The application of minimum apparent diffusion coefficient value on diagnosing the primary tumors in the fourth ventricle with diffusion-weighted imaging / 中国医学装备

ABSTRACT

Objective:To analyze the differences and common differential diagnostic value on the fourth ventricle magic resonance imaging (MRI) findings of primary tumors, diffusion-weighted imaging (DWI) and minimum apparent diffusion coefficient (ADC).Methods:A total 100 cases with the fourth ventricle of the primary tumor who were given MRI examination, were selected from March 2011 to April 2012 in our hospital, recording an average minimum ADC value of tumor parenchyma.Results: 43 cases of medulloblastoma showed cerebellar hemisphere pressed shift or tonsillar herniation and restricted diffusion on DWI tumors showed high signal tumor. The minimum ADC value was (0.43±0.15)×10-3mm2/s. 33 cases of astrocytomas showed significant mass effect and the minimum ADC value was (1.58±0.58)×10-3mm2/s. 24 cases of ependymoma MRI showed typical “melting wa×” degeneration and tumor minimum ADC value was(0.93±0.18)×10-3mm2/s. The minimum ADC value of the three different forms of tumor cell lines was calculated by variance test and twenty-two row-LSD-t test, and the results were statistically significant difference (F=21.985,P=0.001). DWI high signal is limited to an average minimum ADC value of 0.875×10-3mm2/s as a threshold value. Compared with the pathology, the specificity of the fourth ventricle medulloblastoma was 98.5%, the sensitivity was 97.3%, the negative predictive value was 98.5%, and a positive predictive value was 100%. The suppression test was carried out between all the results above and the results of histological findings and Kappa value was 0.912.Conclusion: The primary tumor of the fourth ventricle was diagnosed with the ADC, DWI and conventional MRI, which showed that the specificity, sensitivity, negative predictive value and positive predictive value were high. It had obvious diagnostic effect and great value.