[68Ga]DOTATOC PET-derived radiomics to predict genetic background of head and neck paragangliomas: a pilot investigation.

PURPOSE: To investigate the [68Ga]DOTATOC PET radiomic profile of head and neck paragangliomas (HNPGLs) and identify radiomic characteristics useful as predictors of succinate dehydrogenase genes (SDHx) pathogenic variants. METHODS: Sporadic and SDHx HNPGL patients, who underwent [68Ga]DOTATOC PET/CT, were retrospectively included. HNPGLs were analyzed using LIFEx software, and extracted features were harmonized to correct for batch effects and confronted testing for multiple comparison. Stepwise discriminant analysis was conducted to remove redundancy and identify best discriminating features. ROC analysis was used to define optimal cut-offs. Multivariate decision-tree analysis was performed using CHAID method. RESULTS: 34 patients harboring 60 HNPGLs (51 SDHx in 25 patients) were included. Three sporadic and nine SDHx HNPGLs were metastatic. At stepwise discriminant analysis, both GLSZM-Zone Size Non-Uniformity (ZSNU, reflecting tumor heterogeneity) and IB-TLSRE (total lesion somatostatin receptor expression) were independent predictors of genetic status, with 96.4% of lesions and 91.6% of patients correctly classified after cross validation (p < 0.001). Among non-metastatic patients, GLSZM-ZSNU and IB-TLSRE were significantly higher in sporadic than SDHx HNPGLs (p < 0.001). No differences were revealed in metastatic patients. Decision-tree analysis highlights multifocality and IB-TLSRE as useful variables, correctly identifying 6/9 sporadic and 24/25 SDHx patients. Model failed to classify one SDHA and three sporadic patients (2 metastatic). CONCLUSION: Radiomics features GLSZM-ZSNU and IB-TLSRE appear to reflect HNPGLs SDHx status and tumor behavior (metastatic vs. non-metastatic). If validated, especially IB-TLSRE might represent a simple and time-efficient radiomic index for SDHx variants early screening and prediction of tumor behavior in HNPGL cases.

Present and future of the labyrinth imaging: Focus on the use of T2-weighted and contrast-enhanced delayed FLAIR (1 h) sequences.

OBJECTIVE: Part of the recent progress in the labyrinth imaging has been made possible by the rise of contrast-free T2-weighted and delayed (1h) FLAIR sequences. The aim of this article is to review evidence for the use of these two sequences to image the inner ear, especially the posterior membranous labyrinth. MATERIAL AND METHODS: We analyzed MRI-based papers (2007-2020)using high-resolution T2-weighted or contrast-enhanced FLAIR (1h) sequences to image the inner ear. RESULTS: T2-weighted sequences (3T MRI)enabled the visualization of the posterior membranous labyrinth with good correlation when compared to corresponding histological slices.Significant progress has been made, especially in terms of scanning time, aiming at reducing it, in order to decrease motions artifacts. The saccule is visible on a 3T MRI without significant motion artifacts. Its shape is ovoid, with a maximum height and width of 1.6 and 1.4 mm, respectively. An enlarged saccule was observed in 84%of patients with unilateral Meniere's disease, in 28%of patients with vestibular schwannomas (VS) and 47%of patients with intralabyrinthine schwannomas. VS obstructing the internal auditory canal caused a decrease of the perilymphatic signal (more moderate decrease in meningiomas) on T2 gradient-echo images. Contrast-enhanced FLAIR sequences are useful to image vestibular/facial neuritis and inflammatory inner ear diseases. CONCLUSION: Precise analysis of the posterior membranous labyrinth, in terms of size, shape and signal intensity, is possible on a 3T MRI using high-resolution gradient-echo T2-weighted sequences. Such sequences are an interesting add-on to delayed (4h30) FLAIR-based protocols for labyrinth imaging.

Proceedings of the GDR Vertige 2019 annual meeting devoted to endolymphatic hydrops.

