Evaluation of Static Thermal and Near-infrared Hyperspectral Imaging for the Diagnosis of Acute Maxillary Rhinosinusitis

Although acute maxillary rhinosinusitis may be confidently diagnosed based on a history and physical examination by trained specialists, its diagnosis by primary health workers is less dependable, with a tendency for overdiagnosis, often resulting in inappropriate treatment. It is commonly perceived among the otolaryngology community that a new and objective diagnostic tool would be beneficial, facilitating the widespread and reliable diagnosis of rhinosinusitis. Numerous merits of thermal imaging make it an attractive modality to fulfill this role. Although modern systems possess ample sensitivity to detect small thermal abnormalities that accompany various physiologic conditions, reservations remain over whether a rhinosinusitis-induced thermal response in the overlying tissues is dominant enough to yield reliable diagnostic information in a normal clinical setting. Hence, a small preliminary study was conducted with the objective of testing the hypothesis that acute maxillary rhinosinusitis results in hyperthermia over the affected site and subsequent contralateral thermal asymmetry that is clearly distinguished from the normal population. The complementary yet distinct modality of near-infrared hyperspectral imaging, which detects changes in tissue perfusion, was assessed concurrently. We have not found a diagnostic test based on static thermal imaging or near-infrared hyperspectral imaging as viable options for the widespread and routine diagnosis of human sinus conditions. The presence and prevalence of visually inconspicuous epidermal features have been identified as representing a major confounding factor for facial thermal imaging. This article also serves as an overview of diagnostic imaging techniques employed in the detection of maxillary rhinosinusitis.