Professor Paul Keall


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Professor Paul Keall is an NHMRC Leadership Fellow at the University of Sydney. He is the Director of the Image X Institute. His career has taken him to positions around Australia and in the USA. Prior to his current role, he was the Director of the Radiation Physics Division at Stanford University. He returned to Australia via an NHMRC Australia Fellowship, one of only 39 people given this award.

Prof. Keall and his team of 20+ scientists in Image X have the mission to improve the lives of cancer patients by inventing and advancing new ways to image and target their disease with radiation therapy. His team have achieved significant bench-to-bedside clinical translational milestones in 4D imaging, real-time tumour position localisation, real-time adaptive radiotherapy, CT ventilation imaging and audiovisual biofeedback. Additional programs include the research and development of the Australian MRI-Linear accelerator, and the Nano-X cancer radiotherapy system.

Prof. Keall’s research is funded by over $10M of competitive government grant funding. The scientific work has resulted in over 350 articles with a high number of citations (h-index 76). He is regularly invited to speak at large international meetings. The cutting-edge technological nature of the research has resulted in a number of patents, licenses and industrial engagement, including founding three companies. Prof. Keall is engaged professionally in several roles within the American Association of Physicists in Medicine (AAPM) and other professional societies. Outside of work, he enjoys time with his family, and loves (almost) all forms of sport and outdoor recreation.



Professor Ricky O’Brien

Deputy Director

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Professor Ricky O’Brien is the Deputy Director of the ACRF Image-X Institute, University of Sydney. Ricky completed his undergraduate studies in Pure and Applied Mathematics from RMIT University and his Ph.D. in biological mathematics at the University of Western Australia. After completing his Ph.D. studies, he worked in industry developing astrodynamics applications for space debris tracking and satellite laser ranging at EOS Space Systems in Canberra. He then went on to further industry roles developing financial optimisation software as a Senior Developer at Optimo Financial.

Prof. O’Brien leads the ACRF Image X Institute’s Patient Connected Imaging Program, which develops novel solutions to predict and mitigate the effects of patient motion on medical imaging. Prof. O’Brien’s primary research interest is in developing new medical imaging technologies with a focus on radiotherapy, for which he has been awarded three international patents. This work is cross disciplinary and covers novel applications in medicine, physics, mathematics, computer science and engineering. Funded by more than $10M of competitive government grant funding from the NHMRC, Cancer Australia, NSW Health and the Cancer Institute NSW, Prof. O’Brien leads a multi-disciplinary team of 6 post-doctoral researchers.

In 2019 Prof. O’Brien launched the ADAPT clinical trial to reduce scan times and imaging dose by more than 75% for lung cancer patients. In this trial, a novel form of respiratory motion guided cancer imaging is being implemented for the first time to improve the imaging of lung cancer patients.

Having a keen focus on translating technology from bench to bedside, he has forged strong relationships with industry leaders Siemens and Elekta. Formal partnership agreements with these companies allows his technology to be implemented in experimental setups using some of the world’s most cutting-edge medical imaging systems.

Outside of work, Ricky devotes time to his young family, and competes in grueling cycling challenges.



Dr Michelle Dunbar

Research Associate | View academic profile
Project: The Patient Connected Imaging Program

Dr Michelle Dunbar completed her PhD in Applied Mathematics at the University of New South Wales in 2012, and from 2012-2015 was a Vice Chancellor’s Postdoctoral Research Fellow in the SMART Infrastructure Facility at the University of Wollongong.

Michelle has experience in applying mathematical optimisation techniques to both medicine and public transport networks, to assist in key operational decisions and provide robust solutions under uncertainty. She also has experience in applying non-linear optimisation tools to a variety of medical datasets to allow for improved disease detection and diagnosis; one of these tools has subsequently been taken up by a health care company. In her spare time, Michelle enjoys surfing, cycling and bushwalking.

Dr Paul Liu

Research Fellow | View academic profile
Project: The Australian MRI-Linac Program

Paul Liu is a postdoctoral associate working on the Australian MRI-Linac program which aims to combine high quality MRI with radiotherapy. He has a background in medical physics and his current projects include improved imaging techniques, real-time treatment adaptation and MRI-Linac clinical trials. Previously he has worked on the NanoX project to develop a low-cost linear accelerator. In 2020, he was awarded an Early Career Fellowship from the Cancer Institute of NSW to develop radiotherapy with patients in an upright position. In his spare time, Paul enjoys playing sport, travelling and photography.