The GDR Vertige is a federative research group gathering the different components of the French neuro-otology community. The annual meeting of the GDR Vertige is an opportunity for interactive exchanges between scientists, clinicians and industrialists, on basic issues related to vestibular function, as well as translational questions regarding the management of vestibular disorders. For its fifth edition, the annual meeting of the GDR Vertige, which took place in September 2019 in Marseille (France), was devoted to one of the most peculiar phenomena of neuro-otology: endolymphatic hydrops. For two days, international scientists and clinicians presented the most recent advances regarding the biophysical correlates of endolymphatic hydrops, the genetic and endocrine tableaux that favor its manifestation, new methods of clinical imaging, and current and upcoming therapeutic strategies to overcome the associated clinical manifestations. This special issue of the Journal of Vestibular Research aims at providing the proceedings of this meeting.

Skull Vibration-Induced Nystagmus Test in a Human Model of Horizontal Canal Plugging.

BACKGROUND/AIM: the aim of this study was to assess the skull vibration-induced nystagmus test (SVINT) results and vestibular residual function after horizontal semicircular canal (HSCC) plugging. METHODS: In this retrospective chart review performed in a tertiary referral center, 11 patients who underwent unilateral horizontal semicircular canal plugging (uHSCCP) for disabling Menière's disease (MD) were included. The skull vibration-induced nystagmus (SVIN) slow-phase velocity (SPV) was compared with the results of the caloric test (CaT), video head impulse test (VHIT), and cervical vestibular-evoked myogenic potentials (cVEMP) performed on the same day. RESULTS: Overall, 10 patients had a strong SVIN beating toward the intact side (Horizontal SVIN-SPV: 8.8°/s ± 5.6°/s), 10 had a significant or severe ipsilateral CaT hypofunction, 10 had an ipsilateral horizontal VHIT gain impairment, and 3 had altered cVEMP on the operated side. Five had sensorineural hearing worsening. SVIN-positive results were correlated with CaT and horizontal VHIT (HVHIT) results (p < 0.05) but not with cVEMP. SVIN-SPV was correlated with CaT hypofunction in % (p < 0.05). Comparison of pre- and postoperative CaT % hypofunction showed a significant worsening (p = 0.028). CONCLUSION: SVINT results in a human model of horizontal canal plugging are well correlated with vestibular tests exploring horizontal canal function, but not with cVEMP. SVINT always showed a strong lesional nystagmus beating away from the lesion side. SVIN acts as a good marker of HSCC function. This surgical technique showed invasiveness regarding horizontal canal vestibular function.

Study of the Comorbidity Between Cases of Acute Peripheral Vestibulopathies and COVID-19.

IMPORTANCE: An infective etiology of acute peripheral vestibulopathy (APV) has long been hypothesized. In the context of coronavirus disease 2019 (COVID-19), we examined the possible comorbidity between these two entities. OBJECTIVES: APV is the second most common cause of vestibular disorders and results from a sudden and unilateral loss of vestibular inputs. The characteristic signs and symptoms include sudden and prolonged vertigo, absence of auditory symptoms, and absence of other neurological symptoms. An infective etiology of APV has long been hypothesized on the basis of its association with respiratory tract infections and its frequent occurrence in epidemics. Possible comorbidity with herpes simplex virus type 1 reactivation or influenza virus infection has also been proposed. This study was designed to assess the possible comorbidity between APV and COVID-19. DESIGN/SETTING/PARTICIPANTS: Quantification of the number of hospital admissions for APV over the period from February to May 2020 was carried out in 5 French hospitals. A comparison with 2018 and 2019 entries over the same period was made. Comorbidity between APV and COVID-19 infection was investigated. RESULTS: No significant increase in admission for APV was noticed over the examination period. No significant difference was noticed among hospitals located in COVID-19 high- and low-risk zones for SARS-CoV-2. No significant increase in the severity of the APV cases was noticed. No case of comorbidity between APV and SARS-CoV-2 infection was reported. Based on our observations, no correlation was made between APV and COVID-19. CONCLUSION: Based on our observations, COVID-19 is not statistically correlated with APV.

