title: Multiband RF pulses with improved performance via convex optimization.
abstract: Selective RF pulses are commonly designed with the desired profile as a low pass filter frequency response. However, for many MRI and NMR applications, the spectrum is sparse with signals existing at a few discrete resonant frequencies. By specifying a multiband profile and releasing the constraint on "don't-care" regions, the RF pulse performance can be improved to enable a shorter duration, sharper transition, or lower peak B1 amplitude. In this project, a framework for designing multiband RF pulses with improved performance was developed based on the Shinnar-Le Roux (SLR) algorithm and convex optimization. It can create several types of RF pulses with multiband magnitude profiles, arbitrary phase profiles and generalized flip angles. The advantage of this framework with a convex optimization approach is the flexible trade-off of different pulse characteristics. Designs for specialized selective RF pulses for balanced SSFP hyperpolarized (HP) (13)C MRI, a dualband saturation RF pulse for (1)H MR spectroscopy, and a pre-saturation pulse for HP (13)C study were developed and tested.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA. Electronic address: shanghong@berkeley.edu.
authors.forename: Hong
authors.initials: H
authors.lastname: Shang
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
authors.forename: Peder E Z
authors.initials: PEZ
authors.lastname: Larson
authors.affiliation: Electrical Engineering, Stanford University, Stanford, CA, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Kerr
authors.affiliation: HeartVista, Menlo Park, CA, USA.
authors.forename: Galen
authors.initials: G
authors.lastname: Reed
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Subramaniam
authors.initials: S
authors.lastname: Sukumar
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Elkhaled
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Jeremy W
authors.initials: JW
authors.lastname: Gordon
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Ohliger
authors.affiliation: Electrical Engineering, Stanford University, Stanford, CA, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Pauly
authors.affiliation: Electrical Engineering and Computer Science, University of California, Berkeley, CA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Lustig
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Vigneron
mesh_terms: D000465:Algorithms; D001921:Brain; D002138:Calibration; D002247:Carbon Isotopes; D006801:Humans; D007773:Lactates / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D019047:Phantoms, Imaging; D011522:Protons; D011773:Pyruvates / Q000737:chemistry; D011846:Radio Waves; D014508:Urea / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D007773:Lactates; D011522:Protons; D011773:Pyruvates; D014508:Urea
keywords: Convex optimization; Generalized flip angle; Improved pulse performance; Multiband; RF pulse design; Shinnar–Le Roux algorithm