title: Clinical validation of free breathing respiratory triggered retrospectively cardiac gated cine balanced steady-state free precession cardiovascular magnetic resonance in sedated children.
abstract: BACKGROUND
  Cine balanced steady-state free precession (SSFP), the preferred sequence for ventricular function, demands uninterrupted radio frequency (RF) excitation to maintain the steady-state during suspended respiration. This is difficult to accomplish in sedated children. In this work, we validate a respiratory triggered (RT) SSFP sequence that drives the magnetization to steady-state before commencing retrospectively cardiac gated cine acquisition in a sedated pediatric population.
  
  
  METHODS
  This prospective study was performed on 20 sedated children with congenital heart disease (8.6 ± 4 yrs). Identical imaging parameters were used for multiple number of signal averages (MN) and RT cine SSFP sequences covering both the ventricles in short-axis (SA) orientation. Image quality assessment and quantitative volumetric analysis was performed on the datasets by two blinded observers. One-sided Wilcoxon signed rank test and Box plot analysis were performed to compare the clinical scores. Bland-Altman (BA) analysis was performed on LV and RV volumes.
  
  
  RESULTS
  Scan duration for SA stack using RT-SSFP (3.9 ± 0.8 min) was slightly shorter than MN-SSFP (4.6 ± 0.9 min) acquisitions. The endocardial edge definition was significantly better for RT than MN, blood to myocardial contrast was better for RT than MN without reaching statistical significance, and inter slice alignment was comparable. BA analysis indicates that the variability of volumetric indices between RT and MN is comparable to inter and intra-observer variability reported in the literature.
  
  
  CONCLUSIONS
  The free breathing RT-SSFP sequence allows diagnostic images in sedated children with significantly better edge definition when compared to MN-SSFP, without any penalty for total scan time.
authors.affiliation: EB Singleton Department of Pediatric Radiology, Texas Children's Hospital, Baylor College of Medicine, 6701 Fannin St, Suite 1280, Houston 77030, TX, USA. rxkrishn@texaschildrens.org.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Krishnamurthy
authors.forename: Amol
authors.initials: A
authors.lastname: Pednekar
authors.forename: Lamya A
authors.initials: LA
authors.lastname: Atweh
authors.forename: Esben
authors.initials: E
authors.lastname: Vogelius
authors.forename: Zili David
authors.initials: ZD
authors.lastname: Chu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Shiraz
authors.initials: S
authors.lastname: Maskatia
authors.forename: Prakash
authors.initials: P
authors.lastname: Masand
authors.forename: Shaine A
authors.initials: SA
authors.lastname: Morris
authors.forename: Ramkumar
authors.initials: R
authors.lastname: Krishnamurthy
authors.forename: Raja
authors.initials: R
authors.lastname: Muthupillai
mesh_terms: D002648:Child; D016292:Procedural Sedation; D006330:Heart Defects, Congenital / Q000473:pathology*; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D011446:Prospective Studies; D012119:Respiration