title: Measurement of pancreatic cystic lesions on magnetic resonance imaging: efficacy of standards in reducing inter-observer variability.
abstract: OBJECTIVE
  The purpose of this study is to assess inter-observer variability in the measurement of pancreatic cystic lesions with MRI and to determine the impact of measurement standards.
  
  
  METHODS
  In this IRB-approved, HIPAA-compliant study with waiver of informed consent, 144 MRI examinations, containing pancreatic cystic lesions measuring between 5 and 35 mm, were reviewed independently by two radiology attendings and two abdominal imaging fellows. Measurements were repeated by the same reviewers 12 weeks later after the introduction of measurement standards. Results were analyzed using within-subject standard deviation, intraclass correlation coefficient, and kappa.
  
  
  RESULTS
  Prior to standardization, the within-subject standard deviation, showing measurement variability in each cyst, was 4.0 mm, which was reduced to 3.3 mm after introduction of measurement standards (p < 0.01). Overall inter-observer agreement, kappa, improved from 0.59 to 0.65 (p = 0.04). The frequency of all four reviewers agreeing on size category increased from 51% to 60%. The intraclass correlation coefficient increased from 0.81 to 0.86.
  
  
  CONCLUSIONS
  There is significant and frequent inter-observer variability in the measurement of pancreatic cystic lesions with MRI which could affect clinical management. Implementation of measurement standards reduces measurement variability and aids in preventing erroneous reporting of growth and potentially unwarranted changes in management.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Ansin 224, Boston, MA, 02115, USA. delldunn@gmail.com.|Department of Radiology, David Grant Medical Center, Travis AFB, CA, USA. delldunn@gmail.com.
authors.forename: Dell P
authors.initials: DP
authors.lastname: Dunn
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Ansin 224, Boston, MA, 02115, USA.
authors.forename: Olga R
authors.initials: OR
authors.lastname: Brook
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Ansin 224, Boston, MA, 02115, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Brook
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Ansin 224, Boston, MA, 02115, USA.|Medical Imaging Department, Ottawa Hospital, Ottawa, ON, Canada.
authors.forename: Giselle
authors.initials: G
authors.lastname: Revah
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Ansin 224, Boston, MA, 02115, USA.|Department of Radiology, St. Vincents Hospital, Worcester, MA, USA.
authors.forename: Sumayya
authors.initials: S
authors.lastname: Jawadi
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Ansin 224, Boston, MA, 02115, USA.
authors.forename: Maryellen
authors.initials: M
authors.lastname: Sun
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Ansin 224, Boston, MA, 02115, USA.
authors.forename: Karen S
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Ansin 224, Boston, MA, 02115, USA.
authors.forename: Koenraad J
authors.initials: KJ
authors.lastname: Mortele
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010179:Pancreas / Q000000981:diagnostic imaging; D010181:Pancreatic Cyst / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: IPMN; MRI; Pancreas; Pancreatic cysts; Variability