RPS 2308 - Stepping forward in paranasal and skull-based imaging

Author Block: G. Ressa, L. A. Cappellini, R. Levi, G. Savini, S. Aimola, A. Spinello, D. Villari, G. Spriano, L. S. Politi; Milan/IT
Purpose: Compare Photon Counting CT (PCCT) with conventional CT in detecting pathological alterations in fine anatomical ear structures, also evaluating potential radiation dose reduction with PCCT.
Methods or Background: In this prospective, single-center study, patients with otolaryngological clinical indications (e.g., hearing loss, otorrhea, tinnitus) underwent PCCT (NAEOTOM Alpha, Siemens Healthineers). PCCT imaging employed an Ultra High Resolution Mode protocol (120 × 0.2 mm collimation), Hr92 kernel, 0.2 mm slice thickness, tube voltage of 120 or 140 kV with Sn filter, pitch 0.55, rotation time 1s, and IQ level 150. Images were reconstructed axially and coronally with 0.2 mm slices bilaterally. All patients had prior conventional CT scans (100–140 kV, 0.4–0.7 mm slice thickness). Three neuroradiologists (3, 4, and >25 years experience) independently reviewed PCCT and conventional CT images for 15 otologic pathologies, scoring likelihood via a 5-point Likert scale after a 3-month washout. Interobserver agreement was assessed with Spearman’s correlation, and diagnostic improvement with linear regression. Radiation doses (DLP) were compared using Mann–Whitney U test.
Results or Findings: Thirty-two ears sections from 16 patients (mean age 55, 8 women) were evaluated. PCCT demonstrated superior detection of otospongiotic foci (OR 1.56; p=0.006), tegmen tympani erosion (OR 1.79; p=0.004), ossicular erosion (ORs 1.72–2.15; p<0.05), tympanic membrane thickening/retraction (ORs 2.21, 2.72; p=0.001) and facial canal erosion (OR 1.5; p=0.01) compared to conventional CT.
PCCT reduced mean DLP by 60% (236 ± 23 vs. 525 ± 277 mGy*cm; p=0.004).
Conclusion: PCCT improves detection of otologic pathology while significantly reducing radiation dose compared to conventional CT.
Limitations: Small sample size
Funding for this study: ANTHEM (AdvaNced Technology for Human centEred Medicine)
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Humanitas Research Hospital : [email protected]

Author Block: S. Neveu, D. Daskalou, N. Guinand, P. Senn, M. Becker; Geneva/CH
Purpose: Vestibular dysfunction is frequent in vestibular schwannoma (VS) and has a major impact on quality of life. We aimed to determine whether MRI-derived features are associated with baseline vestibular function as measured by objective testing.
Methods or Background: We retrospectively studied untreated, unilateral VS patients evaluated between 2014 and 2021 at a tertiary center. Vestibular function was assessed using bithermal bilateral caloric testing, video head impulse testing (vHIT), and ocular and cervical vestibular evoked myogenic potentials (oVEMP; cVEMP). MRI predictors included tumor volume (small 0–100 mm³, medium 101–1000 mm³, large >1000 mm³), Koos grade, and fundal contact.
Results or Findings: A total of 149 patients were included (median age 58 years). Large tumours showed markedly greater caloric weakness compared with small tumours (median 52% vs 10%, p<0.0001). For the lateral canal, vHIT gain was significantly lower in large than in small tumours (0.77 vs 0.98, p<0.0001), with significant reductions also observed in the anterior (p<0.0001) and posterior (p=0.004) canals. Fundal contact was associated with greater caloric weakness (median 39% vs 24%, p=0.003) and predicted reduced anterior (p=0.04) and lateral (p=0.03) canal vHIT gains. In multivariable analysis, tumour volume, Koos grade and fundal contact emerged as independent predictors of caloric weakness and vHIT gain of the lateral canal. Absent oVEMP and cVEMP responses were observed predominantly in large tumours and Koos 4 lesions and were not associated with fundal contact.
Conclusion: Tumor volume, Koos grade, and fundal contact are independent MRI predictors of vestibular dysfunction in untreated VS. Recognizing these imaging markers at diagnosis can prompt targeted vestibular testing, inform counselling and treatment planning, and lay the groundwork for predictive models of functional decline.
Limitations: Not applicable.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was approved by the Regional Research Ethics Committee (CCER, Project ID: 2022‑01257) and conducted in accordance with the principles of the Declaration of Helsinki.

