BACKGROUND AND PURPOSE: Ultrahigh-field 7T promises more than doubling the signal-to-noise ratio (SNR) of 3T for magnetic resonance imaging (MRI), particularly for MRI of magnetic susceptibility effects induced by B0 . Quantitative susceptibility mapping (QSM) is based on deconvolving the induced phase (or field) and would therefore benefit substantially from 7T. The purpose of this work was to compare QSM performance at 7T versus 3T in an intrascanner test-retest experiment with varying echo numbers (5 and 10 echoes). METHODS: A prospective study in N = 10 healthy subjects was carried out at both 3T and 7T field strengths. Gradient echo data using 5 and 10 echoes were acquired twice in each subject. Test-retest reproducibility was assessed using Bland-Altman and regression analysis of region of interest measurements. Image quality was scored by an experienced neuroradiologist. RESULTS: Intrascanner bias was below 3.6 parts-per-billion (ppb) with correlation R2 > .85. Interscanner bias was below 10.9 ppb with correlation R2 > .8. The image quality score for the 3T 10 echo protocol was not different from the 7T 5 echo protocol (P = .65). CONCLUSION: Excellent image quality and good reproducibility was observed. 7T allows equivalent image quality of 3T in half of the scan time.
BACKGROUND AND PURPOSE: Ultrahigh-field 7T promises more than doubling the signal-to-noise ratio (SNR) of 3T for magnetic resonance imaging (MRI), particularly for MRI of magnetic susceptibility effects induced by B0 . Quantitative susceptibility mapping (QSM) is based on deconvolving the induced phase (or field) and would therefore benefit substantially from 7T. The purpose of this work was to compare QSM performance at 7T versus 3T in an intrascanner test-retest experiment with varying echo numbers (5 and 10 echoes). METHODS: A prospective study in N = 10 healthy subjects was carried out at both 3T and 7T field strengths. Gradient echo data using 5 and 10 echoes were acquired twice in each subject. Test-retest reproducibility was assessed using Bland-Altman and regression analysis of region of interest measurements. Image quality was scored by an experienced neuroradiologist. RESULTS: Intrascanner bias was below 3.6 parts-per-billion (ppb) with correlation R2 > .85. Interscanner bias was below 10.9 ppb with correlation R2 > .8. The image quality score for the 3T 10 echo protocol was not different from the 7T 5 echo protocol (P = .65). CONCLUSION: Excellent image quality and good reproducibility was observed. 7T allows equivalent image quality of 3T in half of the scan time.
Authors: Christian Langkammer; Kristian Bredies; Benedikt A Poser; Markus Barth; Gernot Reishofer; Audrey Peiwen Fan; Berkin Bilgic; Franz Fazekas; Caterina Mainero; Stefan Ropele Journal: Neuroimage Date: 2015-02-27 Impact factor: 6.556
Authors: Tian Liu; Pascal Spincemaille; Ludovic de Rochefort; Richard Wong; Martin Prince; Yi Wang Journal: Magn Reson Imaging Date: 2010-08-04 Impact factor: 2.546
Authors: Xu Li; Deepti S Vikram; Issel Anne L Lim; Craig K Jones; Jonathan A D Farrell; Peter C M van Zijl Journal: Neuroimage Date: 2012-04-28 Impact factor: 6.556
Authors: Christian Langkammer; Ferdinand Schweser; Karin Shmueli; Christian Kames; Xu Li; Li Guo; Carlos Milovic; Jinsuh Kim; Hongjiang Wei; Kristian Bredies; Sagar Buch; Yihao Guo; Zhe Liu; Jakob Meineke; Alexander Rauscher; José P Marques; Berkin Bilgic Journal: Magn Reson Med Date: 2017-07-31 Impact factor: 4.668
Authors: El-Sayed H Ibrahim; V Emre Arpinar; L Tugan Muftuler; Jadranka Stojanovska; Andrew S Nencka; Kevin M Koch Journal: World J Radiol Date: 2020-10-28