title: Impact of image analysis methodology on diagnostic and surgical classification of patients with thoracic aortic aneurysms.
abstract: BACKGROUND
  For patients with thoracic aortic aneurysms (TAA), aortic size on imaging is widely used to guide clinical decision making. This study examined the impact of methodological variance on aortic quantification.
  
  
  METHODS
  We studied enrollees in the National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions. Aortic size on computed tomography was quantified by 2 linear methods; cross-sectional dimensions in axial (AX) and double oblique (DO) plane. Calculated area was compared to planimetry. Established cutoffs (area/height>10 cm2/m, diameter≥5 cm) for prophylactic TAA repair were used to compare surgical eligibility by each method.
  
  
  RESULTS
  Fifty subjects were studied. Aortic size differed between AX and DO at all locations (p≤0.001), with magnitude greatest at the sinotubular junction (4.8±1.1 vs 4.0±1.0 cm, p<0.001). The difference between AX and DO correlated with aortic angular displacement (r=0.37, p<0.01), which was threefold larger at the sinotubular junction (37±12 degrees) than the ascending aorta (12±5 degrees; p<0.001). At all locations, aortic area calculated using DO yielded smaller differences with planimetry than AX (p<0.05). DO and planimetry yielded equal prevalence (24%) of subjects eligible for prophylactic TAA repair based on area-height cutoff, whereas AX prevalence was higher (44%; p=0.006). Using a linear cutoff, AX yielded over a twofold greater prevalence of surgically eligible subjects (56%) than did DO (24%; p<0.001).
  
  
  CONCLUSIONS
  Established linear methods for aortic measurement yield different results that impact surgical eligibility. DO yielded improved agreement with planimetry and differed with AX in proportion to aortic geometric obliquity. Findings support DO measurements for imaging evaluation of subjects with TAA.
authors: Department of Medicine, Weill Cornell Medical College, New York, New York 10021, USA.
authors: Dorinna D
authors: DD
authors: Mendoza
authors: Minisha
authors: M
authors: Kochar
authors: Richard B
authors: RB
authors: Devereux
authors: Craig T
authors: CT
authors: Basson
authors: James K
authors: JK
authors: Min
authors: Kathryn
authors: K
authors: Holmes
authors: Harry C
authors: HC
authors: Dietz
authors: Dianna M
authors: DM
authors: Milewicz
authors: Scott A
authors: SA
authors: LeMaire
authors: Reed E
authors: RE
authors: Pyeritz
authors: Joseph E
authors: JE
authors: Bavaria
authors: Cheryl L
authors: CL
authors: Maslen
authors: Howard
authors: H
authors: Song
authors: Barbara L
authors: BL
authors: Kroner
authors: Kim A
authors: KA
authors: Eagle
authors: Jonathan W
authors: JW
authors: Weinsaft
mesh_terms: D000328:Adult; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging* / Q000601:surgery; D017545:Aortic Aneurysm, Thoracic / Q000145:classification / Q000000981:diagnostic imaging / Q000601:surgery; D003657:Decision Making; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014656:Vascular Surgical Procedures