Usman M, Atkinson D, Heathfield E, Greil G, Schaeffter T, Prieto C
Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, SE1 7EH, UK.
Phys Med Biol. 2015 Apr 7;60(7):N93-107. doi: 10.1088/0031-9155/60/7/N93. Epub 2015 Mar 13.
Two major challenges in cardiovascular MRI are long scan times due to slow MR acquisition and motion artefacts due to respiratory motion. Recently, a Motion Corrected-Compressed Sensing (MC-CS) technique has been proposed for free breathing 2D dynamic cardiac MRI that addresses these challenges by simultaneously accelerating MR acquisition and correcting for any arbitrary motion in a compressed sensing reconstruction. In this work, the MC-CS framework is combined with parallel imaging for further acceleration, and is termed Motion Corrected Sparse SENSE (MC-SS). Validation of the MC-SS framework is demonstrated in eight volunteers and three patients for left ventricular functional assessment and results are compared with the breath-hold acquisitions as reference. A non-significant difference (P > 0.05) was observed in the volumetric functional measurements (end diastolic volume, end systolic volume, ejection fraction) and myocardial border sharpness values obtained with the proposed and gold standard methods. The proposed method achieves whole heart multi-slice coverage in 2 min under free breathing acquisition eliminating the time needed between breath-holds for instructions and recovery. This results in two-fold speed up of the total acquisition time in comparison to the breath-hold acquisition.
心血管磁共振成像(MRI)面临的两大挑战是:由于磁共振采集速度慢导致扫描时间长,以及由于呼吸运动产生的运动伪影。最近,一种运动校正压缩感知(MC-CS)技术被提出用于自由呼吸二维动态心脏MRI,该技术通过在压缩感知重建中同时加速磁共振采集和校正任意运动来应对这些挑战。在这项工作中,MC-CS框架与并行成像相结合以进一步加速,并被称为运动校正稀疏敏感性编码(MC-SS)。在八名志愿者和三名患者中对MC-SS框架进行了验证,用于左心室功能评估,并将结果与作为参考的屏气采集结果进行比较。在所提出的方法和金标准方法获得的容积功能测量值(舒张末期容积、收缩末期容积、射血分数)和心肌边界清晰度值方面,观察到无显著差异(P>0.05)。所提出的方法在自由呼吸采集中2分钟内实现全心多切片覆盖,消除了屏气之间用于指令和恢复所需的时间。与屏气采集相比,这使得总采集时间加快了两倍。