Interrater Reliability of Ultrasound in the Diagnosis of Sialolithiasis.

PURPOSE:  The aim of this study was to assess the interrater reliability of ultrasound for diagnosing sialolithiasis.

MATERIALS AND METHODS:  A total of 100 consecutive patients with signs of obstructive sialadenopathy were evaluated. The patients all underwent ultrasound examinations in a standardized manner conducted by one specialist with extensive experience in the management of salivary gland disorders and proficiency in head and neck ultrasonography. The video recordings were sent to six colleagues with comparable experience without providing any further information about the patients' medical history and physical examination.

RESULTS:  The overall agreement between the seven observers was substantial, with a κ of 0.765 for the 100 cases and a percentage agreement level of 88.29 ± 3.01 % (range: 83 - 94 %). The range of agreement on this video set for observer pairs varied from substantial to almost perfect agreement (0.663 to 0.878). Among the few false-negative findings (5.4 %), 71.8 % were due to distal sialolithiasis. Two-thirds of the false-positive findings (3.7 %) were due to fibrotic stenosis.

CONCLUSION:  The study confirmed the diagnostic value of ultrasound in sialolithiasis and demonstrated a very high level of interrater agreement, even in the absence of additional clinical patient information, thus further underscoring the importance of ultrasound as the examination of first choice in sialolithiasis.