Mrs Metabolic Imaging Navigation In The Research And Application Of Brain Lesion Biopsy

Objective:To evaluate the clinical results of the combined application of1H-MRS guided navigation and iMRI in biopsy of intracranial lesions.Method:3. OT iMRI and neuronavigation was used in28brain biopsy procedures.1H-MRS was used to analyze the metabolism of the lesions and find out the best biopsy point, and1H-MRS metabolic imaging and a navigation imaging was combined by designed software Biopsy NAV to guide biopsy. The biopsy points in21cases diagnosed glioma were classified into3types:(1)tumor tissue:enhanced parenchyma;(2) nearer-tumor tissue:distance from the margin of enhanced parenchyma less than3cm or T2W hyperintense region;(3) further-tumor tissue:the distance more than3cm or out of T2W hyperintense region. The ratio of Cho/NAA were measured in tumor parenchyma, nearer-tumor tissue and further-tumor tissue and average value, variance and ROC curve of the tumor typical tissue was made respectively. The critical value was defined as the reference value corresponded to maximum Youden index (sensitivity+specificity-1) in ROC curve of the Cho/NAA. Tumors were classified into high-grade and low-grade by critical value compared with histopathological result. Correlation analysis was performed by Pearson and Spearman method, and matched data by chi-square test P<0.05indicated statistical significance.Results:1. Biopsies were successfully performed in all28cases (success rate100%), and pathological diagnosis were made in28patients, with a success rate of100.0%(28/28). High degree of accuracy of1H-MRS guided biopsy was proved by iMRI. None of the patients suffered from significant complications such as severe bleeding, intracranial infections or neurological deficit.2.27samples were acquired in low-grade group,10in tumor tissue,8in nearer-tumor tissue and9in further-tumor tissue with average value of Cho/NAA equal to3.88±2.54,1.47±0.37and0.84±0.26respectively.62samples were acquired in high-grade group,20in tumor tissue,24in nearer-tumor tissue and18in further-tumor tissue with average value of Cho/NAA equal to7.02±5.13,2.41±1.60and1.15±1.02respectively. The Cho/NAA value of tumor parenchyma and nearer-tumor tissue in low-grade glioma had significant differences with high-grade glioma(P<0.05). No difference was observed in further-tumor tissue(P>0.05). In the correlated evaluation of tumor pathological grading with the parameter, significance was acquired and the correlation coefficient were r=0.368, P<0.05, which showed that Cho/NAA value can be used in the evaluation of glioma grading.3. The critical value of Cho/NAA in tumor parenchyma equal to2.53corresponded to maximum Youden index in ROC curve, a number of sensitivity(92.9%)、specificity(71.4%) and positive predictive value(86.7%) were obtained compared with pathology. Significance was obtained compared the result judged by with conventional MRI(P<0.05).Conclusion:1H-MRS guided biopsy is an accurate, effective and safe technique in biopsy of intracranial lesions. Moreover, proper critical value of Cho/NAA value can obtain greater positive predictive values, which improve the diagnostic probability of grading. And it can be used in evaluation of glioma grading before operation.