title: Interpretation of cardiac wall motion from cine-MRI combined with parametric imaging based on the Hilbert transform.
abstract: OBJECTIVE
  The aim of this study was to test and validate the clinical impact of parametric amplitude images obtained using the Hilbert transform on the regional interpretation of cardiac wall motion abnormalities from cine-MR images by non-expert radiologists compared with expert consensus.
  
  
  METHODS
  Cine-MRI short-axis images obtained in 20 patients (10 with myocardial infarction, 5 with myocarditis and 5 with normal function) were processed to compute a parametric amplitude image for each using the Hilbert transform. Two expert radiologists blindly reviewed the cine-MR images to define a gold standard for wall motion interpretation for each left ventricular sector. Two non-expert radiologists reviewed and graded the same images without and in combination with parametric images. Grades assigned to each segment in the two separate sessions were compared with the gold standard.
  
  
  RESULTS
  According to expert interpretation, 264/320 (82.5%) segments were classified as normal and 56/320 (17.5%) were considered abnormal. The accuracy of the non-expert radiologists' grades compared to the gold standard was significantly improved by adding parametric images (from 87.2 to 94.6%) together with sensitivity (from 64.29 to 84.4%) and specificity (from 92 to 96.9%), also resulting in reduced interobserver variability (from 12.8 to 5.6%).
  
  
  CONCLUSIONS
  The use of parametric amplitude images based on the Hilbert transform in conjunction with cine-MRI was shown to be a promising technique for improvement of the detection of left ventricular wall motion abnormalities in less expert radiologists.
authors.affiliation: University of Tunis El Manar, Higher Institute of Medical Technologies of Tunis, Laboratory of Biophysics and Medical Technology, Tunis, Tunisia. narjes.benameur@yahoo.fr.
authors.forename: Narjes
authors.initials: N
authors.lastname: Benameur
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy.
authors.forename: Enrico Gianluca
authors.initials: EG
authors.lastname: Caiani
authors.affiliation: Military Hospital of Instruction of Tunis, Tunis, Tunisia.
authors.forename: Younes
authors.initials: Y
authors.lastname: Arous
authors.affiliation: Military Hospital of Instruction of Tunis, Tunis, Tunisia.
authors.forename: Nejmeddine Ben
authors.initials: NB
authors.lastname: Abdallah
authors.affiliation: University of Tunis El Manar, Higher Institute of Medical Technologies of Tunis, Laboratory of Biophysics and Medical Technology, Tunis, Tunisia.
authors.forename: Tarek
authors.initials: T
authors.lastname: Kraiem
mesh_terms: D000328:Adult; D000368:Aged; D057791:Cardiac Imaging Techniques / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D015331:Cohort Studies; D005104:Expert Testimony / Q000592:standards; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods / Q000592:standards; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology; D009205:Myocarditis / Q000000981:diagnostic imaging / Q000503:physiopathology; D015588:Observer Variation; D010210:Papillary Muscles / Q000000981:diagnostic imaging / Q000503:physiopathology; D012189:Retrospective Studies; D055815:Young Adult
keywords: Cardiac contraction; Hilbert transform; Magnetic resonance; Myocardial infarction; Regional assessment