Clinical application value of 3.0T MR diffusion tensor imaging in grade diagnosis of gliomas

Abstract

The clinical value of MR diffusion tensor imaging (DTI) in grade diagnosis of gliomas was investigated. A total of 31 patients with glioma were administered 3.0T MR convention and DTI examination, with quantitative measurement of anisotropy coefficient fractional anisotropy (FA) and apparent dispersion coefficient (ADC) value, and the comparison of quantitative parameters of glioma between low- and high-grade, which was detected by Mann-Whitney U test. The receiver operation characteristic (ROC) curve was drawn to take the value of ADC and FA in tumor ROI as a critical point, to calculate the area under the curve and to confirm the diagnosis threshold value and evaluate its diagnostic efficiency. The FA value of 14 low-grade glioma cases was 139.4±81.3, with an ADC value of (1.36±0.21) ×10^-3 mm²/sec. The FA value of 17 high-grade glioma cases was 103.1±41.5, with ADC value of (1.09±0.28)^-3 mm²/sec; the difference between the two groups was statistically significant (P<0.05). The ADC value was taken as the critical point to judge tumor grade and draw the ROC curve; the area under the curve was 0.79. As the diagnosis threshold value, the ADC value of 1.11×10^-3 mm²/sec was used to distinguish between low- and high-grade tumor with a sensitivity of 58.8% and specificity of 92.9%. The FA value was taken as a critical point to judge tumor grade and draw the ROC curve; the area under the curve was 0.62. As the diagnosis threshold value, the FA value of 178.9 was applied to distinguish between low- and high-grade tumor sensitivity of 94.1% and specificity of 35.7%. Therefore, the FA value and ADC value in DTI has an important estimated value for the pathological grade of glioma.

Keywords: MR dynamic contrast-enhanced scan; diffusion tensor imaging; glioma; pathology.

Figure 1.

Male, 59 years old, left frontal lobe astrocytoma (WHO grade II). (A) Enhancement scan of left frontal lobe focus, without clear reinforcement; (B) Directionally encoded color image showed low signal of focus and shifted alba under oppression; (C) pathological examination displayed that tumor consisted of neoplastic astrocyte with better differentiation, with loose cell arrangement and mild atypia; (D) CD34 immunohistochemistry stain showing micrangium dispersion, with regular tubular.

Figure 2.

Male, 58 years old, with bilateral frontal lobe spongioblastoma (WHO grade IV). (A) After enhancement, scanning bilateral frontal lobe, with irregular lobulated lesion with obvious wreath reinforcement, uneven wall thickness, internal flakiness necrosis area without reinforcement; (B and C) directionally encoded color and fibet tracking image show focus invasion callosum knee fiber bundle and partial dissolution damage; (D) Pathologic examination displays obvious atypia of focus cell nucleus, cell density increasing significantly, blood vessel distributing as glomerulus.

Figure 3.

Spongioblastoma, with lesion of left frontal lobe and basal ganglia, T1W1 mixed signal. (A) T2W1 high mixed signal, (B) uneven regiment massive enhancement and (C) peripheral edema. (D) FA image red callosum knee fibers, green left frontal lobe fiber infiltration, under oppression to shift, with (E-H) fiber tractogrpahy display.

Figure 4.

Receiver operation characteristic curve that takes ADC/FA value as critical point to judge low- and high-grade tumor, with area under curve of 0.79 (ADC)/0.62 (FA). ADC, apparent dispersion coefficient, FA, fractional anisotropy.