title: Usefulness of India ink artifact in steady-state free precession pulse sequences for detection and quantification of intramyocardial fat.
abstract: OBJECTIVE
  In steady state free precession (SSFP) images acquired with a repetition time/echo time (TR/TE) ≈ 2, fat is surrounded by a black boundary, called "India Ink" artifact. Indian Ink artifact may improve detection of intramyocardial fat. Aims of this study were: (i) to assess the accuracy of SSFP technique for the detection of fat metaplasia in remote myocardial infarction (RMI); (ii) to evaluate the inter- and intraobserver reproducibility for the quantification of intramyocardial fat using SSFP and fast spin echo/short TI inversion recovery (FSE/STIR) techniques.
  
  
  METHODS
  A total of 200 patients (age 64 ± 10 years) with RMI (>1000 days) underwent MRI using a 1.5 Tesla (T) scanner. SSFP images (with a TR/TE ≈2), FSE and STIR images were acquired in short and long axis views. Fat was detected in FSE/STIR and SSFP images and its extent manually measured . The inter- and intraobserver agreement for the quantification of fat metaplasia using both the SSFP image and the FSE images was evaluated.
  
  
  RESULTS
  Left ventricle intramyocardial fat was detected in SSFP images of 95 patients (47.5%) and in FSE/STIR images of 84 patients (42%). A very good agreement was found using the SSFP technique between investigators.
  
  
  CONCLUSIONS
  SSFP sequence with TR/TE=2 is a valuable technique for identifying and quantifying the presence of fat tissue within the left ventricle myocardium in RMI.
authors.affiliation: Fondazione G. Monasterio CNR-Regione Toscana, Italy.
authors.forename: Giovanni Donato
authors.initials: GD
authors.lastname: Aquaro
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Todiere
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Strata
authors.forename: Andrea
authors.initials: A
authors.lastname: Barison
authors.forename: Gianluca
authors.initials: G
authors.lastname: Di Bella
authors.forename: Massimo
authors.initials: M
authors.lastname: Lombardi
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D016477:Artifacts; D002244:Carbon; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000473:pathology*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: C028433:chinese ink; D002244:Carbon
keywords: FSE; India Ink artifact; Myocardial infarction; SSFP; STIR; left ventricular fat metaplasia