title: Relaxation enhanced compressed sensing three-dimensional black-blood vessel wall MR imaging: Preliminary studies.
abstract: OBJECTIVE
  In this study, we sought to investigate the feasibility of a new technique termed relaxation enhanced compressed sensing three-dimensional motion-sensitizing driven equilibrium prepared 3D rapid gradient echo sequence (RECS-3D MERGE).
  
  
  METHODS
  The RECS-3D MERGE sequence consisted of a 3D MERGE sequence for imaging, a period of delay time (TD) for relaxation enhancement, and a pseudo-centric phase encoding order used for under-sampling acquisition to maintain scan efficiency. Seven healthy volunteers and six patients with 40% to 75% carotid artery stenosis were recruited in this study. Healthy subjects underwent 3D MERGE, RECS-3D MERGE and two-dimensional (2D) T1-weighted double inversion recovery fast spin echo (T1W DIR-FSE) scans. The signal ratio (SR) values of 21 RECS-3D MERGE scans were compared in order to determine the optimal scan parameter set of acceleration factor (AF) and delay time (TD) for RECS-3D MERGE sequence. Patients then underwent 3D MERGE, RECS-3D MERGE using the aforementioned optimal scan parameter set and 2D T1W DIR-FSE scans. Two radiologists, blinded to the imaging technique, qualitatively graded each image on a six-point ordinal scale.
  
  
  RESULTS
  The highest value of SR occurred with the scan parameter set of 3-fold AF and 800ms TD. Compared to 3D MERGE, RECS-3D MERGE with the parameter set significantly improved the image quality for both healthy subjects and patients experiments, while the scan efficiency was not sacrificed. And no significant differences were observed in the subjective scores of RECS-3D MERGE and 2D T1W DIR-FSE image qualities.
  
  
  CONCLUSIONS
  RECS-3D MERGE technique achieved significant improvement in black-blood image quality compared with 3D MERGE. And the image quality of this 3D rapid carotid black-blood imaging technique is comparable to 2D T1W DIR-FSE while it has much higher scan efficiency.
authors: College of Engineering, Peking University, 100871, Beijing, P.R. China.
authors: Bo
authors: B
authors: Li
authors: Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, P.R. China.
authors: Hao
authors: H
authors: Li
authors: Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029, Beijing, P.R. China.
authors: Jun
authors: J
authors: Li
authors: Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, 100029, Beijing, P.R. China.
authors: Yuchen
authors: Y
authors: Zhang
authors: Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, P.R. China; Department of Radiology, Peking University First Hospital, 100051, Beijing, P.R. China.
authors: Xiaoying
authors: X
authors: Wang
authors: College of Engineering, Peking University, 100871, Beijing, P.R. China; Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, P.R. China. Electronic address: zhangjue@pku.edu.cn.
authors: Jue
authors: J
authors: Zhang
authors: Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029, Beijing, P.R. China. Electronic address: lidonglxh@163.com.
authors: Li
authors: L
authors: Dong
authors: College of Engineering, Peking University, 100871, Beijing, P.R. China; Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, P.R. China.
authors: Jing
authors: J
authors: Fang
mesh_terms: D000328:Adult; D000465:Algorithms; D016893:Carotid Stenosis / Q000473:pathology*; D044962:Data Compression / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: Compressed sensing; Pseudo-centric phase encoding order; RECS-3D MERGE; Three dimensional black-blood imaging; Vessel wall imaging