title: Breath-hold T2-weighted sequences of the liver: a comparison of four techniques at 1.0 and 1.5 T.
abstract: T2-weighted images are considered the most sensitive for lesion detection at high field; however, long imaging time is problematic. Accordingly, the authors compared four breath-hold T2 or T2* weighted sequences comprising T2*-weighted FLASH, T2*-weighted PSIF, T2-weighted rapid spin echo (RASE), and T2-weighted Turbo-FLASH (Turbo) in 20 different healthy volunteers, 10 at 1.0 T and 10 at 1.5 T with reference to regular T2-weighted spin echo. Images were evaluated quantitatively by liver signal to noise (S/N) and spleen-liver signal difference to noise (SD/N) ratios and qualitatively for presence of artifacts and image quality. Data were evaluated for 1.0 T and 1.5 T separately and combined. In the combined evaluation, T2*-FLASH had good S/N (23.1 + 5.1) but low SD/N (2.9 + 1.7) and suffered from susceptibility artifacts. T2* PSIF had good S/N (28.1 + 10.0) and moderate SD/N (6.0 + 2.4), but occasionally had heterogeneous signal intensity. Flow signal void was an attractive feature. T2 RASE had very low S/N (4.4 + 1.9) and low SD/N (2.3 + 1.1) and suffered from flow artifacts. T2-Turbo had good S/N (24.6 + 8.6) and SD/N (8.9 + 2.5). Flow signal void was present, but small matrix size decreased image quality. The results of our study suggest that T2*-PSIF and T2-Turbo have good S/N and SD/N and fair image quality which may be clinically useful for breath-hold T2-weighted sequences of the liver.
authors.affiliation: Siemens AG, Medical Engineering Group, Erlangen, Germany.
authors.forename: F C
authors.initials: FC
authors.lastname: Simm
authors.forename: R C
authors.initials: RC
authors.lastname: Semelka
authors.forename: M
authors.initials: M
authors.lastname: Recht
authors.forename: M
authors.initials: M
authors.lastname: Deimling
authors.forename: G
authors.initials: G
authors.lastname: Lenz
authors.forename: G A
authors.initials: GA
authors.lastname: Laub
mesh_terms: D000328:Adult; D016477:Artifacts; D005069:Evaluation Studies as Topic; D006801:Humans; D008099:Liver / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D012119:Respiration; D013997:Time Factors