The Application Of MRI In Left Ventricular Structure And Function Evaluation

Part 1 A study on structure and function of left ventricular among 40~65 aged healthy people: quantification by MRIObjective: To investigate the medical reference values for the left ventricle(LV) anatomic structure and function of 40~65 aged healthy people with cardiac magnetic resonance(MRI) and confirm the indicators and relationships between age and gender.Methods: Total 90 volunteers, age from 40~49 years old(30), 50~59 years old(30), 60~65 years old(30) without any history of cardiovascular disease and associated risk factors were recruited in the study. Balanced turbo field echo sequences were used to obtain the cine images for LV volume analysis. All parameters were analyzed based on age and gender, and normalized to body surface area(BSA).Results: The EDV, ESV, SV, CO and MM in males group were significant higher than those in females group(P<0.05). EF was no significant difference between males and females groups(P>0.05). Between different gender groups EDVI, ESVI and SVI has no obvious difference(P>0.05), and The MI in male group was significantly higher than that in female(P<0.001). Analysis showed that, left ventricular volumes normalized for BSA decreased with greater age(P<0.05), whereas the EF increased with age(P>0.05).Left ventricular myocardial mass index significantly decreased over the three different age groups(P>0.05).After the BSA standardized, the 95 % medical reference range of EDVI, ESVI, SVI, CI and MI was(70.3, 72.1) ml/m2,(23.0, 23.8) ml/m2,(47.1, 48.5) ml/m2,(3.2, 3.5) L/min/m2 and(48.7, 51.8) g/m2 respectively.Conclusion: This study primarily established 95% medical reference of the left ventricular structure and function, which plays important role in diagnosis cardiac function with cardiac disease.Part 2 Assessment of left ventricular volume and function with 256 i CT: comparison with 3.0 T MRIObjective: To assess the left ventricular volume and function with 256 i CT, and compared with cardiac magnetic resonance(CMR), which was considered as the standard reference technique.Methods: Forty patients referred for CT coronary angiography were enrolled in this study and received CMR within one week. All images were analyzed to obtain left ventricular volume and function values. EDV, ESV, SV and EF were analyzed by paired t-test, Pearson correlation, intraclass correlation coefficient and Bland-Altman plots.Results:Except for EDV, there were significant difference between CMR and 256 i CT measurements. However, the correlation coefficients between CMR and 256 i CT measurements for EDV, ESV, SV and EF were 0.89, 0.85, 0.79, 0.64 respectively. Compared with CMR, EDV and ESV were overestimated by 2.9ml and 8.7ml, while EF and SV were underestimated by 6.8% and 5.8ml. The agreement was reliable.Conclusion:256i CT provided accurate and reproducible measurements of left ventricular volume and function, which can be converted by the correction formula for accurate number.Part 3 Assessment of left ventricular volume and function with echocardiography: comparison with 3.0 T MRIObjective: Cardiac magnetic resonance(CMR) is often considered to be the gold standard in measuring left ventricular volumes and function. The aim of this study was to assess the correlation and agreements between echocardiography and CMR.Methods: Forty patients with clinically suspect of Coronary Heart Disease were underwent CMR and 2DE within one week. EDV, ESV, SV and EF were analyzed by paired t-test, Pearson correlation and Bland-Altman plots.Results: Except for EF, a statistically significant difference was observed in EDV, ESV and SV(P<0.05). The correlation coefficients between 2DE and CMR measurements for EDV, ESV, SV and EF were 0.77, 0.55, 0.79 and 0.62 respectively. Compared with CMR, EDV, ESV, SV and EF were underestimated by 9.4ml, 3.5ml and 5.8ml and 1.0%. Bland-Altman plots of EDV, ESV, SV and EF measured by two imaging modalities showed generally low mean difference but wide limits of agreement.Conclusion: 2DE still can’t replace the use of CMR because of poor evaluation for LV volume and function measurements.Part 4 Assessment of left ventricular volume and function in patients with hypertrophic cardiomyopathy by 3.0 T MRIObjective: This study was conducted to assess the role of cardiac magnetic resonance(CMR) for the evaluation of left ventricular volume and function in patients with hypertrophic cardiomyopathy(HCM) compared to healthy controls.Methods: We enrolled 12 consecutive patients affected by HCM and 30 healthy subjects as control cases(CC). CMR was performed for acquisition of left two chamber, four chamber and short axis view using a 3.0 T scanner. Image post-processing was carried out for left ventricular volume and function analysis.Results: Left ventricular volumes were significantly lower and SV decreased obviously in patients with HCM compared to CC(P<0.01). Wall thickness and left ventricular mass were significantly higher in patients with HCM(P<0.01). A statistically significant difference was also observed in EF and PFR in patients with HCM compared to CC, 69.4±7.0% and 65.8±3.2% for EF, 249.6±79.7ml/s and 300.2±51.4ml/s for PFR.Conclusion: Cardiac magnetic resonance can provide useful and important information for evaluating HCM in diagnosis, risk rating and prognosis.