Patel S H, Cunnane M E, Juliano A F, Vangel M G, Kazlas M A, Moonis G
From the Departments of Radiology (S.H.P., M.E.C., A.F.J., G.M.)
From the Departments of Radiology (S.H.P., M.E.C., A.F.J., G.M.).
AJNR Am J Neuroradiol. 2014 Sep;35(9):1830-5. doi: 10.3174/ajnr.A3943. Epub 2014 Apr 24.
The lateral rectus-superior rectus band is an orbital connective tissue structure that has been implicated in a form of strabismus termed sagging eye syndrome. Our purpose was to define the normal MR imaging and CT appearance of this band in patients without strabismus.
Orbital MR imaging and CT examinations in 100 consecutive patients without strabismus were evaluated. Readers graded the visibility of the lateral rectus-superior rectus band on coronal T1WI, coronal STIR, and coronal CT images. Readers determined whether the band demonstrated superotemporal bowing or any discontinuities and whether a distinct lateral levator aponeurosis was seen. Reader agreement was assessed by κ coefficients. Association between imaging metrics and patient age/sex was calculated by using the Fisher exact test.
The lateral rectus-superior rectus band was visible in 95% of coronal T1WI, 68% of coronal STIR sequences, and 70% of coronal CT scans. Ninety-five percent of these bands were seen as a continuous, arc-like structure extending from the superior rectus/levator palpebrae muscle complex to the lateral rectus muscle; 24% demonstrated superotemporal bowing; and in 82% of orbits, a distinct lateral levator aponeurosis was visible. Increasing patient age was negatively associated with lateral rectus-superior rectus band visibility (P=.03), positively associated with lateral rectus-superior rectus band superotemporal bowing (P=.03), and positively associated with lateral levator aponeurosis visibility (P=.01).
The lateral rectus-superior rectus band is visible in most patients without strabismus on coronal T1WI. The age effect with respect to its visibility and superotemporal bowing could represent age-related connective tissue degeneration.
外直肌-上直肌束是一种眶内结缔组织结构，与一种称为下垂眼综合征的斜视形式有关。我们的目的是明确该束在无斜视患者中的正常磁共振成像（MR）和计算机断层扫描（CT）表现。
对100例连续的无斜视患者的眼眶MR成像和CT检查进行评估。阅片者对冠状位T1加权成像（T1WI）、冠状位短T1反转恢复序列（STIR）和冠状位CT图像上外直肌-上直肌束的显示情况进行分级。阅片者确定该束是否表现为颞上弓形或任何连续性中断，以及是否可见明显的外侧提上睑肌腱膜。通过κ系数评估阅片者间的一致性。使用Fisher精确检验计算成像指标与患者年龄/性别的相关性。
在95%的冠状位T1WI、68%的冠状位STIR序列和70%的冠状位CT扫描中可见外直肌-上直肌束。其中95%的束表现为从眼上直肌/提上睑肌复合体延伸至外直肌的连续弧形结构；24%表现为颞上弓形；82%的眼眶中可见明显的外侧提上睑肌腱膜。患者年龄增加与外直肌-上直肌束的显示呈负相关（P = 0.03），与外直肌-上直肌束的颞上弓形呈正相关（P = 0.03），与外侧提上睑肌腱膜的显示呈正相关（P = 0.01）。
在大多数无斜视患者的冠状位T1WI上可见外直肌-上直肌束。其显示及颞上弓形的年龄效应可能代表与年龄相关的结缔组织退变。
