Okumura A, Kuwata K, Takenaka K, Nishimura Y, Shirakami S, Sakai N, Hayashi T, Era S
Department of Neurosurgery, Gifu University School of Medicine, Japan.
Neurol Res. 1998 Jun;20(4):313-9. doi: 10.1080/01616412.1998.11740524.
We investigated the clinical applicability of pulsed off-resonance magnetization transfer (MT) technique in magnetic resonance (MR) imaging for the estimation of the histological feature of brain tumor. The parameters were optimized using bovine serum albumin (BSA) solutions and gels in 1.5-tesla MR system as follows: TR, 50 msec; TE, 5 msec; flip angle, 30 degree; offset frequency, 1000 Hz. MT effect was evaluated by measuring the MT ratio (MTR) and reconstructing calculated MTR color image. The MTRs of the BSA solutions and gels increased with increasing concentrations of protein, while the MTRs of the gels were remarkably higher than those of the solutions. The optimized sequence was performed in 20 healthy volunteers and 30 patients with brain tumors. In normal brains, the MTRs were significantly higher in white matter than in gray matter (p < 0.05). The MTR in brain tumor was significantly lower than that in normal brain tissue (p < 0.05) and the calculated MTR image produced contrast between brain tumor and normal brain tissue. There was a statistically significant difference in MTR between benign (0.30 +/- 0.05, n = 17) and malignant (0.26 +/- 0.04, n = 13) tumors (p < 0.05). The optimized MT technique is quite sensitive for estimating the degree of intermolecular interaction between macromolecules and water within the central nervous system.
我们研究了脉冲非共振磁化传递（MT）技术在磁共振（MR）成像中用于评估脑肿瘤组织学特征的临床适用性。在1.5特斯拉MR系统中，使用牛血清白蛋白（BSA）溶液和凝胶对参数进行了如下优化：重复时间（TR）为50毫秒；回波时间（TE）为5毫秒；翻转角为30度；偏移频率为1000赫兹。通过测量MT比率（MTR）并重建计算出的MTR彩色图像来评估MT效应。BSA溶液和凝胶的MTR随着蛋白质浓度的增加而升高，而凝胶的MTR明显高于溶液的MTR。在20名健康志愿者和30名脑肿瘤患者中实施了优化后的序列。在正常脑内，白质的MTR显著高于灰质（p < 0.05）。脑肿瘤中的MTR显著低于正常脑组织中的MTR（p < 0.05），并且计算出的MTR图像在脑肿瘤和正常脑组织之间产生了对比。良性肿瘤（0.30±0.05，n = 17）和恶性肿瘤（0.26±0.04，n = 13）之间的MTR存在统计学显著差异（p < 0.05）。优化后的MT技术对于评估中枢神经系统内大分子与水之间的分子间相互作用程度非常敏感。