New Compartmental Reading Method for MRI Enables Accurate Localization of Cholesteatomas With High Sensitivity and Specificity.

OBJECTIVES: Cholesteatoma is an inflammatory disease, frequently observed in childrens and young adults, with a risk of relapse or recurrence. The few studies which analyzed cholesteatoma localization on magnetic resonance imaging (MRI) usually merged CT-MR images or relied on their authors' anatomical knowledge. We propose a compartmental reading method of the compartments of the middle ear cavity for an accurate localization of cholesteatomas on MR images alone. MATERIAL AND METHODS: Our method uses easily recognizable anatomical landmarks, seen on both computed tomography (CT) and MRI, to delimit the middle ear compartments (epitympanum, mesotympanum, hypotympanum, retrotympanum, protympanum, antrum-mastoid cavity). We first tested it on 50 patients on non-enhanced temporal bone CT. Then, we evaluated its performances for the localization of cholesteatomas on MRI, compared with surgery on 31 patients (validation cohort). RESULTS: The selected anatomical landmarks that delimited the middle ear compartments were applicable in 98 to 100% of the cases. In the validation cohort, we were able to accurately localize the cholesteatoma on MRI in 83% of the cases (n = 26) with high sensitivity (95.7%) and specificity (98.6%). CONCLUSION: With our compartmental reading method, based on the recognition of well-known anatomical landmarks to differentiate the compartments of the middle ear cavity on MRI, we were able to accurately localize the cholesteatoma with high (>90%) sensitivity and specificity. Such landmarks are widely applicable and only require limited learning time based on key images. Accurate localization of the cholesteatoma is useful for the choice of surgical approach.

The dynamics of endolymphatic hydrops and vestibular disorders.

Endolymphatic hydrops is defined as an accumulation of endolymph in the inner ear leading to a buildup of pressure and distortion of intralabyrinthine structures. The pressure variation is neither obvious nor easy to measure and remains not clearly confirmed. The distortion of endolymphatic structures has been the main described phenomenon since Hallpike, Cairns and Yamakawa in 1938. However, some clinical symptoms associated with endolymphatic hydrops are in addition to the typical triad of symptoms of Meniere's disease. This introduction to the state of the art is an analysis of the relationship between hydrops and clinical vestibular disorders, with a focus on the dynamics of endolymphatic hydrops. The distortion of endolabyrinthine structures can be considered as a dynamic process modeled with mechanical elastic behavior.

Vestibular schwannomas with spontaneous shrinkage: about 35 cases.

PURPOSES: The first aim is to describe the epidemiological, clinical, and radiological characteristics of regressive vestibular schwannomas (VS), based on volumetric measurements on MRI to define which regressions are significant. The secondary aim is to look for a correlation between a shrinkage of the tumor and the medical history, and the presence of clinical symptoms. METHODS: We first selected all patients presenting with a VS who underwent two or more MRI of the internal auditory canal on the same 3 T MRI machine retrospectively between January 2013 and June 2018. All MRI images were evaluated independently by two radiologists. The volumetric analysis was performed contrast-enhanced 2D spin-echo T1-weighted sequence and expressed in cubic centimeters. RESULTS: Thirty-five patients presented with a regressive VS on MRI (14%). The annual mean shrinkage rate was 0.08 cm3/year. Eighty percent of the patients present both a shrinkage by more than 0.01 cm3/year and a decrease of the initial tumor volume by more than 20%. The majority of patients are asymptomatic or presented moderate balance disorders, which remained stable or improved over time. Tinnitus was observed in 47% and was stable or improved in the majority of cases and the mean annual mean hearing loss was by < or = 4 dB/year. CONCLUSION: Out of 247 VS, 14% decreased using follow-up (by > or = 2 MRI), and a spontaneous shrinkage greater than 0.01 cm3/year and greater than 20% could be considered significant.

