A Tutorial on Diagnostic Benefit and Radiation Risk in Videofluoroscopic Swallowing Studies

Does Reducing Videofluoroscopy Frame Rate Affect DIGEST Grades in Modified Barium Swallow Studies?

Understanding the effects of reduced frame rates on the reliability of Modified Barium Swallow (MBS) ratings for swallowing safety and efficiency is essential for clinical practice. While previous research has examined frame rate (simulated pulse rates) implications concerning penetration, aspiration, and residue ratings, the impact on summary grading systems like the Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) remains unclear. This study analyzed a total of 315 full MBS videos collected from 278 patients, and 76.25% of patients were diagnosed with head and neck cancer (mean age 62.51 years, SD 8.53; 12.23% female). We performed pairwise comparisons of DIGEST grades and DIGEST grade components (Safety and Efficiency) derived independently across studies with 30, 15, and 7.5 frames per second (FPS). Weighted Cohen's kappa values consistently exceeded 0.84 across all assessments, indicating "almost perfect" agreement among the different simulated pulse rates. Exact agreement for all comparisons surpassed 85%. These findings suggest that the DIGEST grading system is robust to variations in frame rate, allowing for reliable assessments even under reduced pulse rate conditions.

Determination of oral feeding skills in late preterm, early term, and full-term infants using the neonatal oral feeding monitor (NeoSAFE)

BACKGROUND

Mature oral feeding is a complex function involving numerous muscles and nerves, typically developing between the postmenstrual age of 34-36 weeks in newborn infants. The objective of this study was to analyze the oral feeding skills of healthy late preterm, early term, and full-term infants using a neonatal oral feeding monitor.

METHODS

We used the oral feeding parameters reported by NeoSAFE which is a certified medical device, to assess the swallowing and swallow-respiration coordination in newborn infants. Oral feeding parameters were recorded over a 2-minutes long bottle-feeding session. The total swallow count, swallow time, maximum rhythmic swallows, resting interval duration, time between rhythmic swallows and inspiration after swallow count were recorded by NeoSAFE. We planned to examine the relationship of oral feeding parameters according to the gestational age. We also investigated whether the coordination of swallowing and respiration changes with respect to gestational age in newborn infants.

RESULTS

A total of 88 infants were included; 34 late preterm, 34 early term, and 20 full term. The gestational age was found to have significant negative correlation with the average time between rhythmic swallows and positive correlation with the swallow time. Feeding volume was found to have a negative correlation with the resting interval duration and average time between rhythmic swallows. It was also found that the feeding volume has a positive correlation with total swallow count, swallow time, maximum rhythmic swallow and inspirium after swallow count.

CONCLUSION

Although the oral feeding skills of infants at 34 weeks gestation are still developing, this study identified differences in oral feeding skills among late preterm, early term, and full-term infants when assessed using a neonatal swallow and respiration detection system. However, conducting larger cohort studies using NeoSAFE would be beneficial for guiding oral feeding approaches in infants.

TRIAL REGISTRATION

Not applicable.

Bedside diagnosis of silent aspiration using mobile dynamic digital radiography: a preliminary study

PURPOSE

This study aimed to assess reliable options for bedside diagnosis of silent aspiration in the intensive care unit by examining the use of default grayscale images (DGI) obtained using a mobile, general-purpose, radiography system capable of dynamic digital radiography (M-DDR) and inverted grayscale images (IGI) of DGI.

METHODS

This cohort study (exploratory and preliminary) involved 18 adult patients (mean age, 89.0 years) for whom a swallowing assessment request was received from their primary physicians. Fifty-six IGI videoclips were evaluated by three specialists using the penetration-aspiration scale (PAS), with the gold standard being the consensus reading of all three specialists. Another three speech-language pathologists (SLPs) assessed 56 DGI and IGI videoclips using the PAS. PAS scores 1 and 2 were classified as normal range, PAS scores 3-5 as pathological laryngeal penetration, and PAS scores 6-8 as aspiration. The correct rates with IGI and DGI were then determined, and the level of agreement of IGI and DGI evaluations was evaluated.

