Chapon Catherine, Herlihy Amy H, Bhakoo Kishore K
Stem Cell Imaging, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, UK.
J Cardiovasc Magn Reson. 2008 Jan 24;10(1):6. doi: 10.1186/1532-429X-10-6.
To demonstrate the feasibility of using an inversion recovery pulse sequence and to define the optimal inversion time (TI) to assess myocardial infarction in mice by late gadolinium enhancement (LGE) MRI at 9.4T, and to obtain the maximal contrast between the infarcted and the viable myocardium.
MRI was performed at 9.4T in mice, two days after induction of myocardial infarction (n = 4). For cardiovascular MR imaging, a segmented magnetization-prepared fast low angle shot (MP-FLASH) sequence was used with varied TIs ranging from 40 to 420 ms following administration of gadolinium-DTPA at 0.6 mmol/kg. Contrast-to-noise (CNR) and signal-to-noise ratio (SNR) were measured and compared for each myocardial region of interest (ROI).
The optimal TI, which corresponded to a minimum SNR in the normal myocardium, was 268 ms +/- 27.3. The SNR in the viable myocardium was significantly different from that found in the infarcted myocardium (17.2 +/- 2.4 vs 82.1 +/- 10.8; p = 0.006) leading to a maximal relative SI (Signal Intensity) between those two areas (344.9 +/- 60.4).
Despite the rapid heart rate in mice, our study demonstrates that LGE MRI can be performed at 9.4T using a protocol similar to the one used for clinical MR diagnosis of myocardial infarction.
通过9.4T场强下的延迟钆增强（LGE）磁共振成像（MRI），证明使用反转恢复脉冲序列评估小鼠心肌梗死的可行性，确定最佳反转时间（TI），并获得梗死心肌与存活心肌之间的最大对比度。
在诱导心肌梗死后两天（n = 4），对小鼠进行9.4T场强的MRI检查。对于心血管磁共振成像，在注射0.6 mmol/kg钆喷酸葡胺后，使用分段磁化准备快速低角度激发（MP-FLASH）序列，TI范围为40至420 ms。测量并比较每个心肌感兴趣区域（ROI）的对比噪声比（CNR）和信噪比（SNR）。
对应于正常心肌最小SNR的最佳TI为268 ms±27.3。存活心肌中的SNR与梗死心肌中的SNR有显著差异（17.2±2.4对82.1±10.8；p = 0.006），导致这两个区域之间的最大相对信号强度（SI）（344.9±60.4）。
尽管小鼠心率较快，但我们的研究表明，使用与心肌梗死临床磁共振诊断类似的方案，可在9.4T场强下进行LGE MRI检查。
