University of Washington, Department of Radiology, Seattle, Washington, USA.
J Magn Reson Imaging. 2012 Dec;36(6):1490-5. doi: 10.1002/jmri.23743. Epub 2012 Jul 6.
To use magnetization tagged magnetic resonance imaging (MRI) (tag-MRI) to quantify cardiac induced liver strain and compare strain of cirrhotic and normal livers.
Tag-MRI was performed at 1.5T on eight subjects with no history of liver disease and 10 patients with liver cirrhosis. A breath-hold peripheral pulse-gated (PPG) conventional tag-MRI cine sequence was performed with planes to include the left lobe of the liver and the inferior wall of the heart. Commercially available software HARP (Diagnosoft, Palo Alto, CA) was used for image analysis and strain calculation. Three regions-of-interest (ROIs) were selected: segment II of the liver near the heart (A), right liver lobe far from the heart (B), and the left ventricular wall (C). The average and maximal (max) strain were measured in A, B, and C. The maximum strains were used to generate a cardiac-corrected strain gradient: (maxA-maxB)/maxC. Results were compared with Student's t-test (SPSS, Chicago, IL).
In subjects with no history of liver disease vs. cirrhotic patients, the average strain was 22% ± 7% vs. 4% ± 3% (P < 0.001), the max strain was 63% ± 15% vs. 17% ± 5% (P < 0.001), and the corrected strain gradient was 0.52 ± 0.16 vs. 0.11% ± 0.08%.
There is a significant difference in liver strain measured with tag-MRI between subjects with no history of liver disease and patients with cirrhosis.
使用磁化标记磁共振成像（tag-MRI）来量化心脏引起的肝应变，并比较肝硬化和正常肝脏的应变。
在 1.5T 上对 8 名无肝病病史的受试者和 10 名肝硬化患者进行 tag-MRI。使用屏住呼吸的外周脉搏门控（PPG）常规 tag-MRI 电影序列进行平面成像，包括肝脏的左叶和心脏的下壁。使用商业上可用的软件 HARP（Diagnosoft，Palo Alto，CA）进行图像分析和应变计算。选择三个感兴趣区域（ROI）：靠近心脏的肝段 II（A）、远离心脏的右肝叶（B）和左心室壁（C）。测量 A、B 和 C 中的平均和最大（max）应变。使用最大应变生成心脏校正应变梯度：（maxA-maxB）/maxC。结果与 Student's t 检验（SPSS，芝加哥，IL）进行比较。
在无肝病病史的受试者与肝硬化患者之间，平均应变分别为 22%±7%和 4%±3%（P<0.001），最大应变为 63%±15%和 17%±5%（P<0.001），校正应变梯度分别为 0.52±0.16%和 0.11%±0.08%。
tag-MRI 测量的肝脏应变在无肝病病史的受试者和肝硬化患者之间存在显著差异。