RESULTS

The correct rate of all evaluators was 100% for normal range, 80-100% for pathological laryngeal penetration, and 83-100% for aspiration with IGI and 100% for normal range, 90% for pathological laryngeal penetration, and 83% for aspiration with DGI. The kappa coefficient for IGI and DGI showed almost complete agreement for abnormal conditions.

CONCLUSION

Dynamic imaging of swallowing 2-5 ml of liquid using M-DDR performed for elderly patients at the bedside showed that aspiration assessments by SLPs obtained from DGI videos immediately after imaging are acceptable.

Prediction of Pharyngeal 3D Volume Using 2D Lateral Area Measurements During Swallowing

This study evaluated the validity of pharyngeal 2D area measurements acquired from the lateral view for predicting the actual 3D volume in healthy adults during swallowing. Seventy-five healthy adults (39 females, 36 males; mean age 51.3 years) were examined using 320-row area detector computed tomography (320-ADCT). All participants swallowed a 10 mL honey-thick barium bolus upon command while seated in a 45° semi-reclining position. Multi-planar reconstruction images and dynamic 3D-CT images were obtained using Aquilion ONE software. Pharyngeal 2D area and 3D volume measurements were taken before swallowing and at the frame depicting maximum pharyngeal constriction. Pharyngeal volume before swallowing (PVhold) was accurately predicted by 2D area (R2 = 0.816). Adding height and sex to the model increased R2 to 0.836. Regarding pharyngeal volume during maximum constriction (PVmax), 2D area also exhibited acceptable predictive power (R2 = 0.777). However, analysis of statistical residuals and outliers revealed a greater tendency for prediction errors when there is less complete constriction of the pharynx as well as asymmetry in bolus flow or movement. Findings highlight the importance of routinely incorporating anterior-posterior views during VFSS exams. Future work is needed to determine clinical utility of pharyngeal volume measurements derived from 320-ADCT.

Videofluoroscopic Swallowing Studies: A Proposed Checklist

PURPOSE

The videofluoroscopic swallowing study (VFSS) is used widely in dysphagia research. However, variations exist in the conduct and interpretation of VFSS, including differences in contrast agents, food and fluid consistencies tested, patient positioning, intervention strategies trialed, fluoroscopy settings, resolution, and image storage solutions. It cannot be assumed that VFSS exams yield directly comparable results across different studies. It is essential that relevant elements of VFSS be clearly reported in research. The goal of this article is to outline optimal VFSS reporting as part of the Framework for RigOr aNd Transparency In REseaRch on Swallowing (FRONTIERS), a critical appraisal tool intended to promote rigor and transparency in dysphagia research.

METHOD

We developed a set of 27 questions regarding the rigor and transparency of VFSS reporting, based on review of previous research articles. These were reviewed by all members of the FRONTIERS Framework collaborative, to determine which questions were mandatory, unnecessary, or needed revision, prior to inclusion in the final critical appraisal tool.

RESULTS

The final FRONTIERS Framework tool contains 20 questions and seven subquestions regarding VFSS. These are grouped into four themes: patient/participant positioning, equipment and recording settings, contrast agents, and rating methods, including operational definitions and reliability.

CONCLUSIONS

The VFSS section of the FRONTIERS Framework tool is intended to facilitate and promote rigorous and transparent reporting of all elements that may influence the interpretation of VFSS in research. This critical appraisal tool can also be used to guide research design and the evaluation of study outcomes contributing to best practices in the field of dysphagia research.

Advancing stroke patient care: a network meta-analysis of dysphagia screening efficacy and personalization

Introduction

The increasing incidence of stroke globally has led to dysphagia becoming one of the most common complications in stroke patients, with significant impacts on patient outcomes. Accurate early screening for dysphagia is crucial to avoid complications and improve patient quality of life.

Methods

Included studies involved stroke-diagnosed patients assessed for dysphagia using bedside screening tools. Data was sourced from Embase, PubMed, Web of Science, Scopus, and CINAHL, including publications up to 10 December 2023. The study employed both fixed-effect and random-effects models to analyze sensitivity, specificity, positive predictive value (PPV), and Negative Predictive Value (NPV), each with 95% confidence intervals. The random-effects model was particularly utilized due to observed heterogeneity in study data.

