Sub specialities: Musculoskeletal radiology, PET CT
Following successful completion of both the Fellow of the Faculty of Radiologists of the Royal College of Surgeons in Ireland (FFR RCSI) and the Fellow of the Royal College of Radiologists, Professor Johnston completed fellowships in musculoskeletal imaging at Cappagh National Orthopaedic Hospital and Duke University Hospital in North Carolina.
During this time he amassed significant experience in musculoskeletal imaging, including image-guided intervention. He runs image guided joint injection clinics and is the lead clinician for musculoskeletal imaging in St James’s Hospital. In late 2017 he was appointed associate professor in surgery, Trinity College Dublin. In January 2019 he took up the position of clinical director in radiology in St James’s Hospital.
Professor Johnston also completed fellowships in the Dana Farber Cancer Institute (part of the Harvard Comprehensive Cancer Centre in Boston, MA), subsequently being promoted to attending radiologist and head of MRI. He followed this with an appointment as lead radiologist in the St Bart’s PET CT Centre in London and was subsequently appointed as director of PET CT at St James’s Hospital. Professor Johnston is the current clinical director for the hospital's Diagnostic Imaging Directorate.
Professor Johnston is actively involved in undergraduate teaching in radiology in Trinity College Dublin, postgraduate teaching in the Faculty of Radiologist’s Programme for SpRs, and on allied health professional courses including the MSc in Nuclear Medicine, Trinity College Dublin (TCD) and graduate entry MSc in Radiography (TCD). In 2019 he retired as chief part 1 examiner for the radiology part 1 FFR RCSI examinations following five years as an examiner and then chief examiner.
Professor Johnston is the only Irish member on the Oncologic Imaging Subcommittee for the European Society of Radiology.
Professor Johnston has published widely in the field and is a co-author of a highly regarded text on musculoskeletal imaging (Sports Injuries: Examination, Imaging and Management). He has also published widely on the topic of cancer imaging and played a significant role in establishing St James’s Hospital as the busiest PET CT department in the country. More recently, as part of the St James's Hospital PET CT team, he has helped establish the first Gallium PET CT service in the country, using both PSMA and Dotanoc radiopharmaceuticals to aid diagnostic accuracy in prostate and neuroendocrine tumours respectively.