title: Compressed sensing reconstruction for undersampled breath-hold radial cine imaging with auxiliary free-breathing data.
abstract: OBJECTIVE
  To improve compressed sensing (CS) reconstruction of accelerated breath-hold (BH) radial cine magnetic resonance imaging (MRI) by exploiting auxiliary data acquired between different BHs.
  
  
  METHODS
  Cardiac function is usually assessed using segmented cine acquisitions over multiple BHs to cover the entire left ventricle (LV). Subjects are given a resting period between adjacent BHs, when conventionally no data are acquired and subjects rest in the scanner. In this study the resting periods between BHs were used to acquire additional free-breathing (FB) data, which are subsequently used to generate a sparsity constraint for each cardiac phase. Images reconstructed using the proposed sparsity constraint were compared with conventional CS using a composite image generated by averaging different cardiac phases. The efficacy of the proposed reconstruction was compared using indices of LV function and blood-myocardium sharpness.
  
  
  RESULTS
  The proposed method provided accurate LV ejection fraction measurements for 33% and 20% sampled datasets compared with fully sampled reference images, and showed 14% and 11% higher blood-myocardium border sharpness scores compared to the conventional CS.
  
  
  CONCLUSIONS
  The FB data acquired during resting periods can be efficiently used to improve the image quality of the undersampled BH data without increasing the total scan time.
authors.affiliation: Department of Medicine (Cardiovascular Division), Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA; School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA.
authors.forename: Seunghoon
authors.initials: S
authors.lastname: Nam
authors.forename: Susie N
authors.initials: SN
authors.lastname: Hong
authors.forename: Mehmet
authors.initials: M
authors.lastname: Akçakaya
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Kwak
authors.forename: Beth
authors.initials: B
authors.lastname: Goddu
authors.forename: Kraig V
authors.initials: KV
authors.lastname: Kissinger
authors.forename: Warren J
authors.initials: WJ
authors.lastname: Manning
authors.forename: Vahid
authors.initials: V
authors.lastname: Tarokh
authors.forename: Reza
authors.initials: R
authors.lastname: Nezafat
mesh_terms: D000465:Algorithms; D062485:Breath Holding; D003326:Coronary Circulation; D004562:Electrocardiography / Q000379:methods; D064368:Healthy Volunteers; D006321:Heart / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D019028:Magnetic Resonance Imaging, Cine; D009206:Myocardium / Q000473:pathology*; D012119:Respiration; D016277:Ventricular Function, Left
keywords: accelerated acquisition; breath-hold acquisition; cardiac MR; cine imaging; compressed sensing; radial acquisition