Results

From 6,979 records, 21 studies met the inclusion criteria, involving 3,314 participants from 10 countries. The analysis included six assessment tools: GUSS, MASA, V-VST, BSST, WST, and DNTA, compared against gold-standard methods VFSS and FEES. GUSS, MASA, and V-VST showed the highest reliability, with sensitivity and specificity rates of 92% and 85% for GUSS, 89% and 83% for MASA, respectively. Heterogeneity among studies was minimal, and publication bias was low, enhancing the credibility of the findings.

Conclusion

Our network meta-analysis underscores the effectiveness of GUSS, MASA, and V-VST in dysphagia screening for stroke patients, with high sensitivity and specificity making them suitable for diverse clinical settings. BSST and WST, with lower diagnostic accuracy, require more selective use. Future research should integrate patient-specific outcomes and standardize methodologies to enhance dysphagia screening tools, ultimately improving patient care and reducing complications.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#recordDetails.

Impact of Reducing Fluoroscopy Pulse Rate on Adult Modified Barium Swallow Studies

Modified Barium Swallow Studies (MBSS) are a critical part of the evaluation, treatment planning, and outcome assessment for persons with swallowing disorders. Since MBSSs use ionizing radiation with associated cancer risks, many clinicians have reduced radiation exposure by reducing the fluoroscopic pulse rate. However, by reducing pulse rate, we also decrease the temporal resolution of MBSSs which has been shown in pilot studies to significantly reduce diagnostic accuracy. Two hundred MBSSs from patients routinely undergoing MBSS as standard of care conducted at 30 pulses per second (pps) using the Modified Barium Swallow Study Impairment Profile (MBSImP™) standardized administration protocol were selected. A stratified sampling method ensured that a full range of swallowing impairments (etiology, type, and severity) was represented. Recordings were down sampled from 30 pps to 15, 7.5, and 4 pps. MBSSs were rated using the MBSImP components and Penetration-Aspiration Scale (PAS) score for each swallow. Percent agreement was calculated across raters for MBSImP and PAS scores by bolus type and volume. The Least-Squares Method was used for hypothesis testing. Statistically significant and clinically meaningful changes in scores of swallowing physiology and penetration/aspiration occurred when reducing pulse rate below 30pps. These changes were evident across bolus types and volumes. Given the impact on diagnostic accuracy and the low radiation risks to adults undergoing MBSSs, reducing pulse rate to 15pps or below is not aligned with the As Low As Reasonably Achievable (ALARA) principle and should not be used as a viable method to reduce radiation exposure from MBSSs.

Computer-aided screening of aspiration risks in dysphagia with wearable technology: a Systematic Review and meta-analysis on test accuracy

Aspiration caused by dysphagia is a prevalent problem that causes serious health consequences and even death. Traditional diagnostic instruments could induce pain, discomfort, nausea, and radiation exposure. The emergence of wearable technology with computer-aided screening might facilitate continuous or frequent assessments to prompt early and effective management. The objectives of this review are to summarize these systems to identify aspiration risks in dysphagic individuals and inquire about their accuracy. Two authors independently searched electronic databases, including CINAHL, Embase, IEEE Xplore^® Digital Library, PubMed, Scopus, and Web of Science (PROSPERO reference number: CRD42023408960). The risk of bias and applicability were assessed using QUADAS-2. Nine (n = 9) articles applied accelerometers and/or acoustic devices to identify aspiration risks in patients with neurodegenerative problems (e.g., dementia, Alzheimer's disease), neurogenic problems (e.g., stroke, brain injury), in addition to some children with congenital abnormalities, using videofluoroscopic swallowing study (VFSS) or fiberoptic endoscopic evaluation of swallowing (FEES) as the reference standard. All studies employed a traditional machine learning approach with a feature extraction process. Support vector machine (SVM) was the most famous machine learning model used. A meta-analysis was conducted to evaluate the classification accuracy and identify risky swallows. Nevertheless, we decided not to conclude the meta-analysis findings (pooled diagnostic odds ratio: 21.5, 95% CI, 2.7-173.6) because studies had unique methodological characteristics and major differences in the set of parameters/thresholds, in addition to the substantial heterogeneity and variations, with sensitivity levels ranging from 21.7% to 90.0% between studies. Small sample sizes could be a critical problem in existing studies (median = 34.5, range 18-449), especially for machine learning models. Only two out of the nine studies had an optimized model with sensitivity over 90%. There is a need to enlarge the sample size for better generalizability and optimize signal processing, segmentation, feature extraction, classifiers, and their combinations to improve the assessment performance. Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/), identifier (CRD42023408960).