Author Block: H. Viitanen¹, J. Hakumäki¹, H. P. Matikka¹, S. M. Kaartinen¹, A-P. Ronkainen¹, J. Koivisto², S. Sipari¹, A. Dietz¹, M. Iso-Mustajärvi¹; ¹Kuopio/FI, ²Helsinki/FI
Purpose: Artefact removal algorithms (ARA) for pacemakers (PM) and neurostimulators (NS) are available but the use of ARAs haven’t been reported in cochlear implant (CI) imaging, where metal artefacts obscure the evaluation of electrode placement. Additionally, cone-beam computed tomography (CBCT) has been shown to be superior in postoperative CI imaging regarding metallic artefacts. The aim of the present study is to evaluate computed tomography (CT) images with and without ARA in comparison with CBCT images to determine the most suitable postoperative imaging modality for clinical use.
Methods or Background: Three SlimJ electrodes and three MidScala electrodes (Advanced Bionics) were inserted into six freshly frozen temporal bones (TB), which were scanned with CT (Siemens Somatom) and CBCT (Promax Planmeca) with our institution’s clinical protocols with and without ARAs (PM and NS). Images were evaluated by two neuroradiologists and two ENT specialists. Scores (1-5) were given to the overall image quality (OIQ), suitability for trauma evaluation (TE), and for blooming, ring, and streak artifacts.
Results or Findings: The CBCT protocols were ranked best in OIQ (means 4.12 and 4.08), TE (means 4.42 and 4.08) and blooming (means 4.04 and 4.21). The difference between CBCT protocols was not statistically significant (p=0.775) in a pairwise comparison. The results were mixed with ring and streak artifacts. CT protocols without ARA had a mean OIQ of 2.92 and 3 and with NC of 1.29 and PM of 2.92. CBCT protocols were better than CT protocols in OIQ, TE and blooming (p<0.001).
Conclusion: CBCT was better than CT in postoperative CI imaging of TBs, and ARAs did not provide any benefit. No specific ARA exists for CI imaging and the use of ARAs developed for other regions/implants cannot be recommended.
Limitations: Cadaver study, limited sample size.
Funding for this study: None.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Valvira 9202/06.01.03.01/2013

Author Block: F. Azizi; Istanbul/TR
Purpose: To evaluate temporal bone pneumatization patterns in adult patients with mastoiditis using a sigmoid sinus-based classification system and to investigate the association between limited mastoid pneumatization and susceptibility to mastoid infection, through comparison with a control group.
Methods or Background: This retrospective case–control study included 250 adult patients (aged 20–45 years) with radiologically confirmed mastoiditis and 200 age-matched control subjects without mastoiditis who underwent high-resolution computed tomography (HRCT) of the temporal bone for other clinical indications. Pneumatization patterns were assessed on axial CT images and classified into four groups—hypopneumatization, moderate, good, and hyperpneumatization—based on their extent relative to the sigmoid sinus. The distribution of pneumatization types was compared between the mastoiditis and control groups using descriptive and inferential statistics.
Results or Findings: In the mastoiditis group, hypopneumatization (58.4%) and moderate pneumatization (39.2%) were predominant, while good (2.4%) and hyperpneumatization (1.2%) patterns were rare. In contrast, the control group exhibited a significantly higher prevalence of good (37.0%) and hyperpneumatization (20.5%) patterns. Chi-square analysis confirmed a statistically significant association between limited pneumatization and mastoiditis (p < 0.001).
Conclusion: Limited mastoid pneumatization is strongly associated with the presence of mastoiditis and may serve as a radiologic marker of increased disease susceptibility. The sigmoid sinus-based classification system provides a practical and reproducible method for assessing pneumatization and may assist in clinical risk stratification, diagnosis, and surgical planning.
Limitations: This retrospective study is limited by potential selection bias and the qualitative assessment of pneumatization rather than volumetric analysis. Clinical outcomes were not evaluated, and the restricted age range (20–45 years) limits generalizability to other populations. Future prospective studies with broader age groups, clinical follow-up, and advanced imaging are needed.
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the IMU Faculty of Medicine Ethics Committee (IRB: 2025.05.22–586).

