title: Faster flow quantification using sensitivity encoding for velocity-encoded cine magnetic resonance imaging: in vitro and in vivo validation.
abstract: OBJECTIVE
  To test the agreement between conventional and sensitivity-encoded (SENSE) velocity encoded cine (VEC) MRI in a flow phantom and in subjects with congenital and acquired heart disease.
  
  
  METHODS
  Flow measurements were performed in a 1.5 T scanner using a segmented k-space VEC MRI sequence and then repeated with a SENSE factor of 2. The flow phantom used a piston pump to generate physiologic arterial waveforms (0.5-4.9 L/min). In the subjects, flow measurements were performed in the ascending aorta (N = 33) and/or the main pulmonary artery (N = 24).
  
  
  RESULTS
  Utilization of SENSE reduced the scan time by 50%. In the phantom, measurements without and with SENSE agreed closely with a mean difference of 0.01 +/- 0.08 L/min or 0.12% +/- 3.8% (P = 0.68). In the subjects, measurements without and with SENSE also agreed closely with a mean difference of 0.08 +/- 0.36 L/min or 1.3% +/- 7.2% (P = 0.08). Compared with standard imaging, the use of SENSE reduced the signal-to-noise ratio (SNR) by 28% in the phantom (N = 10) and 27% in vivo (N = 22).
  
  
  CONCLUSIONS
  VEC MRI flow measurements with a SENSE factor of 2 were twice as fast and agreed closely with the conventional technique in vitro and in vivo. VEC MRI with SENSE can be used for rapid and reliable quantification of blood flow.
authors.affiliation: Department of Cardiology, Children's Hospital Boston, Boston, Massachusetts, USA.
authors.forename: Ashwin
authors.initials: A
authors.lastname: Prakash
authors.forename: Ruchira
authors.initials: R
authors.lastname: Garg
authors.forename: Edward N
authors.initials: EN
authors.lastname: Marcus
authors.forename: Glenn
authors.initials: G
authors.lastname: Reynolds
authors.forename: Tal
authors.initials: T
authors.lastname: Geva
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Powell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001011:Aorta / Q000473:pathology; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000473:pathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors