title: Recent advances in 3D time-resolved contrast-enhanced MR angiography.
abstract: Contrast-enhanced magnetic resonance angiography (CE-MRA) was first introduced for clinical studies approximately 20 years ago. Early work provided 3-4 mm spatial resolution with acquisition times in the 30-second range. Since that time there has been continuing effort to provide improved spatial resolution with reduced acquisition time, allowing high resolution 3D time-resolved studies. The purpose of this work is to describe how this has been accomplished. Specific technical enablers have been: improved gradients allowing reduced repetition times, improved k-space sampling and reconstruction methods, parallel acquisition, particularly in two directions, and improved and higher count receiver coil arrays. These have collectively made high-resolution time-resolved studies readily available for many anatomic regions. Depending on the application, ∼1 mm isotropic resolution is now possible with frame times of several seconds. Clinical applications of time-resolved CE-MRA are briefly reviewed.
authors.affiliation: Mayo Clinic, MR Laboratory, Rochester, Minnesota, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Riederer
authors.affiliation: Mayo Clinic, SPPDG, Rochester, Minnesota, USA.
authors.forename: Clifton R
authors.initials: CR
authors.lastname: Haider
authors.affiliation: Mayo Clinic, MR Laboratory, Rochester, Minnesota, USA.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Borisch
authors.affiliation: Mayo Clinic, MR Laboratory, Rochester, Minnesota, USA.
authors.forename: Paul T
authors.initials: PT
authors.lastname: Weavers
authors.affiliation: Mayo Clinic, Radiology, Rochester, Minnesota, USA.
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Young
mesh_terms: D000465:Algorithms; D000818:Animals; D003287:Contrast Media; D044962:Data Compression / Q000379:methods*; 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*; D010363:Pattern Recognition, Automated / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: D003287:Contrast Media
keywords: MRA; contrast-enhanced MRA; fast imaging; parallel imaging; time-resolved studies