Dr Lionel Broche

Dr Lionel Broche
Dr Lionel Broche

Dr Lionel Broche

PhD, MInstP

The Hall Family Lecturer in Medical Physics

Accepting PhDs

About

Biomedical Physics Building Room F10 Foresterhill

Latest Publications

  • Joint multi-field T1 quantification for fast field-cycling MRI

    Bödenler, M., Maier, O., Stollberger, R., Broche, L., Ross, J., Macleod, M.
    Magnetic Resonance in Medicine, vol. 86, no. 4, pp. 2049-2063
    Contributions to Journals: Articles
  • A New Method for Investigating Osteoarthritis using Fast Field Cycling Nuclear Magnetic Resonance

    Broche, L., Ross, J., Kennedy, B., MacEachern, C., Lurie, D., Ashcroft, G. P.
    Physica Medica, vol. 88, pp. 142-147
    Contributions to Journals: Articles
  • Low-Field NMR Relaxometry for Intraoperative Tumour Margin Assessment in Breast-conserving Surgery

    Bitonto, V., Ruggiero, M. R., Pittaro, A., Castellano, I., Bussone, R., Broche, L. M., Lurie, D., Aime, S., Baroni, S., Geninatti Crich, S.
    Cancers, vol. 13, no. 16, 4141
    Contributions to Journals: Articles
  • Monitoring tissue implants by field-cycling H-1-MRI via the detection of changes in the N-14-quadrupolar-peak from imidazole moieties incorporated in a "smart" scaffold material

    Bitonto, V., Di Gregorio, E., Baroni, S., Stefania, R., Aime, S., Broche, L., Senn, N., Ross, J., Lurie, D., Geninatti Crich, S.
    Journal of Materials Chemistry B, vol. 2021, no. 9, pp. 4863-4872
    Contributions to Journals: Articles
  • A novel class of 1H-MRI Contrast Agents based on the relaxation enhancement induced on water protons by 14N imidazole moieties

    Baroni, S., Stefania, R., Broche, L., Senn, N., Lurie, D., Ross, J. J., Aime, S., Geninatti Crich, S.
    Angewandte Chemie International Edition, vol. 60, no. 8, pp. 4208-4214
    Contributions to Journals: Articles

View My Publications

Research

Research Overview

I am a mix between a physicist and an engineer, blended with a nice squeeze of medical sciences.

My research aims to develop FFC imaging, which is a new type of medical scanner that can characterise the dynamics of water in vivo non-invasively. I am particularly interested in the following research topics:

- medical applications of FFC imaging

- technology developments of FFC imaging

- dissemination of FFC imaging using open-source hardware

Research Areas

Accepting PhDs

I am currently accepting PhDs in Engineering.


Please get in touch if you would like to discuss your research ideas further.

Email Me

Engineering

Supervising
Accepting PhDs

Biomedical Sciences

Supervising

Research Specialisms

  • Biomedical Engineering
  • Diagnostic Imaging
  • Systems Engineering
  • Medical Physics
  • Electromagnetism

Our research specialisms are based on the Higher Education Classification of Subjects (HECoS) which is HESA open data, published under the Creative Commons Attribution 4.0 International licence.

Current Research

Clinical applications of Fast Field-Cycling MRI

Fast Field-Cycling MRI (FFC MRI) is a promising imaging technique that has the ability to combine high contrast and good image resolution, two key components of MRI that are notoriously famous for being incompatible, without the need of a contrast agent. This unique ability, combined with the low risk associated to the low magnetic fields used and the low scanning cost, makes this imaging platform a good candidate for patient screening. Several clinical trials are ongoing to probe the potential of FFC in medicine:

Characterisation of brain stroke in vivo

The management of stroke has increasingly focused on early identification, early scanning and thrombolysis and/or clot retrieval. These techniques rely heavily on imaging of the stroke but there are practical and interpretational limitations to current imaging modalities for early diagnosis of ischaemic stroke.

Fast Field-Cycling (FFC) imaging uses low magnetic fields to extract non-invasively information on the molecular dynamics of tissues that is not accessible by any other imaging modalities. Our PUFFINS pilot study shows great potential to identify ‘what is going on’ at the molecular level after a brain infarct and to give information on the composition of intra-arterial thrombus, which might aid choice of treatments for acute strokes. Other potential benefits of FFC MRI are foreseen for patients with small vessel disease and amyloid deposition, not to mention other brain diseases such as vasculitis, tumour and multiple sclerosis.

Detection of osteoarthritis using the quadrupolar signal

Osteoarthritis (OA) is the most prevalent joint disorder and cause of disability in the United Kingdom with an estimated 8.5 million persons suffering from joint pain due to OA, and it is a major cause of disability in the world. Multiple risk factors appear to be involved in the onset and progression of OA, including age, genetics, gender, overuse, trauma and obesity, even though none of these have been identified as a clear cause of the disease. There are currently no pharmacological interventions available to patients for modifying the underlying disease but early patient management can help to slow down its progression. it is therefore crutial to detect OA before irreversible damages develop.

The underlying pathophysiology of OA has been extensively studied and recent research identifying the importance of matrix-degrading enzymes, chondrocyte hypertrophy and apoptosis, subchondral bone metabolism, cytokines and inflammation has identified a number of potential targets for disease modifying agents. Interest in developing potential therapeutic agents has highlighted the need for biomarkers of disease progression with imaging biomarkers currently appearing to offer the best prospect.

