Healthcare research in the Physics Department Dr S J Doran Lecturer in Magnetic Resonance Imaging Department of Physics School of Electronics and Physical Sciences S Department of Physics, University of Surrey, Guildford, GU2 7XH, UK S J Doran, P Jenneson, P McDonald, E Morton, N Spyrou

Structure of talk Physics personnel with medical interests and healthcare-related projects underway in Physics Four brief case studies  MRI of the diffusion properties of tumours  Skin imaging  Radiation dosimetry  Characterisation of distortion in MRI

Physics department “healthcare”personnel Prof Tony Clough Ion beam analysis (healthcare products) Dr Simon Doran Magnetic Resonance Imaging Radiation dosimetry e-Health Dr Walter Gilboy Radiation dosimetry and protection Dr Paul Jenneson Ion beam analysis X-ray CT micro-tomography Radiation transport (Monte Carlo simulation) Prof Peter McDonald Soft condensed matter Physics Skin imaging Imaging of solvent ingress into dental resins Dr Ed Morton (on secondment to Creative X-ray Ltd.) X-ray imaging Novel control systems for dose-reduction Prof Nicholas Spyrou Positron Emission Tomography Nuclear Medicine Epigastrography Trace element detection in medical conditions (e.g., Alzheimer’s) Ion beam analysis … and many more!

MRI measurements of diffusion: (1) Cancer Magnetic Resonance Imaging can be used to measure the speed of diffusion of water molecules. The technique is widely applied in brain imaging, as there is a well- established link between altered diffusion values and stroke. Extra-cranially, the technique has obvious potential, but this has been difficult to realise for a number of technical reasons. Lancet 360, 307–308 (2002)

MRI measurements of diffusion: (1) Cancer We developed novel MRI methodology to allow diffusion coefficients to be measured as part of a rectal tumour study. The Lancet 360, 307–308 (2002) A Dzik-Jurasz, C Domenig, S Doran et al. Data acquisition is at the limit of what is technically possible with the current generation of scanners With improved methodology, this could become a prognostic test. % regression in tumour size after chemoradiation Diffusion coefficient / cm 2 s -1 The diffusion coefficient measured before treatment was correlated with the tumour response.

MRI measurements of diffusion: (2) Skin Most Magnetic Resonance Imaging scanners are based round a magnet with a cylindrical geometry. This is good for whole-body scans, but not for scanning thin samples. Dr Glover and Prof McDonald put forward a novel magnet design, called GARField (Gradient At Right- Angles to Field). Resolution of the new scanner is now of the order of tens of microns, rather than the few mm of a routine clinical scan. J Magn. Reson. 139, 90 P Glover, P Aptaker, J Bowler, E Ciampi, P McDonald

MRI measurements of diffusion: (2) Skin This type of imaging is very different from the sort of MR “pictures” we are used to seeing. We can measure quantitatively the diffusion of compounds through the skin and follow them with time. P Glover, B Newling, P McDonald (UniS) M Dias, J Hadgraft (University of Cardiff) Position (microns) Intensity (a.u.) “Dry” skin before cream applied (normal) Result after application of cream for 5 mins.

Measurement of radiation dose in 3D Modern radiotherapy treatments can be extremely complicated, in order to try and spare healthy tissue whilst killing the cancer. Such treatments require extremely high spatial accuracy of delivery. Hence, there is a pressing need to be able to measure the dose delivered. Until recently, this has not been possible. Organs to spare Target organ Schematic prostate treatment Treatment planMRI-derived dose map Phys. Med. Biol. 43, (1998) M Oldham et al.

Measurement of radiation dose in 3D Methods based on MRI have previously been used to measure the dose distribution in 3D. However, these can be extremely slow (~ 6 hours for a 3-D scan). Phys. Med. Biol. (2001) S Doran, K Kleinkoerkamp, P Jenneson, E Morton, W Gilboy Wavelength / nm  (optical absorbance) / cm -1 FXG spectral dose-response For a number of years, we have been investigating a novel method based on a gel that changes colour when irradiated from orange to purple.

Measurement of radiation dose in 3D We have developed a new method of scanning the gels — 3-D optical computed tomography (OCT). Hg lamp Cylindrical lens, pinhole and filter  pseudo point-source Lens  parallel beam Scanning tank with matching medium Exposed gel Unexposed gel Diffuser screen on which real shadow image forms CCD detector Standard 50mm camera lens PC with frame- grabber card Turntable controlled by acquisition computer via stepper motors 0 Gy 10 Gy 57 mm OCT is potentially two orders of magnitude cheaper than its MRI rival. OCT is potentially two orders of magnitude faster than MRI. Applications include brachytherapy, conformal radiotherapy and IMRT, radiation protection/ accident prevention. Phys. Med. Biol. (2001) S Doran, K Kleinkoerkamp, P Jenneson, E Morton, W Gilboy

Distortion in Magnetic Resonance Images S Doran (UniS), L Moore, S Reinsberg, M Leach (Institute of Cancer Research) What would you say if you knew that MRI scans could turn this … … into this? Would you rely on MRI data to plan your surgery or radiotherapy?

Distortion in Magnetic Resonance Images S Doran (UniS), L Moore, S Reinsberg, M Leach (Institute of Cancer Research) We are researching how to correct MR images to make them reliable enough for surgery. By using a specially designed test object, we can work out how each pixel of the image is displaced x / mm y / mm x-distortion / mm By analysing around 40,000 point-to-point correspondences between CT and MR images, we obtain 3-D distortion maps.

Distortion in Magnetic Resonance Images S Doran (UniS), L Moore, S Reinsberg, M Leach (Institute of Cancer Research) Data from the test object is used in conjunction with patient image data in order to produce distortion corrected maps. The eventual aim is to make it possible to eliminate the necessity for CT scans in the planning of some radiotherapy treatments. No radiation Less patient discomfort / inconvenience Saves NHS money