Simon J, Szumowski J, Totterman S, Kido D, Ekholm S, Wicks A, Plewes D
Department of Radiology, University of Rochester Medical Center, NY 14642.
AJNR Am J Neuroradiol. 1988 Sep;9(5):961-8.
The effect of fat suppression on orbital MR imaging was tested by using a derivative of the Dixon method called chopper fat suppression in eight normal volunteers and eight patients with normal conventional orbital MR studies. Chopper fat suppression requires no postacquisition image processing or increased scan time and can be applied through a wide range of T1 to T2 weighting. In normal orbits, fat suppression was found to be advantageous for imaging the lacrimal gland and the optic nerve. Using fat-suppressed T1- or intermediate-weighted sequences, 2000/30 (TR/TE), the optic nerve was recognized by its high signal intensity relative to adjacent CSF, dural sheath, and surrounding fat. The technique minimized loss of anatomic detail by reducing chemical shift misregistration artifact. Disadvantages included an overall lower orbital signal/noise ratio. When used in conjunction with a TR/TE combination carefully selected for both anatomic region of interest and suspected pathology, the fat-suppression technique has the potential for improving the visualization of orbital lesions.
在8名正常志愿者和8名常规眼眶磁共振成像（MR）检查结果正常的患者中，采用一种名为斩波脂肪抑制的Dixon方法衍生技术，测试脂肪抑制对眼眶MR成像的影响。斩波脂肪抑制无需采集后图像处理，也不会增加扫描时间，并且可应用于广泛的T1至T2加权范围。在正常眼眶中，发现脂肪抑制有利于泪腺和视神经的成像。使用脂肪抑制的T1加权或中等加权序列（2000/30，TR/TE），相对于相邻的脑脊液、硬脑膜鞘和周围脂肪，视神经因其高信号强度而得以识别。该技术通过减少化学位移配准错误伪影，将解剖细节的损失降至最低。缺点包括眼眶整体信号/噪声比降低。当与根据感兴趣的解剖区域和可疑病变仔细选择的TR/TE组合一起使用时，脂肪抑制技术有可能改善眼眶病变的可视化。
