Application of ADC value in diagnosis of glioma grading before operation

Objective: To study the value of apparent diffusion coefffcient (ADC) value in diagnosis of glioma before operation by analyzing the differences of ADC value between low grade glioma and high grade glioma. Methods: The imagines of 14 cases of low grade gliomas (I, II grade) and 20 cases of high grade gliomas (III, IV grade) with glioma histologically proved including conventional MRI, enhanced scanning and DWI were retrospectively analyzed. The ADC map in the station building was constructed and the ADC values of tumor substantial part, peritumoral edema, cystic necrotic area and the corresponding contralateral normal brain were measured. The relationship between the ADC value about the measurement area and the grade of glioma was analyzed. Results: The ADC value of tumor substantial part of low grade glioma [(1.47 ± 0.18) x 10-3 mm2 · s-1] was significantly higher than that of high grade glioma [(0.97 ± 0.18) x 10-3 mm2 · s-1] (P<0.01), the ADC values of the corresponding contralateral brain white matter were (0.76 ± 0.06) x 10-3 mm2 · s-1 and (0.75 ± 0.06) x 10-3 mm2 · s-1; and the ADC value of tumor peritumoral edema of low grade glioma [(1.61 ± 0.19) x 10-3 mm2 · s-1] was significantly higher than that of high grade glioma [(1.26 ± 0.14) x 10-3 mm2 · s-1] (P<0.01), the ADC values of the corresponding contralateral brain white matter were (0.74 ± 0.04) x 10-3 mm2 · s-1 and (0.77 ± 0.06) x 10-3 mm2 · s-1. The ADC value of cystic necrotic area of low grade glioma [(1.88 ± 0.11) x 10-3 mm2 · s-1] was higher than that of high grade glioma [(1.34 ± 0.14) x 10-3 mm2 · s-1] (P<0.01), the ADC values of the corresponding contralateral brain white matter were(0.75 ± 0.08) x 10-3 mm2 · s-1 and (0.73 ± 0.06) x 10-3 mm2 ·s-1. The ADC values of tumor substantial part,peritumoral edema, cystic necrotic area were inversely associated with the degree of malignancy of the gliomas (the r values were -0.821, -0.726 and -0.919, respectively, P<0.01). Conclusion: The ADC values of tumor substantial part,peritumoral edema, cystic necrotic area between low grade glioma and high grade glioma have significantly differences, the measurement of ADC value play an important role in diagnosis of glioma grading before operation. (authors)