Thermography for the Diagnosis of Acute Inflammation in the Paranasal Sinus

THIEME Original Research Thermography for the Diagnosis of Acute Inflammation in the Paranasal Sinus Tadashi Ishimaru1 Hitomi Ishimaru1 1 Department of Otorhinolaryngology, Hyotan-machi ENT Clinic, Kanazawa, Ishikawa, Japan Int Arch Otorhinolaryngol 2020;24(2):e221–e226. Abstract Keywords ► Thermography ► sinusitis ► paranasal sinuses ► maxillary sinus ► inflammation Introduction Although computed tomography scanning is the most common method for the diagnosis of sinusitis today, X-ray imaging is still used in outpatient clinics. Because X-ray imaging is beneficial for patients with severe sinusitis but not for those with mild sinusitis, an alternative method to visualize sinusitis without X-ray imaging is desirable. Objective To study the possibility of using thermography to visualize sinusitis. Methods In the present study, heat distribution on the faces of individuals with and without sinusitis was studied using thermography. Overall, 10 control subjects and 20 patients with sinusitis were included. Original thermography data were cropped, resized, and converted to relative thermography data based on the average temperature for visualization and statistical analysis. Results The shape of the maxillary and/or frontal sinuses was determined based on regions indicating increased temperature in patients with sinusitis. The region with increasing temperature was statistically visualized, and the significant side (t test, p < 0.05) coincided with the maxillary shadow on X-ray imaging. Conclusion Thermography demonstrates visually the correlation between the surface temperature of the face and inflammation patterns in the paranasal sinus. Therefore, our comparative study using thermography to visually differentiate individuals with and without sinusitis was effective, indicating that thermography is a possible alternative to X-ray imaging to detect sinusitis. Introduction Sinusitis is a commonly encountered disease in the outpatient clinic. Inflammation of the paranasal sinus is primarily diagnosed via X-ray imaging, although the precise diagnosis of sinusitis depends upon computed tomography (CT) scanning. If an imaging study that does not involve X-rays could be conducted for the diagnosis of sinusitis, it would be more useful and safer for patients. The applications of thermography in otorhinolaryngology have been reported by pioneer studies.1–3 Sergeev et al3 examined the difference between temperatures measured received September 23, 2018 accepted September 8, 2019 published online January 28, 2020 Address for correspondence Tadashi Ishimaru, MD, PhD, Department of Otorhinolaryngology, Hyotan-machi ENT Clinic, Hyotan-machi 2-13, Kanazawa, Ishikawa 9200845, Japan (e-mail: ). DOI https://doi.org/ 10.1055/s-0039-1698778. ISSN 1809-9777. by a thermometer in contact with the inferior turbinate and those measured by infrared thermography of the face and found a relationship between the temperatures of the inferior turbinate and facial skin. Although this work indicated the usefulness of thermography, the technique did not yield visual results. Because tissue temperature increases during inflammation, heat distribution on the face is possibly influenced by sinusitis. Previous researchers who used thermography reported that facial temperatures near the paranasal sinus increased when sinusitis was observed.3–5 Because the increase in the temperature differed between the two sides, we Copyright © 2020 by Thieme Revinter Publicações Ltda, Rio de Janeiro, Brazil 221 222 Thermography for the Diagnosis of Acute Inflammation in the Paranasal Sinus could effectively differentiate between the right and left sides through observation.4 Facial temperatures are easily influenced by individual differences and the environment. Haddad et al6 reported the heat distribution on the face in a healthy subject in a heatcontrolled room. The preparations for the thermographic examination included the regulation of room temperature, humidity, airflow, window size, electric lights etc. The effects of the environment on the examination room are reduced by digital technology; therefore, thermography may be a useful device in clinical settings. Recently, the development of a thermographic camera for the iPhone (Apple Inc., Cupertino, CA, US) or iPad (Apple Inc.) using the iOS (Apple Inc.) system has made thermography easy to use. We examined both thermography and postdigital image processing to analyze differences between subjects with and without sinusitis. Ishimaru, Ishimaru Table 1 Characteristics of the patients with sinusitis Side Gender Age Diagnosis Right Female 19 ARS Left Body temperature 36.2 Male 31 ARS 36.4 Male 32 OMS 36.4 Male 36 ARS 36.7 Female 54 AECS 36.9 Male 66 ARS 36.3 Female 23 ARS 36.7 Female 39 ARS 36.9 Female 52 PMC 36.6 Female 53 ARS 36.6 Female 64 PMC 37.0 Male 69 ARS 36.4 Male 39 ARS 36.5 Subjects Male 41 ARS 36.4 The present study included 10 control subjects (5 males and 5 females, aged [mean
standard deviation] 34
15 years) and 20 patients with sinusitus (9 males and 11 females, aged 43
14 years). The subjects who were declared disease-free and were diagnosed as free from nasal disease by anterior rhinoscopy were included on the study as controls. Of the 20 patients with acute rhinosinusitis (ARS), 16 were chosen according to the guidelines of the European Rhinology Society.7 Two patients with a postoperative maxillary cyst (PMC), 1 patient with acute exacerbation of chronic sinusitis (AECS), and 1 patient with odontogenic maxillary sinusitis (OMS) were included among the patients with sinusitis. The diagnoses of PMC, AECS, and OMS were made based on acute inflammation symptoms, past history, nasal cavity observations, X-ray imaging, and CT scans, and these conditions were included in the definition of “sinusitis.” All patients had complaints of maxillary pain, headache, and/or rhinorrhea. According to the laterality of the shadow of the maxillary sinus on X-ray imaging, the patients were divided into right, left, and bilateral groups. Patients with frontal sinusitis and no maxillary sinusitis were included into the “others” group (►Table 1). All subjects provided informed written consent. Each subject received a small monetary award in the form of a gift card. The experimental protocol was approved by the Review Board of the Ishikawa Medical Association in Japan. Male 44 ARS 36.3 Materials and Methods Bilateral Methods A FLIR-ONE (FLIR Inc., Wilsonville, OR, US) thermographic camera, which has automatic calibration, with an iPod-nano (Apple Inc.) were used, and all thermographic images were taken at room temperature. Thermographic image files (with 240  320 pixels of resolution and 0.1°Cof thermal sensitivity) were loaded to a personal computer by FLIR TOOLS (FLIR Inc.). These files were processed using the ImageJ (National Institutes of Health, Bethesda, MD, US) and LabVIEW8.1 Internatio (...truncated)