title: Real-time 3D fusion echocardiography.
abstract: OBJECTIVE
  This study assessed 3-dimensional fusion echocardiography (3DFE), combining several real-time 3-dimensional echocardiography (RT3DE) full volumes from different transducer positions, for improvement in quality and completeness of the reconstructed image.
  
  
  BACKGROUND
  The RT3DE technique has limited image quality and completeness of datasets even with current matrix transducers.
  
  
  METHODS
  RT3DE datasets were acquired in 32 participants (mean age 33.7 +/- 18.8 years; 27 men, 5 women). The 3DFE technique was also performed on a cardiac phantom. The endocardial border definition of RT3DE and 3DFE segments was graded for quality: good (2), intermediate (1), poor (0), or out of sector. Short-axis and apical images were compared in RT3DE and 3DFE, yielding 2,048 segments. The images were processed to generate 3DFE and then compared with cardiac magnetic resonance.
  
  
  RESULTS
  In the heart phantom, fused datasets showed improved contrast to noise ratio from 49.4 +/- 25.1 (single dataset) to 125.4 +/- 25.1 (6 datasets fused together). In subjects, more segments were graded as good quality with 3DFE (805 vs. 435; p < 0.0001) and fewer as intermediate (184 vs. 283; p = 0.017), poor (31 vs. 265; p < 0.0001), or out of sector (4 vs. 41; p < 0.001) compared with the single 3-dimensional dataset. End-diastolic volume (EDV) and end-systolic volume (ESV) obtained from 3-dimensional fused datasets were equivalent to those from single datasets (EDV 118.2 +/- 39 ml vs. 119.7 +/- 43 ml; p = 0.41; ESV 48.1 +/- 30 ml vs. 48.4 +/- 35 ml; p = 0.87; ejection fraction [EF] 61.0 +/- 10% vs. 61.8 +/- 10%; p = 0.44). Bland-Altman analysis showed good 95% limits of agreement for the nonfused datasets (EDV +/-46 ml; ESV +/-36 ml; EF +/-14%) and the fused datasets (EDV +/-45 ml; ESV +/-35 ml; EF +/-16%), when compared with cardiac magnetic resonance.
  
  
  CONCLUSIONS
  Fusion of full-volume datasets resulted in an improvement in endocardial borders, image quality, and completeness of the datasets.
authors.affiliation: Department of Cardiovascular Medicine, University of Oxford, Oxford, UK.
authors.forename: Cezary
authors.initials: C
authors.lastname: Szmigielski
authors.forename: Kashif
authors.initials: K
authors.lastname: Rajpoot
authors.forename: Vicente
authors.initials: V
authors.lastname: Grau
authors.forename: Saul G
authors.initials: SG
authors.lastname: Myerson
authors.forename: Cameron
authors.initials: C
authors.lastname: Holloway
authors.forename: J Alison
authors.initials: JA
authors.lastname: Noble
authors.forename: Richard
authors.initials: R
authors.lastname: Kerber
authors.forename: Harald
authors.initials: H
authors.lastname: Becher
mesh_terms: D000293:Adolescent; D000328:Adult; D019560:Echocardiography, Three-Dimensional / Q000295:instrumentation; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D010865:Pilot Projects; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013318:Stroke Volume; D016277:Ventricular Function, Left; D055815:Young Adult