Imaging of facial neuritis using T2-weighted gradient-echo fast imaging employing steady-state acquisition after gadolinium injection.

BACKGROUND: MRI is the modality of choice for the imaging of facial neuritis. Previously, gadolinium-enhanced T1-weighted imaging of the petrous bone, then FLAIR sequences were thought to be most informative for acute facial neuritis imaging. The aim of this study is to evaluate the value of contrast-enhanced T2-weighted sequence for the diagnosis of acute facial neuritis and compare it to contrast-enhanced T1-weighted and FLAIR sequences. METHODS: We included 50 patients with an acute unilateral idiopathic peripheral facial neuritis. An MRI (3 T) with three sequences was performed (T1-weighted, T2-weighted and FLAIR), all acquired after intravenous contrast-media injection. RESULTS: The contrast-enhanced T2-weighted sequence appeared to be the most accurate one for the diagnosis of acute facial neuritis (Se 94%, Sp 100%, accuracy 98.2%, p < 0.001), with a pathological facial nerve strongly (grade 2-3) enhancing and a homogenous enhancement along the course of the entire facial nerve. Contrast-enhanced T1-weighted (Se 80%, Sp 100%, accuracy 94.1%) and FLAIR sequences (92%, Sp 88%, accuracy 90%, p < 0.001) showed lower accuracy. On T1-weighted sequence, a strong enhancement (blurred margins) of the canalicular segment was observed in 80% of the cases when it was never observed in normal nerves. CONCLUSION: A strong (= iso to hyperintense to the petrous fat signal) and diffuse (all segments) enhancement of the facial nerve on T2-weighted steady-state free precession sequence is a sensitive and specific sign for the diagnosis of acute idiopathic facial neuritis, and appears superior to T1WI and FLAIR sequences.

MRI of endolymphatic hydrops in patients with intralabyrinthine schwannomas: a case-controlled study using non-enhanced T2-weighted images at 3 T.

OBJECTIVE: Like other vestibular schwannomas developing in the internal auditory canal, intralabyrinthine schwannomas (ILS) may present with similar symptoms as in endolymphatic hydrops. Two different studies have described MR saccular hydrops in ~ 30% of internal auditory canal vestibular schwannomas, but this association has never been studied in ILS before. The aim of this work is to study the prevalence of a saccular dilation in ILS, on a T2-weigthed sequence at 3 T, compared to a control group. MATERIAL AND METHODS: All patients presenting with typical ILS between January 2008 and October 2018 were included (n = 28, two patients with bilateral tumors) and compared to a control group (n = 53). All underwent a high-resolution T2-weighted 3D sequence (FIESTA-C). The height and width of the saccule were measured on a coronal plane by two radiologists. RESULTS: The saccule was dilated on the side of the schwannoma in 47% of the cases (p = 0.0006 for the height, p = 0.0487 for the width). Bilateral saccular dilation was observed in 37% of the cases. There was a statistically significant correlation between the presence of a saccular hydrops and balance disorders (p = 0.02) as 50% of the patients with an intralabyrinthine schwannoma who presented with such symptoms had a saccular dilation. CONCLUSION: Forty-seven percent of ILS are associated with homolateral saccular dilation, which is an MR sign of endolymphatic hydrops (bilateral in 37%) and it appears related to the presence of balance disorders. This opens new therapeutic potentialities with the possible use of anti-vertiginous drugs, which could have a beneficial effect on their clinical symptomatology.

Mindfulness Improves Otolaryngology Residents' Performance in a Simulated Bad-News Consultation: A Pilot Study.

