title: Automated estimation of aortic strain from steady-state free-precession and phase contrast MR images.
abstract: The strain values extracted from steady-state free-precession (SSFP) and phase contrast (PC) images acquired with a 1.5T scanner on a compliant flow phantom and within the thoracic aorta of 52 healthy subjects were compared. Aortic data were acquired perpendicular to the aorta at the level of the pulmonary artery bifurcation. Cross sectional areas were obtained by using an automatic and robust segmentation method. While a good correlation (r = 0.99) was found between the aortic areas extracted from SSFP and PC sequences, a lower correlation (r = 0.71) was found between the corresponding aortic strain values. Strain values estimated using SSFP and PC sequences were equally correlated with age. Interobserver reproducibility was better for SSFP than for PC. Strain values in the ascending and descending aorta were better correlated for SSFP (r = 0.8) than for PC (r = 0.65) and fitted with the expectation of a larger strain in the ascending aorta when using SSFP. The spatial and temporal resolutions of the acquisitions had a minor influence upon the estimated strain values. Thus, if PC acquisitions can be used to estimate both pulse wave velocity and aortic strain, an additional SSFP sequence may be useful to improve the accuracy in estimating the aortic strain.
authors.affiliation: Inserm, UMR_S 678, Laboratoire d'Imagerie Fonctionnelle, Paris, France. Alain.Herment@imed.jussieu.fr
authors.forename: Alain
authors.initials: A
authors.lastname: Herment
authors.forename: Muriel
authors.initials: M
authors.lastname: Lefort
authors.forename: Nadjia
authors.initials: N
authors.lastname: Kachenoura
authors.forename: Alain
authors.initials: A
authors.lastname: De Cesare
authors.forename: Valentina
authors.initials: V
authors.lastname: Taviani
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Graves
authors.forename: Claire
authors.initials: C
authors.lastname: Pellot-Barakat
authors.forename: Frédérique
authors.initials: F
authors.lastname: Frouin
authors.forename: Elie
authors.initials: E
authors.lastname: Mousseaux
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001013:Aorta, Thoracic / Q000033:anatomy & histology* / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008858:Microscopy, Phase-Contrast / Q000295:instrumentation / Q000379:methods; D008875:Middle Aged; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult