Meet the team

Dr Matthew Guy

Dr Matt Guy, lead for imaging physics

Dr Guy leads our imaging physics team. He has extensive experience across both diagnostic and therapeutic applications of nuclear medicine, including PET and CT scans. He has also been involved in the development of dual-energy CT imaging techniques. He's the Trust’s medical physics expert (MPE) for nuclear medicine.

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Dr Sofia Michopoulou, principal clinical scientist

Sofia is a principal clinical scientist, one of the medical physics experts (MPE) for nuclear medicine and the deputy lead for nuclear medicine physics. She supports the general nuclear medicine, SPECT/CT and PET/CT services at UHS and leads the introduction of new diagnostic and therapeutic techniques.

Sofia teaches medical imaging at BSc and MSc level at the University of Southampton and University of Surrey, and delivers part of the Fellows of Royal College of Radiology (FRCR) physics module.

Sofia’s research interests focus on the development of imaging biomarkers for disease characterisation in neurology and oncology.

Sofia's key achievements include

  • developing one of the early computer aided diagnosis systems for spine MRI during her PhD
  • supporting the service development of the first PET/MRI centre in the UK (while working as a clinical scientist at University College London Hospital)
  • introducing the duty physicist role here at UHS
  • supporting the introduction and development of the static PET/CT centre, in Southampton
  • updating national guidance as a member of the IPEM NM SIG.

You can email or call 023 8120 6628.

Dr Livia Tossici-Bolt, principal clinical scientist

Livia is a member of the imaging physics team supporting the department of nuclear medicine in the delivery of its diagnostic and therapeutic services. Her particular interest is in brain imaging with SPECT/CT for the diagnosis of dementia and movement disorders and in methods for their quantitative analysis.

Livia is involved in teaching the nuclear medicine physics module to the Fellows of Royal College of Radiology (FRCR) and in supervising students in the Scientist Training Programme (STP); she has also supervised a number of MSC physics projects.

Livia's key achievements include

  • developing a method for the quantification of images of the brain dopamine transporter (DaT), known worldwide as the “Southampton” method
  • contributing to the establishment of databases of healthy controls for brain SPECT scintigraphy - specifically for brain perfusion images in a joint effort with University Hospitals Bristol, and for DaT images as part of a multicentre European initiative
  • contributing to the ongoing revision of European guidelines on  dopaminergic imaging.
You can email or call 023 8120 5483.

Gemma Lewis

Gemma works as a nuclear medicine physicist providing physics support for the diagnostic and therapeutic nuclear medicine service. She has experience in diagnostic nuclear medicine and radionuclide therapy. Gemma is also involved in a number of research trials and supports the training of clinical scientists and practitioners in nuclear medicine physics.

Gemma’s key roles and achievements include

  • supporting the introduction of the PRRT service here at UHS
  • establishing diagnostic protocols for the new Intevo SPECT/CT scanner at UHS
  • supporting and developing the non-imaging nuclear medicine service
  • performing patient specific dosimetry for radionuclide therapy in clinical trials at UHS.

You can email or call 023 8120 5486.

Timothy Melhuish

Tim joined the medical physics team having previously worked clinically in nuclear medicine. With a background in science and a practical understanding of the equipment used in the nuclear medicine department, Tim plays a significant role in

  • the quality assurance program for the department equipment in nuclear medicine, radiopharmacy and PET
  • development of software used for processing scans in nuclear medicine
  • research and clinical audits to make sure the department stays in line with Trust’s value of 'always improving'
  • training and development of clinical staff.


  • Presenting in the ‘Young Investigator Award’ category at the 2017 BNMS Spring meeting.

You can email or call 023 8120 3141.

Contact us

Email us at or call 012 8120 6628.

Please note, enquiries regarding the clinical nuclear medicine service, including appointments, bookings and reports, should be directed to radiology on 023 8120 6202.

Write to: Nuclear medicine physics, mailpoint 29, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD.