Todua F, Chedia S
Radiology Department, Clinical Medicine Centre, Tbilisi, Georgia.
Georgian Med News. 2012 May(206):16-22.
The purpose of the study was to investigate the utility of diffusion-weighted (DW) and perfusion-weighted (PW) MR imaging to differentiate benign and malignant meningiomas which were verified histologically. A total of 29 patients with meningiomas (22 benign and 7 malignant) underwent conventional, perfusion and diffusion MR imaging. Conventional MRI revealed the ordinary signs of tumor. The absolute apparent diffusion coefficient (ADC) and normalized ADC (NADC) ratio, maximal relative cerebral blood volume (rCBV) and the corresponding relative mean time to enhance (rMTE) in both tumour parenchyma and peritumoral edema were measured. The mean ADC of malignant meningiomas (0.64±0.12 x 10(-3) mm(2)/s) was significantly lower compared with benign meningiomas (0.89±0.09 x 10(-3) mm(2)/s; P<.0001). Mean NADC ratio in the malignant group (0.93±0.18) was also significantly lower than in the benign group (1.29±0.12; P<.0001). The mean maximal rCBV values of benign and malignant meningiomas were 7.18±4.12 and 6.01±3.89, in the tumour parenchyma, and 1,07±0,95 and 3,85±1,41 in the peritumoral edema. The mean rMTE values were 1.14±0.23 and 1.24±0.27, in the tumour, and 0.88±0.24 and 1.21±0.31, in the peritumoral edema. The differences in rCBV and rMTE values between benign and malignant meningiomas were not significant (P>0.05) in the tumour parenchyma, but both were significant (p<0.05) in the peritumoral edema. Diffusion and perfusion MR imaging are useful in the preoperative differentiation between benign and malignant meningiomas.
本研究的目的是探讨扩散加权（DW）和灌注加权（PW）磁共振成像在鉴别经组织学证实的良性和恶性脑膜瘤中的应用价值。共有29例脑膜瘤患者（22例良性和7例恶性）接受了常规、灌注和扩散磁共振成像检查。常规MRI显示了肿瘤的常见征象。测量了肿瘤实质和瘤周水肿中的绝对表观扩散系数（ADC）和标准化ADC（NADC）比值、最大相对脑血容量（rCBV）以及相应的相对平均强化时间（rMTE）。恶性脑膜瘤的平均ADC（0.64±0.12×10⁻³mm²/s）显著低于良性脑膜瘤（0.89±0.09×10⁻³mm²/s；P<0.0001）。恶性组的平均NADC比值（0.93±0.18）也显著低于良性组（1.29±0.12；P<0.0001）。良性和恶性脑膜瘤在肿瘤实质中的平均最大rCBV值分别为7.18±4.12和6.01±3.89，在瘤周水肿中分别为1.07±0.95和3.85±1.41。平均rMTE值在肿瘤中分别为1.14±0.23和1.24±0.27，在瘤周水肿中分别为0.88±0.24和1.21±0.31。良性和恶性脑膜瘤在肿瘤实质中的rCBV和rMTE值差异无统计学意义（P>0.05），但在瘤周水肿中两者均有统计学意义（P<0.05）。扩散和灌注磁共振成像有助于术前鉴别良性和恶性脑膜瘤。
