Development and Performance of an Instrumentation Laboratory for Infrared Medical Imaging

TL;DR

This paper introduces an experimental setup and methodology for high-precision infrared thermal measurements in medical imaging, capable of detecting temperature variations below 0.1 K at depths of a few centimeters.

Contribution

The authors develop a comprehensive infrared imaging system with corrections and validation methods, demonstrating its effectiveness for sensitive thermal measurements in medical applications.

Findings

Achieved measurement uncertainty of approximately 25 mK.

Successfully reconstructed 3D thermal images matching thermocouple data.

Validated the system's ability to detect internal temperature contrasts of 1-3 K.

Abstract

We present an experimental setup and methodology designed to facilitate high-precision thermal measurements required for infrared medical tomography. The approach which is best suited for the study of specialized hardware phantoms comprises a controlled environmental enclosure, infrared detection, internal thermal reference elements, and a comprehensive data acquisition counting chain and protocol. Temporal and spatial corrections applied to sequential thermal images and panoramic projections reduce measurement fluctuations resulting in measurement uncertainty to approximately 25~mK. The capability to resolve weak surface temperature variations, well below 0.1~K, meets the requirement of medical imaging sensitivity. The methodology was validated using wax phantoms with elevated-temperature sources ($\Delta T$ = 1.5 to 10~K). Reconstructed 3D thermal tomographic images of hot spots embedded in hardware phantoms are found to be in quantitative agreement with thermocouple measurements and $\mu CT$ derived source positions. The results demonstrate that the proposed setup and methodology enable high-precision thermal measurements and establish the feasibility of detecting surface temperature variations below 0.1 K, consistent with low-temperature localized internal contrasts ($\Delta T =$ 1-3 K) at subsurface depths of a few centimeters, relevant to biological tissue.