Diffusion-weighted magnetic resonance imaging in glioma classification / 国际肿瘤学杂志

ABSTRACT

Objective To evaluate the usefulness of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficients (ADC) in differentiating tumor, edema, and normal brain tissue, and in classification of cerebral gliomas. Methods Using Philips Achieva 1.5T super conduct MR scanner, 46 patients with gliomas underwent conventional MR imaging and DWI. The ADC of regions of interest ( ROI ) were measured with two different b values, 0s/mm2 and 1000s/mm2. ROIs were manually placed over areas of tumor,edema, and normal brain tissue. Results The signals of DWI and ADC map in tumor tissue were respectively higher and lower than those in normal brain tissue. The ADC values in tumor were 1.68 ± 0.18,1.65 ± 0.20,1.29 ±0.16,1.21 ±0.21 for grade Ⅰ、Ⅱ、Ⅲ、Ⅳ gliomas, respectively; the corresponding figures in edema were 1.74 ±0.22,1.72 ±0.19,1.35 ±0.20,1.28 ±0.19, respective. The ADC values in tumor were not significantly different from the values in edema (P ＞0.05); however, both values were significantly different from those in normal brain ( P ＜0.05 ). The ADC value of low grade ( grade1-2 ) gliomas was significantly higher than that of high grade (grade3-4) glioma (P＜0.05). Conclusion ADC values can aid in distinguishing tumors from normal tissues, but can not distinguish tumors from adjacent edema. Individually, ADC values overlapped considerahly. ADC value is associated with cellularity of gliomas. DWI can help characterizing the malignancy of gliomas.