Comparative analysis of radiation dose and image quality between organ dose modulation and 3D smart mA modulation during head-neck CT angiography

Article type: Research Article

Authors: Zhao, Yongxia^{a; *} | Xu, Yize^b | Bao, Yunfeng^c | Geng, Xue^b | Zhang, Tianle^b | Li, Dongxue^b

Affiliations: [a] Department of Radiology, The Affiliated Hospital of Hebei University, China | [b] Medical school, Hebei University, China | [c] Department of Radiology, Hebei General Hospital, China

Correspondence: [*] Corresponding author: Yongxia Zhao, Ph.D., Affiliated Hospital of Hebei University, 212 Yuhua East Road, Lianchi District, Baoding City, Hebei Province, 071000, China. Tel.: +86 1513 1221591; E-mail: [email protected].

Abstract: OBJECTIVE:To assess the difference in absorbed organ dose and image quality for head-neck CT angiography using organ dose modulation compared with 3D smart mA modulation in different body mass indices (BMIs) using an adaptive statistical iterative reconstruction (ASiR-V) algorithm. METHODS:Three hundred patients underwent head-neck CTA were equally divided into three groups: A (18.5 kg/m2≦BMI < 24.9 kg/m2), B (24.9 kg/m2≦BMI < 29.9 kg/m2) and C (29.9 kg/m2≦BMI≦34.9 kg/m2). The groups were randomly subdivided into two subgroups (n = 50): A1-A2, B1-B2 and C1-C2. The patients in subgroups A1, B1 and C1 underwent organ dose modulation with the ASiR-V algorithm, while other patients underwent 3D smart mA modulation. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of all head-neck CT angiography images were calculated. Images were then subjectively evaluated. Mean values of several indices including dose-length product (DLP) were computed. The DLP was converted to the effective dose (ED). SNR, CNR and ED in groups A, B, and C were compared in statistical data analysis. RESULTS:SNR, CNR, and subjective image scores show no statistical differences in three groups (P  >  0.05). However, there is significant difference of ED values (P  <  0.05) . For example, in subgroup A1 mean ED values are 15.30% and 23.66% lower than those in subgroup A2 at thyroid gland and eye lens, respectively. Similar patterns also exist in groups B (B1 vs. B2) and C (C1 vs. C2). CONCLUSIONS:Using organ dose modulation and applying the ASiR-V algorithm can more effectively reduce the radiation dose in head-neck CT angiography than using 3D smart mA modulation, while maintaining image quality. Thus, using organ-based dose modulation has the additional benefit of reducing dose to the thyroid gland and eye lens.

Keywords: Organ dose modulation, 3D smart mA modulation, radiation dose, image quality, head-neck CT angiography

DOI: 10.3233/XST-180443

Journal: Journal of X-Ray Science and Technology, vol. 27, no. 1, pp. 97-110, 2019