Cadmium Telluride Semiconductor Detector for Improved Spatial and Energy Resolution Radioisotopic Imaging

Abstract

The detector in single-photon emission computed tomography has played a key role in the quality of the images. Over the past few decades, developments in semiconductor detector technology provided an appropriate substitution for scintillation detectors in terms of high sensitivity, better energy resolution, and also high spatial resolution. One of the considered detectors is cadmium telluride (CdTe). The purpose of this paper is to review the CdTe semiconductor detector used in preclinical studies, small organ and small animal imaging, also research in nuclear medicine and other medical imaging modalities by a complete inspect on the material characteristics, irradiation principles, applications, and epitaxial growth method.

Keywords: Cadmium telluride; image quality; radiation detector; semiconductor; single-photon emission computed tomography.

Figure 1

Linear attenuation coeffcients of cadmium telluride, thallium-activated sodium iodide, germanium, and silicon materials. The dashed lines are results for the mass energy-absorption coefficient. Cadmium telluride has a higher photoelectric attenuation coeffcient than do the other materials (used with permission from the author)

Figure 2

Detection effciency for 140-keV gamma rays for various thicknesses of cadmium telluride, thallium-activated sodium iodide, germanium, and silicon detectors. The drawn lines are results for the total detection effciency; the dashed lines are results for the photoelectric detection effciency (used with permission from the author)

Figure 3

(color online) Detection effciency of the cadmium telluride pixelated semiconductor detector at different energies; the dashed lines are results for the photoelectric detection effciency (used with permission from the author)

Figure 4

Planar configuration of a semiconductor detector. Electron-hole pairs, generated by radiation, are swept toward the appropriate electrode by the electric field (used with permission from the author)

Figure 5

N-isopropyl-p-[123I] Iodoamphetamine (IMP) of brain phantom (a), planar image by cadmium telluride detector module (b) and by anger-type (c), the distance from the phantom surface to collimator surface was 50 mm. The image of cadmium telluride detector (b) is superior in contrast and sharpness than of anger-type (used with permission from the author)