title: Performance of adaptive iterative dose reduction 3D integrated with automatic tube current modulation in radiation dose and image noise reduction compared with filtered-back projection for 80-kVp abdominal CT: Anthropomorphic phantom and patient study.
abstract: OBJECTIVE
  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.
  
  
  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.
authors: 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.
authors: Chien-Ming
authors: CM
authors: Chen
authors: 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.
authors: Yang-Yu
authors: YY
authors: Lin
authors: 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.
authors: Ming-Yi
authors: MY
authors: Hsu
authors: 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.
authors: Chien-Fu
authors: CF
authors: Hung
authors: 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.
authors: Ying-Lan
authors: YL
authors: Liao
authors: 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.
authors: Hui-Yu
authors: HY
authors: Tsai
mesh_terms: D000368:Aged; D000465:Algorithms; D016477:Artifacts; D015992:Body Mass Index; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011446:Prospective Studies; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D011860:Radiography, Abdominal / Q000379:methods; D011874:Radiometry; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Imaging; Multidetector computed tomography; Observer variation; Phantoms; Radiation dosage; Radiographic image enhancement