Image characteristics of cone beam computed tomography using a CT performance phantom

Han, Choong Wan; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan

Abstract

PURPOSE: To evaluate the characteristics of (widely used) cone beam computed tomography (CBCT) images.
MATERIALS AND METHODS
Images were obtained with CT performance phantoms (The American Association of Physicists in Medicine; AAPM). CT phantom as the destination by using PSR 9000N(TM) dental CT system (Asahi Roentgen Ind. Co., Ltd., Japan) and i-CAT CBCT (Imaging Science International Inc., USA) that have different kinds of detectors and field of view, and compared these images with the CT number for linear attenuation, contrast resolution, and spatial resolution.
RESULTS
CT number of both PSR 9000N(TM) dental CT system and i-CAT CBCT did not conform to the base value of CT performance phantom. The contrast of i-CAT CBCT is higher than that of PSR 9000N(TM) dental CT system. Both contrasts were increased according to thickness of cross section. Spatial resolution and shapes of reappearance was possible up to 0.6 mm in PSR 9000N(TM) dental CT system and up to 1.0 mm in i-CAT CBCT. Low contrast resolution in region of low contrast sensitivity revealed low level at PSR 9000N(TM) dental CT system and i-CAT CBCT.
CONCLUSION
CBCT images revealed higher spatial resolution, however, contrast resolution in region of low contrast sensitivity was the inferiority of image characteristics.