1357495 - An exploration of Low-field MRI in Cardiac Imaging

Cardiac MRI is usually carried out on 1.5T and 3T systems due to the inherent advantage of signal to noise ratio benefits of higher field systems. However, there is increasing focus on lower field systems, such as the 0.55T Free.Max MRI system(Siemens Healthcare, Erlangen, Germany). This contemporary low field system features an 80cm wide bore with modern hardware and the latest imaging capabilities. It has regulatory approval (CE-marking) for most standard imaging, but not for cardiac imaging.  King’s College London Imaging Clinical Research Facility recently became the first in the UK to install one of these advanced low-field MRI systems for clinical and research use. We intend to explore the potential of the Free.Max MRI system for cardiac imaging applications and for improving access and quality of care for patient groups whose access to MRI has been sub-optimal.

Methods:

We are recruiting 20 healthy volunteers and 10 patients over the next 3 months.  Both healthy volunteers and patients will undergo a range of non-contrast cardiac MRI scans, including short and long axis views of the heart and great vessels, flow and views of the lung.  Patients will additionally receive contrast injection and undergo late gadolinium enhancement (LGE) scans using prototype sequences.  The selected patients will fulfil at least one of the following criteria: (a) patients who are claustrophobic and unable to tolerate scans on one of the 60 or 70 cm bore 1.5T and 3.0T MRI scanners, and thus may benefit from the wider bore of the Free.Max scanner, (b) patients with devices, e.g. MR conditional ICD devices, or other prosthetics, e.g. aortic valves and stents, for whom scans on higher field MRI systems are generally poor-quality, and for whom the 0.55T MRI system could overcome image distortion and produce better quality images, (c) patients previously hospitalised for COVID-19, in whom higher field MRI of lung and pulmonary vasculature imaging is difficult and for whom low-field MRI system may create better, clearer and more precise lung images, and (d) patients whose high BMI or body habitus precludes the use of 60 or 70cm bore higher field MRI scanners, and for whom the 80cm wide bore of the Free.Max system provides greater scanning opportunities and improved quality of care.

Results:

So far, anatomical cardiac images acquired on healthy volunteers show very promising results.  We are currently working on developing cardiac perfusion and LGE prototype sequences.  We anticipate that over the next 3 months we will be able to make progress and report back our findings for conference delegates.

Conclusion:

Based on our early experience we believe that a low field MRI systems such as our 0.55T Free.Max MRI system has the potential to generate clinically useful cardiac imaging in patient populations who are currently not well served by conventional systems.  We intend to exploit this potential to improve access to healthcare for wide range of patient groups and also enable greater research potential.