Sachs Jeffrey R, Zapadka Michael E, Elster Allen D
From the Department of Radiology, Wake Forest School of Medicine, Wake Forest Baptist Health, Winston-Salem, NC.
J Comput Assist Tomogr. 2018 Jul/Aug;42(4):497-501. doi: 10.1097/RCT.0000000000000716.
The aim of the study was to describe the prevalence and characteristics of orbital interstitial fluid seen on magnetic resonance (MR) images of infants and young children.
Fat-suppressed axial T2-weighted MR images of 100 consecutive infants and young children (<6 years) without orbital pathology were retrospectively reviewed by 2 neuroradiologists. The presence, location, and extent of high-signal orbital interstitial fluid were characterized and tabulated as a function of age.
Orbital interstitial fluid was detected in 90 (90%) of the 100 subjects overall, present in 100% (75/75) of infants and children younger than 3 years, 75% (12/16) of those aged 3 to 5 years, and 33% (3/9) of those aged 5 to 6 years. The fluid was bilateral and symmetric in all cases. Two morphologic patterns were distinguished, which often co-existed: (1) a focal discrete curvilinear band of fluid in the posterior-lateral orbit, more common in younger patients, and (2) an ill-defined, lace-like pattern primarily in the superior orbit seen in subjects of all ages.
Orbital interstitial fluid as detected by fat-suppressed T2-weighted MR imaging is a nearly universal finding in infants and young children and should not be considered pathologic. It may have either a focal or lace-like pattern or both. Orbital interstitial fluid decreases in size and prevalence as a function of age but is still present in nearly half of children aged 4 to 6 years. Possible explanations concerning the nature and origin of this fluid are presented, including the fascinating possibility that the fluid represents an extracranial pathway for outflow of cerebrospinal fluid.
本研究旨在描述婴幼儿磁共振（MR）图像上眼眶间质液的患病率及特征。
2名神经放射科医生对100例连续的无眼眶病变的婴幼儿（<6岁）的脂肪抑制轴向T2加权MR图像进行回顾性分析。眼眶高信号间质液的存在、位置及范围按年龄进行特征描述并制成表格。
100名受试者中，90名（90%）检测到眼眶间质液，3岁以下婴幼儿中100%（75/75）存在，3至5岁儿童中75%（12/16）存在，5至6岁儿童中33%（3/9）存在。所有病例中液体均为双侧且对称。区分出两种形态学模式，且常同时存在：（1）眼眶后外侧局限性离散曲线状液带，在较年幼患者中更常见；（2）所有年龄段受试者中主要位于眼眶上部的边界不清的花边样模式。
脂肪抑制T2加权MR成像检测到的眼眶间质液在婴幼儿中几乎普遍存在，不应视为病理性的。它可能呈局限性或花边样模式，或两者皆有。眼眶间质液的大小和患病率随年龄增长而降低，但在4至6岁儿童中仍近半数存在。文中提出了关于这种液体的性质和来源的可能解释，包括这种液体代表脑脊液颅外流出途径这一引人入胜的可能性。
