What is radiology?

Radiology is a medical specialty. Radiologists are specialist medical practitioners who perform and interpret diagnostic imaging tests and interventional procedures or treatments that involve the use of x-ray, ultrasound and magnetic resonance imaging equipment. Radiologists are trained to assist other doctors and specialists with the treatment of their patients by making a diagnosis and providing treatment using medical imaging. They have the medical knowledge to understand and explain a patient’s medical problem or symptoms through the images that are taken of various parts of the patient's body.

Radiology is central to the clinical practice of medicine across a wide range of disciplines. It is the best practical way to diagnose, monitor treatment and detect progression or relapse of many important and common diseases in a minimally invasive and anatomically precise manner. As a consequence of the increasing sophistication and accuracy of clinical imaging, the utilisation and importance of radiology has increased dramatically and consistently over the last 20 years.

From X-Rays to MRI

The world’s first x-ray was produced in 1895 by Wilhelm Roentgen; the first x-ray in Australia was performed in 1896, just one year later. X-rays are a form of radiation similar to visible light, radiowaves and microwaves. X-radiation is special because it has a very high energy level that allows the x-ray beam to penetrate through the body and create an image or picture. Since the discovery of the x-ray, the practice of radiology has been continuously evolving. With the advent of computers, the capability of imaging technology has advanced exponentially over the past 30 years; new forms of imaging technology have emerged, while the conventional x-ray film is now digital. The advent of digital imaging means that analogue film techniques are no longer required to capture an image, enabling a patient's images to be transmitted electronically from one physical location to another.

Radiologists now have at their disposal a range of imaging technologies to capture images of the inside of the human body including x-ray, Computed Tomography (CT), Magnetic Resonance Imaging (MRI) and Ultrasound. MRI and ultrasound technologies increasingly allow radiologists to target very specific regions of the human anatomy and without radiation exposure.

Benefits of technology

The benefits of these advances in technology for patients include: earlier, faster, and more accurate diagnosis; less-invasive diagnostic pathways, with reduced morbidity; lower radiation to achieve diagnosis; elimination of some surgical procedures and hospital costs; development of interventional techniques to replace some open surgery procedures; less need for hospitalisation, and shorter stays; painless and accurate monitoring of treatment; facilitating the efficacy and safety of complex surgery; accurate exclusion of serious disease in many instances, leading to more complete patient reassurance and reduced levels of stress; higher confidence levels in the diagnostic process; higher return to the workforce and less social dependency cost.

Unlike some other areas of medicine where automation-induced productivity gains have replaced some human functions, the role of radiologists to drive these technologies and make specific clinical decisions is increasingly complex and more important than ever.

The role of the radiologist

Large, expensive and complex pieces of equipment are used to produce medical images. However this technology is dependent on the specialist doctors who use it. The often indirect nature of service delivery in radiology with its lack of ‘visibility’ to patients and other health professionals frequently leads to a misunderstanding of what the imaging process is, and a misunderstanding of the role of the radiologist.

Radiologists have an in depth knowledge of anatomy, pathology, and imaging technology which is combined with clinical knowledge gained over many years of training and clinical experience. Their role is to bring medical imaging expertise to guide clinical decision making; they are asked to confirm, exclude, stage or monitor almost all types of serious illness and injury in Australia. They may choose to work in various sub-specialties of radiology such as interventional radiology, musculoskeletal imaging, breast imaging, cardiac imaging, or paediatric imaging.

To achieve high-quality imaging results, Radiologists liaise with other clinicians to obtain clinical information to assist them in determining if and what type of imaging is required for a patient’s particular clinical problem. They then ensure that the examination is performed correctly by leading the team of radiographers, sonographers, nurses and other imaging team members. The radiologist interprets the images and provides a specialist medical opinion in a radiology report, which is the end product of an imaging examination. Their findings and opinions must be effectively communicated and understood for optimal patient management.

However, this clinical expertise is currently not utilised to its full potential. Through their specialist training radiologists are the gate-keepers and experts on the relevance and appropriateness of imaging, but are expected to somehow fulfill this duty without having the power of test substitution. More direct involvement of radiologists in the clinical decision making process would reduce unnecessary and inappropriate requests for imaging.

