Sener R N
Department of Radiology, Ege University Hospital, Bornova, 35100 Izmir, Turkey.
Eur Radiol. 2002 Jan;12(1):138-43. doi: 10.1007/s003300101029. Epub 2001 Aug 28.
Diffusion MRI has mainly been used for detection of acute ischemia, and for distinction of cytotoxic and vasogenic edema. We applied diffusion MRI in patients with tuberous sclerosis in order to evaluate diffusion imaging characteristics of parenchymal changes. Five children with known tuberous sclerosis were included in this study. The MRI examinations were performed on a 1.5-T MR unit. Diffusion MRI was obtained using the echo-planar imaging sequence. Apparent diffusion coefficient (ADC) values from the abnormal brain parenchyma were calculated directly from automatically generated ADC maps. Seven normal children were available for comparison. In this control group the mean ADC value of the normal white matter was 0.84 +/- 0.12 x 10(-3) mm(2)/s. In tuberous sclerosis patients the mean ADC value of the white matter hamartomas ( n=20) was apparently high (1.52 +/- 0.24 x 10(-3) mm(2)/s) compared with that of normal white matter. The ADC value of calcified hamartomas was "zero". The ADC value within a giant cell tumor was 0.89 x 10(-3) mm(2)/s, similar to that of normal cerebral white matter. The ADC maps were superior to b=1000 s/mm(2) (true diffusion) images with respect to lesion evaluation, and they provided mathematical information on tissue integrity. With respect to detection of the exact numbers and sizes of the parenchymal hamartomas fluid-attenuated inversion recovery images were superior to ADC maps. It is believed that diffusion MRI can be useful in evaluation of various parenchymal changes associated with tuberous sclerosis. Further studies on tuberous sclerosis, and on various brain lesions, would provide increasing data on this relatively new MRI sequence.
扩散加权磁共振成像（Diffusion MRI）主要用于检测急性缺血以及区分细胞毒性水肿和血管源性水肿。我们对结节性硬化症患者应用扩散加权磁共振成像，以评估脑实质改变的扩散成像特征。本研究纳入了5名已知患有结节性硬化症的儿童。磁共振成像检查在一台1.5-T磁共振设备上进行。使用回波平面成像序列获得扩散加权磁共振成像。异常脑实质的表观扩散系数（ADC）值直接从自动生成的ADC图计算得出。有7名正常儿童可供比较。在这个对照组中，正常白质的平均ADC值为0.84±0.12×10⁻³mm²/s。在结节性硬化症患者中，白质错构瘤（n = 20）的平均ADC值与正常白质相比明显较高（1.52±0.24×10⁻³mm²/s）。钙化错构瘤的ADC值为“零”。巨细胞瘤内的ADC值为0.89×10⁻³mm²/s，与正常脑白质相似。在病变评估方面，ADC图优于b = 1000 s/mm²（真实扩散）图像，并且它们提供了关于组织完整性的数学信息。在检测脑实质错构瘤的确切数量和大小时，液体衰减反转恢复图像优于ADC图。据信，扩散加权磁共振成像在评估与结节性硬化症相关的各种脑实质改变方面可能有用。对结节性硬化症以及各种脑病变的进一步研究将为这个相对较新的磁共振成像序列提供越来越多的数据。