Author Block: M. M. Moll, L. Karssemakers, B. Plakke, A. Te Boekhorst, L. C. ter Beek, M. Valstar, M. Van Alphen, L. Braun; Amsterdam/NL
Purpose: Facial nerve injury is a concerning complication in parotid tumour surgery, affecting the patient’s quality of life. A tool that facilitates preoperative visualisation of the facial nerve and its spatial relationship to parotid tumours may complement intraoperative facial nerve monitoring. Due to advances in high-resolution MR, especially in the field of neurography, the development of such a tool is more feasible. This study aims to evaluate and compare various neurography sequences for facial nerve imaging across different sequences from different MR manufacturers.
Methods or Background: We scanned fifteen healthy volunteers to compare four promising 3D sequences described in the literature: Philips NerveVIEW (turbo spin echo sequence with motion sensitised driven equilibrium pulse), Siemens CISS (Constructive Interference in Steady State), Siemens DESS-WE (double-echo steady-state water-excitation), and Siemens SPACE (Sampling Perfection with Application optimised Contrast using different flip angle Evolution). Sequences were compared based on qualitative (radiologist assessment) and quantitative assessments (signal-to-noise ratio and signal-to-contrast ratio).
Results or Findings: Preliminary observations indicate that different neurography sequences yield distinct signal characteristics for the intraparotid facial nerve, with hypointense visualisation in CISS and SPACE, and hyperintense visualisation in DESS-WE and NerveVIEW. Complete qualitative and quantitative analyses are currently underway.
Conclusion: The neurography sequences exhibit distinct signal characteristics in visualising the intraparotid facial nerve. Ongoing comprehensive qualitative and quantitative analyses will provide further insight into the optimal imaging approach for preoperative visualisation in parotid gland surgery.
Limitations: As the scans were performed on volunteers, no contrast was administered.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved Institutional Review Board of the Netherlands Cancer Institute – Antoni van Leeuwenhoek (IRBd25-044) and written informed consent was obtained from participants.

Author Block: T. Klail¹, E. Kalioras², M. Von Gernler², R. Giger², A. K. Exadaktylos², M. Müller², F. Wagner³; ¹Münsterlingen/CH, ²Bern/CH, ³Aarau/CH
Purpose: Internal carotid artery dissection (ICA-D) is a cause of stroke in adults. The styloid process may be a risk factor for ICA-D due to potential (micro)trauma from its proximity to the ICA. This systematic review with meta-analysis investigates the association between SP characteristics, particularly SP-ICA distance, and ICA-D.
Methods or Background: A systematic review was conducted across six databases to identify observational studies comparing ICA-D patients to controls. The primary association of interest was SP-ICA distance and ICA-D. Secondary studied associations were ICA-D with SP length and angulation. Random-effects meta-analysis evaluated associations, with a subgroup analysis of moderate/high-quality studies with standardised mean difference (SMD, Hedges' g) as an effect size.
Results or Findings: Six studies were included. Subgroup analysis of moderate/high-quality studies with measurement of the SP-ICA distance ipsilateral to the ICA-D (4 studies) showed a negative SMD -0.29, p = 0.047 indicating shorter SP-ICA distance in ICA-D cases. Moderate heterogeneity (I² = 63%) existed. A pooled meta-analysis of all five case-control studies (270 ICA-D patients, 377 controls) showed no significant difference in SP-ICA distance (SMD = -0.92, p = 0.143) with high degree of heterogeneity. SP length meta-analysis (3 studies) found no significant differences (SMD 0.24, p = 0.139) and two studies found no significant association between ICA-D and SP angulation.
Conclusion: Shorter SP-ICA distance might be a risk factor for ICA-D. SP-ICA distance seems to be a more reliable parameter than SP length for risk stratification in evaluating potential underlying cause in ICA-D.
Limitations: Despite excluding studies with significant methodological differences to address heterogeneity, inconsistencies in SP-ICA distance measurement persist and may obscure a true association. Furthermore, the inclusion of studies utilizing adjusted SP-ICA distances could have influenced the overall results.
Funding for this study: The authors declare no financial support for the present study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information:

