title: Detection and size measurements of pulmonary nodules in ultra-low-dose CT with iterative reconstruction compared to low dose CT.
abstract: BACKGROUND
  In this study, the accuracy of ultra-low-dose computed tomography (CT) with iterative reconstruction (IR) for detection and measurement of pulmonary nodules was evaluated.
  
  
  METHODS
  Eighty-four individuals referred for lung cancer screening (mean age: 54.5±10.8 years) underwent low-dose computed tomography (LDCT) and ultra-low-dose CT. CT examinations were performed with attenuation-based tube current modulation. Reference tube voltage and current were set to 120kV/25mÅs for LDCT and 80kV/4mÅs for ultra-low-dose CT. CT images were reconstructed with filtered back projection (FBP) for LDCT, and with FBP and IR for ultra-low-dose CT datasets. A reference standard was established by a consensus panel of 2 different radiologists on LDCT. Volume and diameter of the solid nodules were measured on LDCT with FBP and ultra-low dose CT with FBP and IR. Interobserver and interscan variability were analyzed and compared by the Bland-Altman method.
  
  
  RESULTS
  A total of 127 nodules were identified, including 105 solid nodules, 15 part solid nodules, 7 ground glass nodules. On ultra-low-dose CT scans, the effective radiation dose was 0.13±0.11mSv. A total of 113 (88.9%) and 110 (86.6%) true-positive nodules with FBP versus 117 (92.1%) and 118(92.9%) with IR were detected by two observers, respectively. The volume and size of the 105 solid nodules were measured, with mean volume/diameter of 46.5±46.6 mm(3)/5.1±1.6mm. There was no significant difference in nodule volume or diameter measurements between ultra-low-dose CT and LDCT protocols for solid nodules.
  
  
  CONCLUSIONS
  Ultra-low-dose CT with iterative reconstruction has high sensitivity for lung nodule detection without significant difference in nodule size and volume measurement compared to LDCT.
authors: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China. Electronic address: lena_sui@163.com.
authors: Xin
authors: X
authors: Sui
authors: Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA; Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany. Electronic address: felix.meinel@gmail.com.
authors: Felix G
authors: FG
authors: Meinel
authors: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors: Wei
authors: W
authors: Song
authors: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China. Electronic address: xxllpositive@163.com.
authors: Xiaoli
authors: X
authors: Xu
authors: Department of Epidemiology and Biostatistics, Institute of Basic Medical Science, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, China. Electronic address: wangzi969@126.com.
authors: Zixing
authors: Z
authors: Wang
authors: Department of Epidemiology and Biostatistics, Institute of Basic Medical Science, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, China. Electronic address: yuyang@163.com.
authors: Yuyan
authors: Y
authors: Wang
authors: Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China. Electronic address: jin_zhengyu@163.com.
authors: Zhengyu
authors: Z
authors: Jin
authors: Siemens China, Beijing, China. Electronic address: jiuhong.chen@siemens.com.
authors: Jiuhong
authors: J
authors: Chen
authors: Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA; University of Groningen, University Medical Center Groningen, Center for Medical Imaging-North East Netherlands, Department of Radiology, Groningen, The Netherlands. Electronic address: r.vliegenthart@umcg.nl.
authors: Rozemarijn
authors: R
authors: Vliegenthart
authors: Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA. Electronic address: schoepf@musc.edu.
authors: U Joseph
authors: UJ
authors: Schoepf
mesh_terms: D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D055613:Multiple Pulmonary Nodules / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D011829:Radiation Dosage; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Computed Tomography; Imaging; Solitary Pulmonary Nodule; Three-Dimensional; radiation dosage