RPS 508 - New developments in imaging of the oral cavity and the oropharynx

Author Block: A. R. J. Péporté¹, J. Kostova¹, F. B. Schön², G. Andreisek², L. Diem³, F. Wagner⁴; ¹Frauenfeld/CH, ²Münsterlingen/CH, ³Lucerne/CH, ⁴Aarau/CH
Purpose: The mylohyoid muscle is commonly considered a continuous muscular sling, but it is frequently discontinuous, forming mylohyoid boutonnières (MHB) that can contain salivary tissue, fat, blood vessels, or lymph nodes. The MR prevalence remains largely unexplored. This study assesses the prevalence, age- dependence, anatomical distribution, and content of MHBs on MRI.
Methods or Background: A retrospective review of MRI scans of the head and neck from 294 patients between 2016 and 2020 was conducted. MR images were analyzed for the presence, location, and contents of MHBs. Inter-rater agreement from the three independent readers with different levels of experience and statistical analysis were performed to assess consistency across readers.
Results or Findings: MHBs were identified in 50.7% of individuals, with bilateral deficiencies occurring in 45.6% of cases. Most defects were located in the anterior (45.6%) and middle (51.0%) thirds of the mylohyoid muscle. The herniated content consisted predominantly of salivary tissue (69.3%), followed by fat (15.9%), and blood vessels (14.2%). No significant association was found between MHB prevalence and age. There was a high level of inter-rater agreement among all three raters regarding the presence, side, location, and content of the MHB, with no statistically significant discrepancies observed across the assessed parameters.
Conclusion: A MHB is a true and common anatomical variant, with a prevalence of 50.7% in this study, and most defects are bilateral. This knowledge aids in preventing diagnostic errors when evaluating oral cavity lesions, minimizing the need for unnecessary invasive procedures.
Limitations: This retrospective study, while involving a heterogeneous referral population and excluding about 20% of cases due to MRI artifacts, benefits from a large sample size, multi-reader interpretation, and provides valuable non-invasive anatomical assessment complementary to cadaveric data.
Funding for this study: No funding was received.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Institutional board approval was obtained (Req-2024-01600; EKOS 24/237) from the Eastern Swiss Ethics Committee.

Author Block: R. B. Venkatasubramanian¹, R. Sivakumar¹, V. Sai¹, R. Ramachandran¹, B. Dev¹, R. Rangasami¹, M. Lokesh¹, H. Sivakumar²; ¹Chennai/IN, ²CHENNAI/IN
Purpose: To set gingival ultrasonography protocols as a screening tool to evaluate post operative healing in collage tissue graft patients for gingival recession.
Methods or Background: Gingival recession is a common condition when gingival margin moves proximally beyond cemento-enamel junction.
It can increase risk of dental carries and have cosmetic issues.
Root coverage procedures like autologous collagen tissue graft are a common surgery for gingival recession.
A cohort of 15 patients of gingival recession planned for autologous collagen tissue graft, aged 30-50, were sonographically assessed pre-operatively, 1 and 2 weeks post-op for healing assessment.
Anterior gingival thickness and vascularity(spectral Doppler) were assessed pre-op.
Surgical site echogenicity, neovascularisation status(Power and spectral Doppler) and anterior gingival thickness were assessed on post-op follow up.
Protocols were set to assess anterior gingival thickness from anterior gingival margin to interdentine papilla at incisor plane, low PRF for Doppler evaluation.
Results or Findings: All 15 patients(100%) had decreased mean anterior gingival thickness - 1.3+/-0.3 mm, demostrating high resistance flow (RI>0.7) in Doppler.
Post surgery, mean anterior gingival thickness was - 1.6+/-0.4 mm in week 1 and 1.5+/-0.2 mm in week 2.
14 out of 15 patients (93.3%) showed increased relative echogenicity on both follow up scans signifying inflammation.
One patient had ~0.5 cc persistent collection in surgical site. Post operative Doppler showed low resistance flow (RI<0.6) with decreased PSV in all cases signifying inflammation/healing.
Conclusion: Post operative intraoral/gingival ultrasonography is an effective tool to assess inflammation, post-operative changes, abscess formation and neovascularisation in post autologous collagen tissue graft, in adjunct to clinical and visual assessment.
Presence of hypoechoic areas, collections, high resistance vascular flow and decreased gingival thickness are markers of poor prognosis.
Limitations: Limited sample size can be expanded to cover other dental surgeries.
Funding for this study: Self funded.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Part of MD thesis dissertation.

