Repeatability and Intermediate Precision in Thermographic Clinical Imaging

Thermography is increasingly used in the biomedical field as a screening and assessing tool. Today it is considered a technique useful to make an early diagnosis of specific pathologies. Literature is full of numerous applications; however, the lack of standardized measurement procedures makes the results coming from different studies difficult to be compared. So reproducibility, repeatability and intermediate measurement precision are important requirements to be assured. The matter becomes more complex if the results coming from different experimentations are considered. In this paper, the authors aim to face these metrological issues in order to provide a guide for operators using this technique. Reference to GUM and ISO Standards is here made to give an overview of the current technical documentation in this field. Most common measurement issues are here described to advice the operator to avoid errors and external interferences so assuring data reliability. Repeatability and intermediate precision are computed to provide quantitative information on measurement uncertainty contributions. Such information adds relevant knowledge on the measurement precision associated with the thermographic images, and consequently provides quantitative details on the reliability of data which is based the final clinical diagnosis.