MRI contribution for the detection of endolymphatic hydrops in patients with superior canal dehiscence syndrome.

PURPOSE: Patients with superior semicircular canal dehiscence syndrome, which can only be treated by surgery, present cochleo-vestibular symptoms related to a third-mobile window but also endolymphatic hydrops. Since cVEMP and oVEMP are disturbed by the presence of the dehiscence, the aim of the study is to assess the value of MRI for the diagnosis of endolymphatic hydrops in patients with superior semicircular canal dehiscence syndrome in comparison with cVEMP and oVEMP. METHODS: In this retrospective cohort study we enrolled 33 ears in 24 patients with superior semicircular dehiscence syndrome who underwent a 4-h delayed intravenous Gd-enhanced 3D-FLAIR MRI and pure tone audiometry, cVEMP and oVEMP. For each patient MRI images were evaluated by two radiologists who used a compartmental endolymphatic hydrops grading system in comparison with cVEMP and oVEMP. RESULTS: Endolymphatic hydrops was found on MRI in 9 out of 33 SCDS ears (27.3%). We found no significant correlation between the presence of endolymphatic hydrops on MRI and cVEMP and oVEMP (p = 0.36 and p = 0.7, respectively). However, there was a significant correlation between the presence of endolymphatic hydrops on MRI and the degree of sensorineural hearing loss, Air Conduction-Pure Tone Average level (p = 0.012) and Bone Conduction-Pure Tone Average level (p = 0.09), respectively. CONCLUSION: We demonstrated that EH might be observed in 27.3% of superior semicircular dehiscence syndrome ears. The role of inner ear MRI is important to detect endolymphatic hydrops, since cVEMP and oVEMP are disturbed by the presence of the dehiscence, because these patients could benefit from a medical treatment. LEVEL OF EVIDENCE: Level 3.

MRI diagnosis of saccular hydrops: Comparison of heavily-T2 FIESTA-C and 3D-FLAIR sequences with delayed acquisition.

PURPOSE: Currently, 3D-FLAIR sequence performed 4hours after the intravenous administration of a single dose of contrast media is the imaging technique of choice for the diagnosis of saccular hydrops (SH). Recently, the diagnosis of SH has also been reported with heavily-T2 weighted sequences. MATERIALS AND METHODS: In this retrospective imaging study, we performed 3D-FLAIR sequences 4hours after contrast media administration and 3D FIESTA-C sequences before and 4hours after contrast media administration in 30 patients with unilateral definite, probable or possible clinical diagnosis of Menière's disease (MD). Two radiologists, blinded to the clinical data, independently assessed the presence of saccular hydrops. Inter-reader agreement tests were performed. RESULTS: On delayed post-contrast 3D-FLAIR sequence, 15 patients out of 30 referred with a SH that was never seen on the controlateral asymptomatic side. The specificity and the sensitivity to detect MD side were 100% and 50% respectively. On non-enhanced 3D FIESTA-C sequence, 16 patients out of 30 (53%) referred with a saccular hydrops that was observed in 6 patients on the clinical asymptomatic ear. The specificity and the sensitivity to detect MD side were 80% and 33% respectively. On delayed 3D FIESTA-C sequence, 13 patients out of 30 (43%) referred with a saccular hydrops that was seen in 4 patients on the controlateral asymptomatic side. The specificity and the sensitivity to detect MD side were 83% and 27% respectively. CONCLUSION: Delayed post-contrast 3D-FLAIR is highly specific of MD symptoms while 3D FIESTA-C sequences are less sensitive and specific for the diagnosis of SH.

Detection of intralabyrinthine abnormalities using post-contrast delayed 3D-FLAIR MRI sequences in patients with acute vestibular syndrome.

