简介本研究的目的是确定多体素磁共振波谱成像(MRSI)是否可以区分颅内肿瘤和非肿瘤以及基于其增强和周围区域的主要代谢物比率差异的肿瘤环增强病变(REL)。方法在一项涉及脑内RELs患者的前瞻性观察研究中,使用二维多体素点分辨光谱(PRESS)化学位移成像(CSI)序列在135毫秒(ms)的回波时间(TE)对总共38名患者进行了MRSI。在38个病变中,23例(60.5%)为肿瘤,15例(39.5%)为非肿瘤。在23个肿瘤性病变中,12个是高级别胶质瘤(HGG),七个是转移,和四个是低级别胶质瘤(LGG)。主要代谢物比率,即,胆碱-N-乙酰天冬氨酸(Cho/NAA),胆碱-肌酸(Cho/Cr),和N-乙酰天冬氨酸肌酸(NAA/Cr),在REL的增强和周围增强区域中计算。进行了Mann-WhitneyU检验,以确定肿瘤与非肿瘤病变之间不同体素位置的代谢物比率差异。HGG与转移性病变的比较,以及HGG与LGG。进行受试者工作特征(ROC)曲线分析,以得出病变增强和周围增强部分的Cho/NAA和NAA/Cr比率的截止值。结果灵敏度,特异性,正预测值,使用磁共振成像(MRI)的MRSI对肿瘤或非肿瘤性病变的REL进行分类的阴性预测值为91.3%,73.3%,84%,和84.6%,分别。在23个肿瘤和15个非肿瘤性病变的增强区域中,Cho/NAA(p=0.006)和NAA/Cr(p=0.021)比率之间存在统计学上的显着差异。在放置在周围增强部分中的体素中,Cho/Cr比值之间的差异仅有统计学意义(p=0.047)。增强区域中Cho/NAA>1.67的截止分数给出82.6%的灵敏度和60%的特异性。增强区域NAA/Cr的截止评分<0.80显示出60.9%和86.7%的敏感性和特异性,分别。在23个肿瘤性病变中,在周围增强区域使用Cho/NAA比率区分12个HGs和7个转移灶,截止值为1.21,灵敏度为100%,和特异性为85%。周围增强区域的Cho/Cr≥1.45的临界值显示出83%的敏感性和71.4%的特异性。为了区分23个肿瘤REL组的12个HGS和4个LGG,在≥4.16的增强部分使用Cho/NAA的截止评分显示,敏感性为0.75,特异性为100%.在周围增强区域,≥2.07的截止评分提供了83%和100%的敏感性和特异性,分别。结论常规MRI有时在区分肿瘤性和非肿瘤性病变以及其他肿瘤性RELs方面存在诊断挑战。通过比较这些病变的增强区域和周围增强区域中的主要代谢产物比率来解释MRSI的发现,可以区分两者之间。
Introduction The purpose of this study was to determine whether multi-voxel magnetic resonance spectroscopic imaging (MRSI) can differentiate between intracranial neoplastic and non-neoplastic and between neoplastic ring-enhancing lesions (RELs) based on differences in major metabolite ratios in their enhancing and peri-enhancing regions. Methods In a prospective observational study involving patients with an intracerebral RELs, MRSI using the two-dimensional multi-voxel point-resolved spectroscopy (PRESS) chemical-shift imaging (CSI) sequence at an echo time (TE) of 135 milliseconds (ms) was performed on a total of 38 patients. Of 38 lesions, 23 (60.5%) were neoplastic and 15 (39.5%) were non-neoplastic. Of the 23 neoplastic lesions, 12 were high-grade gliomas (HGGs), seven were metastases, and four were low-grade gliomas (LGGs). Major metabolite ratios, i.e., choline-to-N-acetylaspartate (Cho/NAA), choline-to-creatine (Cho/Cr), and N-acetylaspartate-to-creatine (NAA/Cr), were calculated in the enhancing and peri-enhancing regions of the RELs. A Mann-Whitney U test was run to determine differences in metabolite ratios at different voxel locations between neoplastic versus non-neoplastic lesions, HGGs versus metastatic lesions, and HGGs versus LGGs. A receiver operating characteristic (ROC) curve analysis was performed to derive cut-off values for Cho/NAA and NAA/Cr ratios in the enhancing and peri-enhancing portions of the lesions. Results The sensitivity, specificity, positive predictive value, and negative predictive value for categorizing an REL in either neoplastic or non-neoplastic lesions using MRSI with magnetic resonance imaging (MRI) were 91.3%, 73.3%, 84%, and 84.6%, respectively. There was a statistically significant difference between Cho/NAA (p = 0.006) and NAA/Cr (p = 0.021) ratios in the enhancing region of 23 neoplastic and 15 non-neoplastic lesions. In the voxel placed in the peri-enhancing portions, the differences between Cho/Cr ratios were just significant (p = 0.047). A cut-off score of Cho/NAA >1.67 in the enhancing regions gave a sensitivity of 82.6% and specificity of 60%. The cut-off score for NAA/Cr of <0.80 in the enhancing regions showed a sensitivity and specificity of 60.9% and 86.7%, respectively. Of the 23 neoplastic lesions, 12 HGGs and seven metastases were differentiated using the Cho/NAA ratio in the peri-enhancing region with a cut-off value of 1.21, sensitivity of 100%, and specificity of 85%. A cut-off value of Cho/Cr ≥1.45 in the peri-enhancing regions showed a sensitivity of 83% and a specificity of 71.4%. For discriminating between 12 HGGs and four LGGs both from the 23 neoplastic REL group, using the cut-off score for Cho/NAA in the enhancing portions ≥4.16 showed a sensitivity of 0.75 and specificity of 100%. In the peri-enhancing regions, a cut-off score of ≥2.07 provided a sensitivity and specificity of 83% and 100%, respectively. Conclusion Conventional MRI sometimes poses a diagnostic challenge in distinguishing between neoplastic and non-neoplastic lesions and other neoplastic RELs. Interpreting MRSI findings by comparing the major metabolite ratios in the enhancing and peri-enhancing regions of these lesions may enable distinction between the two.