Technical research

Polarised imaging systems

Hyperpolarised gases

Treatment response map. In green areas showing a positive response to treatment, red a negative response.

Sheffield performed the first clinical studies in the UK with both hyperpolarised 3He and 129Xe gas MRI. In collaboration with pulmonary clinicians from Sheffield and elsewhere in the UK (Manchester, Leicester) and Europe (Rotterdam, Dublin) we have demonstrated the clinical role of these MRI methods in different lung diseases:

• Emphysema - we were the first group in the world to demonstrate alveolar destruction and ventilation inhomogeneity in healthy smokers preceding changes in clinical gold standards spirometry and CT.
• In patients with COPD we were the first group to measure collateral ventilation pathways by measuring gas wash-in.
• Cystic Fibrosis we have shown obstructive changes in lung ventilation in adults and children with sensitivity greater than X ray and equal to CT. The non-ionising nature of lung MRI makes it ideal for longitudinal radiological follow up of this patient group and we were the first to demonstrate the sensitivity to changes in regional lung function with therapy in patients from the Sheffield Childrens Hospital.
• Treatment response mapping (TRM) – we are the first group to regionally quantify the effect of treatment in the lungs. This technique allows an insight into ventilation changes caused by therapy.

Sheffield is the first center to offer clinical patient scanning. More than 60 patients including subjects with asthma, COPD and CF for hospitals in Sheffield, Manchester and Leicester have been scanned.

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Image processing and computational modelling

We develop novel image processing methods for image quantification to extract quantitative indices of regional pulmonary function.

We are also using imaging data as a basis of multi-scale computational models of gas flow and diffusion in the lungs as non-invasive estimators of lung micro structure-function.

This work is being used as a basis for personalized models of lung disease in the Virtual Physiological Human project AIRProm.

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Radio frequency instrumentation laboratory

The radio frequency (RF) instrumentation laboratory is a state-of-the-art laboratory for developing RF coils for magnetic resonance imaging system and other mixed-signal instruments such system on board solution for a spectrometer.

The lab house best of the equipments for rapid prototyping such as:

• 3D full wave electromagnetic solvers (Sim4Life®, Ansys® HFSS®
• printed circuit board milling machine (LPKF® PROTOMAT S103)
• 3D printer (Stratasys® Dimension SST), Network Analyzers (Keysights® ENA series)
• Multi-Channel function generators (Tabor) and Oscilloscopes (Keysights® infiniium S series).

With ample components and consumables, along with rapid prototyping equipments, this lab can developing several custom-made RF coils without the need to await for supplier lead times, and provide scientific insight that is not possible with readily available RF coil from vendors. Nevertheless, the RF lab collaborates well with premium RF coil vendors.

The RF lab has and is aimed at prototyping transmit-receive RF coil, transmit-only RF coils and receive-only RF coils. With RF lab situated right next to MR scanner, the lab works well in synchronous with other cross-functional activities for uninterrupted conduct of research experiments.

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Innovative MR acquisition strategies for multinuclear lung MR

We have a world leading track record in the development of MR sequences for rapid functional imaging of inhaled hyperpolarised gases in the lungs.

Using non-Cartesian sampling, compressed sensing, steady state free precession and parallel imaging we have pushed the sensitivity of the methods and opened up sensitivity to new aspects of lung physiology.

In recent work we have developed methods for simultaneous imaging of 1H, 3He and 129Xe in the lungs maximizing the structure and functional information attainable.