Three-dimensional imaging core laboratory of the endovascular aneurysm repair trials: validation of methodology.
OBJECTIVE
The aim of this study was to establish and validate a three-dimensional imaging protocol for the assessment of Computed Tomography (CT) scans of abdominal aortic aneurysms in UK EVAR trials patients. Quality control and repeatability of anatomical measurements is important for the validity of any core laboratory.


METHODS
Three different observers performed anatomical measurements on 50 preoperative CT scans of aortic aneurysms using the Vitrea 2 three-dimensional post-imaging software in a core laboratory setting. We assessed the accuracy of intra and inter observer repeatability of measurements, the time required for collection of measurements, 3 different levels of automation and 3 different automated criteria for measurement of neck length.


RESULTS
None of the automated neck length measurements demonstrated sufficient accuracy and it was necessary to perform checking of the important automated landmarks. Good intra and limited inter observer agreement were achieved with three-dimensional assessment. Complete assessment of the aneurysm and iliacs took an average (SD) of 17.2 (4.1) minutes.


CONCLUSIONS
Aortic aneurysm anatomy can be assessed reliably and quickly using three-dimensional assessment but for scans of limited quality, manual checking of important landmarks remains necessary. Using a set protocol, agreement between observers is satisfactory but not as good as within observers.
Wyss
T R
TR
Vascular Surgery Research Group, Imperial College London, Charing Cross Hospital, Fulham Palace Road, London, United Kingdom.
Dick
F
F
England
A
A
Brown
L C
LC
Rodway
A D
AD
Greenhalgh
R M
RM
D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000601:surgery*; D001027:Aortography / Q000592:standards*; D057205:Automation, Laboratory / Q000592:standards; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation; D019411:Clinical Laboratory Techniques / Q000592:standards*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000592:standards*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000592:standards*; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D015203:Reproducibility of Results; D015607:Stents; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000592:standards*; D016896:Treatment Outcome