What Do They Do in Radiology?

  • A medical doctor is often the first person who advises a patient to see a radiologist. A radiologist’s job is to analyze data from medical imaging procedures to diagnose and treat various medical conditions. 
  • Radiologists are medical doctors who supervise radiologic technologists performing diagnostic imaging tests. At least thirteen years of training must be completed to become a radiologist(1).
  • Diagnostic radiology, interventional radiology, and radiation oncology are the types of medical specialties in radiology(2)
Radiology is the branch of medicine wherein imaging technology is used to diagnose and treat various conditions, such as cancer and trauma. A person who specializes in the field of radiology is called a radiologist. Referring doctors rely on radiologists to identify inconsistencies and make conclusions for diagnosis. Radiologists analyze imaging and test results from computerized tomography (CT), X-ray, magnetic resonance imaging (MRI), mammogram (mammography), positron emission tomography (PET), and ultrasound scans(3) A radiologist sends scan reports to the physician and may speak with them on the phone if there are inquiries. The radiologist may sometimes see an immediate need for additional tests to help diagnose or treat a patient. They then confer with the referring physician if they believe more scans are needed. A radiologist supervises radiologic technologists (radiographers) when performing diagnostic imaging examinations. These radiographers may have inquiries concerning a specific patient. A radiologist acts as a guide who answers any questions they may have. Radiologists may also see patients directly when diagnostic imaging tests are needed and prescribing necessary medications.  They could also perform interventional procedures, such as ultrasound-guided biopsy and angioplasty. According to the American College of Radiology (ACR), at least thirteen years of training is required to be a radiologist(4) This experience includes their medical education (medical school), a four-year residency, and usually an additional one or two years of specialized training.

Types of Radiologists and Their Role

There are three types of medical specialties in the field of radiology: diagnostic radiology, interventional radiology, and radiation oncology(5). Doctors practicing in the field of radiology may certify in other subspecialties and also in medical physics.

Diagnostic Radiologists

Diagnostic radiologists use X-rays, ultrasound, electromagnetic radiation, and radionuclides when diagnosing and treating diseases. Five years of training is necessary to be a diagnostic radiologist: one year for clinical practice and four for radiology training. Most of the trainees complete another year of training during a fellowship. The following are the subspecialties of diagnostic radiology:
  • Hospice and palliative medicine
  • Neuroradiology
  • Nuclear radiology
  • Pain medicine
  • Pediatric radiology
  • Vascular and interventional radiology
A radiologist must first be certified in diagnostic radiology before becoming an expert in any of these subspecialties.

Interventional Radiologists

Experts who specialize in interventional radiology are knowledgeable in image-guided minimally invasive procedures, periprocedural patient care, and imaging technology Interventional radiologists diagnose and treat benign and malignant conditions affecting the abdomen, thorax, pelvis, and extremities. Therapies associated with the specialty include angioplasty, ablation, drainage, embolization, stent placement, and thrombus management. The subspecialties of interventional radiology are:
  • Hospice and palliative medicine
  • Neuroradiology
  • Nuclear radiology
  • Pain medicine
  • Pediatric radiology
At least three years of diagnostic radiology and two years of interventional radiology training is required for this specialty.

Radiation Oncologists

A radiation oncologist makes use of radiation, including other modalities, to treat benign and malignant diseases.  These specialists may also use MRI, ultrasound, hyperthermia, and CT scans to help in treatment planning and delivery. The subspecialties of radiation oncology are:
  • Hospice and palliative medicine
  • Pain medicine
At least five years of training is needed to specialize in this area. One year is spent in general clinical work, while four years are dedicated to radiation oncology training.

Subspecialty Descriptions

A radiologist must first undergo additional training and examination to be certified in one of the following subspecialties.

Hospice and Palliative Medicine

An expert in hospice and palliative medicine specializes in preventing and relieving the hardship experienced by patients with life-limiting conditions.  They work with an interdisciplinary care team to improve quality of life while addressing the physical, mental, and social needs of patients and families. One year of training is needed to be certified for this subspecialty.


Specialists in neuroradiology are highly trained physicians who diagnose and treat medical conditions affecting the brain, spine, head, and neck(6) These disorders include aging and degenerative diseases, cancer, seizure, stroke, trauma, and cerebrovascular diseases. The imaging procedures often involved in neuroradiology are angiography, interventional techniques, MRI scans, and myelography. One year fellowship and another year of practice are required for this subspecialty.

