Reliability of Microwave Radiometry for the Assessment of Charcot Foot

Area of Science:

• Biomedical Engineering
• Diabetology
• Orthopedics

Background:

• Charcot neuro-osteoarthropathy (CNO) diagnosis and monitoring commonly utilize infrared thermometry.
• Microwave radiometry (MWR) offers a non-invasive method for detecting temperature changes in human tissues.
• Evaluating the concordance between infrared thermometry and MWR is crucial for potential advancements in CNO assessment.

Purpose of the Study:

• To assess the agreement between infrared thermometry and microwave radiometry (MWR) with varying sensor sizes (0.8cm, 2cm, 5cm) for Charcot neuro-osteoarthropathy (CNO) evaluation.
• To determine if MWR could serve as a viable alternative or complementary tool to infrared thermometry in managing CNO.
• To analyze the clinical implications of discrepancies between the two measurement methods on patient management decisions.

Main Methods:

• A comparative study involving individuals with diabetes mellitus (DM) and active CNO, alongside a control group with DM but without CNO.
• Temperature measurements were taken using infrared thermometry and MWR with 0.8cm, 2cm, and 5cm sensors.
• Statistical analysis was performed to evaluate the agreement and temperature discrepancies between the methods, with follow-up data on CNO activity.

Main Results:

• High agreement was observed between infrared thermometry and MWR using the 0.8cm sensor (average discrepancy 0.034°C, P=.676).
• Lower agreement was found between infrared thermometry and MWR 2cm (average discrepancy -0.323°C, P<.001) and MWR 5cm (average discrepancy -0.315°C, P=.002) sensors.
• Discrepancies between methods minimally affected clinical decisions regarding offloading device use, with only one participant's management potentially differing.

Conclusions:

• Infrared thermometry demonstrates strong agreement with MWR utilizing a small (0.8cm) sensor for CNO assessment.
• Larger MWR sensors (2cm and 5cm) exhibit significant temperature discrepancies compared to infrared thermometry, limiting their current utility for CNO.
• The findings suggest MWR with a 0.8cm sensor may be a promising adjunct for CNO monitoring, though clinical impact requires further investigation.