Author Block: L. Wucherpfennig¹, M. Lulay¹, A. Seitz¹, I. Baumann¹, M. Stahl², H-U. Kauczor¹, M. A. Mall², O. Sommerburg¹, M. O. Wielpütz³; ¹Heidelberg/DE, ²Berlin/DE, ³Greifswald/DE
Purpose: Previous cross-sectional study employing magnetic resonance imaging (MRI) of paranasal sinuses showed a high extent of chronic rhinosinusitis (CRS) in children with primary ciliary dyskinesia (PCD). However, longitudinal imaging data on CRS onset and progression is lacking. The aim of this study is to longitudinally assess CRS in PCD from infancy through adolescence with MRI.
Methods or Background: 22 children with PCD (mean baseline age 7.6±5.7yr, range 0-18yr) underwent a mean of 2.8±1.8 (range 1-9) annual standardised paranasal sinus MRI examinations. MRI were assessed using the previously evaluated CRS-MRI score by two readers.
Results or Findings: At infancy (0yr), 83-100% of paranasal sinuses and mastoid cells were opacified. Mucosal swelling was the most prevalent (83-100%) and dominant abnormality (50-100%). At preschool age (1-5yr), the prevalence of opacified sphenoid sinus (83% vs. 100%, p<0.01) as well as mastoid cells increased (p=0.567-0.999 vs. infancy). Mucosal swelling remained the most prevalent (100%) and dominant abnormality (47-100%), while the prevalence and subscore of mucopyoceles increased (81% vs. 13% and 2.0 ± 1.6 vs. 4.1 ± 2.1, respectively; p<0.05). At school age (≥6yr), almost all maxillary, sphenoid and ethmoid sinuses (91-100%), and 87% of mastoid cells were opacified (p=0.122-0.999 vs. preschool age). The prevalence of mucopyoceles, polyps and sinus deformation decreased (60% vs. 81%, 40% vs. 70% and 51% vs. 78%, respectively; p<0.05 vs. preschool age), especially in maxillary sinuses. The CRS-MRI sum score averaged 27.8±4.9 at infancy, tended to increase at preschool age (31.9±5.6, P>0.999) and decreased at school age to 25.6±8.3 (p<0.01).
Conclusion: Longitudinal paranasal sinus MRI detects high prevalence and extent of paranasal sinuses abnormalities from infancy. Our data support its role for comprehensive non-invasive monitoring of CRS in PCD.
Limitations: The number of patients was only moderate.
Funding for this study: This study was supported by grants from the German Federal Ministry of Education and Research (BMBF) (82DZL004A1, 82DZL009B1, 82DZL009C1 and 01GL2401A), and the German Research Foundation (STA 1685/1-1 and CRC 1449 – project 431232613). MS participates in the BIH-Charité Clinician Scientist Program funded by the Charité – Universitätsmedizin Berlin and the BIH. LW is participant of the Career Development Programm funded by the University of Heidelberg. Funders had no involvement in the collection, analysis and interpretation of data, in the writing of the report and in the decision to submit the article for publication.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Approved by institutional ethics committees (S-509/2019, S-184/2025, EA2/003/21)

Author Block: S. Lavalle¹, E. Masiello², P. Romeo³, A. Maniaci¹, A. Lo Casto⁴; ¹Enna/IT, ²Milan/IT, ³Catania/IT, ⁴Palermo/IT
Purpose: Rhinogenic contact point headache (RCPH) is still an unsolved diagnostic problem in routine medical practice. In this prospective study, we sought to create and validate a complete radiologic classification system built on anatomic phenotypes, to standardize
the diagnosis and inform treatment.
Methods or Background: A prospective observational study of 120 patients with suspected RCPH was performed from January 2023 to June 2025. All the patients received high-resolution CT scans and clinical data were retrieved. Five radiological anatomical features (CP, CI, SD,
CB, ME, TH, and AV) were evaluated.
Results or Findings: In our cohort (42.7±13.5 years and 58.3% female), CP-I (septum-middle turbinate contact) was the most frequent contact type (37.5%), followed by CP-II (22.5%), CP-III (18.3%), CP-IV (12.5%), and CP-V (9.2%). Moderate contact intensity (CI-2) was observed in 45.8% of cases. Septal deviation was categorised as mild (SD-A) in 28.3%, 1.7%, moderate in 41.7% (SD-B) and severe (SD-C) in 30.0% of patients.
Concha bullosa was observed in 54.2% of patients and the bulbous type (CB-B) was most frequent (26.7%). Mucosal oedema at contact point (ME-1) was significantly correlated with higher pain scores (p=0.003). Mild and moderate turbinate hypertrophy (TH-I and TH-II) were found in 10% and 40.8% of subjects, respectively. Paradoxical middle turbinate (AV-P) was the most common anatomical variation (22.5%) followed by Haller cells (18.3%).
Conclusion: Based on the radiological phenotype, a standardized diagnostic method can guide targeted therapies. The importance of anatomical variants is crucial for proper management.
Limitations: Validation in larger series is warranted. It is could be useful to evaluate the inter-reader agreement on larger shorts
Funding for this study: No funding
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: approval number N. 00208/2024