Wallner B, Edelman R R, Mattle H P
Abteilung Radiologie, Beth Israel Hospital, Boston, MA 02215.
Digitale Bilddiagn. 1990 Sep-Dec;10(3-4):86-91.
A Turbo FLASH sequence consisting of an initial non-selective 180 degree inversion pulse followed by an ultrafast FLASH sequence with very short repetition and echo times (TR = 7 ms, TE = 4 ms) was used to study 20 patients with focal liver lesions. The results were compared to T1-weighted gradient-echo (108/5/80 for TR/TE/flip angle) and T2-weighted spin-echo sequences (TR/TE/excitations = 2500 ms/40 ms, 90 ms, 140 ms/2). Liver-spleen contrast of the fast scans was superior to T1- and T2-weighted images for TI = 300 ms (0.59 +/- 0.12 vs 0.33 +/- 0.07 and 0.42 +/- 0.14 respectively). Liver-lesion contrast of the fast scans for TI = 300-700 ms was superior to the T1-weighted gradient echo sequence (0.49 +/- 0.21 vs 0.23 +/- 0.09), equal to the T2-weighted spin echo sequence for TE = 90 ms (0.54 +/- 0.17) but inferior to the 140 ms echo (0.63 +/- 0.18). On Turbo FLASH scans, there were no flow or motion artifacts and lesions borders and structures were better delineated than on the spin-echo images. Imaging time for the whole liver is less than a minute.
采用一种Turbo FLASH序列,该序列由一个初始非选择性180度反转脉冲,随后是具有非常短重复时间和回波时间(TR = 7毫秒,TE = 4毫秒)的超快FLASH序列,用于研究20例有局灶性肝脏病变的患者。将结果与T1加权梯度回波序列(TR/TE/翻转角为108/5/80)和T2加权自旋回波序列(TR/TE/激励次数 = 2500毫秒/40毫秒、90毫秒、140毫秒/2)进行比较。对于TI = 300毫秒,快速扫描的肝脾对比度优于T1加权和T2加权图像(分别为0.59±0.12 vs 0.33±0.07和0.42±0.14)。对于TI = 300 - 700毫秒,快速扫描的肝病变对比度优于T1加权梯度回波序列(0.49±0.21 vs 0.23±0.09),与TE = 90毫秒的T2加权自旋回波序列相等(0.54±0.17),但低于140毫秒回波(0.63±0.18)。在Turbo FLASH扫描中,没有血流或运动伪影,病变边界和结构比自旋回波图像上显示得更好。整个肝脏的成像时间不到一分钟。