Tien R D, Lai P H, Smith J S, Lazeyras F
Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
AJR Am J Roentgenol. 1996 Jul;167(1):201-9. doi: 10.2214/ajr.167.1.8659372.
The Single-Voxel Proton Brain Exam (PROBE/SV) is an automated MR spectroscopic technique. The purpose of this study was to investigate the use of PROBE/SV as a diagnostic tool in patients with primary brain tumors and to compare our findings with the known information obtained from conventional nonautomated MR spectroscopic techniques.
We used PROBE/SV to image 10 normal adults and 46 patients with primary brain tumors: 29 glioblastoma multiformes (GBMs), five anaplastic astrocytomas, and 12 low-grade astrocytomas. All studied were performed on a 1.5-T Signa unit. Average voxel sizes were 6-8 cm3. A corresponding point-resolved spectroscopy spectrum was obtained from normal-appearing brain parenchyma in each patient for comparison with the spectra from known areas of pathology.
In patients with low-grade gliomas (grades 1 and 2), we observed decreased N-acetylaspartate (12 of 12) and slightly increased choline (11 of 12) when we compared these metabolites with those in the spectra of patients' normal brains. This comparison in patients with GBM yielded markedly decreased N-acetylaspartate (29 of 29) and prominently increased choline (27 of 29). In the short TE spectra, we frequently saw lipid signal in high-grade tumors, especially in GBMs (12 of 20). We identified lactate peaks in high-grade tumors (anaplastic astrocytoma and GBM, 29 of 34) and also in low-grade tumors (four of 12). The creatine signal in all gliomas was slightly less than that of healthy brain tissue. The lowest N-acetylaspartate, choline, and creatinine levels in conjunction with the highest lactate levels were usually found in necrotic portions of high-grade tumors.
PROBE/SV is a simplified MR spectroscopy technique that reduces setup time and provides automatic on-line data processing and display. The voxel location can be selected to focus on the area of interest and to minimize voxel contamination from unwanted tissue. The results from our experimentation with PROBE/SV in patients with brain tumors generally concur with published reports of tumor spectra obtained by conventional MR spectroscopic techniques. The ease and accuracy of this new technique make it a useful clinical tool in differentiating human brain tumor grades.
单体素质子脑检查（PROBE/SV）是一种自动化磁共振波谱技术。本研究的目的是探讨PROBE/SV作为原发性脑肿瘤患者诊断工具的应用，并将我们的研究结果与通过传统非自动化磁共振波谱技术获得的已知信息进行比较。
我们使用PROBE/SV对10名正常成年人和46例原发性脑肿瘤患者进行成像：29例多形性胶质母细胞瘤（GBM）、5例间变性星形细胞瘤和12例低级别星形细胞瘤。所有研究均在1.5-T Signa设备上进行。平均体素大小为6 - 8 cm³。从每位患者外观正常的脑实质中获取相应的点分辨波谱，以便与已知病理区域的波谱进行比较。
在低级别胶质瘤（1级和2级）患者中，当我们将这些代谢物与患者正常脑波谱中的代谢物进行比较时，观察到N - 乙酰天门冬氨酸减少（12例中的12例），胆碱略有增加（12例中的11例）。在GBM患者中进行的这种比较显示N - 乙酰天门冬氨酸明显减少（29例中的29例），胆碱显著增加（29例中的27例）。在短TE波谱中，我们在高级别肿瘤中经常看到脂质信号，尤其是在GBM中（20例中的12例）。我们在高级别肿瘤（间变性星形细胞瘤和GBM，34例中的29例）以及低级别肿瘤（12例中的4例）中发现了乳酸峰。所有胶质瘤中的肌酸信号略低于健康脑组织。通常在高级别肿瘤的坏死部分发现最低的N - 乙酰天门冬氨酸、胆碱和肌酐水平以及最高的乳酸水平。
PROBE/SV是一种简化的磁共振波谱技术，可减少设置时间并提供自动在线数据处理和显示。可以选择体素位置以聚焦于感兴趣的区域，并最大限度地减少来自不需要组织的体素污染。我们在脑肿瘤患者中使用PROBE/SV的实验结果总体上与通过传统磁共振波谱技术获得的肿瘤波谱的已发表报告一致。这种新技术的简便性和准确性使其成为区分人脑肿瘤级别的有用临床工具。
