[Correlation between minimal apparent diffusion coefficient and expression of Ki-67 in glioma]

To explore the correlation between minimal apparent diffusion coefficient (minADC) and expression of Ki-67 in glioma.

Findings from 78 patients with pathologically proven gliomas (grade II:n = 28, grade III: n = 21, grade IV: n = 29) were analyzed retrospectively. The minADC value of each tumor was determined on ADC maps. The Ki-67 labeling index (LI) of surgical specimen was measured. The results were analyzed statistically.

The mean value of minADC for gliomas of grade II ((1.23 ± 0.23)×10(-3) mm(2/s)) was higher than that of grade III ((0.92 ± 0.20)×10(-3) mm(2/s)) (P < 0.01) and than that of grade IV ((0.80 ± 0.16)×10(-3) mm(2)/s) (P < 0.01). But no significant difference existed between the mean value of minADC of grade III and that of grade IV (P = 0.069). There were significant negative correlations between minADC and different tumor grades (r = -0.678, P < 0.01). The mean value of Ki-67 LI showed significant differences between grade II (3.6% ± 2.3%), grade III (14.8% ± 7.3%) and grade IV (29.9% ± 13.1%) (P < 0.01). There were significant positive correlations between Ki-67 LI and different tumor grades (r = 0.835, P < 0.01). And a negative correlation existed between minADC and Ki-67 LI (r = -0.556, P < 0.01).

The value of minADC is useful for predicting glioma grade.