with standard cardiovascular magnetic resonance (CMR) compared to conventional feature tracking (FT) derived longitudinal strain.

Methods

We studied 50 normal controls, 30 patients with hypertrophic cardiomyopathy, and 100 heart failure (HF) patients, including 40 with reduced ejection fraction (HFrEF), 30 mid-range ejection fraction (HFmrEF) and 30 preserved ejection fraction (HFpEF). LA longitudinal strain and SR parameters were derived by tracking the distance between the left atrioventricular junction and a user-defined point at the mid posterior LA wall on standard cine CMR two- and four-chamber views. LA performance was analyzed at three distinct cardiac phases: reservoir function (reservoir strain ε_s and strain rate SR_s), conduit function (conduit strain ε_e and strain rate SR_e) and booster pump function (booster strain ε_a and strain rate SR_a).

Results

There was good agreement between LA longitudinal strain and SR assessed using the fast and conventional FT-CMR approaches (r?=?0.89 to 0.99, p?<?0.001). The fast strain and SRs showed a better intra- and inter-observer reproducibility and a 55% reduction in evaluation time (85?±?10 vs. 190?±?12 s, p?<?0.001) compared to FT-CMR. Fast LA measurements in normal controls were 35.3?±?5.2% for ε_s, 18.1?±?4.3% for ε_e, 17.2?±?3.5% for ε_a, and 1.8?±?0.4, ??2.0?±?0.5, ??2.3?±?0.6 s^??1 for the respective phasic SRs. Significantly reduced LA strains and SRs were observed in all patient groups compared to normal controls. Patients with HFpEF and HFmrEF had significantly smaller ε_s, SR_s, ε_e and SR_e than hypertrophic cardiomyopathy, and HFmrEF had significantly impaired LA reservoir and booster function compared to HFpEF. The fast LA strains and SRs were similar to FT-CMR for discriminating patients from controls (area under the curve (AUC)?=?0.79 to 0.96 vs. 0.76 to 0.93, p?=?NS).

Conclusions

Novel quantitative LA strain and SR derived from conventional cine CMR images are fast assessable parameters for LA phasic function analysis.

     

Impact of the ECG gating method on ventricular volumes and ejection fractions assessed by cardiovascular magnetic resonance imaging.

PURPOSE: Most MRI centers currently use prospective ECG triggering and fast gradient-echo sequences for image acquisition. Retrospectively gated sequences allow the coverage of the entire cardiac cycle. There is concern about whether ventricular volumes and ejection fraction (EF) differ according to the gating method used for image acquisition. We sought to evaluate the impact of the gating method on measurements of right and left ventricular volumes and EF in normal subjects. MATERIALS AND METHODS: Fifteen subjects with no cardiovascular disease were investigated by MRI using a 1.5 Tesla scanner. Images were acquired with a gradient-echo sequence with steady-state free precession (SSFP) using the standard short-axis method for volume and EF measurements. Images were acquired with 6-mn-thick slices using both prospective triggering and retrospective gating. Left and right ventricular volumes (EDV, ESV, SV) and EF were determined with a commercially available software package (Argus, Siemens). RESULTS: EDV and SV calculated from short-axis images were significantly smaller with the prospectively triggered SSFP sequence (mean difference: EDV left: 13.9 +/- 4.4 mL, p < 0.0001; SV left: 13.5 +/- 4.8 mL, p < 0.0001; EDV right: 14.2 +/- 3.9 mL, p < 0.0001; SV right: 14.7 +/- 5.9 mL, p < 0.0001). EF was significantly smaller for the right ventricle (mean difference -3.6 +/- 3.3%, p = 0.0008) and the left ventricle (mean difference -2.3 +/- 3.3%, p = 0.02). ESV remained unchanged (mean difference: ESV left: 0.47 +/- 3.5 mL, p = 0.6179; right ESV: 0.5 +/- 3.7 mL, p = 0.6083). CONCLUSION: The gating method has a significant impact on volume and EF measurements. The global ventricular EF is underestimated by using the prospective triggering technique. However, the difference in the left ventricle is small and might not be of clinical relevance.     

组织速度成像结合应变率成像技术对房颤状态下左心耳功能的评价

目的应用应变率成像（SRI）结合组织速度（TVI）显像技术评价持续性房颤患者左心耳机械运动特点以及变化特点。方法对29例患者和31例对照者行经食管超声检查,比较各节段运动速度（PSV和PDVE）以及局部心肌沿长轴的应变率（Ssr和Dsr）变化特点。结果对照组左心耳壁顶部Ssr、Dsr、PSV和PDVE均高于其余节段（P〈0.01,0.05）。房颤组左心耳顶部Ssr、PSV仅高于间隔壁及侧壁中段（P〈0.05）,心耳顶部Dsr仅高于间隔壁中段（P〈0.05）。对照组心耳顶部Ssr、PSV与左心耳面积变化率（LAA-EF）和左心耳充盈速度（LAA-EV）呈正相关（r=0.724、0.637、0.656、0.712,P〈0.001）,房颤组心耳顶部PSV与LADd呈线性负相关（r=-0.66,P〈0.001）。房颤组各节段Ssr、Dsr、PSV以及PDVE较对照组均降低（P〈0.01）。结论左心耳顶部Ssr以及PSV决定了心耳整体的排空能力,房颤患者由于心耳壁舒缩功能明显降低导致的心耳壁运动不协调。TVI和SRI技术相结合,能更为全面地反映左心耳功能变化特点。     

Normal human left and right ventricular and left atrial dimensions using steady state free precession magnetic resonance imaging.

