Objective:

To investigate the value of apparent diffusion coefficient (ADC) for differential diagnosis of histopathologic grade of meningiomas and its relationship with Ki-67 proliferation index.

Methods:

The data of 51 patients with meningioma confirmed by surgery and pathology were reviewed and analyzed. According to the World Health Organization (WHO) pathological grade

patients were divided into low-grade meningioma (LGM) group (45 cases) and high-grade meningioma (HGM) group (6 cases). The average ADC (ADC

mean

)

minimum ADC (ADC

min

)，and their relative values (rADC

mean

and rADC

min

) were calculated. The differences of ADC

mean

ADC

min

rADC

mean

and rADC

min

between the two groups were compared. The receiver operating characteristic (ROC) curve was used to assess the diagnostic efficacy of each ADC parameter’s diagnostic efficacy

and DeLong’s test was used to compare the difference in area under curve (AUC) of the ROC curve. Spearman correlation analysis was performed to assess the correlation between each of the ADC parameters and Ki-67 proliferation index.

Results:

The ADC

mean

ADC

min

rADC

mean

and rADC

min

values of the LGM group were higher than those of the HGM group

and the differences between the groups were all statistically significant (

P

＜0.05). The four ADC parameters all had good diagnostic efficacy

DeLong test showed that there was no significant difference in AUC between any two groups (

P

＞0.05). And ADC

min

had the best differential diagnostic efficacy. The optimal cut-off value of ADC

min

was 0.657×10

-3

mm

2

/s

and the sensitivity was 66.67%

and the specificity was 95.56%. ADC

mean

ADC

min

rADC

mean

and rADC

min

values were

all negatively correlated with Ki-67 proliferation index (

P

＜0.05).

Conclusion:

ADC values were helpful to predict the pathological grade of meningiomas and Ki-67 proliferation index before operation

and it can provide support for clinical diagnosis and treatment.