摘要
目的评价扩散加权成像(DWI)和表观扩散系数(ADC)值对儿童第四脑室区髓母细胞瘤和室管膜瘤的鉴别诊断价值。方法经手术病理证实的第四脑室区12例髓母细胞瘤和8例室管膜瘤患儿均接受常规MRI平扫、增强和DWI并测量肿瘤实质的ADC值。观察并比较两组肿瘤DWI的信号强度和ADC值。结果 12例髓母细胞瘤DWI上,10例呈高信号,2例呈稍高信号,相应ADC图10例呈低信号,2例呈略低信号,ADC均值(0.76±0.15)mm2/s;8例室管膜瘤DWI上,5例呈等低信号,3例呈稍高信号,相应ADC图5例呈等、略高信号,3例呈略低信号,ADC均值(1.10±0.13)×10-3mm2/s。髓母细胞瘤较室管膜瘤的ADC值减低,差异有统计学意义(P<0.01)。当以肿瘤实质ADC<0.94×10-3mm2/s诊断髓母细胞瘤时,诊断特异性为91.7%(11/12)。结论 DWI和ADC值是术前诊断及鉴别诊断儿童第四脑室区髓母细胞瘤和室管膜瘤的简单可靠的检查方法。
Objective To observe the value of diffusion weighted imaging （DWI） and apparent diffusion coefficient （ADC） value in differential diagnosis of medulloblastoma and ependymoma in the pediatric fourth ventricular. Methods 12 medulloblastomas and 8 ependymomas were confirmed with surgically and pathologically. All pediatric patients received conventional, contrast enhanced and DWI examination. ADC value was calculated in the solid part of tumors. The DWI signal and ADC values of two groups were compared. Results In 12 lesions of medulloblastomas, hyperintensity was showed in ten patients and slightly hyperintensity in two patients on DWI image. The corresponding region ADC map showed hypointensity in ten patients and slightly hypointensity in two patients, the average ADC value of medulloblastomas was （0.76 ± 0.15 ） mm2/s. In eight lesions of ependymomas, isointensity/slightly hypointensity was showed in 5 patients and slightly hyperintensity in three patients on DWI image. The corresponding region ADC map showed isointensity/slight- ly hyperintensity in 5 patients and slightly hypointense in three patients, the average ADC value of ependymomas was （ 1.10 ±0.13） x 10-3 mm2/s. The ADC value of medulloblastoma was lower than that of epeudymoma, which has statistically significant difference（ P 〈 0.01 ）. The specificity of with a cut off value of 〈 0.94 x 10 -3 mm2/s for medulloblastomas were 91.7%. Conclusion The DWI signal and ADC values provides a simple and reliable method for preoperative diagnosis and differential diagnosis of medulloblastoma and ependymoma in the fourth ventricular of pediatric.
出处
《临床放射学杂志》
CSCD
北大核心
2013年第12期1761-1765,共5页
Journal of Clinical Radiology
