Fukamatsu Fumiaki, Yamada Akira, Hayashihara Hayato, Kitou Yoshihiro, Fujinaga Yasunari
Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
Division of Radiology, Shinshu University Hospital, Matsumoto, Japan.
BJR Open. 2021 Nov 24;3(1):20210018. doi: 10.1259/bjro.20210018. eCollection 2021.
To optimize the scan protocol for high temporal resolution magnetic resonance (MR) imaging of the liver under single breath-holding, using compressed sensing (CS) and parallel imaging (PI) techniques in a 1.5 T MR system.
31 healthy volunteers who underwent fat-suppressed gradient-echo weighted imaging using a 1.5 T MR system were included. Image quality was evaluated on altering various imaging parameters in CS and PI so that the scan time was adjusted to 10 and 6 s within a single breath-holding. Normalized standard deviation (nSD = SD/mean value) and signal-to-noise ratio (SNR = mean value/SD) of liver signal intensity were measured. Visual scores for the outline of the liver and inferior right hepatic vein (IRHV) were evaluated using a 4-point scale and compared with that of the reference standard (20 s scan without CS).
The nSD and SNR were not significantly different when the 10 s scan with CS factor 2.0 and the 6 s scan with CS factor 2.0 and 2.5 were compared to the 20 s scan. Overall visual score (mean score of the outline of the liver and IRHV) was significantly better ( < 0.05) with the 10 s scan with CS factor 2.0 compared to the other scan protocols.
The 10 s scan with CS factor 2.0 should be recommended for high temporal resolution MR imaging of the liver using CS and PI in a 1.5 T MR system.
This study conducts a novel MR imaging of the liver using CS and PI in a 1.5 T MR system.
在1.5T磁共振(MR)系统中,利用压缩感知(CS)和平行成像(PI)技术,优化单次屏气下肝脏高时间分辨率磁共振成像的扫描方案。
纳入31名接受1.5T MR系统脂肪抑制梯度回波加权成像的健康志愿者。通过改变CS和PI中的各种成像参数来评估图像质量,以便在单次屏气内将扫描时间调整为10秒和6秒。测量肝脏信号强度的归一化标准差(nSD = SD/平均值)和信噪比(SNR = 平均值/SD)。使用4分制评估肝脏轮廓和肝右下静脉(IRHV)的视觉评分,并与参考标准(无CS的20秒扫描)进行比较。
将CS因子为2.0的10秒扫描、CS因子为2.0和2.5的6秒扫描与20秒扫描进行比较时,nSD和SNR无显著差异。与其他扫描方案相比,CS因子为2.0的10秒扫描的总体视觉评分(肝脏轮廓和IRHV的平均评分)显著更好(<0.05)。
对于1.5T MR系统中使用CS和PI进行肝脏高时间分辨率MR成像,推荐使用CS因子为2.0的10秒扫描。
本研究在1.5T MR系统中利用CS和PI对肝脏进行了新型MR成像。