Nuclear Radiology

Those who subspecialize in nuclear radiology administer small amounts of radioactive substances, known as radionuclides, to obtain medical images and data for a diagnosis. Imaging techniques that require nuclear radiology are single-photon emission computed tomography (SPECT) and PET scans. A year of fellowship training is needed to further specialize as a nuclear medicine radiologist.

Pain Medicine

Experts in pain medicine provide health care for individuals with chronic, acute, and cancer pain in both inpatient and outpatient settings. They also coordinate patient care requirements with other specialists. To be qualified for this subspecialty, a radiologist must undergo one more year of fellowship training.

Pediatric Radiology

Pediatric radiology specialists are competent in medical imaging and interventional techniques related to the diagnosis, care, and management of congenital disorders and diseases in infants and children. A pediatric radiologist is also responsible for treating illnesses that arise during childhood. Two years of fellowship and training are required for this subspecialty.

Vascular and Interventional Radiology

An expert in vascular and interventional radiology is responsible for diagnosing and treating diseases using a range of radiologic imaging technologies Some of the techniques they use include fluoroscopy, sonography (sound waves), and digital radiography. The therapies involved in this subspecialty are angioplasty, embolization, stent placement, thrombolysis, abscess drainages, and biliary and genitourinary drainages. Radiologists are required to undergo one year of fellowship and one year of training to be qualified for this subspecialty.

Medical Physics

There are three specialty areas in the discipline of medical physics: diagnostic medical physics, nuclear medical physics, and therapeutic medical physics. Medical physicists use their knowledge of scientific principles in imaging and therapeutic procedures to help diagnose and treat diseases.  They use their expertise to ensure the effective and safe delivery of radiation for diagnostic and therapeutic purposes.

Diagnostic Medical Physics

Specialists in diagnostic medical physics are responsible for facilitating image scans in diagnostic procedures, monitoring equipment performance, and applying safety standards.  They mostly use X-rays, magnetic resonance, and ultrasound in diagnostic procedures.

Nuclear Medical Physics

Nuclear medical physicists facilitate the appropriate use of radionuclides, monitor equipment performance, and apply the safety standards for using radiation safely.  They often use radionuclides in diagnosing and treating diseases.

Therapeutic Medical Physics

Certified medical physicists need to specialize in at least one subspecialty. However, they can also hold separate primary certifications in two or all areas.  They often use gamma rays, X-rays, and electrons for treating diseases.

What Is Interventional Radiology?

Interventional radiology, also called IR, is a field in radiology referring to a range of techniques that rely on using radiological image guidance to precisely target therapy.  Many IR procedures are considered minimally invasive techniques that can result in fewer side effects overall. The vital skills required in interventional radiology are diagnostic image interpretation, needle manipulation, and the use of advanced catheter tubes (angiogram) and wires.  Interventional radiologists are those who are trained in radiology and interventional therapy. Interventional radiology procedures are intended to reduce recovery time and hospital stay in patients who would otherwise require conventional open surgery(7). They also result in less pain and less risk overall. In comparison to traditional surgery, procedures in IR do not require general anesthesia.

Medical Conditions Treated in Interventional Radiology

Here are some of the most common disorders that are treated by an interventional radiologist.


Interventional radiologists treat the narrowing of arteries that lead to restricted blood flow by using balloons (balloon angioplasty) that expand the blood vessel Stenting, or the use of metal springs known as stents, can also be used to hold the arteries open. In some cases, arteries can suddenly become blocked, resulting in rapid blood loss to the affected limb. Unless the supply of blood is restored, these scenarios can lead to an amputation. The job of an interventional radiologist is to apply clot-busting drugs directly to the artery through small catheters to help save the limb. Patients with expanded arteries or aneurysms are at risk of experiencing a rupture and bleeding. An interventional radiologist treats these individuals by relining their blood vessels using a stent graft. Bleeding (hemorrhage) is the most common vascular emergency treated in IR. It is often stopped by blocking (embolization), stenting, or by using a balloon until emergency surgical procedures can be performed.


Interventional radiologists can treat blood clots that occur in the lungs (pulmonary embolism) in two ways.  The first is to use devices (inferior vena cava or IVC filters) to capture blood clots, and the second is to utilize catheter tubes to break the clump. Dilated varicose veins are common in the legs but can also appear in the scrotum or pelvis. These veins can be treated by using heat or irritant drugs and embolization techniques.

