Kanematsu Masayuki, Semelka Richard C, Matsuo Masayuki, Kondo Hiroshi, Enya Mayumi, Goshima Satoshi, Moriyama Noriyuki, Hoshi Hiroaki
Department of Radiology, Gifu University School of Medicine, Japan.
Radiology. 2002 Nov;225(2):407-15. doi: 10.1148/radiol.2252010852.
To investigate the optimal imaging delays for hepatic arterial and portal venous phases of gadolinium-enhanced dynamic spoiled gradient-recalled-echo magnetic resonance (MR) imaging of the liver in patients with chronic liver damage.
MR images were obtained after intravenous bolus injection of gadopentetate dimeglumine in 100 patients with chronic liver damage. Test bolus imaging was performed to determine the aortic transit time. A 26-second spoiled gradient-recalled-echo sequence was used. Patients were randomized into four groups so that the middle of k space was acquired at 5, 10, 15, and 20 seconds for the first phase and 45, 50, 55, and 60 seconds for the second phase, respectively, from the time of arrival of contrast material in the abdominal aorta. Mean signal intensities of the liver, spleen, and abdominal aorta were measured, and images were reviewed prospectively by three radiologists in consensus. Analysis of variance, the Scheffé criterion for continuous data, and the Kruskal-Wallis test for categorical data were used for statistical evaluation.
Intense splenic enhancement with the moiré pattern without intense hepatic enhancement occurred at 10-15 seconds. Aortic and splenic enhancement significantly decreased from 45 to 50 seconds (P <.05). Spleen-to-liver contrast-to-noise ratio began to decrease at 20 seconds and decreased constantly over time. Qualitative results correlated well with quantitative results.
Biphasic imaging with k space centered at 10-15 and 50 seconds or later after arrival of contrast material in the abdominal aorta may be the optimal technique to obtain ideal contrast enhancement. Empirically, delays of 28-34 and 68 seconds or later after initiating contrast material injection may be effective for biphasic imaging.
探讨钆增强动态扰相梯度回波磁共振成像（MR）对慢性肝损伤患者肝脏肝动脉期和门静脉期的最佳成像延迟时间。
对100例慢性肝损伤患者静脉团注钆喷酸葡胺后行MR成像。通过试验性团注成像确定主动脉通过时间。采用26秒扰相梯度回波序列。将患者随机分为四组，使得从对比剂到达腹主动脉开始，第一期分别在5、10、15和20秒采集k空间中心数据，第二期分别在45、50、55和60秒采集k空间中心数据。测量肝脏、脾脏和腹主动脉的平均信号强度，并由三名放射科医生进行前瞻性的一致性图像评估。采用方差分析、连续数据的谢费准则和分类数据的克鲁斯卡尔 - 沃利斯检验进行统计学评估。
在10 - 15秒时脾脏出现明显的莫尔条纹样强化，而肝脏强化不明显。从45秒到50秒，主动脉和脾脏强化显著降低（P <.05）。脾脏与肝脏的对比噪声比在20秒时开始下降，并随时间持续降低。定性结果与定量结果相关性良好。
以腹主动脉内对比剂到达后10 - 15秒和50秒及更晚时间为中心采集k空间数据的双期成像，可能是获得理想对比增强效果的最佳技术。根据经验，在开始注射对比剂后28 - 34秒和68秒及更晚的延迟时间可能对双期成像有效。
