Jurkiewicz Elżbieta, Pakuła-Kościesza Iwona, Chełstowska Sylwia, Nowak Katarzyna, Roszkowski Marcin, Grajkowska Wiesława, Szary Cezary
MR Unit, The Children's Memorial Heath Institute, Warsaw, Poland.
Pol J Radiol. 2010 Oct;75(4):18-23.
The purpose of this study was to evaluate ADC values in the preoperative grading of primary infratentorial brain tumors in children. MATERIAL /METHODS: We retrospectively reviewed 50 MR examinations of patients with infratentorial tumors. All children were operated on and tumors were histopathologically proved as low-grade - 25 (24 pilocytic astrocytomas, 1 ependymoma) and high-grade lesions - 25 (19 medulloblastomas, 6 anaplastic ependymomas). In all patients with contrast-enhanced tumors, ROIs were placed in the enhanced region. In patients with non-enhancing tumors, ROIs were placed in the solid part of the lesion. Cystic, hemorrhagic and necrotic areas of tumors were excluded. Statistical analysis was performed by using a Student's t-test.
Statistically significant differences were found in the comparisons of mean ADC of pilocytic astrocytomas (1.54×10(-3)mm(2)/s ±0.2) with medulloblastomas (0.75×10(-3)mm(2)/s ±0.075) and pilocytic astrocytomas (1.54×10(-3)mm(2)/s ±0.2) with anaplastic ependymomas (0.99×10(-3)mm(2)/s ±0.25). Statistical analysis including ependymomas should be discussed, because of small number of these tumors and a non-homogenous group of lesions.
DWI imaging and ADC map provide useful information for preoperative grading of infratentorial tumors in children.
本研究的目的是评估儿童幕下原发性脑肿瘤术前分级中的表观扩散系数（ADC）值。
材料/方法：我们回顾性分析了50例幕下肿瘤患者的磁共振成像（MR）检查。所有儿童均接受了手术，肿瘤经组织病理学证实为低级别病变25例（24例毛细胞型星形细胞瘤，1例室管膜瘤）和高级别病变25例（19例髓母细胞瘤，6例间变性室管膜瘤）。对于所有有强化肿瘤的患者，在强化区域放置感兴趣区（ROI）。对于无强化肿瘤的患者，在病变的实性部分放置ROI。排除肿瘤的囊性、出血性和坏死区域。采用学生t检验进行统计学分析。
毛细胞型星形细胞瘤的平均ADC值（1.54×10⁻³mm²/s±0.2）与髓母细胞瘤（0.75×10⁻³mm²/s±0.075）以及毛细胞型星形细胞瘤（1.54×10⁻³mm²/s±0.2）与间变性室管膜瘤（0.99×10⁻³mm²/s±0.25）之间的比较，差异具有统计学意义。由于这些肿瘤数量较少且病变组不均一，因此应讨论包括室管膜瘤在内的统计学分析。
扩散加权成像（DWI）和ADC图为儿童幕下肿瘤的术前分级提供了有用信息。
