1
|
Abdurakman E, Bencsik M, Cave GWV, Hoad CL, McGowan S, Fairhurst DJ, Major G, Gowland PA, Bowtell R. Design and testing of microbubble-based MRI contrast agents for gastric pressure measurement. Magn Reson Med 2019; 83:1096-1108. [PMID: 31524306 PMCID: PMC6899603 DOI: 10.1002/mrm.27992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/19/2019] [Accepted: 08/19/2019] [Indexed: 11/06/2022]
Abstract
PURPOSE This work demonstrates specifically tailored microbubble-based preparations and their suitability as MRI contrast agents for ingestion and measuring temporal and spatial pressure variation in the human stomach. METHODS Enhanced alginate spheres were prepared by incorporating gas-filled microbubbles into sodium alginate solution followed by the polymerization of the mixture in an aqueous calcium lactate solution. The microbubbles were prepared with a phospholipid shell and perfluorocarbon gas filling, using a mechanical cavitational agitation regime. The NMR signal changes to externally applied pressure and coming from the enhanced alginate spheres were acquired and compared with that of alginate spheres without microbubbles. In vivo investigations were also carried out on healthy volunteers to measure the pressure variation in the stomach. RESULTS The MR signal changes in the contrast agent exhibits a linear sensitivity of approximately 40% per bar, as opposed to no measurable signal change seen in the control gas-free spheres. This novel contrast agent also demonstrates an excellent stability in simulated gastric conditions, including at body temperature. In vivo studies showed that the signal change exhibited in the meal within the antrum region is between 5% and 10%, but appears to come from both pressure changes and partial volume artifacts. CONCLUSION This study demonstrates that alginate spheres with microbubbles can be used as an MRI contrast agent to measure pressure changes. The peristaltic movement within the stomach is seen to substantially alter the overall signal intensity of the contrast agent meal. Future work must focus on improving the contrast agent's sensitivity to pressure changes.
Collapse
Affiliation(s)
- Edwin Abdurakman
- Department of Physics & Mathematics, School of Science & Technology, Nottingham Trent University, Nottingham, United Kingdom.,Division of Radiography & Midwifery, School of Health Sciences, City, University of London, United Kingdom
| | - Martin Bencsik
- Department of Physics & Mathematics, School of Science & Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Gareth W V Cave
- Department of Chemistry & Forensic, School of Science & Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Caroline L Hoad
- Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, Nottingham, United Kingdom.,National Institute for Health Research (NIHR) Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom
| | - Scott McGowan
- Department of Physics & Mathematics, School of Science & Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - David J Fairhurst
- Department of Physics & Mathematics, School of Science & Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Giles Major
- National Institute for Health Research (NIHR) Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom.,Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Penny A Gowland
- Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, Nottingham, United Kingdom
| | - Richard Bowtell
- Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, Nottingham, United Kingdom
| |
Collapse
|