INTRODUCTION: Delivering bad news is a stressful moment for both patient and clinician. As poor bad-news consultation quality may lead to misunderstandings, lack of treatment adherence, acute or even post-traumatic stress in patients, training interventions to improve communication skills and stress-management are necessary. Mindfulness is a recognised stress-management strategy that has shown its efficacy in reducing stress in both health professionals and students. We then supposed that a short mindfulness meditation session performed just before a simulated breaking bad-news consultation to patients with laryngeal cancer may help ear, nose and throat (ENT) residents to master their stress and improve their management of this consultation. This study aims at showing how a short mindfulness meditation performed before a simulated bad-news consultation may improve performance in its realisation by ENT residents. MATERIALS AND METHODS: We enrolled 53 ENT residents, randomised in 2 groups. The first group completed a 5-minute mindfulness session while the other group listened to a control track. Thereafter, every resident completed an 8-minute simulated bad-news consultation with a standardised patient. Two blinded expert assessors evaluated their performance on a 25-point grid (BNC-OSAS). Residents self-assessed their stress before and after the intervention and simulated patients rated their perception of physician's empathy. RESULTS: The performance was significantly better in the mindfulness group than in the control group (m = 19.8, sd = 3.2 and m = 17.4, sd = 3.7 respectively, F(1,45)=5.27, p = 0.026, d = 0.67), especially in the communication and knowledge subdomains. There was no significant difference in perceived stress between the 2 groups. Empathy perceived by simulated patients was positively correlated to residents' performance. CONCLUSION: A short mindfulness meditation is effective for improving ENT residents' performance in a simulated bad-news consultation. These results encourage further assessments of this method with objective measures of physiological stress. More research is required concerning the feasibility and efficacy of mindfulness before daily clinical activities such as stressing bad-news consultation.

Unusual Locations of Benign Paroxysmal Positional Vertigo: Rare Entity or Regular Occurrence?

INTRODUCTION: According to the literature and our recent experience, even if patients present with symptoms strongly suggestive of benign paroxysmal positional vertigo (BPPV), the observed positional nystagmus does not always correspond to any previously described typical location. The aim of this multicentric study was to evaluate the frequency of both typical and less common forms of BPPV. MATERIAL AND METHODS: All consecutive patients presenting with BPPV in two hospitals between November 2016 and October 2017 were included. For each subject, answers to a standardized evaluation form and a recorded videonystagmoscopy were obtained by two otorhinolaryngologists. Appropriate diagnostic and therapeutic maneuvers were performed. RESULTS: A total of 532 patients were studied and 491 cases of typical BPPV were found: 370 cases of canalolithiasis of the posterior semicircular canal (SCC), 3 cases of canalolithiasis of the anterior SCC, 107 cases of canalolithiasis of the lateral SCC, and 11 cases of cupulolithiasis of the lateral SCC. Fourty one patients reported symptoms suggestive of BPPV with positional nystagmus that could correspond to unusual locations of otoconia in the SCC: 18 cases of canalolithiasis in the anterior ampulla of the lateral SCC, 16 cases of posterior short arm canalolithiasis, four cases of pseudo-spontaneous nystagmus in canalolithiasis of the lateral SCC, and three cases of canalolithiasis of the posterior third of SCC. DISCUSSION: Unusual BPPV accounted for almost 8% of BPPV treated in our clinics; it is paramount to know how to diagnose them, to carry out the appropriate therapeutic maneuvers and relieve these patients.

CT and MRI for the diagnosis of perilymphatic fistula: a study of 17 surgically confirmed patients.

