局部射频增益技术在心脏黑血MRI中的应用初探

Preliminary study on the application of localized TG in black-bood cardiac magnetic resonance imaging

目的探讨局部射频增益(Localized TG)技术在心脏MR成像中对提升黑血图像质量的价值。方法选取27例患者行心脏MR检查,对比观察在黑血双反转速自旋回波T2WI及与化学饱和脂肪抑制相结合的黑血双反转速自旋回波T2WI序列(简称黑血双反转T2WI和黑血双反转脂肪抑制T2WI)扫描中应用局部射频增益(localized TG)和整体射频增益(global TG)技术所获取的图像,并对图像质量进行客观和主观评价。结果1)客观图像质量评价:与传统的Global TG技术相比,Localized TG技术对于黑血心肌图像信噪比(SNR)和对比噪声比(CNR)的提升明显,且差异具有统计学意义(P<0.05);2)主观图像质量评价:对于心肌黑血双反转T2WI及与黑血双反转脂肪抑制T2WI序列,应用Localized TG和Global TG所得的图像质量主观评分差异均具有统计学意义(P<0.05)。结论与传统的Global TG技术相比,Localized TG技术可有效改善3.0T MR心脏黑血图像的质量,提高心肌信号均一性,为临床提供可靠的影像学依据。

Objective To explore the value of Localized Transmit Gain(Localized TG)technology in improving the quality of black blood images in cardiac magnetic resonance imaging.Methods 27 patients were selected for cardiac magnetic resonance examination.The scanning sequence included black blood double inversion recovery fast spin echo(DIR FSE)T2WIand double inversion recovery fast spin echo(DIR FSE)T2WI sequence combined with chemical saturated fat suppression(Referred to as black blood double inversion T2WI and black blood double inversion fat suppression T2WI),specifically.The quality of images obtained by the above black blood sequence using Localized TG and Global TG technique respectively were observed,compared and evaluated objectively and subjectively.Results 1)The image quality evaluation objectively compared with the traditional Global TG technology,Localized TG technology significantly improves the signal-to-noise ratio(SNR)and contrast noise ratio(CNR)of myocardial images in black blood sequences,and the difference was statistically significant(P<0.05);2)image quality evaluation subjectively for the myocardial images obtained by using the double inversion T2WI and the double inversion fat suppression T2WI sequences,the differences in the subjective scores of the image quality obtained by Localized TG and Global TG were statistically significant(P<0.05).Conclusion Compared with the traditional Global TG technology,Localized TG technology can effectively improve the image quality of black blood imaging and the uniformity of myocardial signal in 3.0T cardiac magnetic resonance,and provide a reliable imaging basis for clinic.