Inter-field Strength Agreement of CMR Derived Strain

Inter-field Strength Agreement of Myocardial Strain Measurements Using Cardiovascular Magnetic Resonance Imaging

• Magnetic Resonance Imaging (MRI) scanners create a strong magnetic field around the body to produce a detailed picture of parts of the body. This can provide a lot of useful information about how the heart looks and works.
• Different strengths of magnets can be used in an MRI scanner and this can affect the pictures that are produced. To scan the heart, two different magnet field strengths (1.5 tesla (T) and 3T) are mainly used.
• It is currently unclear if when the heart is scanned using these different field strengths, if the measurements that tell us how well the heart squeezes and relaxes (known as 'myocardial strain') will be the same between them.
• This study is investigating if myocardial strain measurements using 1.5T and 3T MRI scanners are different or if they can be used interchangeably.
• Twenty healthy people without heart disease will be recruited to have two MRI scans on the same day. The order that they have their scan (either on a 1.5T MRI scanner first or a 3T MRI scanner first) will be decided randomly.
• All images will then be analysed using specialist software to provide measurements of myocardial strain. These measured can then assessed to see if there is agreement between the myocardial strain results at the two MRI field strengths.

• This is a single-centre, randomised, cross-sectional, cross-over observational study.
• Twenty healthy volunteers, aged 18 years and over will be recruited and will undergo cardiovascular magnetic resonance scans for long axis and short axis cine imaging at 1.5T and 3T.
• Participation will involve one single visit where participants will be consented, randomised and then undergo scanning at both field strengths; the order of scanning at 1.5T and 3T will be randomised. There will be no follow up period.
• All subjects will undergo balanced steady-state free precession (bSSFP) cine imaging at 3T and 1.5T. Tagging images will also be acquired at both field strengths. Participants will also be randomized to either have cine or tagging images obtained first on each scan.
• All scans at both field strengths will be anonymised and analysed offline by a single experienced observer to determine inter-field strength agreement of left ventricular systolic and diastolic strain measurements.
• Further imaging analysis will take place for secondary outcomes, including analysis using other software vendors, tagging images and aortic cine images.

Inclusion Criteria:

• Participant is willing and able to give informed consent for participation in the study.
• Understands written and verbal English sufficiently to be able to consent and participate in study
• Male or Female, aged 18 years or above.
• No history of cardiovascular, respiratory, metabolic (including diabetes) or renal disease.

Exclusion Criteria:

• Prior cardiovascular, respiratory, metabolic (including diabetes) or renal disease.
• Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the study, or may influence the result of the study, or the participant's ability to participate in the study.
• Any contra-indication to magnetic resonance imaging (MRI), including the presence of an implanted metal device or suspected metal foreign bodies.
• Pregnant women