RPS 1008 - Temporal bone and auditory pathway

RPS 1008-1
11:15
Reliability and clinical correlation of different grading scales in the MRI evaluation of endolymphatic hydrops
Purpose: To analyse the degree of interobserver agreement in the detection and grading of endolymphatic hydrops (EH) with different scales and to correlate MRI findings with clinical information.
Methods: 75 patients, diagnosed with unilateral definite Meniere's disease (MD), undergoing 3T-MRI of the inner ear were recruited. Cisternography, T2-FLAIR, and REAL IR imaging were performed 4 hours after intravenous contrast administration. Two independent radiologists blinded to clinical data analysed the images. Vestibular EH was evaluated using 4-stage (none/mild/moderate/severe), 3-stage (none/moderate/severe), and 2-stage (none/present) visual scales. Three-point (none/present/severe) and two-point (none/present) scales were employed for cochlear EH assessment. Discrepancies were solved by consensus. Interobserver agreement was evaluated with weighted-kappa (w-?) statistics. The association of pure tone audiometry (PTA) and caloric test with MR findings of EH was analysed with one-way ANOVA (p<0.05).
Results: Out of 75 patients, we identified EH in 90.6% of the clinically affected ear and in 17.3% on the silent side. Substantial or excellent interobserver agreement was found in all cases (mean w-?=0.83; range 0.7-0.91). The agreement was almost perfect with the 4-point vestibular EH scale (0.91±0.1). For cochlear EH, the highest consistency was obtained with the 2-point-scale (0.76±0.1). A statistically significant association was found between PTA and vestibular and cochlear EH, with all the scales. The strongest association was observed with the 2-stage cochlear (49.5±22 vs 25.4±21.5,F=45.1, p<0.001) and vestibular EH (54.8±20.1 vs 27.1±21.2,F=64.9, p<0.001) grading systems. The caloric test was also associated with 2-stage and 4-stage vestibular EH scales (F=4.5, p=0.034 and F=2.9, p=0.035, respectively).
Conclusion: A 4-stage vestibular EH grading system gave the best interobserver consistency. Vestibular and cochlear EH detected by MRI were associated with PTA and caloric tests, especially with the 2-scale grading system.
Limitations: A retrospective, single-institution study.
Ethics: Ethics committee approval obtained and informed consent waived.
Funding: No funding was received for this work.
RPS 1008-2
11:21
Early radiologic manifestations of endolymphatic sac tumours in von Hippel-Lindau disease
Purpose: To characterise the imaging features of small (<1 cm) endolymphatic sac tumours (ELSTs) in von Hippel-Lindau disease (VHL).
Methods: 19 VHL patients with 22 small ELST (3 with bilateral small ELSTs), 10 males and 9 females with ages between 11 and 74, were enrolled in a longitudinal natural history study of VHL.
High-resolution temporal-bone CT (<1.5 mm) and contrast enhanced MR (<3.0 mm, typically 1.5 thick/0.75 mm spacing T1-weighted) were available in all patients. Endolymphatic hydrops was evaluated in 9 cases using delayed FLAIR obtained 6-12 hours after contrast injection.
Results: Indirect MR findings: endolymphatic hydrops (4/9), intralabyrinthine haemorrhage (7/22), and enhancement within the ipsilateral vestibular aqueduct (13/22).
Direct MRI findings: intratemporal mass around the aqueduct (11/22) and distension/mass involving the extraosseous portion of the endolymphatic sac (10/22).
CT findings: erosion adjacent to the aqueduct (13/22) and asymmetric enlargement of the ipsilateral aqueduct (6/22).
Four cases were CT negative, no case was MRI negative, but 5 cases exhibited only ?indirect? signs on MRI. One of these ?indirect MRI only? cases were confirmed by erosion on CT.
Of the 4 cases with hydrops, 2 had neither intratemporal mass nor CT findings, and 1 had neither erosion nor intratemporal mass.
Conclusion: As VHL associated ELSTs cause irreversible audiovestibular morbidity independent of tumour size, early diagnosis and surgery have been advocated. ELSTs are locally invasive so that erosion on CT is diagnostic. Direct MRI tumour findings may be present when CT is negative. In some cases, radiologists must rely on indirect findings, e.g. intralabyrinthine haemorrhage or hydrops (requiring delayed FLAIR imaging) to establish the diagnosis of a small ELST.
Limitations: n/a
Ethics: n/a
Funding: No funding was received for this work.