BACKGROUND: We evaluated the usefulness of CT and MRI for the diagnosis of perilymphatic fistula (PLF) of the round (RW) and/or oval (OW) windows, with surgery as gold standard. METHODS: We retrospectively enrolled 17 patients who presented a surgically confirmed PLF of the round (RW) or oval (OW) windows. All patients were imaged by CT + MRI (T2W SSFP without contrast) prior to surgery (= gold standard). Two radiologists, analyzed the RW and OW on the side of the clinical symptoms and sensitivity (Se) + Specificity (Sp) were calculated. RESULTS: Round window fistula was the most frequent (71%). The best sign of PLF on imaging was a fluid filling of the window niches, which had good Se (83-100% for RW, 66-83% for OW) and Sp (60% for RW, 91-100% for OW). Disorientation of the footplate and pneumolabyrinth were also only observed in 50% of OW PLF. CONCLUSION: The combination of CT and MRI is a reliable tool for a fast and accurate diagnosis of round and oval window perilymphatic fistula, with good sensitivity (> 80%). The most common sign of PLF on imaging is the presence of a fluid-filling in the RW (especially if > 2/3 of the RW niche) or in the OW niches on both CT and MRI. A disorientation of the footplate or the presence of a pneumolabyrinth are clearly in favor of an oval window perilymphatic fistula.

Importance of signal intensity on T1-weighted spin-echo sequence for the diagnosis of chronic cholesteatomatous otitis.

OBJECTIVE: The aim of our study was to evaluate the importance of a non-injected T1-weighted spin-echo sequence (T1WSE) combined with a non-echo-planar diffusion-weighted (non-EPDW) sequence for the pre-operative detection of cholesteatoma by the radiologist on MRI, compared to surgery. MATERIALS AND METHODS: In this retrospective case review, 113 patients with chronic otitis underwent surgery (gold standard) for a clinical suspicion of cholesteatoma. Our primary outcome was to compare non-EPDW images + a contrast-free T1WSE sequence for cholesteatoma detection. Our secondary outcome was to quantify the signal intensity value of the suspected lesions, relative to the signal intensity of the cerebellum (Sic) to calculate Signal Intensity Ratios (SIR = SI/Sic). The SIR values of cholesteatomatous and non-cholesteatomatous tissue were compared to surgical findings. Receiver-operating characteristic curve analysis determined an optimum SIR cut-off value for the prediction of cholesteatoma. RESULTS: The sensitivity (96.9%) of non-EPDW for the diagnosis of cholesteatoma was high, with good specificity (74.2%), and increased to 85.5% when combined to a T1WSE sequence. Additionally, the mean SIR values (on T1WSE) of cholesteatoma were significantly lower than non-cholesteatomatous tissue (p < 0.05). When nonEPDW and T1WSE were combined, a cut-off SIR value < 1.04, diagnosed cholesteatoma pre-operatively with very high specificity and sensibility (92.7% and 90.3% respectively). CONCLUSION: Our study showed that combining a nonEPDW sequence with the quantitative analysis of contrast-free T1W SE sequence in pre-operative patients enables the correct diagnosis of cholesteatoma with good sensitivity and specificity (> 90%) and reduces risks of false-positive cases for surgeons.

Superior vestibular neuritis: improved detection using FLAIR sequence with delayed enhancement (1 h).

INTRODUCTION: Vestibular neuritis is the second cause of vertigo and new imaging protocols using delayed FLAIR with double-dose of gadolinium are proposed for its diagnosis. Our aim is to demonstrate that a single dose of gadolinium is sufficient. METHODS: Thirty-three patients with a unilateral vestibular neuritis are compared to a control group. All patients underwent a FLAIR sequence, 1 hour after intravenous injection of a single dose of gadolinium, on a 1.5 Tesla MRI. Two radiologists analyzed the enhancement intensity of the superior (sup VN) and inferior vestibular nerve (inf VN) and ratios to the signal of the cerebellum were calculated (supVN/C). The statistics were performed using Bayesian analysis. RESULTS: A strong enhancement of the sup VN was observed on the pathological side in 85% of patients with vestibular neuritis. The average signal intensity of the pathological sup VN (139 units ± 44) was more than two times the average intensity in the control group (58.5 units ± 5). The average ratios supVN/C were significantly different between the pathological side in vestibular neuritis (2.43 units ± 0.63) and the control group [1.16 ± 0.14 (Pr(diff > 0) = 1)]. A delayed enhancement > 71.5 units had a sensitivity of 96% and a specificity of 100% for the diagnosis of superior vestibular neuritis. CONCLUSION: A delayed FLAIR sequence, acquired 1 hour after a single dose of gadolinium injection, is a useful method for the diagnosis of vestibular neuritis. An enhancement of the sup VN > 71.5 units was in favor of the diagnosis.

