cad a22 4500 551414464 20200123034616.0 cr unu---uuuuu 181214e20190301xx s 000 0 eng 10.5167/uzh-159306 doi 10.1097/RLI.0000000000000523 doi (ZORA)oai:www.zora.uzh.ch:159306 610 ddc 30418261 pmid Clinical Magnetic Resonance Imaging of the Knee at 7 T: Optimization of Fat Suppression [Elektronische Daten] [Michael Wyss, Andrei Manoliu, Magda Marcon, Georg Spinner, Roger Luechinger, Klaas P Pruessmann, Gustav Andreisek] openAccess eu-repo PURPOSE The aim of this study was to evaluate the efficiency and performance of different fat suppression techniques for clinical 7 T knee magnetic resonance imaging including the slice-selective gradient reversal (SSGR) technique. MATERIALS AND METHODS This article is an ethical board-approved prospective study with written informed consent from 8 volunteers (mean, 31 ± 4 years). It included fat phantom and knee magnetic resonance imaging at 3 T (Magnetom Skyra; Siemens Healthcare) and at 7 T (Achieva, Philips Healthcare). At 3 T, an axial proton density-weighted turbo spin echo sequence with spectral adiabatic inversion recovery (SPAIR) was acquired. At 7 T, a series of 5 proton density-weighted turbo spin echo sequences was acquired: (a) without fat suppression, (b) with spectral presaturation with inversion recovery (SPIR), (c) with SPAIR, (d) with SSGR, and (e) with the combination of SSGR + SPIR. Additional noise scans allowed pixelwise calculation of signal-to-noise ratio and contrast-to-noise ratio maps. Quantitative data at 7 T were compared with each other but not to 3 T. Two independent radiologists evaluated overall image quality, homogeneity and grade of fat suppression, and the delineation between 2 adjacent structures. Results were compared using Wilcoxon signed rank and paired sample t tests. RESULTS Relative signal-to-noise ratios of fat demonstrated that the SPIR technique reduced the fat signal to 45% ± 5.4%; SPAIR, 18% ± 1.2%; SSGR, 14% ± 1.1%; and SSGR + SPIR, 11% ± 0.3%. Contrast-to-noise ratio showed superior contrast between muscle-fat (P < 0.001) and fluid-fat (P ≤ 0.001) for SSGR and SSGR + SPIR. The radiologists rated the overall image quality higher at 7 T than 3 T. The homogeneity and grade of fat suppression as well as the delineation between 2 different (adjacent) structures were rated best for SSGR + SPIR. CONCLUSIONS At 7 T, fat saturation for clinical knee imaging using SSGR and the combination of SSGR + SPIR was superior compared with standard methods based on spectrally selective radiofrequency pulses. Clinic for Diagnostic and Interventional Radiology zora Institute of Biomedical Engineering zora Wyss Michael joint author Manoliu Andrei joint author Marcon Magda joint author Spinner Georg joint author Luechinger Roger joint author Pruessmann Klaas P. joint author Andreisek Gustav joint author Investigative Radiology 54(3):160-168 https://www.zora.uzh.ch/id/eprint/159306/1/00004424-900000000-98958.pdf text/html WWW-Backlink auf das Repository 1 Journal Article PeerReviewed zora ZORA 856 40 https://www.zora.uzh.ch/id/eprint/159306/1/00004424-900000000-98958.pdf text/html WWW-Backlink auf das Repository ZORA 700 1- Wyss Michael joint author ZORA 700 1- Manoliu Andrei joint author ZORA 700 1- Marcon Magda joint author ZORA 700 1- Spinner Georg joint author ZORA 700 1- Luechinger Roger joint author ZORA 700 1- Pruessmann Klaas P. joint author ZORA 700 1- Andreisek Gustav joint author ZORA 773 0- Investigative Radiology 54(3):160-168 BK010053 XK010053 XK010000 ZORA ZORA ZORA Journal Article openAccess