Author Block: M. Fusina, M. Parillo, M. Neri, M. Antolini, D. Vo, F. De Rosa, C. C. Quattrocchi; Trento/IT
Purpose: To investigate the level of agreement among radiologists with varying levels of expertise when interpreting MRI scans using NI-RADS system for monitoring oropharyngeal squamous cell carcinoma (OPSCC) patients.
Methods or Background: An observational retrospective study was conducted to analyze follow-up MRIs in patients treated for OPSCC. NI-RADS scores were assigned by five radiologists (two residents in radiology, one general radiologist and two head and neck experts). Agreement was evaluated using percentage of agreement (POA) and kappa values (κ) for NI-RADS final score and for each MRI specific feature of the NI-RADS (lymph nodes, primary tumor size, primary site signal on T2-weighted, contrast-enhanced and diffusion-weighted images). Concordance was assessed separately for the first follow-up MRI and subsequent follow-up scans.
Results or Findings: A total of 91 patients were evaluated, and each reader analyzed 218 MRI. Overall inter-reader agreement was moderate for NI-RADS score (κ = 0.53, POA = 89%) and for individual MRI features (κ = 0.42–0.52, POA = 84%–93%). Agreement was notably lower between the expert radiologist and the two radiology residents during the first follow-up MRI, particularly for assessing contrast-enhancement at the primary site (κ = 0.25–0.36, POA = 77%–90%) and lymph nodes (κ = 0.38–0.41, POA = 72%–88%).
Conclusion: MRI NI-RADS in the surveillance of OPSCC patients shows moderate agreement among readers with varying expertise, especially in the evaluation of the first post-treatment scans. Routine use of NI-RADS in clinical practice and educational programs could improve uniformity in imaging assessments.
Limitations: We included examinations from different MRI scanners within a considerable timeframe. In a limited number of instances, DWI sequences were missing because standardized head and neck imaging protocols were not in place during earlier examinations.
Funding for this study: The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The retrospective study was approved by the institutional review board and conducted in accordance with the principles of the Declaration of Helsinki. Informed consent to participate in the study was waived due to the retrospective-observational study design.

Author Block: J. Pan, X. Hui, L-Z. Liu, W. Huang; Guangzhou/CN
Purpose: Current T-staging for oral tongue squamous cell carcinoma (OTSCC) primarily relies on postoperative pathology, which offers suboptimal preoperative risk stratification, limiting precision in the neoadjuvant therapy era. This study aimed to optimize the clinical T-staging for OTSCC using a structured MRI reporting system and evaluate its value in guiding patient selection for neoadjuvant chemoimmunotherapy (NACI).
Methods or Background: In this retrospective study, we analyzed patients with pathologically confirmed OTSCC who underwent pretreatment MRI between January 2010 and January 2025. Based on a structured MRI report, patients were stratified into four risk groups: "Very-low-risk" (no structural invasion), "Low-risk" (hyoglossus/styloglossus invasion), "Medium-risk" (Mild structural invasion: eg., lingual artery, sulcus terminalis, sublingual gland), and "High-risk" (Severe structural invasion: eg., mylohyoid, retromolar trigone, oropharynx). Network and survival analyses were employed to assess prognostic differences. The survival benefit of NACI was specifically evaluated in the high-risk group defined by the new staging system.
Results or Findings: Among 1202 enrolled patients, the optimized T-staging system showed significantly superior risk stratification for 5-year overall survival (OS) (48.1%, 74.8%, 85.9%, 95.1% for the four groups, P <0.001) versus the current T-staging (86.9%, 77.8%, 70.4%, 53.1%, P>0.05). Crucially, high-risk patients receiving NACI had markedly better 5-year OS than those who did not (84.2% vs. 45.9%, p<0.05). The revised T-staging system showed better stratification in OS (C-index: 0.712 vs. 0.652, p < 0.05).
Conclusion: A structured MRI-based T-staging system provides superior prognostic stratification and effectively identifies high-risk OTSCC patients who derive significant survival benefit from NACI, facilitating preoperative personalized treatment planning.
Limitations: This was a retrospective, single-center study. Additionally, there is inherent subjectivity in interpreting structural invasion, although excellent inter-observer agreement was confirmed (kappa > 0.82 for all evaluated structures).
Funding for this study: The National Natural Science Foundation of China (No. 82171906) and the Guangdong Basic and Applied Basic Research Foundation (2025A1515011590, 2024A1515140147).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This retrospective study was conducted in accordance with the ethical guidelines outlined in the 1964 Declaration of Helsinki and approved by the ethics committee (approval number: B2019-047-Y02; date of approval: November 07, 2022).

