Correcting slice selectivity in hard pulse sequences

• Published in: Journal of magnetic resonance (1997) Vol. 214; no. 1; pp. 61 - 67
• Main Authors: Grodzki, David M., Jakob, Peter M., Heismann, Bjoern
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 2012
• Subjects: Algorithms; Biomedical materials; Brain - anatomy & histology; Excitation; Humans; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Image quality; Imaging; In vivo testing; In vivo tests; Magnetic Resonance Imaging - instrumentation; Magnetic Resonance Imaging - methods; Non-selective excitation; Phantoms, Imaging; Reproducibility of Results; Sensitivity and Specificity; Signal Processing, Computer-Assisted; Slice-selective excitation; Surgical implants; Ultrashort echo time; Non-selective excitation; Slice-selective excitation; Ultrashort echo time
• ISSN: 1090-7807; 1096-0856
• DOI: 10.1016/j.jmr.2011.10.005

[Display omitted] ► Investigate the influence of hard pulse excitation in the presence of gradients. ► Demonstrate artefacts by simulation and measurements. ► Derive a correction algorithm to eliminate artefacts. ► Enhanced image quality proves functionality. ► Limitations are found if the first minimum of excitation profile lies within the imaged object. Many MRI sequences use non-selective hard pulse excitation in the presence of imaging gradients. In this work, we investigate to which extent the sinc-shaped frequency excitation profiles of the pulse can be used for imaging without the generation of artefacts. A correction algorithm is proposed that eliminates the influence of the excitation profile. Phantom as well as in vivo measurements prove that enhanced image quality can be obtained as long as the first minimum of the excitation profile lies outside the imaged object.