Magnetic resonance imaging after cochlear implants.

INTRODUCTION: Most cochlear implants are currently compatible with magnetic resonance imaging (MRI) up to 3 T. Nevertheless, this does not completely eliminate the risk of serious accidents. Implant displacements and other adverse events with compatible implants have been reported in the literature. CASE REPORTS: Among the six patients who had MRI after receiving implants at our center, we report three cases with adverse events related to the examination. The first case was complicated by magnet displacement with partial demagnetization. The second case showed total demagnetization, which necessitated removal and reimplantation of the implant. The third case involved severe pain sensation which disrupted the MRI scan. The smallest artifact was found with 3D MRI angiography, and largest artifact was found with diffusion and T2 FLASH. DISCUSSION: Moving the patient into the MRI apparatus must be supervised by an otorhinolaryngology specialist or an experienced radiologist. It is important to consider the magnetic field directions, so that angle between the implant magnetic fields and the MRI B0 always remains less than or equal to 90°. In addition, we recommend the use of an "arrow drawing" to facilitate the orientation of the magnetic field directions. Furthermore, to prevent magnet displacement, we recommend systematic use of a protective splint in addition to bandaging.

MRI of endolymphatic hydrops in patients with vestibular schwannomas: a case-controlled study using non-enhanced T2-weighted images at 3 Teslas.

OBJECTIVE: Vestibular schwannomas (VS) may present with similar symptoms endolymphatic hydrops. Association between hydrops and internal auditory canal VS has been described by Naganawa et al. (Neuroradiology 53:1009-1015, 2011), but has never been confirmed since. The aim of this work was to study the prevalence of a saccular dilation on a T2-weighted sequence at 3 T MRI in VS compared to a control group. MATERIALS AND METHODS: All patients presenting with typical VS between May 2009 and July 2018 were included (n = 183) and compared to a control group (n = 53). All underwent a high-resolution T2-weighted 3D sequence (FIESTA-C). The height and width of the saccule were measured on a coronal plane by two radiologists. RESULTS: The saccule was dilated on the side of the schwannoma in 28% of the cases (p = 2.81 × 10- 5), with 15.7% of bilateral dilation. Saccular dilation was correlated to sensorineural hearing loss (OR 3.26, p = 0.02). There was also a significant correlation between saccular hydrops on the normal contralateral side of patients with VS and vertigo (p = 0.049), and between saccular hydrops on the side of the tumour and tinnitus (p = 0.006). CONCLUSION: A third (29%) of VS are associated with a saccular dilation on the side of the tumour, which is an MR sign of endolymphatic hydrops (bilateral in 15.7% of the cases) and it appears related to sensorineural hearing loss and tinnitus, as well as vertigo if a contralateral dilation is present. This opens new therapeutic potentialities with the use of anti-vertiginous drugs, which could have a beneficial effect on the clinical symptoms.

Extension patterns of vestibular schwannomas towards the middle ear: three new cases and review of the literature.