Radiation risk

Over the past two years the issue of radiation risk from medical imaging has been regularly debated by the media and in a range of medical journals; this debate has focused mainly on CT.

The risks from exposure to high-dose radiation are well known. However, the risks from the very low-level radiation that is employed in diagnostic imaging are uncertain and continue to be debated among experts in the field. For example, there have been no large-scale prospective epidemiologic studies that would allow confirmation or quantification of the amount of risk conferred to an individual from a single CT scan. Although these studies are in progress in a number of countries, even if a very small increase in risk is demonstrated, it will take a large number of patients and many years of follow up to prove this.

Therefore, our current ‘best guess’ about the possible risks of low levels of radiation from diagnostic imaging are extrapolated from higher-dose exposures such as those experienced by people who lived some distance from epicentre of the atomic bomb blasts in Nagasaki and Hiroshima, and who were followed to determine whether they developed cancer years later.

The process of determining the appropriateness of an imaging examination for an individual patient is known as ‘justification’. It is important also to remember that all of us are exposed to radiation every day. This is mostly from natural radiation in the soil, rocks, air and cosmic radiation from space. The level of this background radiation varies considerably, depending on geographic location. The potential health risks of radiation exposure are less than risks we are exposed to on a daily basis through activities like driving and bike riding.

The Royal Australian and New Zealand College of Radiologists has been leading efforts to reduce exposure of patients to unnecessary radiation during medical imaging examinations. CT imaging should only be performed in circumstances where the medical benefit outweighs any associated risk, and where the required clinical information that will support a patient’s treatment cannot be achieved by other imaging methods such as ultrasound or MRI, which do not involve radiation exposure.

Challenges of technology

Teleradiology, the advent of digital images and the associated introduction of Picture Archiving and Communication System (PACS) have revolutionised diagnostic-imaging provision and brought great benefits such as rapid remote reporting, the ability to share workloads and faster delivery times. This makes second radiological and subspecialist opinions easier to obtain and provides previously unavailable remote reporting services. However, teleradiology poses a risk if it is not managed clinically and very carefully with the potential for fragmentation of radiology services if the image capture component of the service is disconnected from the process of interpretation.

Diagnostic imaging services are increasingly provided by large entities such as corporations, public hospitals or statewide service networks which generate large reporting loads which can be outsourced to services which compete on price. Increasing pressure on radiologists to perform reporting services as quickly as possible also poses a real risk of disconnecting the radiologist from the rest of the service.

All components of the radiological service need to be performed or overseen by the radiologist while still realising the advantages of state-of-the-art technology. Innovative approaches are sometimes required to maintain this vital role and effective communication processes are essential. Optimising the integration of diagnostic systems and other information and communications technology tools into Australia’s e-health system is an ongoing challenge.

The future

Radiologists are central and indispensable specialist consultants who should have an increasing role in overall patient management. A key focus of training in the diagnostic radiology curriculum is now directed towards a more clinical model in which diagnostic and interventional radiologists are key members of multi-disciplinary teams focused on patient treatment and care; and this focus is long overdue.

Further information

Specifically designed for both referrers and patients, the Inside Radiology website is a collaboration of information from Australia’s radiology community. It sets out easy-toread details about imaging tests and general information on radiology services www.insideradiology.com.au

About the authors

Crystal Whitmore, BA (Hons), Senior Policy Officer, The Royal Australian and New Zealand College of Radiologists.

Lisa Penlington, BA, GDAM, Director, Standards of Practice and Accreditation, The Royal Australian and New Zealand College of Radiologists.

Matthew Andrews, MBBS (Hons) FRANZCR, President, The Royal Australian and New Zealand College of Radiologists; Radiologist in private practice in Melbourne with a special interest in ultrasound.

The Royal Australian and New Zealand College of Radiologists is the leading professional organisation for the promotion of the science and practice of the medical specialties of Radiology and Medical Imaging (Diagnostic and Interventional) and Radiation Oncology in Australia and New Zealand.