DESCRIPTION AND EVALUATION OF THE VALLECULA SIGN - A NEW RADIOLOGIC SIGN IN THE DIAGNOSIS OF ADULT EPIGLOTTITIS

Study objective: To describe and prospectively evaluate a new radiolog ic sign with the potential to increase the diagnostic accuracy of soft -tissue radiography of the neck in the identification of adult epiglot titis. Methods: We conducted a prospective, before-and-after blinded s tudy at two tertiary care institutions. A convenience sample of four s taff emergency physicians, three otolaryngology residents, four radiol ogy residents, and four senior medical students volunteered to partici pate. We assembled 26 soft-tissue radiographs of the neck from consecu tive patients ED with the diagnosis of epiglottitis made on the basis of direct visualization. Twenty-six control radiographs were identifie d from ED patients who were being evaluated for the presence of foreig n bodies or minor cervical trauma. We then randomly mixed the two sets of radiographs. Participants were asked to identify epiglottitis amon g the 52 randomly sequenced radiographs. A standardized 5-minute tutor ial on the vallecula sign was presented to all participants after the first interpretation. We then asked the participants to make a second interpretation of the 52 radiographs without knowledge of correct answ ers from the initial evaluation. Results: The participants accurately classified 80.5% of all radiographs reviewed before the tutorial and 9 8.8% after the tutorial (P<.0001). Similarly, sensitivity improved fro m 78.5% to 98.2% (P<.0001) and specificity improved from 82.8% to 99.5 % (P<.0001). We found no significant differences in performance charac teristics among the different types of participants. Conclusion: We ha ve described a new radiographic sign that improves the diagnostic accu racy of soft-tissue radiography of the neck. If reproduced in prospect ive studies, the absence of the vallecula sign on radiography might ob viate the need for routine use of direct visualization as an initial s creen.