title: Measuring aortic diameter with different MR techniques: comparison of three-dimensional (3D) navigated steady-state free-precession (SSFP), 3D contrast-enhanced magnetic resonance angiography (CE-MRA), 2D T2 black blood, and 2D cine SSFP.
abstract: OBJECTIVE
  To compare nongated three-dimensional (3D) contrast-enhanced magnetic resonance angiography (CE-MRA) with 3D-navigated cardiac-gated steady-state free-precession bright blood (3D-nav SSFP) and noncontrast 2D techniques for ascending aorta dimension measurements.
  
  
  METHODS
  Twenty-five clinical exams were reviewed to evaluate the ascending aorta at 1.5T using: breathhold cine bright blood (SSFP), cardiac-triggered T2 black blood (T2 BB), axial 3D-nav SSFP, and nongated 3D CE-MRA. Three radiologists independently measured aortic size at three specified locations for each sequence. Means, SDs, interobserver correlation, and vessel edge sharpness were statistically evaluated.
  
  
  RESULTS
  Measurements were greatest for 3D-nav SSFP and 3D CE-MRA and smallest for T2 BB. There was no significant difference between 3D-nav SSFP and 3D CE-MRA (P = 0.43-0.86), but significance was observed comparing T2 BB to all sequences. Interobserver agreement was uniformly >0.9, with T2 BB best, followed closely by 3D-nav SSFP and 2D cine SSFP, and 3D CE-MRA being the worst. Edge sharpness was significantly poorer for 3D CE-MRA compared to the other sequences (P < 0.001).
  
  
  CONCLUSIONS
  If diameter measurements are the main clinical concern, 3D-nav SSFP appears to be the best choice, as it has a sharp edge profile, is easy to acquire and postprocess, and shows very good interobserver correlation.
authors.affiliation: Department of Radiology, University of Washington, Seattle, Washington, USA.
authors.forename: Silke
authors.initials: S
authors.lastname: Potthast
authors.forename: Lee
authors.initials: L
authors.lastname: Mitsumori
authors.forename: Luana A
authors.initials: LA
authors.lastname: Stanescu
authors.forename: Michael L
authors.initials: ML
authors.lastname: Richardson
authors.forename: Kelley
authors.initials: K
authors.lastname: Branch
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Dubinsky
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Maki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D019412:Anatomy, Cross-Sectional / Q000379:methods*; D001013:Aorta, Thoracic / Q000033:anatomy & histology*; D002648:Child; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media