Quesson B, Bouzier A K, Thiaudiere E, Delalande C, Merle M, Canioni P
Résonance Magnétique des Systèmes Biologiques, UMR 5536, CNRS-Université Victor Segalen Bordeaux 2, France.
J Magn Reson Imaging. 1997 Nov-Dec;7(6):1076-83. doi: 10.1002/jmri.1880070621.
C6 glioma cells were implanted in the left caudate nucleus of the rat brain. Histologic studies confirmed the presence of neoplastic tissue surrounded by a thin edematous region. Proton magnetization transfer contrast (MTC) fast imaging, using continuous wave off-resonance irradiation, was performed in vivo at 4.7 T with the rapid acquisition with relaxation enhancement (RARE) sequence. The observed MTC allowed very clear distinction of the tumoral region, in which magnetization transfer (MT) ratios were lower than in healthy tissues. Contrasts were analyzed as a function of the offset frequency and the amplitude of the radiofrequency (RF) irradiation. The contrast was higher between the contralateral basal ganglia and the tumor and lower between the tumor and the temporal lobe. Modeling of MT in the three brain regions was performed using a system including free water and a pool of protons with restricted motions. The rate of exchange between the two pools exhibited a decreasing hierarchy from the basal ganglia to the tumor. T2B values for the immobile protons ranged from 9.3 microsec in the basal ganglia to 7.5 microsec for the glioma. The acquisition conditions leading to the highest contrasts between the tumor and the healthy tissues correspond to 3,000 Hz offset frequency and 300 to 700 Hz RF irradiation amplitude.
将C6胶质瘤细胞植入大鼠脑左侧尾状核。组织学研究证实存在被薄水肿区域包围的肿瘤组织。使用连续波失谐照射的质子磁化传递对比（MTC）快速成像，在4.7 T下采用快速采集弛豫增强（RARE）序列进行体内成像。观察到的MTC能够非常清晰地区分肿瘤区域，其中磁化传递（MT）比率低于健康组织。根据失谐频率和射频（RF）照射幅度对对比度进行分析。对侧基底神经节与肿瘤之间的对比度较高，而肿瘤与颞叶之间的对比度较低。使用包括自由水和一组运动受限的质子的系统对三个脑区的MT进行建模。两个池之间的交换率呈现出从基底神经节到肿瘤递减的层级关系。固定质子的T2B值范围从基底神经节的9.3微秒到胶质瘤的7.5微秒。导致肿瘤与健康组织之间对比度最高的采集条件对应于3000 Hz失谐频率和300至700 Hz RF照射幅度。
