Application of low-tube-voltage combined with adaptive iterative reconstruction in lower extremity computed tomography angiography

Abstract

Objective To investigate the feasibility of low-tube-voltage in combination with the three-dimensional adaptive iterative dose reduction (AIDR-3D) algorithm in performing lower extremity computed tomography angiography (CTA). Methods A total of 60 patients suspicious of lower extremity arterial occlusion were randomized into control group (120 Kv, n=30) and experimental group (100 Kv, n=30). The CTA was undertaken with a 320-row scanner (Toshiba Aquilion ONE), and the images was reconstructed with filtered back projection ( FBP) algorithm in control group and FBP as well as the AIDR-3D algorithm in experimental group. The subjective image quality, vascular density (VD), noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and dose length product (DLP) were compared between two groups. Results The DLP was significantly lower in experimental group than that in control group [(503.5±104.7) vs. (1 099.4±151.7) mGy·cm, t=15.7, P<0.05]. The images in experimental group with 100 Kv and FBP protocol had significantly increased VD and noise (t=-3.13, -3.61, P<0.05) than that in the control. The images in experimental group with AIDR-3D had significantly lower noise and higher SNR and CNR than that with FBP ( t=13.59, 2.14, P<0.05), also significantly lower noise and significantly higher VD, SNR, and CNR than that in the control (t=-3.75, -4.19, -4.15, P<0.05). Conclusions Low-tube-voltage (100 Kv) combined with AIDR-3D reconstruction could significantly improve the image quality and reduce radiation dose in lower extremity CTA with a 320-row CT scanner. Trial registration Chinese clinical trial registry, ChiCTR-DPD-16008054. Key words: Lower extremity; Iterative reconstruction; Computed tomography angiography; Radiation dose; Image noise