Retrospective motion gating in cardiac MRI using a simultaneously acquired navigator. (20th December 2017)

• Record Type: Journal Article
• Authors: Kim, Byungjai; Seo, Hyunseok; Kim, Dongchan; Park, HyunWook
• Is Part Of: NMR in biomedicine. Volume 31:Number 3(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-12-20
• Subjects: cardiac magnetic resonance imaging (CMRI) -- cine -- free breathing -- gating; Nuclear magnetic resonance -- Periodicals; Magnetic Resonance Spectroscopy -- Periodicals; 574
• DOI: 10.1002/nbm.3874
• Languages: English
• ISSNs: 0952-3480

Abstract

Abstract : A simultaneous acquisition technique of image and navigator signals (simultaneously acquired navigator, SIMNAV) is proposed for cardiac magnetic resonance imaging (CMRI) in Cartesian coordinates. To simultaneously acquire both image and navigator signals, a conventional balanced steady‐state free precession (bSSFP) pulse sequence is modified by adding a radiofrequency (RF) pulse, which excites a supplementary slice for the navigator signal. Alternating phases of the RF pulses make it easy to separate the simultaneously acquired magnetic resonance data into image and navigator signals. The navigator signals of the proposed SIMNAV were compared with those of current gating devices and self‐gating techniques for seven healthy subjects. In vivo experiments demonstrated that SIMNAV could provide cardiac cine images with sufficient image quality, similar to those from electrocardiogram (ECG) gating with breath‐hold. SIMNAV can be used to acquire a cardiac cine image without requiring an ECG device and breath‐hold, whilst maintaining feasible imaging time efficiency. Abstract : The proposed method overcomes the disadvantages of conventional navigator techniques by simultaneously acquiring an image signal and a navigator signal, and then separating the signals by post‐processing. The proposed method enables the acquisition of a navigator signal for motion gating, whilst maintaining the steady state without any additional acquisition step, whereas previous navigator techniques prolong the imaging time and distort the steady‐state condition.