PURPOSE: 3D-FLAIR sequences with delayed acquisition after contrast medium injection have demonstrated new insights into blood-labyrinthine barrier (BLB) abnormalities in various diseases. The aim of this study was to assess the BLB in patients referred with unilateral acute vestibular syndrome (UAVS). MATERIALS AND METHODS: In this retrospective multicenter imaging study, we performed 3D-FLAIR and steady-state free precession (SSFP) sequences 4 h after contrast medium administration in 26 healthy volunteers and in 30 patients with UAVS. Two radiologists, blinded to the clinical data, independently assessed the asymmetrical enhancement of the labyrinthine structures and the vestibular nerve on 3D-FLAIR sequences, and the signal of the labyrinthine structures on SSFP sequences. Inter-reader agreement tests were performed. RESULTS: An asymmetrical enhancement of the semicircular canals was observed in 26 out of 30 ears (86.6%, p < 0.001) and never observed in healthy subjects. An asymmetrical enhancement of the vestibular nerve was never observed in either patients or healthy subjects. An asymmetrical enhancement of the cochlea was observed on the 3D-FLAIR sequence in 6 out of 30 ears only in the patients' group (20%, p = 0.03) and always associated with an enhancement of at least one semicircular canal. A low signal on SSFP sequences was observed only in 11 out of 30 symptomatic ears (36.7%, p < 0.001), involving the utricle in 7 ears and the superior semicircular canal in 4 ears. CONCLUSION: Patients with typical UAVS presented with semicircular canal enhancement on MRI, while an asymmetrical enhancement of the vestibular nerve was not displayed. TRIAL REGISTRATION: NCT02529475 KEY POINTS: • Patients with typical vestibular neuronitis presented with semicircular canal enhancement on MRI in 87% of cases. • An enhancement of the vestibular nerve was never displayed.

Axillofemoral bypass for kidney transplant protection during open repair of abdominal aortic aneurysm.

The need to treat an abdominal aortic aneurysm (AAA) in kidney transplanted patient is a rare event. To date, no method to protect the kidney during the aneurysm treatment has been identified as undeniably relevant. On the other hand, the advantage of endovascular treatment of the aneurysm (EVAR) is to avoid transplanted kidney injury. Unfortunately, EVAR is not always available leading to open repair and then aortic cross clamping. We report here 3 cases of AAA open repair in kidney transplanted patients using a temporary axillofemoral bypass to protect the renal function.

MRI characteristics of intralabyrinthine schwannoma on post-contrast 4 h-delayed 3D-FLAIR imaging.

PURPOSE: The purpose of this study was to describe the MRI characteristics of intralabyrinthine schwannoma (ILS) on post contrast three-dimensional (3D) fluid-attenuation-inversion-recovery (FLAIR) images obtained four hours after intravenous administration of a gadolinium-based contrast agent (4h-3D-FLAIR). MATERIALS AND METHODS: This IRB-approved retrospective multi-center study included patients presenting with typical ILS from January 2016 to October 2020. All medical charts were systematically collected. All MRI examinations, including 4h-3D-FLAIR images, were reviewed by two board-certified neuroradiologists. Main outcome measures were location, signal intensity and associated anomalies of ILS. RESULTS: Twenty-seven out of 8730 patients (0.31%) referred for the investigation of a cochleovestibular disorder had a final diagnosis of ILS. There were 13 men and 14 women with a mean age of 52 ± 17 (SD) years (age range: 20-86 years). The most common clinical presentation was unilateral progressive sensorineural hearing loss (16/27; 59%). All ILS were unilateral and 15 (15/27; 55%) were intracochlear. All ILS presented as a hypointense filling defect within the labyrinth on T2-weighted images that enhanced on post-contrast T1-weighted images. On 4h-3D-FLAIR images, all ILS presented as a hypointense filling defect, associated with diffuse perilymphatic hyperintensity. Two patients (2/27; 7%) presented with ipsilateral endolymphatic hydrops. CONCLUSION: ILS displays consistent features on post-contrast 4h-3D-FLAIR images. ILS should not be confused with endolymphatic hydrops and requires a systematic analysis of the corresponding T2-weighted images.