[Correlation between magnetic resonance diffusion weighted imaging and cell density in astrocytoma].

OBJECTIVE: To evaluate the apparent diffusion coefficients (ADC) in magnetic resonance diffusion weighted imaging with echo-planar technique in depicting the tumor cellularity and grading of astrocytoma.

METHODS: Thirty-four astrocytoma patients including 18 male and 16 female with age from 10 to 73 years (mean 38.4 years) were examined by MRI and eventually proved by surgical resection and pathological examination. Of them, 26 had low-grade (grade I, II) astrocytoma and 8 high-grade (grade III, IV) astrocytoma. ADC value of astrocytoma was determined on magnetic resonance diffusion weighted images. Cellularity of the astrocytoma was analyzed using Adobe Photoshop 7.0.1 software.

RESULTS: The mean ADC value (in units of 10(-4) mm(2)/s) of the high-grade astrocytomas (7.34 +/- 2.95) was significantly lower than that of the low-grade astrocytomas (13.76 +/- 3.31) (t = 4.91, P < 0.001). The mean cellularity of the high-grade astrocytomas (19.81 +/- 9.73)% was significantly higher than that of the low-grade astrocytomas (4.74 +/- 2.96)% (t = 4.32, P = 0.003). ADC value of the astrocytoma was significantly and negatively correlated with its cellularity (r = -0.535, P = 0.001).

CONCLUSION: ADC value of astrocytoma is significantly and negatively correlated with its cellularity. Magnetic resonance diffusion weighted imaging may well be highly potential in predicting the degree of astrocytoma.