Apparent diffusion coefficient maps obtained from high b value diffusion-weighted imaging in the preoperative evaluation of gliomas at 3T: comparison with standard b value diffusion-weighted imaging

Abstract

Objective

To assess whether ADC maps obtained from high b value DWI were more valuable in preoperatively evaluating the grade, Ki-67 index and outcome of gliomas.

Methods

Sixty-three patients with gliomas, who underwent preoperative multi b value DWI at 3 T, were enrolled. The ADC₁₀₀₀, ADC₂₀₀₀ and ADC₃₀₀₀ maps were generated. Receiver operating characteristic analyses were conducted to determine the area under the curve (AUC) in differentiating high-grade gliomas (HGG) from low-grade gliomas (LGG). Pearson correlation coefficients (R value) were calculated to investigate the correlation between parameters with the Ki-67 proliferation index. Survival analysis was conducted by using Cox regression.

Results

The AUC of the mean ADC₁₀₀₀ value (0.820) was lower than that of the mean ADC₂₀₀₀ value (0.847) and mean ADC₃₀₀₀ value (0.875) in differentiating HGG from LGG. The R value of the mean ADC₁₀₀₀ value (−0.499) was less negative than that of the mean ADC₂₀₀₀ value (−0.530) and mean ADC₃₀₀₀ value (−0.567). The mean ADC₃₀₀₀ value was an independent prognosis factor for gliomas (p = 0.008), while the mean ADC₁₀₀₀ and ADC₂₀₀₀ values were not.

Conclusion

ADC maps obtained from high b value DWI might be a better imaging biomarker in the preoperative evaluation of gliomas.

Key Points

• ADC ₃₀₀₀maps could improve the differentiation between HGG and LGG.

• The mean ADC ₃₀₀₀value had a closer correlation with the Ki-67 index.

• The mean ADC ₃₀₀₀value was an independent prognosis factor for gliomas.