Author Block: H. K. Zhang¹, F. Chen¹, Y. Liao², X. Liu²; ¹Haikou/CN, ²Guangzhou/CN
Purpose: This study aims to investigate the feasibility of preoperative prediction of perineural invasion (PNI) status in tongue squamous cell carcinoma (TSCC) using dual-layer spectral-detector CT(DLCT) histogram features and clinical features.
Methods or Background: We retrospectively analyzed 85 patients with TSCC, comprising 30 PNI-positive and 55 PNI-negative cases. All patients underwent preoperative contrast-enhanced DLCT, and spectral images (including virtual mono-energetic images at 40KeV, 70KeV, 100KeV, 130KeV, iodine density, effective atomic number, and virtual non-contrast images) were reconstructed from venous phase data. A single radiologist manually delineated the tumor region of interest (ROI) on 40-keV virtual mono-energetic images, which was propagated to other spectral images to extract seven histogram features from each image. Clinical and histogram features were compared using appropriate statistical tests (t-test, Wilcoxon, or chi-square). Feature selection involved Spearman correlation filtering (threshold = 0.9) followed by backward stepwise regression. Three predictive models—clinical, spectral-histogram, and a combined model—were developed using logistic regression. Model performance was evaluated and compared via receiver operating characteristic (ROC) analysis and DeLong’s test.
Results or Findings: Pathological T-stage differed significantly between PNI-positive and negative groups (P<0.05). Most spectral histogram features also showed significant intergroup differences (all P<0.05). The clinical, spectral-histogram, and combined models achieved AUCs of 0.751 (0.653–0.849), 0.760 (0.655–0.865), and 0.828 (0.736–0.920), respectively. The spectral-histogram and combined models both significantly outperformed the clinical model (P<0.05).
Conclusion: The combined model integrating DLCT-derived spectral histogram features with clinical data demonstrates promising efficacy for the preoperative prediction of perineural invasion in tongue squamous cell carcinoma.
Limitations: Retrospective, single-center study with a small sample size
Funding for this study: Not applicable
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The Ethics Committee granted a waiver of informed consent for this retrospective study.

Author Block: M. L. Schnitzer, F. Herr, L. Göbel, J. Rübenthaler; Munich/DE
Purpose: Craniomandibular disorders (CMD) are common musculoskeletal conditions, often linked to anterior disc displacement (ADD) of the temporomandibular joint (TMJ). MRI is the diagnostic standard of reference. This study assessed prevalence and demographic patterns of ADD in a large patient cohort.
Methods or Background: We retrospectively analyzed 512 TMJ MRI examinations (2017–2022, LMU Munich). ADD was graded: 1 (10–11 o’clock), 2 (9–10 o’clock), 3 (6–9 o’clock). Borderline cases were assigned to the higher grade.
Results or Findings: The cohort included 382 females and 130 males (mean age 40.9 ± 18.7 years). ADD was present in 63.5%: Grade 1, 20.3%; Grade 2, 10.7%; Grade 3, 32.4%. No displacement was found in 36.5%. Distribution showed polarization (Grade 0 vs. Grade 3). Bilateral symmetry occurred in 58% (r = 0.50, p < 0.000005). Females were more frequently affected by higher-grade ADD (p < 0.001). Younger patients showed more severe grades. A pandemic-related shift was observed, with female predominance in 2020 and male rebound in 2021.
Conclusion: ADD is frequent and shows polarized severity. Female predominance, younger age association, and pandemic-related shifts underline its multifactorial nature. MRI provides essential diagnostic and epidemiological insights.
Limitations: This retrospective, single-center study may reflect referral bias and is not fully representative of the general population. The cross-sectional design precludes causal inference between ADD severity, age, sex, and pandemic-related trends. MRI interpretation was based on categorical grading, which may oversimplify complex disc dynamics. Variability between 1.5T and 3.0T scanners, as well as interobserver differences, could influence diagnostic consistency. Clinical correlation with symptoms and treatment outcomes was beyond the study’s scope, limiting assessment of functional relevance.
Funding for this study: No Third Party funding for this study
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Approved by local ethics committee

Author Block: M. Smoljan; Zagreb/HR
Purpose: The purpose of this presentation is to review the most common pathologies of the maxillofacial region, as well as their imaging characteristics on different imaging modalities, and their differentials.
Methods or Background: Dental radiology is still a relatively unfamiliar part of radiology for many radiologists, even though the maxillofacial region is seen on many neuroradiological examinations, like brain and cervical spine scans, and included in most head & neck scans. Therefore, radiologists come across different odontogenic and non-odontogenic lesions of the jaws and other pathological lesions of this area in their everyday practice.
Results or Findings: Different odontogenic and non-odontogenic lesions of maxillofacial region can be seen on X-rays, CT scans and MRIs. When analyzing brain, head, neck or cervical spine images, radiologists should pay attention to maxillofacial structures as well. Whether the indication for the radiological examination is to diagnose an already suspected dental/maxillofacial pathology or the pathology found is an incidental finding in the examination performed for other indications, the radiologists should be familiar with the nomenclature, the lesions typical for this region, and their differentials.
Conclusion: Odontogenic and non-odontogenic lesions of the jaws, as well as other maxillofacial pathologies, account for a substantial number of pathological changes visible on different radiological modalities. Adding them to the radiological reports may assist the clinicians solve the clinical inquiry and help the patient maintain their oral health.
Limitations: No limitations were identified.
Funding for this study: No funding was received.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: