Abstract:

Objective
To study the value of clinical application of 1H proton magnetic resonance spectroscopy(1H MRS) in the differential diagnosis of intracranial lesions with ring-like enhancement. Methods 28  cases were diagnosed of intracranial lesions with ring-like enhancement by clinical examination and pathologic test.A total of 28 ratios cases included  6 cases high grade glioma, 10 cases of metastatic carcinoma(n=10) and 12 cases of brain abscess,after examined with 1HMRS,the ratios of various metabolites in focal center,enhancement ring,perifocal edema region and normal control group were detected and compared.Results The ratios of NAA/Cho,Cho/Cr and NAA/Cr in focal center had no significantly differences between high grade glioma and metastatic carcinoma（P>0.05）. The peak of NAA was significantly different between high grade glioma and metastatic carcinoma（P<0.05）. The ratios of NAA/Cho and Cho/Cr in the perifocal regions of high grade glioma and metastatic carcinoma were significantly different compared with normal brain (P<0.05). The relative content of Cho was not significantly different between perifocal regions of metastatic carcinoma and normal brain（P>0.05）. The peak of AA was characteristic of brain abscess. The ratio of Cho/Cr0  in brain abscess was significantly lower than those in high grade glioma and metastatic carcinoma（P<0.05） (Cr0 denoted the Cho content of contralateral normal brain region).These resutls  accorded with the result of pathological examination. Conclusion  1HMRS can improve the diagnostic accuracy of intracranial lesions with ring-like enhancement.

Key words: magnetic resonance imaging, spectroscopy, gliomas, metastatic carcinoma of brain, brain abscess