Detection of subclinical synovial inflammation by microwave radiometry.

OBJECTIVE: Microwave Radiometry is a non-invasive method which determines within seconds the in vivo temperature of internal tissues at a depth of 3-7 cm with an accuracy of ±0.2°C. In this proof-of-concept study, we tested the hypothesis that, in absence of relevant clinical signs, increased local...

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Main Authors: Evangelia Zampeli, Ioannis Raftakis, Archontoula Michelongona, Chara Nikolaou, Antonia Elezoglou, Konstantinos Toutouzas, Elias Siores, Petros P Sfikakis
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3669424?pdf=render
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author Evangelia Zampeli
Ioannis Raftakis
Archontoula Michelongona
Chara Nikolaou
Antonia Elezoglou
Konstantinos Toutouzas
Elias Siores
Petros P Sfikakis
author_facet Evangelia Zampeli
Ioannis Raftakis
Archontoula Michelongona
Chara Nikolaou
Antonia Elezoglou
Konstantinos Toutouzas
Elias Siores
Petros P Sfikakis
author_sort Evangelia Zampeli
collection DOAJ
description OBJECTIVE: Microwave Radiometry is a non-invasive method which determines within seconds the in vivo temperature of internal tissues at a depth of 3-7 cm with an accuracy of ±0.2°C. In this proof-of-concept study, we tested the hypothesis that, in absence of relevant clinical signs, increased local temperature detected by microwave radiometry reflects subclinical synovial inflammation, using ultrasound as reference method. METHODS: Knees of healthy controls, subjects with recent knee trauma and symptom-free patients with rheumatoid arthritis (RA) or osteoarthritis were examined by placing the microwave radiometry sensor, a) at the upper one third of the anterior surface of the thigh (control-point), and b) over the suprapatellar recess. Ultrasound was performed immediately after and the possible presence of fluid and/or synovitis was correlated with microwave radiometry findings. RESULTS: In 30 healthy and 10 injured knees the temperature was always lower than thigh (32.3±1.1 and 31.8±1.4 versus 34.1±0.9 and 33.6±1.2°C with a difference (ΔΤ) of -1.8±0.2 and -1.9±0.4°C respectively). Of 40 RA and 20 osteoarthritis knees examined, ultrasound findings indicative of subclinical inflammation (fluid effusion and/or Doppler signal) were found in 24 and 12, respectively, in which the temperature was higher than healthy knees and ΔΤ was lower (-0.9±0.7 in RA and -1.0±0.5 in osteoarthritis versus -1.8±0.2°C, p<0.001). The 5 RA knees with power Doppler findings indicative of grade 2 inflammation had a ΔΤ 3 times lower compared to healthy (-0.6±0.6, p = 0.007), whereas the 9 RA and the 7 osteoarthritis knees with additionally fluid effusion, had even lower ΔΤ (-0.4±0.7, p<0.001). CONCLUSION: Using a safe, rapid and easy-to-perform method, such as microwave radiometry, thermal changes within the knee joint may reflect non-clinically apparent joint inflammation. Refinement of this method, including production of sensors for small joints, could result to the development of the ideal objective tool to detect subclinical synovitis in clinical practice.
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spelling doaj.art-5b0c476e6aff42e0afcd4350e5d1b93c2022-12-21T19:58:14ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0185e6460610.1371/journal.pone.0064606Detection of subclinical synovial inflammation by microwave radiometry.Evangelia ZampeliIoannis RaftakisArchontoula MichelongonaChara NikolaouAntonia ElezoglouKonstantinos ToutouzasElias SioresPetros P SfikakisOBJECTIVE: Microwave Radiometry is a non-invasive method which determines within seconds the in vivo temperature of internal tissues at a depth of 3-7 cm with an accuracy of ±0.2°C. In this proof-of-concept study, we tested the hypothesis that, in absence of relevant clinical signs, increased local temperature detected by microwave radiometry reflects subclinical synovial inflammation, using ultrasound as reference method. METHODS: Knees of healthy controls, subjects with recent knee trauma and symptom-free patients with rheumatoid arthritis (RA) or osteoarthritis were examined by placing the microwave radiometry sensor, a) at the upper one third of the anterior surface of the thigh (control-point), and b) over the suprapatellar recess. Ultrasound was performed immediately after and the possible presence of fluid and/or synovitis was correlated with microwave radiometry findings. RESULTS: In 30 healthy and 10 injured knees the temperature was always lower than thigh (32.3±1.1 and 31.8±1.4 versus 34.1±0.9 and 33.6±1.2°C with a difference (ΔΤ) of -1.8±0.2 and -1.9±0.4°C respectively). Of 40 RA and 20 osteoarthritis knees examined, ultrasound findings indicative of subclinical inflammation (fluid effusion and/or Doppler signal) were found in 24 and 12, respectively, in which the temperature was higher than healthy knees and ΔΤ was lower (-0.9±0.7 in RA and -1.0±0.5 in osteoarthritis versus -1.8±0.2°C, p<0.001). The 5 RA knees with power Doppler findings indicative of grade 2 inflammation had a ΔΤ 3 times lower compared to healthy (-0.6±0.6, p = 0.007), whereas the 9 RA and the 7 osteoarthritis knees with additionally fluid effusion, had even lower ΔΤ (-0.4±0.7, p<0.001). CONCLUSION: Using a safe, rapid and easy-to-perform method, such as microwave radiometry, thermal changes within the knee joint may reflect non-clinically apparent joint inflammation. Refinement of this method, including production of sensors for small joints, could result to the development of the ideal objective tool to detect subclinical synovitis in clinical practice.http://europepmc.org/articles/PMC3669424?pdf=render
spellingShingle Evangelia Zampeli
Ioannis Raftakis
Archontoula Michelongona
Chara Nikolaou
Antonia Elezoglou
Konstantinos Toutouzas
Elias Siores
Petros P Sfikakis
Detection of subclinical synovial inflammation by microwave radiometry.
PLoS ONE
title Detection of subclinical synovial inflammation by microwave radiometry.
title_full Detection of subclinical synovial inflammation by microwave radiometry.
title_fullStr Detection of subclinical synovial inflammation by microwave radiometry.
title_full_unstemmed Detection of subclinical synovial inflammation by microwave radiometry.
title_short Detection of subclinical synovial inflammation by microwave radiometry.
title_sort detection of subclinical synovial inflammation by microwave radiometry
url http://europepmc.org/articles/PMC3669424?pdf=render
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