Ultrasound & Thermography for Diagnosis of Extent & Magnitude of Acute Local Radiation injury

Ronald E. Goans PhD MD MPH (USA)
Carol J. Iddins MD
Doran M. Christensen DO

Abstract

Local radiation injury (LRI) is difficult to diagnose early, both in severity and extent, because of the prolonged time interval for the development of clinical signs and symptoms. A 12 MHz linear array ultrasound transducer has been used clinically at the Radiation Emergency Assistance Center/Training Site (REAC/TS) in conjunction with a thermography system capable of imaging skin lesions in the 6-14 ยต infrared spectrum. This combination has enabled early detection of subcutaneous pathological changes not visible clinically. Two separate animal experiments, one performed at Oak Ridge Associated Universities (ORAU) and other at the University of Tennessee School of Veterinary Medicine (UTCVM) will be presented. In the first experiment (ORAU) using only ultrasound, an early time-dependent response curve for the scattered ultrasound signal was noted after irradiation of Wistar rat tails to 40 Gy with a 120 KeV X-ray low LET spectrum. The rat tail was chosen to simulate a human finger, which is involved in many incidents of LRI. In the second set of experiments (UTCVM) using a Yorkshire porcine model, both ultrasound and thermography were used to analyze the time course of LRI in two animals irradiated locally to 10 and 20 Gy, respectively, using 6 MeV LINAC electrons. Experimental data will be presented along with a clinical correlation from several LRI patients evaluated at REAC/TS.