OBJECTIVE: Middle ear extension of vestibular schwannomas is not a common occurrence, and only a few cases have been described so far in past publications. We report three new cases of vestibular schwannomas extending to the middle ear and reviewed the literature to specify the patterns of such an extension. MATERIALS AND METHODS: We analysed databases of previously published articles to search for additional cases of middle ear extension of vestibular schwannomas and compared them to the cases we have documented. Extension patterns of the tumours were analysed, especially focusing on the extension through the round and oval windows. RESULTS AND CONCLUSION: Middle ear vestibular schwannomas are uncommon tumours and only 13 cases have been published so far. The vestibular schwannoma (internal auditory canal or intralabyrinthine) has to invade the labyrinth first (complete invasion in 88% of the cases, n = 14), before reaching the middle ear. In the majority of cases (69%, n = 11/16), internal auditory canal vestibular schwannomas or intralabyrinthine schwannomas extended in the middle ear though the round window.

Malformations of the lateral semicircular canal correlated with data from the audiogram.

OBJECTIVES: Lateral semicircular canal (LSCC) malformations  are one of the most common inner ear malformations. The purpose of this study is to analyze the prevalence and type of hearing losses associated with LSCC malformations, compared to a control group. MATERIALS AND METHODS: We retrospectively included 109 patients (166 ears) presenting with a CT-confirmed LSCC malformation, compared to a control group (24 patients). The bony island surface and the width of the inner portion of the LSCC were measured to confirm the malformation. There results were correlated to audiogram data: sensorineural (SHNL), mixed (MHL) or conductive hearing loss (CHL) by an otologist. RESULTS: In the LSCC group, 60.9% of patients presented with an audiogram-confirmed hearing loss, especially SNHL (39.2%, n = 65) and MHL (12.7%, n = 21). Hearing was normal in 39.2% (n = 65) of the cases. Bilateral LSCC malformations (n = 57) were frequently associated with hearing loss (80.7%), SNHL in most of the cases (33.3%). Unilateral LSCC malformations were associated with hearing alterations (51.9%, n = 27), but we also observed a high rate (81%, n = 42) of contralateral abnormalities of the audiogram. CONCLUSION: LSCC malformations are commonly associated with hearing loss (61%), especially SHNL (39%). The high rate (81%) of contralateral hearing disturbances in unilateral LSCC malformations should be taken into account in the patient's daily life to avoid triggering or exacerbating any hearing loss. Otologists and radiologists must cooperate to ensure that all malformations are correctly described on CT, especially to improve the patient's education regarding hearing preservation.

18F-FDOPA PET/CT Combined with MRI for Gross Tumor Volume Delineation in Patients with Skull Base Paraganglioma.

In this simulation study, we assessed differences in gross tumor volume (GTV) in a series of skull base paragangliomas (SBPGLs) using magnetic resonance imaging (MRI), 18F-dihydroxyphenylalanine (18F-FDOPA) combined positron emission tomography/computed tomography (PET/CT), and 18F-FDOPA PET/MRI images obtained by rigid alignment of PET and MRI. GTV was delineated in 16 patients with SBPGLs on MRI (GTVMRI), 18F-FDOPA PET/CT (GTVPET), and combined PET/MRI (GTVPET/MRI). GTVPET/MRI was the union of GTVMRI and GTVPET after visual adjustment. Three observers delineated GTVMRI and GTVPET/MRI independently. Excellent interobserver reproducibility was found for both GTVMRI and GTVPET/MRI. GTVPET and GTVMRI were not significantly different. However, there was some spatial difference between the locations of GTVMRI, GTVPET, and GTVPET/MRI. The Dice similarity coefficient median value was 0.4 between PET/CT and MRI, and 0.8 between MRI and PET/MRI. The combined use of PET/MRI produced a larger GTV than MRI alone. Nevertheless, both the target-delivered dose and organs-at-risk conservancy were respected when treatment was planned on the PET/MRI-matched data set. Future integration of 18F-FDOPA PET/CT into clinical practice will be necessary to evaluate the influence of this diagnostic modality on SBPGL therapeutic management. If the clinical utility of 18F-FDOPA PET/CT and/or PET/MRI is confirmed, GTVPET/MRI should be considered for tailored radiotherapy planning in patients with SBPGL.