RPS 1008-4
11:27
Evaluation of necrotising external otitis on CT and MR: assessment of spreading patterns
Purpose: Necrotising external otitis (NEO) is a serious complication of the external otitis. NEO can be classified according to anterior, medial, intracranial, and crossed spreading patterns. Currently, there is no consensus on the optimal imaging modality for diagnosis. This study compares NEO spreading patterns and relevant subsites as assessed on MR and HRCT of the temporal bone in order to evaluate diagnostic comparability.
Methods: We retrospectively examined 21 NEO patients who received an HRCT temporal bone and MR within a 3-month interval. Involvement of subsites and subsequent spreading patterns were assessed by a neuroradiologist blinded for the other imaging modality. The prevalence of spreading patterns by CT and MR were calculated and compared.
Results: In all patients, an anterior spreading pattern was noted on both MR and CT. Retrocondylar fat infiltration was the most consistent subsite of the anterior spreading pattern. The medial spreading pattern was seen in 7 patients at MR and in 5 of these 7 patients at CT, with parapharyngeal fat infiltration as the most consistent subsite. The intracranial spreading pattern matched in 1 out of 6 patients. The majority of patients showed a single (62%) and matching anterior spreading pattern at CT and MR.
Conclusion: The most common anterior spreading pattern of NEO can be assessed with CT as well as MR. However, the more complicated medial and intracranial spreading patterns as seen on MR could only be identified on CT in a small number of patients. Diagnosis of NEO at CT should therefore be complemented with additional imaging.
Limitations: The cohort consisted of a small number of included patients. A wide time interval between CT and MR was present, therefore a disease progression/regression between CT and MR is not excluded.
Ethics: n/a
Funding: No funding was received for this work.
RPS 1008-5
11:33
High-definition MRI for the evaluation of labyrinthic disorders
Purpose: High definition magnetic resonance (HDMR) is the gold standard method in the study of the pathologies of the inner ear, however, there are no precise findings to determine a differential diagnosis between them. We investigated the usefulness of dedicated MR sequences in the characterisation of the intralabyrinthine pathology.
Methods: We included patients evaluated between January 2010 and September 2019. Demographic and imaging data was collected. MRI images included high-resolution T2-weighted (HRT2), pre-enhanced T1-weighted (T1PE) and contrast-enhanced T1-weighted (T1CE). We placed ROIs on both labyrinths and in the fourth ventricle.
Results: MRI scans of 50 patients were analysed. The median age was 63.5 years (IQR 43-73). We found 18 (36%) patients with inflammatory labyrinthitis, 16 (32%) with intra-labyrinthine neurinoma, 9 (18%) with intra-labyrinthine haemorrhage, and 7 (14%) with ossifying labyrinthitis. All patients with intra-labyrinthine neurinoma had a low signal in HRT2, a mild-high signal in T1PE, and contrast enhancement. 14 patients with inflammatory labyrinthitis (77.8%) had low signal intensity in HRT2 and high signal in T1PE, and 13 patients (72.2%) had contrast enhancement. All patients with ossifying labyrinthitis had low signal intensity in HRT2 and 6 patients (87.5%) had high signal intensity in T1PE. All patients with haemorrhage had a high signal in pre-enhanced T1W. When we compared intra-labyrinthine neurinoma with inflammatory labyrinthitis, we found a significant difference in low signal intensity in HRT2 (p 0.001), T1PE (p 0.014), and in T1CE (p 0.003).
Conclusion: There are multiple entities that may alter the labyrinth signal in MR, some with similar radiologic patterns. We found differences in all the sequences studied between inflammatory labyrinthitis and intracochlear neurinoma.
Limitations: A diagnosis based on imaging findings without histopathology.
Ethics: Approved by an ethics committee.
Funding: No funding was received for this work.
RPS 1008-6
11:39
Superior vestibular neuritis: improved detection using FLAIR sequence with delayed enhancement (1 hour)
Purpose: Vestibular neuritis is a secondary 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: 33 patients with unilateral vestibular neuritis were compared to a control group. All patients underwent a FLAIR sequence one hour after intravenous injection of a single-dose of gadolinium at 1.5T. Two radiologists analysed 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 a 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 sup VN/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 one 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 favour of the diagnosis.
Limitations: A study on more patients should be performed to confirm the findings.
Ethics: The ethics committee of our institution approved the study (FC/ 2017-29) and it was registered on clinicaltrials.gov (NCT03452410).
Funding: No funding was received for this work.
