PURPOSE: To develop a framework for prospective free-induction decay (FID)-based navigator gating for suppression of motion artifacts in carotid magnetic resonance imaging (MRI) and to assess its capability in vivo. MATERIALS AND METHODS: An FID-navigator, comprising a spatially selective low flip-angle sinc-pulse followed by an analog-to-digital converter (ADC) readout, was added to a conventional turbo spin-echo (TSE) sequence. Real-time navigator processing delivered accept/reject-and-reacquire decisions to the sequence. In this Institutional Review Board (IRB)-approved study, seven volunteers were scanned with a 2D T2-weighted TSE sequence. A reference scan with volunteers instructed to minimize motion as well as nongated and gated scans with volunteers instructed to perform different motion tasks were performed in each subject. Multiple image quality measures were employed to quantify the effect of gating. RESULTS: There was no significant difference in lumen-to-wall sharpness (2.3 ± 0.3 vs. 2.3 ± 0.4), contrast-to-noise ratio (CNR) (9.0 ± 2.0 vs. 8.5 ± 2.0), or image quality score (3.1 ± 0.9 vs. 2.6 ± 1.2) between the reference and gated images. For images acquired during motion, all image quality measures were higher (P < 0.05) in the gated compared to nongated images (sharpness: 2.3 ± 0.4 vs. 1.8 ± 0.5, CNR: 8.5 ± 2.0 vs. 7.2 ± 2.0, score: 2.6 ± 1.2 vs. 1.8 ± 1.0). CONCLUSION: Artifacts caused by the employed motion tasks deteriorated image quality in the nongated scans. These artifacts were alleviated with the proposed FID-navigator.
PURPOSE: To develop a framework for prospective free-induction decay (FID)-based navigator gating for suppression of motion artifacts in carotid magnetic resonance imaging (MRI) and to assess its capability in vivo. MATERIALS AND METHODS: An FID-navigator, comprising a spatially selective low flip-angle sinc-pulse followed by an analog-to-digital converter (ADC) readout, was added to a conventional turbo spin-echo (TSE) sequence. Real-time navigator processing delivered accept/reject-and-reacquire decisions to the sequence. In this Institutional Review Board (IRB)-approved study, seven volunteers were scanned with a 2D T2-weighted TSE sequence. A reference scan with volunteers instructed to minimize motion as well as nongated and gated scans with volunteers instructed to perform different motion tasks were performed in each subject. Multiple image quality measures were employed to quantify the effect of gating. RESULTS: There was no significant difference in lumen-to-wall sharpness (2.3 ± 0.3 vs. 2.3 ± 0.4), contrast-to-noise ratio (CNR) (9.0 ± 2.0 vs. 8.5 ± 2.0), or image quality score (3.1 ± 0.9 vs. 2.6 ± 1.2) between the reference and gated images. For images acquired during motion, all image quality measures were higher (P < 0.05) in the gated compared to nongated images (sharpness: 2.3 ± 0.4 vs. 1.8 ± 0.5, CNR: 8.5 ± 2.0 vs. 7.2 ± 2.0, score: 2.6 ± 1.2 vs. 1.8 ± 1.0). CONCLUSION: Artifacts caused by the employed motion tasks deteriorated image quality in the nongated scans. These artifacts were alleviated with the proposed FID-navigator.
Authors: Dennis L Parker; K Craig Goodrich; Marilyn Masiker; Jay S Tsuruda; Gregory L Katzman Journal: Magn Reson Med Date: 2002-05 Impact factor: 4.668
Authors: Vitalii V Itskovich; Venkatesh Mani; Gabor Mizsei; Juan Gilberto S Aguinaldo; Daniel D Samber; Frank Macaluso; Paul Wisdom; Zahi A Fayad Journal: J Magn Reson Imaging Date: 2004-04 Impact factor: 4.813
Authors: Morteza Naghavi; Peter Libby; Erling Falk; S Ward Casscells; Silvio Litovsky; John Rumberger; Juan Jose Badimon; Christodoulos Stefanadis; Pedro Moreno; Gerard Pasterkamp; Zahi Fayad; Peter H Stone; Sergio Waxman; Paolo Raggi; Mohammad Madjid; Alireza Zarrabi; Allen Burke; Chun Yuan; Peter J Fitzgerald; David S Siscovick; Chris L de Korte; Masanori Aikawa; K E Juhani Airaksinen; Gerd Assmann; Christoph R Becker; James H Chesebro; Andrew Farb; Zorina S Galis; Chris Jackson; Ik-Kyung Jang; Wolfgang Koenig; Robert A Lodder; Keith March; Jasenka Demirovic; Mohamad Navab; Silvia G Priori; Mark D Rekhter; Raymond Bahr; Scott M Grundy; Roxana Mehran; Antonio Colombo; Eric Boerwinkle; Christie Ballantyne; William Insull; Robert S Schwartz; Robert Vogel; Patrick W Serruys; Goran K Hansson; David P Faxon; Sanjay Kaul; Helmut Drexler; Philip Greenland; James E Muller; Renu Virmani; Paul M Ridker; Douglas P Zipes; Prediman K Shah; James T Willerson Journal: Circulation Date: 2003-10-07 Impact factor: 29.690
Authors: David Rigie; Thomas Vahle; Tiejun Zhao; Björn Czekella; Lynn J Frohwein; Klaus Schäfers; Fernando E Boada Journal: Magn Reson Med Date: 2019-01-07 Impact factor: 4.668
Authors: Robert Frost; Luca Biasiolli; Linqing Li; Katherine Hurst; Mohammad Alkhalil; Robin P Choudhury; Matthew D Robson; Aaron T Hess; Peter Jezzard Journal: Magn Reson Med Date: 2019-11-07 Impact factor: 4.668