氢质子磁共振波谱检测体外心脏心肌脂肪变性

目的评价氢质子磁共振波谱(proton magnetic resonance spectroscopy,1H-MRS)技术对判断体外心脏心肌细胞脂肪变性程度的可行性与准确性。方法使用1.5 T磁共振扫描仪扫描10例体外心脏标本,于左心室中部心腔层面左前降支(LAD)、左回旋支(LCX)、右冠状动脉(RCA)支配区各选一感兴趣区,行1H-MRS扫描,分别计算出各谱线中甘油三酯(TG)含量百分比。分析3支血管支配区域内的波谱检测心肌脂肪含量百分比及脂肪变性心肌细胞计数的相关性。结果所有谱线均可靠有效并可进行分析。心肌1H-MRS共可见5个波峰,分别是水峰、肌醇峰、胆碱峰、肌酸峰和TG峰。3支血管支配区内波谱测定脂肪含量百分比的差异无显著性意义(P=0.868),镜下计数也无显著差异(P=0.101)。波谱测定脂肪含量百分比与镜下脂肪变性细胞计数呈正相关(P=0.001)。结论体外心脏1H-MRS技术,具有高度的可行性,脂肪含量百分比与镜下脂肪变性细胞计数呈正相关。

Assessment of myocardial fatty degeneration ex vivo by proton magnetic resonance spectroscopy

Objective To evaluate the feasibility and accuracy of 1H-MRS in the assessment of myocardial fatty degeneration ex vivo.Methods Ten specimens of heart were examined by 1.5 T GE MR scanner.The sequences of 1H-MRS was scanned in LAD,LCX and RCA distribution areas as ROIs in mid-cavity of left cardiac ventricle respectively.The percentages of TG were calculated.The correlations between TG% assessed by MRS and counts of cardiomyocytes with fatty degeneration in voxels of three distribution areas were analyzed respectively.Results Each spectrum was good for analyzing and the spectral peaks were identified with the following chemical shifts: water,myoinositol,choline,creatine,and TG.Neither the percentage of TG nor the cell counts' differences in distribution areas was statistically significant(P=0.868,P=0.101).There was a positive correlation between the percentage of TG and count of cells with fatty degeneration (P=0.001).Conclusion Assessment of myocardial intracellular TG by 1H-MRS ex vivo is feasible and there is positive correlation between the MRS assesment of TG% and cell count.