脑内环状强化病变质子磁共振波谱研究

Proton MR spectroscopy of intracranial lesions with ring-like enhancement

目的分析脑内环状强化病变的质子磁共振波谱(1H MRS)特征,评价其结果与病理组织学类型的相关性.方法 55例脑内环状强化病灶,胶质母细胞瘤17例、转移瘤19例、放射性坏死11例,脑脓肿8例.单体素PRESS(TE 135 ms)序列采集病灶中心(非强化区)和整个病灶(非强化区和环状强化病灶).结果①胶质母细胞瘤病灶中心和整个病灶高Lip峰3例,高Lac峰14例;病灶中心Cho/Cr 1.80±0.17(0.57～3.47),整个病灶Cho/Cr 4.17±0.26(2.03～8.57),P值0.001.13例病灶中心检测到NAA峰(76.5%).②转移瘤病灶中心和整个病灶高Lip峰11例(57.9%),高Lac峰8例;病灶中心Cho/Cr 1.08±0.24(0.68～2.71),整个病灶Cho/Cr 3.62±0.38 (1.02～7.19),P值0.031.病灶中心检测NAA峰5例(26.3%).胶质母细胞瘤和转移瘤病灶中心NAA和Lip出现几率差异显著,P值分别是0.003和0.013.③放射性坏死病灶中心Cho/Cr 1.67±0.32(0～2.12),整个病灶Cho/Cr 2.13±0.33(1.08～3.59),P值0.334;并与胶质母细胞瘤和转移瘤存在显著性差异,P值分别是0.004和0.028.④8例脑脓肿病灶中心Lac峰外,7例显示AA峰,5例Ace峰,3例Suc峰;2例Ala峰;1例Lip峰;1例Cho和NAA峰.结论 1H MRS能提供脑内环状强化病变的病理组织学信息,高Cho/Cr有助于鉴别肿瘤性和非肿瘤性病变,病灶中心NAA峰提示胶质母细胞瘤可能性,脑脓肿有特征性AA峰.

Objective To analyze 1H MRS features of intracranial lesions with ring-like enhancement, and to evaluate the relation between 1H MRS and pathohistological type. Methods A total of 55 cases including glioblastoma ( n =17), metastasis ( n =19), radiation necrosis ( n =11) and brain abscess ( n =8) were analyzed. Two VOIs (the center of lesion and the whole lesion) were acquired by single-voxel PRESS sequence. Results ① glioblastoma: dominant Lip peak was showed in the center of lesion or the whole lesion in 3 cases, and dominant Lac peak was found in 14 cases. Cho/Cr in the center of lesion was 1.80±0.17 (0.57-3.47), while 4.17±0.26 (2.03-8.57) in whole lesion ( P = 0.001 ). NAA peaks was detected in the center of lesion in 13 cases (76.5%). ② metastasis: dominant Lip peak was detected in 11 cases (57.9%), and dominant Lac peak in 8 cases. Cho/Cr in the center of lesion was 1.08±0.24 (0.68-2.71), and 3.62±0.38 (1.02-7.19) in whole lesion ( P =0.031). NAA peaks was detected in the center of lesion in 5 cases (26.3%). ③ radiation: Cho/Cr in the center of lesion was 1.67±0.32 (0-2.12), and 2.13±0.33 (1.08-3.59) in the whole lesion ( P =0.334). Cho/Cr was distinctly different between gliobalstoma or metastasis and radiation necrosis. ④ brain abscess: Lac peaks was detected in 8 cases, AA peaks in 7 cases, Ace peaks in 5 cases, Suc peaks in 3 cases, Ala peaks in 2 cases, Lip peak in 1 case, and Cho and NAA peak in 1 case. Conclusion 1H MRS is able to obtain pathohistological data about intracranial lesions with ring-like enhencement. High Cho/Cr can differentiate neoplasms from non-neoplasms. NAA peak detected in the center of lesions is cue for gliobastoma. AA peak is characteristic of brain abscess.