Dr Samuel Blake

Research Associate | View academic profile
Project: The Patient Connected Imaging Program

Sam Blake is a research associate in the Patient Connected Imaging Program with a background in Monte Carlo radiation transport simulations and the development of novel radiation detection systems. His current research uses mathematical modelling to improve the quality and efficiency of cone-beam CT image guidance technologies for lung cancer radiotherapy. He is also interested in developing and implementing real time in vivo dosimetry systems to improve the safety of radiotherapy delivery. Outside of work, Sam enjoys running and exploring cafes and parks with his wife and kids.


Dr Owen Dillon

Research Associate | View academic profile
Project: The Patient Connected Imaging Program

Owen Dillon is a Postdoctoral Fellow in the Patient Connected Imaging program. His background is in Image Reconstruction, Inverse Problems and Bayesian Statistics. His work is focussed on Cone Beam Computed Tomography (CBCT) with a particular emphasis on estimating and incorporating patient motion. He is primarily involved in the ADAPT clinical trial, improving lung cancer radiotherapy imaging while reducing imaging time 60% and imaging radiation 85%. His other research work has involved robotic systems in surgical theatres and implementing 3D imaging capabilities on 2D systems. His main pastime outside of work is hiking in and around Sydney.


Dr Tess Reynolds

Research Fellow | View academic profile
Project: The Patient Connected Imaging Program

Tess Reynolds is a Cancer Institute of NSW Early Career Fellow leading a multi-disciplinary research program delivering innovative solutions to clinical imaging challenges in interventional cardiology, neurology, oncology, and orthopaedics. Tess is the Image X Institute’s Career Development/Mentoring Advisor and the Thoracic Imaging Theme Lead, also serving on the Institute’s Management and Executive Committees. In 2021, she was a top-3 finalist for the Outstanding Early Career Researcher Australian Museum Eureka Prize and received the Jack Fowler Early Career Investigator Award from the American Association of Physicists in Medicine. Outside of work, Tess plays ice hockey and has represented Australia at 4 world championships (2014, 2015, 2016 and 2020).


James Grover

Research Associate
Project: The Australian MRI-Linac Program
James completed his Master of Medical Physics at the University of Sydney in 2021 after attaining a Bachelor of Science in 2019. His areas of interest include radiotherapy and machine learning. James is working on the implementation of a neural network-based treatment adaptation on the MRI-Linac Program with Dr. David Waddington. Previously, James completed a research project applying machine learning to CT ventilation imaging with Dr. Hilary Byrne and Prof. Paul Keall. In his free time, he enjoys travelling, self-defence training and playing the guitar.

Dr Chandrima Sengupta

Research Associate | View academic profile
Project: Kilovoltage Intrafraction Monitoring (KIM)

Chandrima is a post-doctoral research associate in the projects related to advancement of the Kilovoltage Intrafraction Monitoring (KIM) technology. Currently, her work focusses to develop, improve and advance real-time adaptive radiotherapy techniques for radiation therapy patients. She is leading two multi-institutional clinical trials related to the KIM technology: TROG 17.03 LARK trial and TROG 18.01 NINJA trial that aim to quantify the geometric and dosimetric accuracy achieved with KIM guidance for liver and prostate cancer patients. In 2021, she was awarded the ‘Best Radiation Oncology Oral presentation’ at the Engineering and Physical Sciences in Medicine (EPSM) Conference in recognition of this work. She collaborates on the Remove the Mask project, on testing the accuracy of novel surface guidance applications using a 6 degree-of-freedom quality assurance device she co-authored and manages. She is also interested in imaging technologies related to proton therapy treatment. After work, Chandrima can be found cooking, watching movies and travelling to unknown destinations.


Dr Lars Mejnertsen

Research Associate | View academic profile
Project: Beam Adaptation

Dr Lars Mejnertsen is a Postdoctoral Research Associate working on beam adaptation. Having graduated with a PhD in Physics from Imperial College London in 2018 in the field of space plasma physics, he worked on the development of the Gorgon simulation code for planetary magnetospheres. The code aims to assist in the forecasting in space weather: the impact of solar activity on the Earth’s infrastructure.

