Hakyemez Bahattin, Yildiz Harun, Ergin Necdet, Uysal Sait, Parlak Müfit
Uludağ Universitesi Tip Fakültesi, Radyoloji Anabilim Dali, Bursa.
Tani Girisim Radyol. 2003 Dec;9(4):418-26.
To explore the use of fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted echo planar imaging sequences in imaging of the intracranial epidermoid and arachnoid cysts and assess the efficiency of those sequences in differentiation of epidermoid cysts from arachnoid cysts.
This study was performed prospectively by using two different MR devices in 24 patients (12 epidermoid cysts, 12 arachnoid cysts). T1-weighted spin echo, T2-weighted fast spin echo, FLAIR and diffusion-weighted echo planar imaging sequences were used. Lesions were evaluated qualitatively and quantitatively. In qualitative evaluation, the signal intensity of the lesions were compared with cerebral spinal flow. Quantitative evaluation was made from the diffusion-weighted images by measuring values of apparent diffusion coefficient (ADC) from the cystic spaces and cerebral white matters. In statistic analyses, Mann-Whitney U test was used.
Arachnoid cysts had the same intensity with cerebral spinal flow in all sequences. Mean ADC value was 3.41 +/- 0.17 x 10(-3) mm2/sn. All epidermoid cysts on diffusion-weighted trace images were more hyperintense than brain parenchyma. The mean ADC value of the epidermoid cysts was 1.15 +/- 10(-3) mm2/sn. The ADC values of the epidermoid cysts were lower than the arachnoid cysts (p < 0.001), but were higher than the cerebral white matter (p < 0.01).
FLAIR sequences were superior to conventional sequences in imaging of epidermoid cysts and in differentiation of epidermoid cysts from arachnoid cysts. It was also shown that diffusion-weighted trace imaging and measurement of ADC values might be used as problem solving tools. Furthermore, those sequences may be a guide to demonstrate postoperative residual lesions.
探讨液体衰减反转恢复（FLAIR）序列和扩散加权回波平面成像序列在颅内表皮样囊肿和蛛网膜囊肿成像中的应用，并评估这些序列在区分表皮样囊肿和蛛网膜囊肿方面的效能。
本研究前瞻性地使用两种不同的磁共振设备对24例患者（12例表皮样囊肿，12例蛛网膜囊肿）进行检查。采用T1加权自旋回波、T2加权快速自旋回波、FLAIR和扩散加权回波平面成像序列。对病变进行定性和定量评估。在定性评估中，将病变的信号强度与脑脊液进行比较。通过测量囊性空间和脑白质的表观扩散系数（ADC）值，从扩散加权图像进行定量评估。在统计分析中，采用曼-惠特尼U检验。
蛛网膜囊肿在所有序列中与脑脊液信号强度相同。平均ADC值为3.41±0.17×10⁻³mm²/s。在扩散加权追踪图像上，所有表皮样囊肿均比脑实质信号高。表皮样囊肿的平均ADC值为1.15±10⁻³mm²/s。表皮样囊肿的ADC值低于蛛网膜囊肿（p<0.001），但高于脑白质（p<0.01）。
FLAIR序列在表皮样囊肿成像及区分表皮样囊肿和蛛网膜囊肿方面优于传统序列。还表明扩散加权追踪成像和ADC值测量可作为解决问题的工具。此外，这些序列可能有助于显示术后残留病变。
