Chien-Ming Chen1, Yang-Yu Lin2, Ming-Yi Hsu3, Chien-Fu Hung4, Ying-Lan Liao5, Hui-Yu Tsai6. 1. Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, 5 Fuxing Street, Kwei-Shan 333, Taoyuan, Taiwan; College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan 333, Taoyuan, Taiwan. Electronic address: dr.cmchen@gmail.com. 2. Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, 5 Fuxing Street, Kwei-Shan 333, Taoyuan, Taiwan; College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan 333, Taoyuan, Taiwan. Electronic address: 8902036@cgmh.org.tw. 3. Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, 5 Fuxing Street, Kwei-Shan 333, Taoyuan, Taiwan; College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan 333, Taoyuan, Taiwan. Electronic address: m7259@cgmh.org.tw. 4. Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital Linkou, 5 Fuxing Street, Kwei-Shan 333, Taoyuan, Taiwan; College of Medicine, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan 333, Taoyuan, Taiwan. Electronic address: hcf5514@cgmh.org.tw. 5. Medical Physics Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Linkou, 259 Wen-Hwa 1st Road, Kwei-Shan 333, Taoyuan, Taiwan. Electronic address: ylliao@mail.cgu.edu.tw. 6. Medical Physics Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Linkou, 259 Wen-Hwa 1st Road, Kwei-Shan 333, Taoyuan, Taiwan; Department of Medical Imaging & Radiological Sciences, Chang Gung University, 259 Wen-Hwa 1st Road, Kwei-Shan 333, Taoyuan, Taiwan. Electronic address: hytsai@mail.cgu.edu.tw.
Abstract
OBJECTIVES: Evaluate the performance of Adaptive Iterative Dose Reduction 3D (AIDR 3D) and compare with filtered-back projection (FBP) regarding radiation dosage and image quality for an 80-kVp abdominal CT. MATERIALS AND METHODS: An abdominal phantom underwent four CT acquisitions and reconstruction algorithms (FBP; AIDR 3D mild, standard and strong). Sixty-three patients underwent unenhanced liver CT with FBP and standard level AIDR 3D. Further post-acquisition reconstruction with strong level AIDR 3D was made. Patients were divided into two groups (< and ≧29cm) based on the abdominal effective diameter (Deff) at T12 level. Quantitative (attenuation, noise, and signal-to-noise ratio) and qualitative (image quality, noise, sharpness, and artifact) analysis by two readers were assessed and the interobserver agreement was calculated. RESULTS: Strong level AIDR 3D reduced radiation dose by 72% in the phantom and 47.1% in the patient study compared with FBP. There was no difference in mean attenuations. Image noise was the lowest and signal-to-noise ratio the highest using strong level AIDR 3D in both patient groups. For Deff<29cm, image sharpness of FBP was significantly different from those of AIDR 3D (P<0.05). For Deff ≧29cm, image quality of AIDR 3D was significantly more favorable than FBP (P<0.05). Interobserver agreement was substantial. CONCLUSIONS: Integrated AIDR 3D allows for an automatic reduction in radiation dose and maintenance of image quality compared with FBP. Using AIDR 3D reconstruction, patients with larger abdomen circumference could be imaged at 80kVp.
OBJECTIVES: Evaluate the performance of Adaptive Iterative Dose Reduction 3D (AIDR 3D) and compare with filtered-back projection (FBP) regarding radiation dosage and image quality for an 80-kVp abdominal CT. MATERIALS AND METHODS: An abdominal phantom underwent four CT acquisitions and reconstruction algorithms (FBP; AIDR 3D mild, standard and strong). Sixty-three patients underwent unenhanced liver CT with FBP and standard level AIDR 3D. Further post-acquisition reconstruction with strong level AIDR 3D was made. Patients were divided into two groups (< and ≧29cm) based on the abdominal effective diameter (Deff) at T12 level. Quantitative (attenuation, noise, and signal-to-noise ratio) and qualitative (image quality, noise, sharpness, and artifact) analysis by two readers were assessed and the interobserver agreement was calculated. RESULTS: Strong level AIDR 3D reduced radiation dose by 72% in the phantom and 47.1% in the patient study compared with FBP. There was no difference in mean attenuations. Image noise was the lowest and signal-to-noise ratio the highest using strong level AIDR 3D in both patient groups. For Deff<29cm, image sharpness of FBP was significantly different from those of AIDR 3D (P<0.05). For Deff ≧29cm, image quality of AIDR 3D was significantly more favorable than FBP (P<0.05). Interobserver agreement was substantial. CONCLUSIONS: Integrated AIDR 3D allows for an automatic reduction in radiation dose and maintenance of image quality compared with FBP. Using AIDR 3D reconstruction, patients with larger abdomen circumference could be imaged at 80kVp.