Videofluoroscopy Practice in India: A Survey of Speech-Language Pathologists

Owing to differences in clinical approaches toward videofluoroscopic swallowing studies (VFSS), professional and governing bodies in some countries have implemented guidelines for performing VFSS. However, in India, the establishment of such practice guidelines is in initial stages of acceptance and there are no uniform guidelines. The aim of the current study was to investigate and describe the clinical practice patterns related to VFSS assessments among Speech-Language Pathologists (SLPs) in India. An electronic survey consisting of 34 questions categorized into four main sections (demographic details and education; current practice; instrumental and technical considerations; protocol and assessment methods) was sent to SLPs registered with the Indian Speech and Hearing Association (ISHA) through email and social media from August 2020 to January 2021. A total of 129 eligible responses were received. More than 50% of the participants used a standard assessment and analysis protocol. Barium and water-soluble contrasts were mostly used, and 97% of participants did not know what percent weight to volume (w/v) or volume to volume (v/v) contrast to fluid were used. Considerable amount of variability was observed in the responses of our participants, which was consistent with international surveys of VFSS practice patterns. Lack of adequate radiation safety measures was also observed. Our findings suggest a need to increase awareness and training among Indian SLPs in technical and procedural aspects of VFSS, and more sensitization toward radiation safety. ISHA should consider forming a committee to develop and adopt uniform nationwide practices in VFSS. Future studies exclusively investigating barriers and facilitators to VFSS practice in the Indian scenario are necessary.

Stakeholder Perspectives on Radiation Use and Interdisciplinary Collaboration in Adult Modified Barium Swallow Studies

The Modified Barium Swallow Study (MBSS) is a videofluoroscopic examination of the anatomy and physiology involved in swallowing. Like other fluoroscopic examinations, the MBSS uses ionizing radiation with related radiation risks. Thus, the procedures and protocols related to MBSSs must balance the benefit of the diagnostic information gained with the risk of radiation exposure. This requires complex decision-making for any given clinician but becomes complicated due to the interprofessional nature of conducting MBSSs, namely the direct involvement of both the speech-language pathologist and radiologist with indirect involvement of the medical physicist and the referring physician. This editorial provides the perspectives of the various stakeholder groups related to radiation use in adult MBSSs, identifies barriers to conducting MBSSs in an evidence-based manner, and suggests areas for improvement.

Correlation between Forced Vital Capacity and the Severity of Frailty-Induced Dysphagia

Introduction: Frailty syndrome is a complex condition characterized by the gradual deterioration of an individual’s physical, mental, and social functions. Dysphagia is a dysfunction triggered by frailty. However, in patients with frailty syndrome, dysphagia is often undermined, and a proper evaluation is not performed. Therefore, we tried to identify the factors that can provide proper information regarding dysphagia in the frail population. Methods: Patients with dysphagia were divided into those with frailty-induced dysphagia and those with brain-lesion-induced dysphagia. Factors related to the participants’ pulmonary function test (PFT) results were evaluated. The severity of dysphagia was evaluated by determining modified videofluoroscopic dysphagia scale (mVDS) and penetration−aspiration scale (PAS) scores based on videofluoroscopic swallowing studies. Statistical analysis was performed to determine the correlation between PFT results and the parameters indicating dysphagia severity. Results: Multivariate logistic regression analysis revealed that forced vital capacity (FVC) was significantly correlated with mVDS scores in frailty-induced dysphagia (p < 0.05). However, no such significance was detected in brain-lesion-induced dysphagia (p ≥ 0.05). Conclusion: FVC was correlated with the severity of dysphagia (mVDS scores) in patients with frailty-induced dysphagia. Thus, serial FVC-based follow-up can be helpful for understanding patients’ dysphagia status. However, studies with a general population of patients with frailty-induced dysphagia are needed for definite generalization.