A previous study of FFC MRI on excised samples of OA cartilage from hip replacement showed promising results: it appeared that this technique can offer degradation-sensitive contrast using a particular signal, the quadrupolar signal. A more extensive study is being undertaken at the moment in collaboration with Mr G.P. Ashcroft and Prof R. Aspden in order to assess this technique.

Characterisation of fibrin clots and applications to thrombosis

Fibrin is one of the main constituents of blood clots. It is derived from fibrinogen, a long, narrow and heavy protein (340 kDa), under the action of thrombin.

Fibrin protein are insoluble and aggregate into long filaments that can cross-link to form a rigid gel structure. The size and diameter of these filaments, together with the amount of cross-linking, can be controled more or less independantly during the clotting process by several paremeters such as the concentration of calcium ions or the content of factor XIII and RS283 proteins.

The rigidity of the clot is an important parameter for the treatment of deep vein thrombosis (DVT), a pathology that may develop in several diseases or conditions such as cast ankle, high saturated fat diet or drug abuse. DVT is treated by thrombolysis when the conditions allow, but response to treatment varies greatly due to the nature of the clot.

FFC NMR studies of fibrin clots have showed that field-cycling can detect fibrin quantitatively, with possible applications to DVT characterisation. A study has been initiated on DVT patients in parternship with the NHS at the Aberdeen Royal Infirmary to assess whether FFC MRI can predict the response to thrombolitic treatment.

An in-vitro  study of fibrin systems is also being developed in partnership with Dr N. Mutch and Dr C. Whyte that aims to detect differences in clot structure due to the effect of polyphosphate chains during the clot.

Detection of tumours at low magnetic fields

one of the parameters of interest that is measured by an MRI scan is the transverse relaxation time of spins, also called T1. This parameteris known to vary greatly between tissues at low magnetic field (typically below 0.05T) but much less at high fields. This is part of the reason why contrast agents are needed for tumour detection on conventional MRI clinical scanners.

Unfortunately, low magnetic fields also come with low image resolution and long scan time. This is the reason why MRI scanners are operating at ever increasing fields.

FFC offers a compromise between high contrast and high resolution that cannot be reached by conventional fixed-field MRI scanners. This opens new avenues for contrast-based studies with potential applications in many fields of medicine.

One particular area of interest is breast cancer: breast tumours are commonly detected by analysis of contrast in MRI scans but may be difficult to assess if their extent is restricted to a few millimeters. A study has been initiated by Dr Lionel Broche in collaboration with Prof S. Heys, Dr I. Miller, Dr T. Gagliardi, Mr G.P. Ashcroft, Dr D. Boddie and Dr S. Dundas to assess FFC MRI in the context of breast cancer.

 

Theoretical developments for FFC MRI pulse sequence and data processing

In addition to clinical projects, Dr Lionel Broche is developing data processing methods tailored to FFC MRI to decrease the scan time and improve data quality.

The management of stroke has increasingly focused on early identification, early scanning and thrombolysis and/or clot retrieval where appropriate. There are practical and interpretational limitations to current imaging modalities for early diagnosis of ischaemic stroke.   CT scan is a ‘blunt’ tool, and gives limited information in early infarction, but allows haemorrhage to be excluded prior administration of thrombolytic agents.

 

The amount of residual salvageable tissue can be difficult to judge from the initial image.   Both CT angiography and perfusion CT and diffusion/perfusion weighted MRI have been shown to improve selection of patients for acute interventions but this is not part of routine practice and does not seem to influence outcome after treatment (1).   Perfusion CT while promising has variable thresholds for diagnosis of salvageable tissue, which limits generalizability and use other than in clinical trials (2).

 

Conventional MRI at 3T or 1.5T is of limited use in hyperacute stroke: patients struggle to tolerate the noise or duration of image acquisition. Due to safety issues and the need for specialist radiographers, availability in most centres is limited to 9-5, Monday to Friday.  This limits the use for ‘wake-up’ stroke, where MRI is most helpful for assessing salvageable tissue (3).

 

Fast Field-Cycling MRI (FFC MRI) is a new imaging modality developed exclusively in Aberdeen that uses low magnetic fields to extract non-invasively information on the molecular dynamics of tissues (4) that is not accessible by any other imaging modalities. Several pilot studies have shown great potential for clinical use in cancer, osteoarthritis and fibrosis, and showed that FFC MRI can identify ‘what is going on’ at the molecular level in the tissue at risk. Imaging may also give information on the composition of intra-arterial thrombus, which might aid choice of treatments for acute strokes.  Other potential benefits of FFC MRI are foreseen for patients with small vessel disease and amyloid deposition, not to mention other brain diseases such as vasculitis, tumour and MS (4).

 

 

Past Research

Detection of Alzheimer disease using FFC MRI

Alzheimer Disease (AD) is a neurodegenerative disease that affects over 750,000 patients in the UK. It is the most common form of dementia and has devastating effect on the patient and their relatives. The mechanisms of progression of AD are still poorly understood but this disease is associated with the formation of protein tangles in the brain.

FFC MRI demonstrated good ability in the detection of low-mobility proteins so it is a good candidate to obtain tangle-dependant contrast in images. We are currently planning a series of large studies on this topic.

Funding and Grants

See my ORCID profile for up-to-date details.

Teaching

Teaching Responsibilities

Dr Lionel Broche teaches the physics of Fast Field-Cycling Magnetic Resonance Imaging on the MSc programmes in Medical Physics, Medical Imaging, and Medical Physics Computing.

Publications

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