title: Dose monitoring using the DICOM structured report: assessment of the relationship between cumulative radiation exposure and BMI in abdominal CT.
abstract: OBJECTIVE
  To perform a systematic, large-scale analysis using the Digital Imaging and Communication in Medicine structured report (DICOM-SR) to assess the relationship between body mass index (BMI) and radiation exposure in abdominal CT.
  
  
  METHODS
  A retrospective analysis of DICOM-SR of 3121 abdominal CT examinations between April 2013 and March 2014 was performed. All examinations were conducted using a 128 row CT system. Patients (mean age 61 ± 15 years) were divided into five groups according to their BMI: group A <20 kg/m(2) (underweight), group B 20-25 kg/m(2) (normal weight), group C 25-30 kg/m(2) (overweight), group D 30-35 kg/m(2) (obese), and group E > 35 kg/m(2) (extremely obese). CT dose index (CTDIvol) and dose-length product (DLP) were compared between all groups and matched to national diagnostic reference values.
  
  
  RESULTS
  The mean CTDIvol and DLP were 5.4 ± 2.9 mGy and 243 ± 153 mGy.cm in group A, 6 ± 3.6 mGy and 264 ± 179 mGy.cm in group B, 7 ± 3.6 mGy and 320 ± 180 mGy.cm in group C, 8.1 ± 5.2 mGy and 375 ± 306 mGy.cm in group D, and 10 ± 8 mGy and 476 ± 403 mGy.cm in group E, respectively. Except for group A versus group B, CTDIvol and DLP differed significantly between all groups (p<0.05). Significantly more CTDIvol values exceeded national diagnostic reference values in groups D and E (2.1% and 6.3%) compared to group B (0.5%, p<0.05).
  
  
  CONCLUSIONS
  DICOM-SR is a comprehensive, fast, and reproducible way to analyse dose-related data at CT. It allows for automated evaluation of radiation dose in a large study population. Dose exposition is related to the patient's BMI and is increased by up to 96% for extremely obese patients undergoing abdominal CT.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Germany. Electronic address: Johannes.Boos@med.uni-duesseldorf.de.
authors.forename: J
authors.initials: J
authors.lastname: Boos
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Germany.
authors.forename: R S
authors.initials: RS
authors.lastname: Lanzman
authors.affiliation: Siemens AG, Regional Cluster Deutschland, Sector Healthcare, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Meineke
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Heusch
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Germany.
authors.forename: L M
authors.initials: LM
authors.lastname: Sawicki
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Antoch
authors.affiliation: Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Kröpil
mesh_terms: D015992:Body Mass Index; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000000981:diagnostic imaging; D009767:Obesity, Morbid / Q000000981:diagnostic imaging; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000706:statistics & numerical data*; D011860:Radiography, Abdominal / Q000379:methods*; D011873:Radiology Information Systems / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*