Digital imaging and telemedicine as a tool for studying inflammatory conditions in the middle ear--evaluation of image quality and agreement between examiners.

OBJECTIVE: To evaluate digital imaging of the tympanic membrane by telemedicine technology and study interpersonal agreement in assessing image quality.
METHODS: In an open consecutive study, 64 children aged 2-16 years who attended three rural health care centres in Northern Sweden with otalgia were examined with video endoscopic photography of their tympanic membrane in a telemedical environment. One hundred and twenty-four images were stored in a central database and later assessed independently regarding image quality by an ENT specialist, a general practitioner and a registrar in general practice. The overall image quality was graded (0-2) regarding assessment of signs of tympanic membrane inflammation. All images were also assessed regarding 8 different components, four image-related components and four anatomically related components.
RESULTS: Overall image quality was good, with 82.3% of acceptable or excellent quality. The position and thickness of the TM were found to be the most important factors of the images to be able to assess inflammatory disease. Image quality tended to be higher later in the study as a sign of improved skills of examiners. Interpersonal agreement between examiners was acceptable. Overall grade showed kappa 0.56, 0.49 and 0.66 respectively, and focus, light and existence of obscuring objects were the components with the highest agreement.
CONCLUSIONS: The image quality of video endoscopy of the tympanic membrane was good overall. Interpersonal agreement in evaluating image quality was acceptable but not excellent. The use of digital imaging of good quality in clinical studies can offer an objective clinical evaluation of the TM in retrospect by independent reviewers using strict criteria.