Value of three-dimensional inversion-recovery with real reconstruction sequence using an ultralong repetition time for endolymphatic hydrops

ObjectiveTo evaluate the value of an optimized three-dimensional inversion-recovery with real reconstruction (3D-real IR) sequence with a longer repetition time (TR, 16 000 ms) based on modulated flip angle technique in refocused imaging with extended echo train (MATRIX) in the endolymphatic hydrops (EH) imaging after intratympanic gadolinium (Gd) administration, and to compare it with a conventional 3D-real IR based on the turbo spin echo (TSE) sequence. MethodsFrom July 2021 to November 2022, twenty-seven patients received both the conventional and optimized 3D-real IR sequences after bilateral intratympanic Gd administration. Images of the two sequences were qualitativly evaluated and compared. Contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and area ratio of endolymph against the total lymphatic space from the two sequences were measured and compared. Results14(25.9%) ears with insufficient contrast for the EH diagnosis on the conventional sequence were clearly displayed on the optimized sequence. Image score, CNR and SNR of the optimized sequence were significantly higher than those of the conventional sequence (P ＜ 0.001). The scanning time of two sequences was similar. The area ratio of endolymph against the total lymphatic space in the cochlear was significantly higher on the conventional 3D-real IR than that on the optimized 3D-real IR (P ＜ 0.001); there was no statistical difference in the vestibule between the two sequences. ConclusionsCompared with conventional sequence, optimized 3D-real IR sequence with a longer TR may be better for evaluation of EH after intratympanic Gd administration.