Magnetic resonance imaging and correlative gross anatomy of the ligamentum semicirculare humeri (rotator cable).

The purpose of this study has been to demonstrate macroscopic and MRI anatomy of the so-called rotator cable, otherwise known as the ligamentum semicirculare humeri (LSCH) of the superior shoulder joint capsule. Twelve shoulder joints from eight cadavers were dissected; seven of which, from four of the cadavers, were studied using MR arthrography (1.5-Tesla device Somatom Symphony, Siemens, Erlangen, Germany) prior to dissection. The MRI protocol included T1WI, PDWI, and DESS 3D WI standard sequences. The results of MRI were compared with gross anatomic dissection findings. The macroscopically recognizable capsular bundle of LSCH fibers was identified by anatomic dissection in all specimens. On MRI, the entire ligament or parts of it could be identified in six of seven cases. It was best visualized on axial images. In the evaluation of magnetic resonance images of superior shoulder joint structures, additional knowledge on the anatomy of the LSCH can be used by the radiologist to facilitate detailed interpretation of the shoulder MRI.