[Evaluation of autologous fat volume with magnetic resonance imaging following vocal cord injection].

Objectives: The aim of this study was to measure the change in the volume of the autologous fat used for the treatment of glottic insufficiency caused by recurrent laryngeal nerve palsy.

Patients And Methods: Six patients who were treated by autologous fat injection for the treatment of glottic closure deficiency were included in the study. MRI was performed one week, and 1, 3, 6, and 12 months after the injection. After MRI, the images were transferred to GE Advantage Windows 2.0 workstation. By three-dimensional multiplanar volume rendering technique (MPVR), a threshold between +1500 and +150 was applied and bone and soft tissue signals except fat tissue were erased from images. The volume of the fat graft was calculated by SAVS/paintbrush common window.

Results: The mean volume of the fat graft in vocal cord was estimated to be 0.9 ml (100%) after one week of the injection. Measurements after one month and three months of the injection revealed that fat volume reduced to 66% (0.6 ml) and 44% (0.4 ml), respectively. The volume reduced to 33% (0.3 ml) of the baseline volume after six months. Finally, three patients had 33% (0.3 ml) of fat volume after 12 months.

Conclusion: Approximately two-thirds of the fat graft injected to the vocal cord is resorbed within the first six months. For this reason, techniques with stable long-term results should be performed in patients who are not expected to recover glottic functions.