[Spin-echo anatomy of the larynx in MRI at 1.5 T]

The larynges of 8 healthy and informed volunteers were studied with a superconductive MR unit at 1.5 T together with those of 10 patients with extra-laryngeal pathologic conditions. The study was performed with round surface coils (5'') and with delicated sellar coils in the anterior neck. Slices were 5 mm thick, and acquired on the coronal, axial, and sagittal planes, with T1-weighting; axial scans were repeated in the same locations with double echoes, with proton-density and T2-weighting. Five patients underwent additional scans after Gd-DTPA. The larynx of a semi-frozen cadaver was examined with sellar surface coils, on similar scanning planes and with similar pulse sequences to those described above; the larynx was removed, investigated with mammographic technique, and subsequently analyzed with thin CT slices and a high-resolution reconstruction algorithm for the study of laryngeal cartilage. Axial anatomical sections were then compared with MR and CT scans, and the anatomical structures were recognized on the triplanar MR scans of a volunteer's larynx. Besides MR anatomy of supporting laryngeal structures, the authors describe in detail the muscles, plicae, spaces and cavities which can be identified on the various planes, together with the changes in signal after Gd-DTPA.