Ito K, Kogure T, Hayashi S, Kaneko I, Shimada M, Tsubuka M, Kusama K
First Department of Radiology, Toho University Hospital, Japan.
Nihon Igaku Hoshasen Gakkai Zasshi. 1996 Feb;56(3):89-93.
We studied 12 cases of right aortic arch (RAA) with MRI, and the anatomical relationship between right aortic arch and the esophagus and trachea were analysed. Three of 12 cases showed RAA with mirror-image branching. Nine cases were RAA with aberrant left subclavian artery. The proximal portion of the aberrant left subclavian artery in the retrotracheoesophageal space was expanded just like a pouch. The pouch was the 8th segment dorsal aortic root and the so-called aortic diverticulum. This was one of the causes of symptoms such as wheezing and dysphagia. We divided the configuration of aortic diverticulum into two types, bulging type and saccular type, on the basis of coronal images. Two cases were bulging type, seven saccular type. The axial images in two cases showed compressed esophagus, and in three cases showed displacement of the trachea, narrowing of the space like a triangle surrounded by the aortic arch, aortic diverticulum and aberrant left subclavian artery. We drew lines and measured the angle of the aortic arch with the aberrant left subclavian artery on the axial images of these cases. We found that cases with an angle of less than 60 degrees showed a high correlation with the causes of compression of the esophagus or displacement of the trachea. It was necessary to follow such patients with MRI.
我们对12例右位主动脉弓（RAA）患者进行了MRI研究，并分析了右位主动脉弓与食管和气管之间的解剖关系。12例中有3例显示右位主动脉弓伴镜像分支。9例为右位主动脉弓伴迷走左锁骨下动脉。迷走左锁骨下动脉在气管食管后间隙的近端部分呈囊袋样扩张。该囊袋为第8节段背主动脉根部，即所谓的主动脉憩室。这是喘息和吞咽困难等症状的原因之一。我们根据冠状位图像将主动脉憩室的形态分为膨出型和囊袋型两种。膨出型2例，囊袋型7例。2例的轴位图像显示食管受压，3例显示气管移位，主动脉弓、主动脉憩室和迷走左锁骨下动脉所围成的间隙呈三角形变窄。我们在这些病例的轴位图像上画线并测量主动脉弓与迷走左锁骨下动脉的夹角。我们发现夹角小于60度的病例与食管受压或气管移位的原因高度相关。对这类患者有必要进行MRI随访。
