title: Temporal/spatial resolution improvement of in vivo DCE-MRI with compressed sensing-optimized FLASH.
abstract: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) provides critical information regarding tumor perfusion and permeability by injecting a T(1) contrast agent, such as Gd-DTPA, and making a time-resolved measurement of signal increase. Both temporal and spatial resolutions are required to be high to achieve an accurate and reproducible estimation of tumor perfusion. However, the dynamic nature of the DCE experiment limits simultaneous improvement of temporal and spatial resolution by conventional methods. Compressed sensing (CS) has become an important tool for the acceleration of imaging times in MRI, which is achieved by enabling the reconstruction of subsampled data. Similarly, CS algorithms can be utilized to improve the temporal/spatial resolution of DCE-MRI, and several works describing retrospective simulations have demonstrated the feasibility of such improvements. In this study, the fast low angle shot sequence was modified to implement a Cartesian, CS-optimized, sub-Nyquist phase encoding acquisition/reconstruction with multiple two-dimensional slice selections and was tested on water phantoms and animal tumor models. The mean voxel-level concordance correlation coefficient for Ak(ep) values obtained from ×4 and ×8 accelerated and the fully sampled data was 0.87±0.11 and 0.83±0.11, respectively (n=6), with optimized CS parameters. In this case, the reduction of phase encoding steps made possible by CS reconstruction improved effectively the temporal/spatial resolution of DCE-MRI data using an in vivo animal tumor model (n=6) and may be useful for the investigation of accelerated acquisitions in preclinical and clinical DCE-MRI trials.
authors.affiliation: School of Nano-Bioscience and Chemical Engineering, UNIST, Ulsan, Republic of Korea.
authors.forename: SoHyun
authors.initials: S
authors.lastname: Han
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Paulsen
authors.forename: Gang
authors.initials: G
authors.lastname: Zhu
authors.forename: Youngkyu
authors.initials: Y
authors.lastname: Song
authors.forename: SongI
authors.initials: S
authors.lastname: Chun
authors.forename: Gyunggoo
authors.initials: G
authors.lastname: Cho
authors.forename: Ellen
authors.initials: E
authors.lastname: Ackerstaff
authors.forename: Jason A
authors.initials: JA
authors.lastname: Koutcher
authors.forename: HyungJoon
authors.initials: H
authors.lastname: Cho
mesh_terms: D000818:Animals; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000175:diagnosis; D019047:Phantoms, Imaging
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA