Serial anatomy of the larynx in MRI: MRI-histologic correlations

The larynx is an organ with a complex anatomic structure. MRI allows the performance of sections in the three planes of space, so that this study of the soft parts of the larynx yields results superior to those of other imaging techniques. Together with laryngoscopy, MRI is most often used in assessing the extension of malignant laryngeal tumors. This assessment is fundamental in choosing the indications for surgery, but the published reports of MRI of the larynx are sometimes discordant. The visualization of certain important anatomic structures such as the conus elasticus is uncertain. Our aim was to study the MRI radio-anatomy of the larynx based on correlations between MRI and histologic sections. Eight anatomic specimens were studied: four in the transverse plane, two in the sagittal plane, and two in the frontal plane. The MRI and histologic sections made at the same levels were compared. These comparisons allowed a description of the sectional radio-anatomy of the larynx and an assessment of the reliability and limitations of MRI. All the major anatomic structures could be identified. It was possible to demonstrate the conus elasticus. We were able to visualize the vocal process of the arytenoid cartilage, which has not to our knowledge been previously described in the literature.