RPS 1008-7
11:45
The length of the organ of Corti in humankind: a meta-analysis study
Purpose: The review question was: what is the length of the Corti organ (OC) in humankind?
Current studies offered that cochlear size might affect implant success in patients with hearing loss.
The hypothesis was: are the covariates (such as gender) affected the OC length?
Methods: This meta-analysis was organised using the PRISMA statement.
The gender, age, country, continent, methods, and materials were determined as covariates, and this data was extracted from the studies.
OC was determined as an outcome. Data was pooled according to a random-effects model.
Meta-regression analysis was performed with Stata software (ver. 14.0) Metareg command. The overall effect was estimated with Metaan command.
Results: The review included 47 studies (n=3,976 material) and found that covariates weren't predictors of outcome.
Estimation of the between?study variance for the OC length (?2=0.7692) and the ratio of residual variance resulting from heterogeneity (I2=0%) was statistically insignificant. Also, the coefficient determination of the model was R2=19.18% (p=0.356). There wasn't a statistically significant relationship between the OC value and covariates.
The overall effect value for the OC length was 32.742 (CI ?:32.270-33.214) mm.
Conclusion: Evaluating each patient's OC size by imaging prior to cochlear implant surgery is important because of the wide variation.
The fact that there is a difference between spiral coefficient methods with the histological method (the gold standard for measuring the OC) necessitates the development of these methods.
Measurements that are made on images obtained by 3D reconstruction seem to be the future topics of radiology.
Limitations: The review includes only English language papers (except cites). There was no study from South America and Africa.
Ethics: n/a
Funding: No funding was received for this work.
RPS 1008-8
11:51
Role of non-echo-planar diffusion-weighted images in the identification of recurrent cholesteatoma of the temporal bone
Purpose: To verify the specificity of non-EPI DWI-MRI in patients operated on for middle ear cholesteatoma who showed positivity at imaging performed 6 to 9 months after surgery and underwent second-look surgery.
Methods: In a single-centre, a consecutive cohort of patients treated for cholesteatoma and undergoing 1.5T non-EPI DWI-MRI 6 to 9 months after surgery was evaluated. Patients showing a hyperintense signal in the middle ear underwent revision surgery and were included in the study, whilst the others were still under radiological follow-up and were excluded. Two radiologists independently placed an ROI inside the brightest part of the observed signal alteration on coronal HASTE-DWI images. The mean signal intensity (SI) and maximum (SImax) SI values were recorded for each patient. Signal intensity ratios (SIR) were calculated using the inferior temporal cortex (SIRT) and the background noise (SIRN) as references.
Results: 143 subjects (210 ears) were evaluated. 27 subjects (40 ears) showed a high signal lesion inside the middle ear and underwent revision surgery. 36 ears were confirmed to be affected by residual/recurrent cholesteatoma. In 4 ears, inflammatory tissue was found. According to the ROC analysis, SI, SIRT, and SIRTmax showed the best statistical values (AUC=1).
Conclusion: Residual/recurrent cholesteatoma can be accurately detected using quantitative evaluation of non-EPI DWI MRI, which may avoid a revision surgery if negative.
Limitations: The analysed cohort was relatively small. The design of this study excluded patients with normal DWI since false-negative DWI-MRI in post-surgical population is only 3% of cases.
Ethics: The study was approved by the Institutional Ethics Board and in line with the Declaration of Helsinki. Informed consent was obtained for MR examination.
Funding: No funding was received for this work.
RPS 1008-9
11:57
Presence of vascular loop in patients with audio-vestibular symptoms: is it a significant finding? Evaluation with a 3-Tesla MRI 3D constructive interference steady state (CISS) sequence
Purpose: To evaluate the association of audio-vestibular symptoms with the presence of vascular loops and vascular contact in the cerebellopontine angle and the internal auditory canal using 3-Tesla magnetic resonance imaging.
Methods: The study included 98 patients (196 ears); 51 females and 47 males, age range 11-73 years, mean 47.6±15 years. The healthy control group with no symptoms in either ear, n=60 (120 ears); 32 females and 28 males, age range 12-69 years, mean 45.3±15.8 years. The non-symptomatic ear in the patients were added to the healthy control group. Patients underwent a neuro-otologic evaluation to exclude an underlying pathologic process. The patients with neuritis or tumours at the CPA were not included in the study. No patients had previous CPA surgery or temporal bone trauma. All MR imaging examinations were performed by using a 3T (Magnetom Verio 3T; Siemens Medical Solutions, Erlangen, Germany). The imaging protocol consisted of axial T2-weighted images of the whole brain and coronal and axial T1-weighted images of the CPA before and after administration of intravenous contrast. 3D constructive interference steady state (CISS) imaging of the CPA was performed. The healthy control group was examined with the 3D CISS sequence in addition to the routine cranial MR imaging protocol.
