Han Dae Hee, Nam Yong Seok, Ahn Myeong Im, Wang Young-Pil, Park Soo-An
Department of Radiology, Seoul Saint Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, South Korea.
Clin Anat. 2010 Oct;23(7):803-10. doi: 10.1002/ca.21035. Epub 2010 Aug 27.
This study was undertaken to provide an anatomical explanation for two soft-tissue structures anecdotally found on axial computed tomography (CT) scan, which are inferior (SI) and lateral (SL) to the head of the clavicle and adjacent to the sternoclavicular joint (SCJ). Three sets of cryosection images were reviewed to identify the anatomical structures corresponding to SI and SL. To demonstrate that SI and/or SL communicate with the SCJ cavity in the living, 312 consecutive chest CT scans were assessed for coexistence of SCJ and SI/SL air. To prove that under-recognition of SI and SL is due to the use of thick-section CT scan, another 50 consecutive chest CT scans were evaluated: visibility of SI and SL, and continuity between them on thick (5 mm)-section images were compared with those on thin (0.75 mm)-section images. The anterior portions of SI and SL were extensions from the SCJ cavity in the cryosection images, with the articular cartilage and disc occupying variable volumes of SI. The posterior portions of the SI and SL corresponded to the thyroid strap muscles. Air was present in 1 SI, 6 SLs, and 10 SCJs. Four of five patients with SI or SL air had coexisting SCJ air. Thick sections provided significantly poor visibility of SI and SL and continuity compared with thin-section images. SI and SL are constant shadows on thin-section CT scan, and their anterior and posterior portions represent extensions of the SCJ cavity and the strap muscles, respectively. The use of thick sections may be responsible for the under-recognition of SI and SL on CT scan.
本研究旨在为在轴向计算机断层扫描（CT）上偶然发现的两个软组织结构提供解剖学解释，这两个结构位于锁骨头部下方（SI）和外侧（SL），且与胸锁关节（SCJ）相邻。回顾了三组冷冻切片图像，以确定与SI和SL相对应的解剖结构。为了证明SI和/或SL在活体中与SCJ腔相通，对312例连续胸部CT扫描评估SCJ与SI/SL空气共存情况。为了证明对SI和SL认识不足是由于使用厚层CT扫描所致，又对50例连续胸部CT扫描进行了评估：比较了厚层（5mm）切片图像与薄层（0.75mm）切片图像上SI和SL的可见性以及它们之间的连续性。在冷冻切片图像中，SI和SL的前部是SCJ腔的延伸，关节软骨和椎间盘占据SI的不同体积。SI和SL的后部对应于甲状腺带状肌。1例SI、6例SL和10例SCJ中有空气存在。5例SI或SL有空气的患者中，4例同时存在SCJ空气。与薄层图像相比，厚层切片提供的SI和SL可见性及连续性明显较差。SI和SL在薄层CT扫描上是恒定的阴影，它们的前部和后部分别代表SCJ腔和带状肌的延伸。使用厚层切片可能是CT扫描时对SI和SL认识不足的原因。
