title: [Development of a Novel Body Phantom with Bone Equivalent Density for Evaluation of Bone SPECT].
abstract: We developed a custom-designed phantom for bone single photon emission computed tomography (SPECT)-specific radioactivity distribution and linear attenuation coefficient. The aim of this study was to evaluate the accuracy of the phantom. The lumbar phantom consisted of the trunk of a body phantom (background) containing a cylinder (vertebral body), a sphere (tumor), and a T-shaped container (processus). The vertebral body, tumor, and processus phantoms contained a K(2)HPO(4) solution of bone equivalent density and 50, 300 and 50 kBq/mL of (99m)Tc, respectively. The body phantom contained 8 kBq/mL of (99m)Tc solution. SPECT images were acquired using low-energy high-resolution collimation, a 128 × 128 matrix and 120 projections over 360° with a dwell time of 15 sec/view × 4 times. Thereafter, CT images were acquired at 130 kV and 70 ref mAs using adaptive dose modulation. The SPECT data were reconstructed with ordered subset expectation maximization with three-dimensional, scatter, and CT-based attenuation correction. Count ratio, linear attenuation coefficient (LAC), and full-width at half-maximum (FWHM) were measured. Count ratios between the background, the vertebral body, and the tumor in SPECT images were 463.8: 2888.0: 15150.3 (1: 6.23: 32.7). The LAC of the background and vertebral body in the CT-derived attenuation map were 0.155 cm⁻¹ and 0.284 cm⁻¹, respectively, and the FWHM measured from the processus was 15.27 mm. The precise counts and LAC indicated that the phantom was accurate and could serve as a tool for evaluating acquisition, reconstruction parameters, and quantitation in bone SPECT images.
authors.affiliation: Department of Radiology, Toyohashi Municipal Hospital.
authors.forename: Hajime
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Kenta
authors.initials: K
authors.lastname: Miwa
authors.forename: Norikazu
authors.initials: N
authors.lastname: Matsutomo
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Toyohiro
authors.initials: T
authors.lastname: Kato
authors.forename: Hideki
authors.initials: H
authors.lastname: Shimada
mesh_terms: D015519:Bone Density; D001859:Bone Neoplasms / Q000175:diagnosis; D006801:Humans; D019047:Phantoms, Imaging; D015899:Tomography, Emission-Computed, Single-Photon