Diffusion-weighted 7.0T Magnetic Resonance Imaging in Assessment of Intervertebral Disc Degeneration in Rats.
Diffusion-weighted 7.0T Magnetic Resonance Imaging in Assessment of Intervertebral Disc Degeneration in Rats.
复制标题
弥散加权7.0T磁共振成像对大鼠腰椎间盘退变的评价
DOI：
10.4103/0366-6999.221261
复制
发表时间：
2018-01-05
影响因子：
6.1
通讯作者：
Chen BH
中科院分区：
文献类型：
--
作者：
Li LY;Wu XL;Roman RJ;Fan F;Qiu CS;Chen BH
椎间盘退变（IDD）是椎间盘突出的主要原因，可能与水分减少有关。本研究采用7.0特斯拉(T)磁共振成像（MRI）机对IDD进行弥散加权成像（DWI）评价。选取健康的sd大鼠24只，随机分为A、B、C、D 4组，每组28、42、56、70日龄，雄性3只，雌性3只。所有大鼠均行7.0T MRI成像，生成T2WI、T1WI和功能性DWI序列。采集数据，绘制表观扩散系数（ADC）图。确定髓核和纤维环区域，选择几个感兴趣的区域，并获得其ADC值。成像后处死大鼠，解剖其L1-L6椎间盘，共144个椎间盘。提取蛋白进行Western blotting。多样本间比较采用单因素方差分析和最小显著性差异法。随着年龄的增长，Sprague-Dawley大鼠椎间盘内信号强度明显降低。椎间盘ADC值由A组（0.00154±0.00008）显著降低至D组（0.00107±0.00007,P < 0.01）；髓核ADC值从A组（0.00164±0.00005）显著降低至D组（0.00140±0.00007,P < 0.01），纤维环ADC值从A组（0.00129±0.00014）显著降低至D组（0.00082±0.00012,P < 0.01）。A组髓核ADC值从L1/L2（0.00163±0.00006）显著降低至L6/S1（0.00139±0.00004,P < 0.01）。A组间纤维环ADC值差异无统计学意义（P < 0.05）。Western blotting显示，随着年龄的增长，A组（1.88±0.16）~ D组（0.17±0.04）椎间盘聚集蛋白含量逐渐降低（P < 0.01）；椎间盘II型胶原含量随年龄的增长由A组（2.22±0.04）降至D组（0.20±0.01）（P < 0.01）。A组l1 ~ l6椎间盘聚集蛋白和II型胶原含量差异无统计学意义（P < 0.05）。不同椎间区平均ADC值与aggrecan、II型胶原含量呈正相关（aggrecan: r = 0.631, P < 0.01； II型胶原：r = 0.680, P < 0.01）。7.0T MRI-DWI可有效诊断和研究微小变异的早期IDD。
Intervertebral disc degeneration (IDD) is a major cause of disc protrusion, likely to be associated with decrease of water content. This research aimed to evaluate IDD by diffusion-weighted imaging (DWI) with a 7.0 Tesla (T) magnetic resonance imaging (MRI) machine. A total of 24 healthy Sprague-Dawley rats were randomly selected and divided into four groups (A, B, C, and D), each consisting of 3 male and 3 female rats (28, 42, 56, and 70 days old, respectively). All the rats were imaged with a 7.0T MRI, producing T2WI, T1WI, and functional DWI sequences. Data were collected and apparent diffusion coefficient (ADC) charts were constructed. Nucleus pulposus and annulus fibrosus regions were identified, several regions of interest were chosen, and their ADC values were obtained. After imaging, rats were sacrificed and their intervertebral discs (L1–L6) were dissected, yielding a total of 144 discs. Protein was extracted for the purpose of Western blotting. Comparison among multiple samples used one-way analysis of variance and least significant difference methods. 7.0T MRI revealed evident decrease in signal intensity within intervertebral discs of Sprague-Dawley rats with age. Intervertebral disc ADC values significantly decreased from Group A (0.00154 ± 0.00008) to Group D (0.00107 ± 0.00007; P < 0.01); nucleus pulposus ADC values significantly decreased from Group A (0.00164 ± 0.00005) to Group D (0.00140 ± 0.00007; P < 0.01) and annulus fibrosus ADC values significantly decreased from Group A (0.00129 ± 0.00014) to Group D (0.00082 ± 0.00012; P < 0.01). Meanwhile, it also revealed evident decrease from high spinal level to low spinal level: nucleus pulposus ADC values in Group A significantly decreased from L1/L2 (0.00163 ± 0.00006) to L6/S1 (0.00139 ± 0.00004; P < 0.01). While annulus fibrosus ADC values did not differ significantly between levels in Group A (P > 0.05). Western blotting showed that aggrecan content of intervertebral discs decreased from Group A (1.88 ± 0.16) to Group D (0.17 ± 0.04) with age (P < 0.01); Type II collagen content of intervertebral discs decreased from Group A (2.22 ± 0.04) to Group D (0.20 ± 0.01) with age (P < 0.01). No significant differences in aggrecan and Type II collagen content of L1–L6 intervertebral discs in Group A were noted (P > 0.05). Mean ADC values of different intervertebral regions were positively correlated with aggrecan and Type II collagen content (aggrecan: r = 0.631, P < 0.01; Type II collagen: r = 0.680, P < 0.01). 7.0T MRI-DWI could be applied to effectively diagnose and research early IDD in tiny variations.