title: Measurements and detection of abdominal aortic aneurysm growth: Accuracy and reproducibility of a segmentation software.
abstract: OBJECTIVE
  To validate the reproducibility and accuracy of a software dedicated to measure abdominal aortic aneurysm (AAA) diameter, volume and growth over time.
  
  
  METHODS
  A software enabling AAA segmentation, diameter and volume measurement on computed tomography angiography (CTA) was tested. Validation was conducted in 28 patients with an AAA having 2 consecutive CTA examinations. The segmentation was performed twice by a senior radiologist and once by 3 medical students on all 56 CTAs. Intra and inter-observer reproducibility of D-max and volumes values were calculated by intraclass correlation coefficient (ICC). Systematic errors were evaluated by Bland-Altman analysis. Differences in D-max and volume growth were compared with paired Student's t-tests.
  
  
  RESULTS
  Mean D-max and volume were 49.6±6.2mm and 117.2±36.2ml for baseline and 53.6±7.9mm and 139.6±56.3ml for follow-up studies. Volume growth (17.3%) was higher than D-max progression (8.0%) between baseline and follow-up examinations (p<.0001). For the senior radiologist, intra-observer ICC of D-max and volume measurements were respectively estimated at 0.997 (≥0.991) and 1.000 (≥0.999). Overall inter-observer ICC of D-max and volume measurements were respectively estimated at 0.995 (0.990-0.997) and 0.999 (>0.999). Bland-Altman analysis showed excellent inter-reader agreement with a repeatability coefficient <3mm for D-max, <7% for relative D-max growth, <6ml for volume and <6% for relative volume growth.
  
  
  CONCLUSIONS
  Software AAA volume measurements were more sensitive than AAA D-max to detect AAA growth while providing an equivalent and high reproducibility.
authors: Department of Radiology, Centre Hospitalier Universitaire de Montréal and CHUM Research Center, University of Montreal, 1560 Sherbrooke Est, H2L 4M1 Montréal, Québec, Canada. claude.kauffmann@gmail.com
authors: Claude
authors: C
authors: Kauffmann
authors: An
authors: A
authors: Tang
authors: Eric
authors: E
authors: Therasse
authors: Marie-France
authors: MF
authors: Giroux
authors: Stephane
authors: S
authors: Elkouri
authors: Philippe
authors: P
authors: Melanson
authors: Bertrand
authors: B
authors: Melanson
authors: Vincent L
authors: VL
authors: Oliva
authors: Gilles
authors: G
authors: Soulez