Joining the ACRF Image-X Institute in 2019, Lars brings his experience in computational physics and algorithm development to the beam adaptation project, which aims to improve the efficacy of radiotherapy. By adapting the profile of the incident radiation, taking into account the presence of multiple tumour targets and their motion during treatment, a tailored dose can be administered to the tumour whilst avoiding healthy tissue. In his spare time, he enjoys making the most of the outdoors by going on long walks and taking part in water sports.

Dr David Waddington

Research Fellow | View academic profile
Project: The Australian MRI-Linac Program

Dr David Waddington is a Cancer Institute NSW Early Career Fellow at the ACRF Image X Institute. David’s research is improves the targeting of cancer treatments by integrating radiotherapy with real time MR imaging of tumours. This work is harnessing the power of artificial intelligence to image tumour anatomy and function with a precision that has never before been possible. David leads the MRI Development research stream within the $25M+ Australian MRI-Linac Program and is the MRI lead at the ACRF Image X Institute.

When he’s done with work for the day, you’ll often find David pounding his way along a trail in the Blue Mountains or throwing his toddler on a mountain bike to go shred the gnar.


Joseph Prinable

Research Associate | View academic profile
Project: The Patient Connected Imaging Program

Joseph Prinable is a research associate in the Translational Program. His background is in machine learning and electrical engineering. Currently his work focusses on respiratory motion prediction and providing robotic engineering support to the group. He is also developing a Dynamic Automated Network in collaboration with USYD Engineering to bridge the gap between physics and machine learning approaches. After work, Joe can be found in the great outdoors, or making limoncello.

Dr Elshin Mathias

Research Associate | View academic profile
Project: The Patient Connected Imaging Program

Elshin is a postdoctoral fellow in the patient connected imaging program. His background is in biomedical engineering and has experience working on various signal/image processing projects, mathematical modelling and designing surgical tools. His current work is focused on improving 4DCT imaging used in radiotherapy treatment planning.

He is primarily involved in the REACT clinical trial which aims to reduce imaging errors in 4DCT images. He is also interested in better acquisition and reconstruction protocols for 3rd generation modern CT scanners. Outside of work, he enjoys time with his family, and loves playing badminton.


Dr Hilary Byrne

Program Manager | View academic profile
Project: CT Ventilation

Hilary’s current research focus is on extracting information about lung function from CT images. This will help in planning radiotherapy to minimize patient side-effects and in diagnosing, assessing and tracking lung disease. She has an interest in helping develop new technologies for use in the clinic, and was awarded a Researcher Exchange and Development within Industry (REDI) Fellowship in 2022. She led the BRAVEHeart clinical trial to completion in 2021, clinically assessing an optical surface motion tracking device developed by our group. Hilary also has an interest in novel techniques to enhance radiotherapy using nanoparticles. She was awarded a Sydney Vital Nanotechnology Fellowship in 2019 and ran a pilot study on radiosensitisation at the Australian MRI-linac.

Away from work, Hilary enjoys family time with her husband and two boys and in her time off indulges in choir singing, learning to play the recorder and fencing (the Olympic sword-fighting, not the agricultural land-enclosing type!)


Emily Hewson

Research Associate
Project: Kilovoltage Intrafraction Monitoring (KIM)

Emily Hewson received her PhD from the University of Sydney in 2022 and is currently a Research Associate specialising in real-time adaptive radiotherapy techniques. Her thesis focussed on developing beam-adaption that can track multiple targets simultaneously for patients with locally advanced cancer and was carried out in collaboration with the Royal North Shore Hospital. Emily’s work in this field was awarded Best in Physics in 2021 at the 63rd AAPM annual meeting. She is now continuing her research in motion monitoring and tracking techniques during radiotherapy. In her spare time she enjoys reading, hiking, and taking her dog to the beach.


Dr Mark Gardner

Research Associate | View Academic Profile
Project: Nano-X

Mark is working on the ‘Remove the Mask’ project, which aims to improve the patient experience during radiation therapy for people with head and neck cancers. Mark is also part of the Nano-X team, which is a low-cost radiation therapy device. Mark’s research interests include automated medical images analysis, machine-learning applications in medicine, cone-beam CT reconstruction, and improving the patient experience in radiotherapy. Mark also is interested in science communication, having made it to the state finals in the FameLab competition in 2020, a public speaking competition requiring researchers to explain their research to the general public in 3 minutes. Outside of work his interests include hiking, video games, basketball and communicating through Simpson’s references.

