Radiation Exposure Time during MBSS: Influence of Swallowing Impairment Severity, Medical Diagnosis, Clinician Experience, and Standardized Protocol Use

Abstract

Purpose Guidelines and preventive measures have been established to limit radiation exposure time during modified barium swallow studies (MBSS) but multiple variables may influence exam duration. This study examines the influence of clinician experience, medical diagnosis category, swallowing impairment severity and use of a standardized protocol on fluoroscopy time. Methods A retrospective review was completed on 739 MBSSs performed on 612 patients (342 males/270 females; age range = 18 to 96 years) completed in one year at the Medical University of South Carolina with IRB approval. All studies were completed by speech-language pathologists trained in the data collection protocol, interpretation, and scoring of the MBSImP™©. Medical diagnosis category, swallowing impairment severity (MBSImP™© score), clinician experience, and fluoroscopy time were the variables recorded for analysis. Results Fluoroscopy time was not significantly associated with medical diagnosis category (p=0.10). The severity of the MBSImP©™ Oral Total and Pharyngeal Total resulted in statistically significant increases in fluoroscopy time (p<0.05). Studies by novice clinicians had longer exposure times when compared to experienced clinicians (p=0.037). Average radiation exposure time using the MBSImP©™ approach was 2.9 minutes, with a 95% confidence interval of 2.8 minutes to 3.0 minutes, which was well within the range of exposure times reported in the literature. Conclusions This study provides preliminary information regarding the impact of medical diagnosis category, swallowing impairment severity and clinician experience on fluoroscopy time. These findings also suggest that a thorough, standardized protocol for MBSSs did not cause unnecessary radiation exposure time during the MBSS.

Methods for Measuring Swallowing Pressure Variability Using High-Resolution Manometry

“…This finding gives support for future study design: it may be more feasible, especially in patients with dysphagia, to perform the least number of swallow trials to give an accurate picture of swallowing pressure variability. Capturing fewer swallowing trials may also spare exposure to radiation in studies that use a videofluoroscopic approach to swallowing evaluation [70].…”

“…Swallowing kinematics are difficult to measure, as most of the relevant musculature is located internally within the mouth and throat. Standard swallowing evaluation techniques involve capturing video using an x-ray or endoscopic approach [67,68], which is limited by low temporal resolution (30 Hz), inadequate measurement reliability [69], and patient exposure to radiation [70]. Recent improvements in diagnostic technology have allowed for the quantification of contact pressures along the pharynx and esophagus at highresolutions in time (50-100 Hz) and space (sensors spaced ≤1 cm apart) [71] (Figure 1).…”

Fluoroscopic Evaluation of Oropharyngeal Dysphagia: Anatomic, Technical, and Common Etiologic Factors

“…delayed oral phase, delayed initiation of the pharyngeal phase, etc. In cases where asymmetry or anatomical/structural differences are suspected, such as pharyngeal diverticula or post-surgical anastomotic leaks, Antero-posterior and/or oblique views are included [33–35]. Valsalva maneuvers may be performed with patient in an Antero-posterior position to distend pharyngeal structures to assess for asymmetry (which may arise from unilateral nerve paresis).…”

Identification of Swallowing Tasks From a Modified Barium Swallow Study That Optimize the Detection of Physiological Impairment

“…Although the MBSS provides invaluable information, the diagnostic conclusions drawn are highly dependent on the assessment protocol presented to the patient (Dodds, Logemann, & Stewart, 1990), the type of barium used (Dietsch, Solomon, Steele, & Pelletier, 2014;Steele, Molfenter, Peladeau-Pigeon, & Stokely, 2013;Stokely, Molfenter, & Steele, 2014), the instructions provided to the patient (Daniels et al, 2007;Nagy et al, 2013), and how the videofluoroscopic image is captured (Bonilha, Blair, et al, 2013). The MBSImP protocol was used to test the research questions addressed in this study because it allows for flexibility in administration, use of maneuvers and compensations, and evaluation of airway invasion.…”

“…The MBSS is a relatively short procedure, averaging approximately 15 min, and every attempt should be made to minimize radiation exposure (e.g., ≤ 3 min) while maximizing clinical yield (Bonilha, Humphries, et al, 2013;Crawley, Savage, & Oakley, 2004;Morishima, Chida, & Watanabe, 2016). Within this context, the primary goal of the MBSS is to identify swallowing impairment and to assess physiological adaptation and compensation strategies that will improve swallowing.…”