title: Short tau inversion recovery and proton density-weighted fat suppressed sequences for the evaluation of osteoarthritis of the knee with a 1.0 T dedicated extremity MRI: development of a time-efficient sequence protocol.
abstract: Aim of this study was to develop a time-efficient sequence protocol for a 1.0 T dedicated MR system to be used for whole-organ scoring of osteoarthritis (OA). Thirty-four knees were examined using a protocol that included fat suppressed fast spin echo proton density weighted sequences (PDFS) in three planes plus a coronal STIR sequence. Two radiologists scored each knee by consensus for five OA features. In separate sessions, all knees were scored using three different combinations of sequences: (1) all four sequences (reference protocol, 16 min 31 s scanning time), (2) three PDFS sequences without STIR ("No STIR", 12 min 25 s scanning time) and (3) sagittal and axial PDFS sequences plus a coronal STIR sequence ("No PDFS", 11 min 49 s scanning time). Agreement of the readings using both subsets of sequences compared to the reference protocol was evaluated using weighted kappa statistics. kappa-coefficients showed good or excellent agreement for both sequence subsets in comparison to the reference protocol for all assessed features. kappa-coefficients for No PDFS/No STIR: bone marrow abnormalities (0.74/0.67), subarticular cysts (0.84/0.63), marginal osteophytes (0.77/0.71), menisci (0.75/0.79), tibial cartilage (0.71/0.78). Optimization of sequence protocols consisting of three sequences results in time savings and cost efficiency in imaging of knee OA without loss of information over a more time consuming protocol.
authors.affiliation: Osteoporosis and Arthritis Research Group, Department of Radiology, University of California, San Francisco, USA. f.w.roemer@gmx.de
authors.forename: Frank W
authors.initials: FW
authors.lastname: Roemer
authors.forename: Ali
authors.initials: A
authors.lastname: Guermazi
authors.forename: John A
authors.initials: JA
authors.lastname: Lynch
authors.forename: Charles G
authors.initials: CG
authors.lastname: Peterfy
authors.forename: Michael C
authors.initials: MC
authors.lastname: Nevitt
authors.forename: Nita
authors.initials: N
authors.lastname: Webb
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Andreas
authors.initials: A
authors.lastname: Mohr
authors.forename: Harry K
authors.initials: HK
authors.lastname: Genant
authors.forename: David T
authors.initials: DT
authors.lastname: Felson
mesh_terms: D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D020370:Osteoarthritis, Knee / Q000473:pathology*; D013997:Time Factors