Dr Shanshan Shan

Research Associate | View Academic Profile
Project: The Australian MRI-Linac Program

Shanshan undertook her PhD at school of Information Technology and Electrical Engineering, University of Queensland. Her project focused on correcting image distortions caused by gradient nonlinearity for the Australian MRI-Linac project. During her candidature, Shanshan was the recipient of the Richard Jago Memorial Prize 2019, and was the winner and runner-up of ‘Three Minute Thesis’ school and faculty finals.  

Shanshan joined the ACRF Image X institute in 2020 to work on the Australian MRI-Linac project. This project aims to develop a real-time image guidance for accurate radiation delivery in cancer treatment. In her spare time Shanshan likes to spend time on cooking and trying nice food; she also likes doing Yoga and Zumba.  

Dr Youssef Ben Bouchta

Research Associate | View Academic Profile
Project: AV Biofeedback

Youssef Ben Bouchta completed his PhD at the university of British Columbia in 2019. His PhD research took place at the Vancouver Cancer Center where he worked on lowering out-of-field dose and risk of radiotherapy induced second malignancies in pediatric and young adult patients. While completing his PhD, he also worked on developing a quality assurance program for a small animal radiation research platform.

Following the completion of his PhD, Youssef joined the ACRF Image-X Institute as a postdoctoral researcher working on improving targeted radiation therapy techniques. In his spare time, Youssef enjoys reading, hiking and, when possible, travelling to remote places.

Dr Brendan Whelan

Research Fellow | View Academic Profile
Project: The Australian MRI-Linac Program

Brendan received his PhD at the Image-X institute in 2016 for a thesis entitled “Maximising the mutual interoperability of an MRI scanner and a cancer therapy particle accelerator”. This work was supervised by Professor Paul Keall, and was awarded the ACPSEM PhD award for the best PhD thesis published in the field of medical physics in 2016. After completion of his PhD, he continued working in the MRI-Linac program in a postdoctoral capacity. In 2018 he moved to Germany, working as a Multiphysics Specialist within the Innovation Department, Advanced Therapies, Siemens Healthineers. Whilst in Germany, his career as a professional skier was cruelly cut short when, skiing for the first time, he broke his ankle.

In 2020 he returned to the Image-X institute to take up a CJ Martin NHMRC Early Career Fellowship. Through this fellowship, he will spend 50% of his time at the Radiation Oncology department at Stanford University working with Professor Billy W. Loo, and 50% of the time at Sydney University under the supervision of Professor Paul Keall. Brendan is widely acknowledged to be the best looking and cleverest member of the research group. He also writes his own bios.

Dr Caterina Brighi

Research Associate | View Academic Profile
Project: The Australian MRI-Linac Program

Caterina graduated with a Masters of Science in Chemistry with Molecular Physics in 2015 and a Masters of Research in Bioimaging Science in 2016 from Imperial College London. In 2017 she moved to Australia to undertake a PhD in Medical Imaging at the Australian Institute for Bioengineering and Nanotechnology at The University of Queensland.

Her PhD work focused on neuroimaging studies evaluating effective strategies to modulate the blood-brain barrier and improve drug delivery to brain tumours. After completing her PhD, Caterina joined the ACRF Image-X Institute in 2020 as a research associate to work on the MR-Linac project, which aims to improve the accuracy of radiation therapies in cancer treatment. With a skillset in different areas of translatable research, from preclinical laboratory work to image analysis of clinical datasets, Caterina brings her experience in MRI and PET imaging for cancer diagnostics and treatment applications.

Outside work, you’ll most likely find Caterina swimming at the pool or enjoying outdoor activities such as scuba diving, hiking, traveling and photography.


Amelia Martin

Research Assistant
Project: Kilovoltage Intrafraction Monitoring (KIM)

Amelia is a BSc student at the University of Sydney in her third year, majoring in Physics and Chemistry. Having worked under Dr Trang Nguyen over the summer with the institute’s scholarship program, she is excited to continue her work under Emily Hewson and Prof. Paul Keall in experimentally evaluating the 6D Internal-External correlation algorithm.

