LESIONS OF THE ALAR LIGAMENTS - IN-VIVO AND IN-VITRO STUDIES WITH MAGNETIC-RESONANCE-IMAGING

Study Design. This study analyzed anatomic characteristics of the alar ligaments and the possibility of imaging them with magnetic resonance imaging. Also determined was whether artificial ruptures of the alar ligament can be recognized experimentally. Objective. To determine the ability of magnetic resonance imaging to visualize normal, torn, and resected alar ligaments. Summary of Background Data. There are no stud ies about computed tomography or magnetic resonance imaging findings o f alar ligaments and after anatomic sections. Direct visualization of the complete ligament is not possible by computed tomography. No preci se diagnostic method for showing a ruptured alar ligaments has been de scribed. Magnetic resonance imaging seems to be the method of choice f or distinguishing between normal and pathologic soft tissue. Methods. Fifteen specimens from accident victims underwent anatomic dissection. In addition, ligaments from three groups were examined: 1) eight volu nteers, 2) seven patients, and 3) 17 fresh cadaveric specimen before a natomic exploratory dissection. In seven of these specimens, one ligam ent was cut to simulate an artificial disruption and magnetic resonanc e imaging was repeated. Results. Lesions of th alar ligaments were fou nd in four of 15 prepared specimens. Using magnetic resonance imaging, the alar ligaments could be identified in all volunteers, patients, a nd specimen except one. No ruptures were found in the 17 specimens Of the seven resected specimens, all cuts could be demonstrated by magnet ic resonance imaging. Conclusion. Magnetic resonance imaging is useful for showing lesions of the alar ligaments because of a high soft tiss ue contrast, plane independence imaging, possibility of functional sca ns, and secondary reconstruction for tree-dimensional data sets.