利用活体质子磁共振波谱对颅内肿块病变进行特征分析。

Characterization of intracranial mass lesions with in vivo proton MR spectroscopy.

作者信息

Poptani H, Gupta R K, Roy R, Pandey R, Jain V K, Chhabra D K

机构信息

Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.

出版信息

AJNR Am J Neuroradiol. 1995 Sep;16(8):1593-603.

PMID:7502961

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8337762/

Abstract

PURPOSE

To assess the use of in vivo proton MR spectroscopy for characterization of intracranial mass lesions and to ascertain its reliability in grading of gliomas.

METHODS

One hundred twenty patients with intracranial masses were subjected to volume selective spectroscopy using stimulated echo acquisition mode (echo time, 20 and 270 milliseconds) and spin echo (echo time, 135 milliseconds) sequences. The intracranial lesions were grouped into intraaxial and extraaxial, as judged with MR imaging. Assignment of resonances was confirmed in two samples each of brain abscess, epidermoid cyst, and tuberculoma using ex vivo high-resolution MR spectroscopy.

RESULTS

The in vivo spectra appeared distinct compared with normal brain in all the cases. All high-grade gliomas (n = 37) showed high choline and low or absent N-acetyl-L-aspartate and creatine along with lipid and/or lactate, whereas low-grade gliomas (n = 23) were characterized by low N-acetyl-aspartate and creatine and high choline and presence of only lactate. N-acetyl-aspartate/choline ratio was significantly lower and choline/creatine ratio was significantly higher in high-grade gliomas than in low-grade gliomas. Presence of lipids suggested a higher grade of malignancy. All metastases (n = 7) showed lipid and lactate, whereas choline was visible in only four cases. Epidermoids showed resonances from lactate and an unassigned resonance at 1.8 ppm. Meningiomas could be differentiated from schwannomas by the presence of alanine in the former. Among the infective masses, pyogenic abscesses (n = 6) showed resonances only from cytosolic amino acids, lactate, alanine, and acetate; and tuberculomas (n = 11) showed only lipid resonances.

CONCLUSIONS

In vivo proton MR spectroscopy, helps in tissue characterization of intracranial mass lesions. Spectroscopy is a reliable technique for grading of gliomas when N-acetyl-aspartate/choline and choline/creatine ratios and presence of lipids are used in combination.

摘要

目的

评估活体质子磁共振波谱用于颅内肿块病变特征分析的情况，并确定其在胶质瘤分级中的可靠性。

方法

对120例颅内肿块患者采用刺激回波采集模式（回波时间分别为20和270毫秒）和自旋回波（回波时间为135毫秒）序列进行容积选择性波谱分析。根据磁共振成像判断，将颅内病变分为轴内和轴外病变。使用离体高分辨率磁共振波谱在脑脓肿、表皮样囊肿和结核瘤的各两个样本中确认共振峰的归属。

结果

在所有病例中，活体波谱与正常脑组织相比均表现出明显差异。所有高级别胶质瘤（n = 37）均显示胆碱升高、N - 乙酰 - L - 天门冬氨酸和肌酸降低或缺失，同时伴有脂质和/或乳酸，而低级别胶质瘤（n = 23）的特征为N - 乙酰天门冬氨酸和肌酸降低、胆碱升高且仅存在乳酸。高级别胶质瘤的N - 乙酰天门冬氨酸/胆碱比值显著低于低级别胶质瘤，胆碱/肌酸比值显著高于低级别胶质瘤。脂质的存在提示恶性程度较高。所有转移瘤（n = 7）均显示脂质和乳酸，而仅4例可见胆碱。表皮样囊肿显示出乳酸的共振峰以及1.8 ppm处一个未明确归属的共振峰。脑膜瘤可通过其中存在丙氨酸与神经鞘瘤相鉴别。在感染性肿块中，化脓性脓肿（n = 6）仅显示胞质氨基酸、乳酸、丙氨酸和乙酸的共振峰；结核瘤（n = 11）仅显示脂质共振峰。