Young Hwa Suh1, Yeonah Kang2, Moo Jin Baek3, Shin Hye Kim3,4, Ho-Joon Lee1, Joonsung Lee5, Jiyeon Baik1. 1. Department of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea. 2. Department of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea. bsb2312@gmail.com. 3. Department of Otorhinolaryngology-Head and Neck Surgery, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea. 4. Department of Otorhinolaryngology-Head and Neck Surgery, Eulji Medical Center, Eulji University School of Medicine, Seoul, Republic of Korea. 5. GE Healthcare Korea, Seoul, Republic of Korea.
Abstract
OBJECTIVES: High cochlear signal intensity on three-dimensional (3D) T2 fluid-attenuated inversion recovery (FLAIR) sequences in patients with sudden sensorineural hearing loss (SSNHL) has been reported. Here, we evaluated the cochlear T2 relaxation time differences in patients with idiopathic SSNHL using quantitative synthetic MRI (SyMRI). METHODS: Twenty-four patients with unilateral SSNHL who underwent precontrast conventional 3D FLAIR and SyMRI were retrospectively included. T1 and T2 relaxation times and the proton density (PD) of the bilateral ears were measured by manually drawn regions of interest. Wilcoxon signed-rank tests and intra- and interobserver correlation analyses were performed. Qualitative analysis was also performed to determine the presence and laterality of the asymmetric high signal intensity on synthetic FLAIR (SyFLAIR) images. RESULTS: The T2 relaxation time was significantly lower in the affected (basal and apico-middle turns) than in the unaffected cochlea (basal turn: 519 ± 181.3 vs. 608.8 ± 203.6, p = 0.042; apico-middle turn: 410.8 ± 163.8 vs. 514.5 ± 186.3, p = 0.037). There were no significant differences in the T1 relaxation time and PD between the affected and unaffected ears (p > 0.05). Additionally, three patients without asymmetric signal intensity on conventional MRI showed asymmetric increased signal intensity in the affected ear on SyFLAIR. CONCLUSIONS: The T2 relaxation time was significantly shorter in the affected than in the unaffected cochlea of patients with idiopathic SSNHL. The SyMRI-derived T2 relaxation time may be a promising imaging marker, suggesting that the changes in inner ear fluid composition are implicated in the idiopathic SSNHL development. KEY POINTS: • T2 relaxation time was significantly lower in the affected than in the unaffected cochlea. • SyFLAIR showed increased lesion conspicuity compared to conventional 3D-FLAIR in detecting asymmetric high signal intensity of the affected side. • SyMRI-derived T2 relaxation time may be a promising imaging marker of the affected ear in patients with idiopathic SSNHL.
OBJECTIVES: High cochlear signal intensity on three-dimensional (3D) T2 fluid-attenuated inversion recovery (FLAIR) sequences in patients with sudden sensorineural hearing loss (SSNHL) has been reported. Here, we evaluated the cochlear T2 relaxation time differences in patients with idiopathic SSNHL using quantitative synthetic MRI (SyMRI). METHODS: Twenty-four patients with unilateral SSNHL who underwent precontrast conventional 3D FLAIR and SyMRI were retrospectively included. T1 and T2 relaxation times and the proton density (PD) of the bilateral ears were measured by manually drawn regions of interest. Wilcoxon signed-rank tests and intra- and interobserver correlation analyses were performed. Qualitative analysis was also performed to determine the presence and laterality of the asymmetric high signal intensity on synthetic FLAIR (SyFLAIR) images. RESULTS: The T2 relaxation time was significantly lower in the affected (basal and apico-middle turns) than in the unaffected cochlea (basal turn: 519 ± 181.3 vs. 608.8 ± 203.6, p = 0.042; apico-middle turn: 410.8 ± 163.8 vs. 514.5 ± 186.3, p = 0.037). There were no significant differences in the T1 relaxation time and PD between the affected and unaffected ears (p > 0.05). Additionally, three patients without asymmetric signal intensity on conventional MRI showed asymmetric increased signal intensity in the affected ear on SyFLAIR. CONCLUSIONS: The T2 relaxation time was significantly shorter in the affected than in the unaffected cochlea of patients with idiopathic SSNHL. The SyMRI-derived T2 relaxation time may be a promising imaging marker, suggesting that the changes in inner ear fluid composition are implicated in the idiopathic SSNHL development. KEY POINTS: • T2 relaxation time was significantly lower in the affected than in the unaffected cochlea. • SyFLAIR showed increased lesion conspicuity compared to conventional 3D-FLAIR in detecting asymmetric high signal intensity of the affected side. • SyMRI-derived T2 relaxation time may be a promising imaging marker of the affected ear in patients with idiopathic SSNHL.