Soler R, Rodríguez E, Marini M
Department of Radiology, Hospital Juan Canalejo, La Coruña, Spain.
J Comput Assist Tomogr. 1999 Jul-Aug;23(4):577-82. doi: 10.1097/00004728-199907000-00018.
The goals of this work were to evaluate the practical utility of MRI to quantify myocardial mass in patients with hypertrophic cardiomyopathy (HCM), define the differences in myocardial mass measurements obtained with three-dimensional and geometric MR methods in patients with normal left ventricular morphology and in patients with wall thickening, and establish the correlation between the two MR methods and the geometric echocardiographic method (GEM).
The same protocol was followed to conduct prospective MR examinations on 72 patients. In 60 of the subjects suspected to have HCM, imaging was performed to confirm or rule out the preliminary clinical diagnosis; the other 12 were healthy volunteers. Multislice SE, single slice multiphase, and multislice multiphase GRE sequences were performed in all cases. Left ventricle mass was calculated using formulas that assume an ellipsoid geometry for the left ventricle (geometric method), and the results were compared with the mass found using the three-dimensional method and subsequent application of Simpson rule. Tests were run to evaluate intraobserver variability in the MR data obtained with the three-dimensional method. The measurements obtained with the two MR methods were compared with the results obtained with GEM.
Although the mean left myocardial mass values obtained using the three-dimensional MR method were smaller than the mean values found with the geometric MR method in all patients, the difference was significant only in patients with HCM. The correlation between the geometric MR method and GEM was very good both in patients with HCM and in those with normal wall thickening. The correlation between the three-dimensional MR method and GEM was good in patients whose left ventricle morphology was normal and poor in patients with HCM. Intraobserver agreement for three-dimensional mass values was excellent.
MR examinations should be a standard technique for calculating myocardial ventricular mass. In patients with normal ventricle wall thickness, the geometric method can be used to calculate myocardial mass because it is less time consuming. However, in patients with abnormal morphology of the left ventricle and/or asymmetric wall thickening such as found in HCM, in whom the geometric method overestimates myocardial mass, measurements should be made using the three-dimensional method.
本研究的目的是评估磁共振成像（MRI）在肥厚型心肌病（HCM）患者中量化心肌质量的实际效用，明确在左心室形态正常和存在室壁增厚的患者中，三维和几何磁共振方法所测得的心肌质量差异，并建立两种磁共振方法与几何超声心动图方法（GEM）之间的相关性。
对72例患者按照相同方案进行前瞻性磁共振检查。其中60例疑似患有HCM的受试者接受成像检查以证实或排除初步临床诊断；另外12例为健康志愿者。所有病例均采用多层自旋回波（SE）、单层多期和多层多期梯度回波（GRE）序列。使用假定左心室为椭球体几何形状的公式计算左心室质量（几何方法），并将结果与使用三维方法及随后应用辛普森法则得出的质量进行比较。进行测试以评估三维方法获得的磁共振数据的观察者内变异性。将两种磁共振方法获得的测量结果与GEM获得的结果进行比较。
尽管在所有患者中，使用三维磁共振方法获得的左心肌质量平均值小于几何磁共振方法测得的平均值，但仅在HCM患者中差异具有统计学意义。在HCM患者和室壁增厚正常的患者中，几何磁共振方法与GEM之间的相关性都非常好。在左心室形态正常的患者中，三维磁共振方法与GEM之间的相关性良好，而在HCM患者中相关性较差。三维质量值的观察者内一致性极佳。
磁共振检查应成为计算心室心肌质量的标准技术。在心室壁厚度正常的患者中，可使用几何方法计算心肌质量，因为其耗时较少。然而，在左心室形态异常和/或存在不对称室壁增厚的患者中，如在HCM患者中，几何方法会高估心肌质量，此时应使用三维方法进行测量。
