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

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.

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.

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.