Beside her passion for science and learning, she spends her spare time with family, playing flute and bushwalking.




Adam Mylonas

PhD Candidate | View Academic Profile
Project: Kilovoltage Intrafraction Monitoring (KIM)

Adam Mylonas graduated with a Bachelor of Engineering Honours (Biomedical) and a Bachelor of Medical Science (Immunobiology) at the University of Sydney in 2021. Adam is currently undertaking a PhD at the ACRF Image X Institute investigating Markerless Tracking. Currently, his work focuses on developing deep learning models for real-time markerless tracking of the prostate and pancreas in intrafraction kilovoltage images. He also collaborates on the implementation of deep learning-based marker tracking as part of the Kilovoltage Intrafraction Monitoring (KIM) project. In his spare time, Adam enjoys exploring nature, going for long hikes, and camping.


Dr Kevin Jang

MPhil Candidate
Project: The Australian MRI-Linac Program

Dr Kevin Jang is a Resident Medical Officer with aspirations to pursue a career in Radiation Oncology. He graduated Bachelor of Medicine, Bachelor of Surgery (MBBS) with the H.Neil Smith Prize from James Cook University in 2019. During his medical studies, he was the recipient of two Research Scholarships (Macquarie University and University of Sydney) where he undertook both laboratory and clinical research. This was followed by Internship and Residency at Nepean Hospital, during which he was awarded the DPET Funding Grant to attend the Basic Sciences of Oncology Course (BSOC). In 2021, he received the Australian Government RTP Scholarship to pursue a Master of Philosophy (MPhil) at the ACRF Image-X Institute, University of Sydney. With a particular interest in neuro-oncology, his thesis explores the use of radiomics and machine learning applied to brain cancer imaging. As a Clinical Associate Lecturer at the Sydney Medical School, Dr Jang has an active role in teaching and supervision of medical students.

Nicholas Hindley

PhD Candidate
Project: Markerless Tracking

Nicholas Hindley graduated from the Advanced Science program at the University of New South Wales where he gained first-class honours in chemistry and pharmacology as well as the Dean’s List Award for Excellence in Research, the Spruson and Ferguson Award for Innovation in Applied Science and the Children’s Cancer Institute Honours Scholarship. He then moved to the University of Sydney where he obtained a second undergraduate degree in philosophy and mathematics, before undertaking a PhD in medicine.

His research at Image-X focuses the use of neural nets and deep learning in medical imaging and radiotherapy. In his spare time, Nicholas enjoys climbing, cycling and singing jazz.

Natasha Morton

PhD Candidate
Project: The Patient Connected Imaging Program

Natasha completed her undergraduate degree in 2014 at the Australian National University, majoring in physics and mathematics. Natasha has recently completed a master of Medical Physics at the University of Sydney. Her project focused on code development for determining 3D tumour control probability (TCP). This was used to determine the effects of motion on TCP during prostate cancer treatment for both real-time multi-leaf collimator (MLC) clinical trial patients and several motion simulated scenarios.

Her research will focus on second generation 4DCT. Natasha enjoys a good fiction book and expanding her culinary skills.

Marco Müller

PhD Candidate
Project: Markerless Tracking

Marco visited us for six months in 2017 to complete his master thesis in physics, and was involved in the Australian MRI-Linac Program. He studied at the University of Heidelberg, Germany, and has been undertaking research at the German Cancer Research Centre (DKFZ) since 2014. In his bachelor thesis he dealt with molecular optical imaging and reconstruction algorithms for optical tomography in mice. In addition to his studies in general physics, Marco went for further education courses like Advanced Physical Methods in Radiology and Medical Physics for Physicists to cover the theory of the different areas of medical physics and performed the quality assurance of linear accelerator in the university hospital in Heidelberg. When not working, during his summer stay in Sydney Marco likes to enjoy the Australian lifestyle, do water sports or go hiking in the Blue Mountains.


