内リンパ水腫評価MRIからみた内耳疾患

抄録

Magnetic resonance (MR)-based volumetric measurement of the endolymphatic space (ELS) was conducted in patients with acute low-tone sensorineural hearing loss (ALHL), sudden deafness (SD), cochlear Meniere’s disease (cMD), and unilateral MD (uMD), and the results were compared with those in control subjects (CS). Seventy-nine patients with ALHL, 99 with SD, 65 with cMD, 77 with uMD, and 47 CS participated in this study. With the exception of the patients with uMD, none of the subjects had vertigo. Images of the inner ear fluid space, positive perilymph and positive endolymph signal were acquired using a 3-T MR imaging scanner. Three-dimensional images were reconstructed semi-automatically by using anatomical and tissue information to fuse the inner ear fluid space images with the ELS images. The cochlear and vestibular ELS/total fluid space (TFS) volume ratios were 10.2%±6.8% and 17.7%±10.2%, respectively. The cochlear ELS/TFS volume ratio in patients with uMD was significantly higher than that in the CS, and patients with ALHL, SD, and cMD (CS=ALHL<SD<cMD<uMD). The vestibular ELS/TFS volume ratio in patients with uMD was significantly higher than that in the CS and other patients groups (CS=ALHL=SD<cMD<uMD). The cochlear and vestibular ELS volume ratio in patients with uMD and other endolymphatic hydrops-related diseases differed from that in the CS. These results suggest that assessment of the prognosis is possible by MR evaluation in patients with endolymphatic hydrops-related inner ear diseases.