title: Performance of simultaneous high temporal resolution quantitative perfusion imaging of bladder tumors and conventional multi-phase urography using a novel free-breathing continuously acquired radial compressed-sensing MRI sequence.
abstract: To investigate the feasibility of high temporal resolution quantitative perfusion imaging of bladder tumors performed simultaneously with conventional multi-phase MR urography (MRU) using a novel free-breathing continuously acquired radial MRI sequence with compressed-sensing reconstruction.
  
  
  
  22 patients with bladder lesions underwent MRU using GRASP (Golden-angle RAdial Sparse Parallel) acquisition. Multi-phase contrast-enhanced abdominopelvic GRASP was performed during free-breathing (1.4×1.4×3.0mm(3) voxel size; 3:44min acquisition). Two dynamic datasets were retrospectively reconstructed by combining different numbers of sequentially acquired spokes into each dynamic frame: 110 spokes per frame for 25-s temporal resolution (serving as conventional MRU for clinical interpretation) and 8 spokes per frame for 1.7-s resolution. Using 1.7-s resolution images, ROIs were placed within bladder lesions and normal bladder wall, a femoral artery arterial input function was generated, and the Generalized Kinetic Model was applied.
  
  
  
  Biopsy/cystectomy demonstrated 16 bladder tumors (13 stage≥T2, 3 stage≤T1) and 6 benign lesions. All lesions were well visualized using 25-s clinical multi-phase images. Using 1.7-s resolution images, K(trans) was significantly higher in tumors (0.38±0.24) than normal bladder (0.12±0.02=8, p<0.001) or benign lesions (0.15±0.04, p=0.033). Ratio between K(trans) of lesions and normal bladder was nearly double for tumors than benign lesions (4.3±3.4 vs. 2.2±1.6), and K(trans) was nearly double in stage≥T2 than stage≤T1 tumors (0.44±0.24 vs. 0.24±0.24), although these did not approach significance (p=0.180-0.209), possibly related to small sample size.
  
  
  
  GRASP allows simultaneous quantitative high temporal resolution perfusion of bladder lesions during clinical MRU examinations using only one contrast injection and without additional scan time.
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016. Electronic address: nainesh.parikh@nyumc.org.
authors.forename: Nainesh
authors.initials: N
authors.lastname: Parikh
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016. Electronic address: Justin.Ream@nyumc.org.
authors.forename: Justin M
authors.initials: JM
authors.lastname: Ream
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016. Electronic address: HoiCheung.Zhang@nyumc.org.
authors.forename: Hoi Cheung
authors.initials: HC
authors.lastname: Zhang
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016. Electronic address: KaiTobias.Block@nyumc.org.
authors.forename: Kai Tobias
authors.initials: KT
authors.lastname: Block
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016. Electronic address: Hersh.Chandarana@nyumc.org.
authors.forename: Hersh
authors.initials: H
authors.lastname: Chandarana
authors.affiliation: Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016. Electronic address: Andrew.Rosenkrantz@nyumc.org.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Rosenkrantz
mesh_terms: D000368:Aged; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055420:Perfusion Imaging; D015203:Reproducibility of Results; D012119:Respiration; D012189:Retrospective Studies; D001743:Urinary Bladder / Q000000981:diagnostic imaging; D001749:Urinary Bladder Neoplasms / Q000000981:diagnostic imaging*; D014567:Urography / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: Bladder cancer; MR urography; MRI techniques; Novel techniques