Minimum Apparent Diffusion Coefficient (ADC) Value in Differentiation of High and Low Grade Gliomas, Does it Make a Difference?

Abstract

Objectives: This study aimed to study the minimum and mean ADC values in the differentiation of high and low grade gliomas. Background: Diffusion-weighted imaging (DWI) has greatly enhanced the ability of MRI to differentiate high and low grade gliomas where the ADC values inversely correlated with the tumor grade. Methods: This retrospective study included 50 patients (M/F 23/27) with pathologically proven gliomas (30 patients with high grade and 20 with low grade gliomas) who underwent MRI with diffusion weighted sequence ((b-value 1000 s/mm2) acquired on a 1.5T scanner at menoufia university hospital. Results: Diffusion restriction was found in 93.3% of cases of high grade gliomas (n=28/30) with mean calculated ADC value of calculated mean and minimum ADC values were 0.87±0.3 x 10-3 mm2/sec and 0.82±0.2 x 10-3 mm2/sec respectively. In low grade gliomas diffusion restriction was identified in 7 cases (n=7/20, 35%) with a mean calculated ADC values of 1.3±0.3 x 10-3 mm2/sec and 1.15±0.2 x 10-3 mm2/sec for the mean and minimum ADC respectively. Statistical significance was found between the calculated ADC values of the high and low grade gliomas when using the minimum and mean ADC values between the high and low grade gliomas (p value <0.001) Conclusion: We have demonstrated that both mean and minimum ADC values measurements can be used when trying to differentiate high and low grade gliomas with both showing statistical significance.