Evaluating the quality characteristics of TLD-100T and TLD-100H exposed to diagnostic X-rays and 64 multislice CT using Taguchi's quality loss function

Abstract

A thorough survey of the quality characteristics of both TLD-100T and TLD-100H is performed using either diagnostic X-rays or 64 MSCT under the same 80 kVp setting of the maximum operating voltage. Two kinds of 12 TLDs (thermoluminescent dosimeters) were randomly assigned to four groups, respectively. Each group of 3 TLDs was placed 5 cm deep in the center of a 15-cm-thick solid water phantom within the measurement and four mAs settings were used for X-rays (56, 100, 200, 315 mAs) and 64 MSCT (50, 100, 200, 400 mAs). The linearity, reproducibility, sensitivity and the minimum detectable dose limit of various TLDs were obtained from dose calibration lines to verify the integrated performance according to the Taguchi's quality loss function. Both TLDs performed similarly when exposed to X-rays. The TLD-100T outperformed TLD-100H when exposed to 64 MSCT. The low reproducibility of TLD-100H could be eliminated by doubling the number of TLDs in one position to reduce the standard deviation of TLD-100H readouts.