title: Assessment of diffusion tensor image quality across sites and vendors using the American College of Radiology head phantom.
abstract: The purpose of this study was to explore the feasibility of assessing quality of diffusion tensor imaging (DTI) from multiple sites and vendors using American College of Radiology (ACR) phantom. Participating sites (Siemens (n = 2), GE (n= 2), and Philips (n = 4)) reached consensus on parameters for DTI and used the widely available ACR phantom. Tensor data were processed at one site. B0 and eddy current distortions were assessed using grid line displacement on phantom Slice 5; signal-to-noise ratio (SNR) was measured at the center and periphery of the b = 0 image; fractional anisotropy (FA) and mean diffusivity (MD) were assessed using phantom Slice 7. Variations of acquisition parameters and deviations from specified sequence parameters were recorded. Nonlinear grid line distortion was higher with linear shimming and could be corrected using the 2nd order shimming. Following image registration, eddy current distortion was consistently smaller than acquisi-tion voxel size. SNR was consistently higher in the image periphery than center by a factor of 1.3-2.0. ROI-based FA ranged from 0.007 to 0.024. ROI-based MD ranged from 1.90 × 10-3 to 2.33 × 10-3 mm2/s (median = 2.04 × 10-3 mm2/s). Two sites had image void artifacts. The ACR phantom can be used to compare key qual-ity measures of diffusion images acquired from multiple vendors at multiple sites.
authors.affiliation: Children's Medical Center Dallas; University of Texas Southwestern Medical Center Dallas. jerry.wang@childrens.com.
authors.forename: Zhiyue J
authors.initials: ZJ
authors.lastname: Wang
authors.forename: Youngseob
authors.initials: Y
authors.lastname: Seo
authors.forename: Evelyn
authors.initials: E
authors.lastname: Babcock
authors.forename: Hao
authors.initials: H
authors.lastname: Huang
authors.forename: Stefan
authors.initials: S
authors.lastname: Bluml
authors.forename: Jessica
authors.initials: J
authors.lastname: Wisnowski
authors.forename: Barbara
authors.initials: B
authors.lastname: Holshouser
authors.forename: Ashok
authors.initials: A
authors.lastname: Panigrahy
authors.forename: Dennis W W
authors.initials: DW
authors.lastname: Shaw
authors.forename: Nolan
authors.initials: N
authors.lastname: Altman
authors.forename: Roderick W
authors.initials: RW
authors.lastname: McColl
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Rollins
mesh_terms: D003284:Contract Services / Q000592:standards*; D056324:Diffusion Tensor Imaging / Q000295:instrumentation* / Q000592:standards*; D006257:Head / Q000033:anatomy & histology*; D006801:Humans; D019047:Phantoms, Imaging / Q000592:standards*; D011785:Quality Assurance, Health Care / Q000379:methods* / Q000592:standards*; D059629:Signal-To-Noise Ratio