Non-Vascular Intervention

Although sometimes referred to as interventional oncology (procedures to treat cancer), non-vascular intervention treatment options can also be used for benign conditions.  These IR therapies may:
  • Treat cancer or tumor (tumor ablation and embolization)
  • Relieve the effects of cancer (nephrostomy and biliary drainage)
  • Drain collections of pus or fluid in the abdomen or chest
  • Insert feeding tubes (jejunostomy and gastrostomy)
  • Treat collapsed bones in the spine (vertebroplasty)
Uterine fibroids are benign tumors that cause substantial menstrual pain and bleeding. The condition can be treated by blocking the uterine artery blood vessels (uterine fibroid embolization or UFE), which results in shrinkage. Fibroids may also block the fallopian tubes, making it difficult for fertilized eggs to attach. Embolization may sometimes be combined with radiation therapy (radioembolization) or drug therapy (chemoembolization). Kidney and liver cancer tumors can be treated with destructive therapies that use heat (laser, microwave, ultrasound, radiofrequency ablation) or cold damage (cryoablation).

Stone Disease

Kidney stones are common and result in infection, pain, and blockage of the organ. Techniques for interventional radiology include inserting a tube in the kidney to let the urine drain. Meanwhile, gallstones can be removed by an interventional radiologist through the use of catheter tubes or stents. These devices allow these deposits to be eliminated by way of drainage.

When Is a Radiologist Needed?

Medical doctors are often the first professionals to recommend patients to visit a radiologist. Some of the most common reasons why a radiologist may be needed are:
  • Torn muscle
  • Pregnancy
  • Broken bone
  • Screening for soft tissue tumors
  • Blocked arteries or other blood vessels
  • Infections
  • Accidents and trauma
  • Presence of foreign objects in the human body
Depending on the procedure, an appointment can take a few minutes or last for several hours. Although patients usually do not need to prepare for the consultation, some tests may require a person to avoid specific food and medications(8). Women should always inform the radiology clinic if they are pregnant or trying to conceive. CT and X-ray scans use low-dose radiation that can be harmful to an unborn child(9).


The job of a radiologist is to analyze imaging and health information test results from CT, X-ray, MRI, mammogram (breast imaging), PET, and ultrasound scans. Referring physicians rely on radiologists to come up with conclusions for diagnosis. Radiologists may sometimes require additional tests to help in diagnosing or treating an individual. They then discuss with the referring doctor if they believe that more scans are necessary. A radiologist may also see patients directly and could even perform interventional procedures, such as angioplasty and ultrasound-guided biopsies. According to the American Board of Radiology, the three types of specialties in the field of radiology are diagnostic radiology, interventional radiology, and radiation oncology(10). Interventional radiology may be an effective alternative to surgery as it can result in fewer side effects and shorter recovery time. Its procedures also cause less pain and less risk compared to open surgery(11). Doctors are often the first professionals to recommend a visit to a radiologist. An appointment with a radiologist can take a few minutes or a few hours, depending on the procedure. Women should always let their doctors know if they are pregnant, as radiation can be harmful to a baby(12).
  1. American College of Radiology. What Is a Radiologist? Retrieved from: https://www.acr.org/Practice-Management-Quality-Informatics/Practice-Toolkit/Patient-Resources/About-Radiology
  2. American Board of Radiology. Radiology Specialties. Retrieved from: https://www.theabr.org/about/radiology-specialties
  3. American College of Radiology. op. cit.
  4. Ibid.
  5. American Board of Radiology. op. cit.
  6. American Society of Neuroradiology. What is Neuroradiology. Retrieved from: https://www.asnr.org/patientinfo/whatisnr.shtml
  7. Johns Hopkins Medicine. Vascular and Interventional Radiology. Retrieved from: https://www.hopkinsmedicine.org/interventional-radiology/what_is_IR.html
  8. UCSF Department of Radiology & Biomedical Imaging. Prepare for Interventional & Neuro Interventional Procedure. Retrieved from: https://radiology.ucsf.edu/patient-care/prepare/ir
  9. Ratnapalan S, Bentur Y, Koren G. “Doctor, will that x-ray harm my unborn child?” [published correction appears in CMAJ. 2009 Apr 28;180(9):952. Dosage error in article text]. CMAJ. 2008;179(12):1293-1296. doi:10.1503/cmaj.080247
  10. American Board of Radiology. op. cit.
  11. Johns Hopkins Medicine. op. cit.
  12. Ratnapalan S, Bentur Y, Koren G. op. cit.

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