Results: No statistically significant association was detected between the studied audiovestibular symptoms; tinnitus, deafness or vertigo and vascular loop (grades I-III) or vascular contact (type I-III) (p<0.05).
Conclusion: It was concluded that no possible role of the presence of vascular loop or vascular contact with the 8th cranial nerve in causing tinnitus, deafness or vertigo using 3D-CISS sequence assessment. Therefore, these findings are not certainly considered pathological but possibly to be normal anatomical variants.
Limitations: The sample size.
Ethics: n/a
Funding: No funding was received for this work.
RPS 1008-10
12:03
A critical appraisal of the quality of vertigo practice guidelines using the AGREE II tool: a EuroAIM initiative
Purpose: To assess the methodologic quality of guidelines for the management of vertigo and dizziness, and to compare their recommendations.
Methods: In May 2019, a systematic search was performed using MEDLINE, EMBASE, the National Guideline Clearinghouse, and the National Institute for Health and Clinical Excellence to find practice guidelines for the management of vertigo and dizziness. The evaluation of guidelines quality was performed independently by four authors using the AGREE II tool. We excluded from the results those guidelines that were not primarily focused on vertigo and dizziness, such as national/international guidelines in which vertigo and dizziness were briefly mentioned.
Results: Our strategy of literature search identified 162 studies and 16 guidelines were selected for the appraisal. Only four guidelines reached the acceptance level in the overall result (at least 60%), with two of them reaching the highest scores (at least 80%). The highest scores were found in domain 6 ?editorial independence? (median value=65%) and domain 4 ?clarity of presentation? (median value=61%). The remaining domains showed a low level of quality: domain 2 "stakeholder involvement", domain 3 "rigour of development", and domain 5 ?applicability? had median values of 23%, 25%, and 24%, respectively. Comparing with other EuroAIM evaluations, the quality of these guidelines was very low because of low involvement of the multidisciplinary team and no use of the AGREE II guidelines in the writing guidelines recommendations.
Conclusion: Considering all guidelines, only two had a "high" overall score, while 10/16 were rated as "low" quality. Future guidelines might take this into account to improve clinical applicability.
Limitations: Our team of evaluators was composed of three radiologists and an otolaryngologist.
Ethics: No ethics committee approval was required for this systematic review.
Funding: No funding was received for this work.
RPS 1008-12
12:09
Characteristics of small-world connectivity and ninety cortical nodes in bilateral sensorineural hearing loss: a study using graph theoretical analysis
Purpose: To explore the topological characteristics of brain connectome following sensorineural hearing loss (SNHL) from the global level and nodal level.
Methods: 36 subjects with long term bilateral SNHL and 37 matched HCs were recruited from the local hospital and community for this study. Every subject underwent pure tone audiometry tests, neuropsychological assessments, and MRI scanning. AAL atlas was employed to divide a brain into 90 cortical and subcortical regions of interest, then investigated the global and nodal properties of ?small world? network in SNHL and control groups using a graph-theory analysis. The global characteristics included small worldness, cluster coefficient, characteristic path length, local efficiency, and global efficiency. Node properties included degree centrality, betweenness centrality, nodal efficiency, and a nodal clustering coefficient. Interregional connectivity analysis was also computed among 90 nodes to find alterations in the SNHL group.
Results: The SNHL group had significantly higher hearing thresholds and cognitive impairments as well as disrupted internal connections among 90 nodes. The SNHL group displayed lower AUC of cluster coefficient, path length lambda, but increased global efficiency. The opercular and triangular part of the inferior frontal gyrus, rectus gyrus, parahippocampal gyrus, precuneus, and amygdala showed abnormal local features. Some of these connectome alterations were correlated with duration and cognitive ability.
Conclusion: SNHL changed some topological properties, proving potential imaging biomarkers and treatment targets for future study.
Limitations: Small sample size and various duration of SNHL. Future work needs to recruit more subjects and control confounding factors.
Ethics: This study was approved by the ethics committee of our hospital and university (2016ZDSYLL031.0). Written informed consent was obtained from each enrollee at the beginning.
Funding: National Natural Science Foundation of China (81520108015).

Moderators

Piotr Golofit (Poland)

tbd tbd

European Society of Radiology

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