PURPOSE: The aim of this project was to establish a database of left and right ventricular and left atrial dimensions in healthy volunteers using steady-state free precession cardiac magnetic resonance imaging, the clinical technique of choice, across a wide age range. METHODS: 108 healthy volunteers (63 male, 45 female) underwent cardiac magnetic resonance imaging using steady-state free precession sequences. Manual analysis was performed by 2 experienced observers. RESULTS: Left and right ventricular volumes and left ventricular mass were larger in males than females: LV end-diastolic volume 160 +/- 29 mL vs. 135 +/- 26 mL, LV end-systolic volume 50 +/- 16 mL vs. 42 +/- 12 mL; RV end-diastolic volume 190 +/- 33 mL vs. 148 +/- 35 mL, RV end-systolic volume 78 +/- 20 mL vs. 56 +/- 18 mL (p < .05 for all). Normalization of values to body surface area removed the statistical differences for LV volumes, but not for LV mass or RV volumes. With increased age, males showed a significant decrease in volume and mass indices for both ventricles, while female values remained unchanged. Compared to females, males had significantly larger maximal left atrial volumes (103 +/- 30 mL vs. 89 +/- 21 mL, p = .01) and left atrial stroke volumes (58 +/- 23 mL vs. 48 +/- 15 mL, p = .01). There was no difference in left atrial ejection fraction between the sexes. CONCLUSION: We have produced a large database of age-related normal ranges for left and right ventricular function and left atrial function in males and females. This will allow accurate interpretation of clinical and research datasets.     

Assessment of left atrial volume by contrast enhanced magnetic resonance angiography.

Left atrial (LA) volume is associated with cardiovascular morbidity, particularly atrial fibrillation. Contrast-enhanced magnetic resonance angiography (CE-MRA) visualizes the LA, but the validity of LA volume measurements using this technique has not been evaluated. We performed CE-MRA and cine magnetic resonance (MR) in 18 consecutive patients referred for CE-MRA prior to atrial fibrillation ablation. The CE-MRA LA volumes were compared to cine MR LA volumes at the maximal LA size and at LA end-diastole using linear regression and limits of agreement analysis. The mean cine MR LA volume was 118 +/- 39 mL at maximal LA size and 91 +/- 38 mL at LA end-diastole. Left atrial volume determined by CE-MRA was 93 +/- 38 mL. Although the CE-MRA LA volume had a strong correlation with the maximal cine MR LA volume (R2 = 0.86, p < 0.001), the 95% limits of agreement were relatively wide (-54 to 3 mL). The cine MR LA end-diastolic and CE-MRA LA volumes were more closely correlated (R2 = 0.98, p < 0.001) with narrow 95% limits of agreement (-8 to 11 mL). The CE-MRA LA volumes correspond most closely to LA end-diastolic cine MR LA volumes and may be a useful measure of LA size.     

小鼠心血管超声生物显微镜显像与磁共振成像的对照研究

目的 探索超声生物显微镜显像(UBM)进行小鼠心血管成像的方法和常用切面观,并通过磁共振(MR)成像印证UBM所显示的解剖结构,探讨UBM在小鼠心血管成像中的可行性及应用价值.方法 采用Signo 3.0T磁共振(MR)成像系统对2只C57BL/6健康成年雄性小鼠进行胸部成像.选择C57BL/6健康成年雄性小鼠16只,采用Vevo 770小动物超声成像系统,经胸骨左缘、心尖、胸骨右缘及胸骨上窝等扫查窗口,观察并分析小鼠心脏及大血管的结构及血流频谱并对左心收缩及舒张功能进行评价.结果 小鼠胸部MR成像的解剖特征:心脏大部分位于左侧胸腔,心脏的长轴与身体的长轴线的角度约为45°.左房、左室、二尖瓣和右室位于胸部中线的左侧,主动脉瓣口及升主动脉、右房和三尖瓣位于胸部中线的右侧.UBM显像能获得左室长轴、左室短轴、右室流人道、心尖四腔、肺动脉长轴、升主动脉长轴、主动脉弓长轴、主动脉短轴等切面观,能显示并测量左房、左室、二尖瓣、主动脉及主动脉弓、室间隔、右房、右室、三尖瓣、肺动脉、无名动脉及左颈总动脉等结构,并可顺利获得各瓣口的血流频谱.对不同周龄小鼠测量数据进行比较,各组间差异无统计学意义.结论 UBM显像采用适当的扫查窗口和切面观能显示止常小鼠心脏和主动脉的形态结构和血流动力学状态,为基因敲除鼠动脉粥样硬化模型的研究奠定了基础.