Suzy Lydiard

PhD Candidate
Project: The Australian MRI-Linac Program

Suzy Lydiard is currently undertaking a PhD part-time investigating the feasibility of non-invasively treating Atrial Fibrillation using an MRI-Linac. She is lucky enough to not only have Professor Paul Keall as her primary supervisor but additionally Professor Stuart Crozier (UQ) and Dr Gary Liney (Ingham Institute, NSW) as auxiliary supervisors. She is conjointly completing her clinical Radiation Oncology Medical Physics accreditation at Auckland City Hospital, NZ. Previously she completed a BTech Degree in Medical Physics and Imaging at Auckland University and graduated with first class honours. Her honours research project assessed the clinical suitability of using compressed sensing in cardiac MRI. When she is not working, studying or jumping across the ditch, Suzy enjoys baking (a welcomed skill in the departments), exploring and reading a good novel. When she is stressed you can find her hitting the pavements and trails with running shoes.



Dr Helen Ball

Operations Manager | Contact

Helen Ball obtained her PhD in molecular biology at the Garvan Institute of Medical Research and has worked as a researcher in the Discipline of Pathology, University of Sydney.  She also provided advice and training for researchers at the School of Medical Sciences, as the facility officer for the Bosch Biostatistics and Bioinformatics Facility. Helen manages the operations of the ACRF Image-X Institute. She enjoys reading, cooking and spending time with her family


Julia Johnson

Design & Communications Officer | Contact

Julia has a unique hybrid role as the only Design & Communications Officer in the university. Julia provides a full suite of design services for the institute including design and fabrication of class 1 medical device prototypes, as well as graphics, branding, scientific figures, and content creation. In addition to this, Julia is passionate about communicating the work of the institute to the public. She manages the website and social media channels, and is working to strengthen the institute’s engagement with the wider community. Outside of work, she enjoys playing music, and in her spare time performs regularly with her banjo and guitar.

Shona Silvester

Clinical Trials Co-ordinator  | Contact

Shona Silvester is responsible for providing support for the clinical trials program at the Image X Institute, with a role spanning development, site start up, data management and trial coordination.  She has extensive experience in clinical trials research, having previously worked in the pharmaceutical industry as well as an academic research organisation. In her spare time Shona volunteers with the NSW SES and enjoys playing tennis with her friends.

Natalie Plant

Clinical Trials Co-ordinator | Contact

Natalie Plant is a clinical trial coordinator supporting the translation of Image-X’s technologies into the clinical setting. Natalie has extensive experience in coordinating the development, implementation, data management and regulatory aspects of clinical trials in the field of radiation oncology. Natalie spends a lot of her spare time bushwalking and swimming.

Kuldeep Makhija

Software Developer | Contact

Kuldeep Makhija graduated with a Bachelor in Management Science and Masters in Computer Application. After that, Kuldeep worked with Dell Perot Systems and Halliburton Energy Services as a software developer in Pune, India and partly in Houston, USA. He is currently building the software tools to advance the various projects underway, under the guidance of Dr Ricky O’Brien. His interests are new Microsoft technologies and team and project dynamics. When not working, Kuldeep likes to travel, discover new places and take his son swimming.


Indrajit Ghosh

Software Developer | Contact

Indrajit Ghosh has a Bachelor of Engineering degree in Computer Technology and has been working as a Software Engineer in the field of Healthcare IT and Medical Device software since 2002. After working on developing a telemedicine solution for connecting Indian ternary care hospitals with primary health centres in C-DAC, Pune India, he worked for a decade with GE Healthcare developing software for surgical imaging devices and then more recently, with Samsung Medical Equipment business in Korea on developing interoperability and data management platforms for multiple imaging modalities.

Indrajit has worked on various subsystems of diagnostic and surgical imaging devices including image management, interoperability, usability and UI, device serviceability and developing real time OS for such devices. Currently he is also pursuing a Master’s degree program at the Georgia Institute of Technology, Atlanta with specialization in Robotics and Perception. In his free time, Indrajit likes reading and taking long walks.


Jonathan Hindmarsh

Clinical Medical Physicist | Contact

Jonathan Hindmarsh is a qualified Medical Physics Specialist whose role is to assist the researchers of the institute in the clinical aspects of their work. He is also a part time PhD student at the institute investigating the implementation of real time treatment techniques.

Jonathan has worked as a Medical Physics Specialist in NSW, Australia and Alberta, Canada since getting his qualification in 2013 and his research interests include the development and improvement of treatment techniques, commissioning methods, and quality assurance processes. Outside of work Jonathan enjoys road and mountain biking, skiing, canyoning and rock climbing as well as the odd tabletop and computer game.