title: Quantitative T(1)(ρ) imaging using phase cycling for B0 and B1 field inhomogeneity compensation.
abstract: T(1)(ρ) imaging is useful in a number of clinical applications. T(1)(ρ) preparation methods, however, are sensitive to non-uniformities of the B0 magnetic field and the B1 RF field. These common system imperfections can result in image artifacts and quantification errors in T(1)(ρ) imaging. We report on a phase-cycling method which can eliminate B1 RF inhomogeneity effects in T(1)(ρ) imaging. This method does not only correct for image artifacts but also for T(2)(ρ) contamination caused by B1 RF inhomogeneity. The presence of B0 magnetic field inhomogeneity can compromise the effectiveness of this method for B1 RF inhomogeneity correction. We demonstrate that, by combining the spin-locking scheme reported by Dixon et al. (Myocardial suppression in vivo by spin locking with composite pulses. Magn Reson Med 1996; 36:90-94) with phase cycling, we can simultaneously correct B0 magnetic field inhomogeneity effects and B1 RF inhomogeneity effects in T(1)(ρ) imaging. Phantom and in vivo data sets are used to demonstrate the proposed methods and to compare them with other existing T(1)(ρ) preparation methods.
authors.affiliation: Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA 94025, USA. Weitian.Chen@ge.com
authors.forename: Weitian
authors.initials: W
authors.lastname: Chen
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takahashi
authors.forename: Eric
authors.initials: E
authors.lastname: Han
mesh_terms: D016477:Artifacts; D002356:Cartilage / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007717:Knee / Q000033:anatomy & histology / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008280:Magnetics; D015233:Models, Statistical; D019047:Phantoms, Imaging