Baby MRI Incubator for Leeds Children’s Hospital

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Background to the project

In adults with CHD, cardiac magnetic resonance imagining (MRI) is the standard approach to assessing the condition as it provides the most accurate picture of the heart. However, these scans require the patient to lie still and hold their breath, meaning babies and small children must undergo general anaesthetic to be scanned, Furthermore, this excludes some babies with certain complex heart conditions, as general anaesthesia increases their risk of cardiac arrest. Other scanning methods such as cardiac catheterisation and computed tomography (CT) scanning are invasive procedures which involve use of either a contrast agent or ionising radiation – which can have a harmful, cumulative effect in CHD patients as they will likely require multiple scans throughout their life.

Given this critical issue affects thousands of babies each year, compounded by the limitations in accurately diagnosing, monitoring, and treating the condition, there exists a clear clinical need to improve the assessment of CHD in neonates. This prompted Dr Malenka Bissell, a consultant in paediatric cardiology and congenital CMR, based within the Leeds Congenital Heart Unit (LCHU), to develop a novel method for assessing CHD in neonates, that seeks to provide a comprehensive measure of the baby’s condition without the need for general anaesthetic.

The three-dimensional (3D), time-resolved, cine phase contrast MRI with 3D velocity encoding – the 4D Flow MRI can produce high quality images of the heart of a neonate, along with evaluation of the baby’s blood flow from a single scan that can be performed in less than 30 minutes. Once the baby has been fed, it is placed into the incubator, wearing headphones, and transported to the MRI scanner. The incubator creates a cosy, peaceful environment for the baby so that they remain asleep during the scan, allowing clinicians to capture a high-quality 3D scan of their heart. This assessment involves no use of anaesthetic, contrast agent, or sedation that could be of potential harm to the baby.

Funding

The Children’s Heart Surgery Fund (CHSF) applied to the Trustees in 2020, for £20,000 to contribute to the overall cost of the project for which they already had raised £123,000. The £20,000 grant was awarded in December 2020. The project has also received funding from the Morrisons Foundation, Ilkley Round Table, and the J9 Advisory Group who funded two infusion pumps for the incubator, which allow for the most clinically unwell children to receive continuous medications during their scan.

Project Implementation

An initial validation study of the 4D Flow MRI was carried out at Leeds Children’s Hospital in 2021 – 14 clinically well neonates were recruited, with 9 undergoing assessment in the new incubator. The results of this study established that the new scanner was successful in producing a complete visualisation of the heart and an assessment of blood flow without the use of contrast, sedation or anaesthetic in 15 minutes, and it was published in the Journal of Magnetic Resonance in 2022.

Following this validation, the researcher team were able to expand the use of the technology to assess heart function in more clinically vulnerable neonates, many of whom are too fragile to undergo general anaesthetic. It was also adapted for use in children who are too big for an incubator, by making use of headphones and a video to distract the patient.

Project Impact

The scanning protocol has now been fully integrated into clinical practice, and a weekly session has been dedicated to outpatients. Ad hoc, urgent scans for newborns are also performed when needed. By July 2023, 50 babies had been scanned, many of whom were too fragile to undergo general anaesthetic; the research team estimates 40-60 babies will be scanned every year.

Dr Bissell intends to continue her research into CHD and is developing a grant proposal to develop more advanced imaging techniques in babies to help assess the potential of the left ventricle in borderline hearts. She has spoken at several conferences in the US, Germany, and Ireland to promote and discuss the incubator. In the 2 years since its publication, the original validation study has been cited in 14 other publications, which is 7.76 times higher than the average publication in its field. She spoke about the project to CHSF in 2023:

I am very grateful to Heart Research UK and their fellow funders for the Baby MRI Incubator. This generous support will make a big difference to the treatment and outcomes for babies categorised as high-risk and help to make Leeds an outstanding centre of excellence for treatment and research into paediatric congenital heart disease. (Malenka Bissell, CHSF Progress Report)