Definition & Overview

Radiology is a medical specialty that uses radiation for the diagnosis and treatment of various diseases. Radiation is used either for therapy or imaging studies.

For use in diagnosing medical conditions, radiation works by providing the energy source for imaging tests. When used in this manner, radiology is also referred to as radioscopy. The radiation enables doctors to visually examine the inside of the human body in a non-invasive way. These tests include:

  • X-ray or radiography – An x-ray creates a black and white image of the inside of the body. It is the most commonly used imaging test due to its speed, availability, and lower cost.
  • Magnetic resonance imaging (MRI) scan – This test can create pictures of almost any body part, including those that are surrounded by bones.
  • Fluoroscopy – This is an imaging test that displays continuous x-ray images on a screen.
  • Computed tomography (CT) scan – This generates a 3D image of the inside of the body. It works by taking 2D x-ray images of the body from different angles. The images are then put together to form a 3D image.
  • Positron emission tomography (PET) scan – This test can produce multiplanar images of the body. It is performed by first injecting a radioactive, biologically active substance into the patient. The substance makes the patient emit radiation, and the emitted energy is used to produce images of the body.

For use in the treatment of diseases, radiation works by providing doctors with a visual guide as they perform minimally invasive procedures. These procedures are used instead of open surgery. They help minimise the risk of bleeding, infection, and scarring. They also shorten patients’ recovery times. This practice falls under interventional radiology. It can treat a wide range of medical conditions. An angioplasty is one example of a procedure that can be performed in this way.

Radiology is also used to perform nuclear medical procedures. Nuclear medicine works by attaching medications to a radioisotope, or a radioactive material called a tracer. They form what is called a radiopharmaceutical drug. This drug can be administered orally, intravenously, or through inhalation. The drug can target specific parts of the body. By enabling targeted therapy, it makes medications more effective.

Doctors who specialise in this field are called radiologists. Radiologists receive an additional five to six years of training in their field of specialty. This is on top of their medical degree. In the course of their work, they are responsible for:

  • Determining which imaging test will be most effective for each patient/case
  • Supervising radiology technologists to ensure the accuracy of the tests
  • Studying the images obtained through radiology tests
  • Interpreting the results of these tests to detect or pinpoint an abnormality
  • Determining what the abnormalities are and their severity
  • Recommending further exams or the patient’s available options moving forward

When Should You See A Radiologist?

Patients should see a radiologist if they are suffering from unexplained symptoms. They are usually referred by a general physician. The radiologist can provide the GP with more information about the patient’s condition. Together, they can diagnose the patient’s medical condition.

An x-ray is considered as the primary diagnostic imaging test. It can help detect:

  • Arthritis
  • Pneumonia
  • Bone tumours
  • Fractures
  • Congenital skeletal anomalies
  • Breast cancer
  • Osteoporosis

If an x-ray cannot provide all the necessary information or images, radiologists turn to other tests. A fluoroscopy, for one, is more effective in detecting problems in the genitourinary system and the gastrointestinal tract.

An MRI scan is more effective than an x-ray in detecting and diagnosing problems involving the heart, brain, spine, and the musculoskeletal system.

A CT scan is one of the most detailed imaging studies in use nowadays. Due to this, it is commonly used to diagnose urgent medical conditions, such as pulmonary embolism, kidney stone obstruction, appendicitis, cerebral haemorrhage, and aortic dissection, among others. Recent developments in the field of CT scanning also helped improve the test’s scanning times and resolution. This also made the test more accurate.

Positron emission tomography or PET scans can measure important body functions, such as blood flow, oxygen supply, glucose metabolism, and so on. By doing so, they help doctors evaluate how well the organs are functioning.

Patients can see radiologists not only for diagnosis but also for treatment. Interventional radiology is helpful in treating peripheral vascular disease, renal artery disease, and so many others.

A PET scan can also be integrated with a CT scan. PET/CT scans are able to pinpoint exactly where abnormal metabolic activity in the body is coming from. When PET and CT are combined, the resulting scan is able to provide more accurate results than when they are used separately.

It is also involved in the placement of interventional medical devices, such as:

  • Inferior vena cava filter
  • Gastrostomy tube
  • Biliary stents

Nuclear medicine, on the other hand, can be used in diagnosing and treating:

  • Heart attacks
  • Epileptic seizures
  • Parkinson’s disease
  • Alzheimer’s disease
  • Hyperthyroidism


  • Nordqvist C. “What is radiology? What is nuclear medicine?” Medical News Today. 2014 September 16.

  • Gunn AJ, Tuttle MC, Flores E, Mangano M. et al. “Differing interpretations of report terminology between primary care physicians and radiologists.” Journal of the American College of Radiology.

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