Synopsis

Keywords: Cardiovascular: Cardiovascular, Cross-organ: Pediatric, Image acquisition: Artefacts

We will discuss mitigation of metallic artifact in cardiac and pediatric magnetic resonance imaging (MRI). We will develop a checklist for exam planning that considers patient, machine, and sequence factors. We will review examples of common instigators of metal artifact, including those outside the field of view like braces, tracheostomies, and gastrointestinal clips as well as those in the chest like ductus arteriosus clips, spinal fusion hardware, and coils of AVMs and aortopulmonary collaterals. Our discussion will include imaging with pacemakers. We will compare and contrast selection and optimization of conventional MRI sequences with metal artifact reduction sequences.

Syllabus

We will discuss mitigation of metallic artifact in cardiac and pediatric magnetic resonance imaging (MRI). We will develop a checklist for exam planning that considers patient, machine, and sequence factors [1]. Patient factors include: Support lines and tubes, such peripheral IV containing springs, tracheostomy devices Removable/temporary metal, such as braces or potentially bullet fragments Orthopedic hardware, including posterior spine fusion hardware, pectus bar, fracture fixation, joint replacement Cardiac-related, such as clips, coils, valve replacement, and pacemakers Gastrointestinal interventions, specifically hemostatic clips and nasogastric tubes MRI machine considerations include field strength and positioning of patient/metal within the scanner. Sequence factors include selection and optimization of conventional MRI sequences as well as metal artifact reduction sequences (MARS). Regarding traditional sequences, we will discuss pros and cons of widening the bandwidth, increasing image matrix size, reducing echo time, use of spin echo rather than gradient echo sequences, fat suppression techniques using STIR and DIXON [2]. We will contrast that with dedicated MARS which aim to reduce in- and through-plane distortions [3]. We will consider the cost of MARS and potential solutions. Lastly, we will review techniques to employ when scanning pacemaker cases, applying the knowledge gained during the session to a challenging cardiac MRI to perform.

Acknowledgements

No acknowledgement found.