What Is Radiology?

  • Radiology is a field of medicine that uses different medical imaging equipment to help doctors diagnose and treat diseases.
  • Radiology is important in the medical industry because doctors from various medical sectors, like surgery, pediatrics, obstetrics, infectious diseases, and oncology, rely on radiologists to give an accurate diagnosis and treatment recommendation.
  • Radiologists use medical imaging procedures like CT, MRI, PET, and mammography to help referring physicians diagnose health issues and treat patients.
  • Becoming a radiologist requires extensive training and education. It takes roughly 10 years to complete education requirements and to receive certification.
  • Radiology subspecialties, like hospice and palliative medicine, neuroradiology, nuclear radiology, and pain medicine, require additional examination and training.

Radiology and Its Use

Radiology or diagnostic imaging is a branch of medicine that relies on medical imaging to support doctors in diagnosing diseases and delivering treatment.

Radiology images are images captured using various imaging techniques, such as X-ray radiography and nuclear medicine

Medical professionals use radiology to detect a wide range of health issues, including broken bones, heart defects, blood clots, and gastrointestinal conditions.

Radiology vs. Radiography

Radiology is a branch of medicine that analyzes images from various modalities, such as computed tomography (CT), magnetic resonance imaging (MRI), X-rays, and ultrasounds. The discipline uses medical images to diagnose and treat various health conditions. 

Radiology should not be confused with radiography, an imaging technique that uses radiation to see the inside of the body or industrial components. 

Radiography is mostly used in the medical field and industrial field. 

In medicine, a radiographer uses various medical imaging equipment to view internal body parts.

Radiography uses medical images from several modalities, like radiographs, CT, MRI, ultrasound, and mammogram.

In industrial radiography, radiation is used for the non-destructive diagnosis of machines, buildings, or other industrial components.

Industrial radiography relies on X-rays, gamma rays, or other forms of radiation to find weaknesses in industrial structures.

Types of Radiology Specialties

There are various types of radiology specialties. According to the American College of Radiology (ACR), some of the most well-known medical specialties under radiology are diagnostic radiology, interventional radiology, and radiation oncology.

Diagnostic Radiology

Diagnostic radiology is focused on diagnosing and treating diseases through the use of medical imaging.

Diagnostic radiologists use X-rays, ultrasound, electromagnetic radiation, and other imaging equipment for accurate detection of abnormalities in the body.

A diagnostic radiologist can take up cardiovascular radiology, pediatric radiology, and interventional subspecialty of radiology.

Interventional Radiology

Interventional radiology combines both minimally-invasive, image-guided procedures and periprocedural patient care for diagnostic and therapeutic purposes. 

Interventional radiology procedures include angiograms, angioplasty, fluoroscopy, and biopsies. Studies discovered that interventional radiology procedures could be as effective as invasive procedures like traditional surgeries[1].

Interventional radiology procedures are guided by real-time imaging to ensure precision and detect abnormalities. 

With interventional radiology, doctors can treat patients without the need for surgeries that require lengthy recovery time.

Radiation Oncology

Radiation oncology uses ionizing radiation and other modalities to treat serious illnesses, like colon cancer and breast cancer.

Aside from ionizing radiation, radiation oncologists use CT, MRI, ultrasound, and hyperthermia as additional interventions to support treatment planning and delivery. 

Importance of Radiology

Medical professionals from every sector of the healthcare field use radiology to diagnose and treat various health issues.

According to research, surgeons rely on radiology for pre-operative planning and image-guided interventions[2].

A 2014 study also showed that interventional radiology played a crucial role in the daily care of sick children. According to the research, radiology helped critically-ill children suffering from liver disease, neonatal tumors, and vascular malformations[3].

Radiology is also used by obstetricians to monitor the health of unborn babies. Obstetric ultrasound uses sound waves to capture images of a baby inside a pregnant woman.

Medical imaging can also be used to know the state of the mother’s uterus and ovaries. 

Conventional radiology is also used to evaluate small bones and small joint trauma. Aside from conventional radiology, multidetector computed tomography and cone beam computed tomography are also used by trauma surgeons[4].

Radiology can also be used in controlling the spread of infectious diseases, like COVID-19 or the disease caused by the new coronavirus.

According to a study, modern imaging techniques are crucial in the assessment of patients with suspected infection[5]

The study concluded that a positron emission tomography (PET) scan with 18F-fluorodeoxyglucose (18F-FDG) imaging could be useful in managing patients with osteomyelitis, infected prostheses, fever of unknown origin, and AIDS[5].

Oncologists also use radiology to treat cancer patients. According to research, radiation therapy could slow down the reproduction of cancer cells[6].

However, radiotherapy also has adverse side effects. Although side effects differ for every condition, the most common side effects include fatigue, hair loss, skin changes, nausea, vomiting, and diarrhea[7].

How Is Radiology Done?

Radiologic technologists use a wide range of medical imaging procedures to know the state of the human body.

  • Radiograph

Radiographs are images developed on sensitive film by X-rays, gamma rays, or other radiation. Radiographs can be used to capture an image of the bones, chest, and abdomen.

  • Computed tomography (CT)

Computed tomography is a medical imaging technique that uses computer-processed combinations of X-ray measurements taken from several angles. Using a CT scan, doctors can see inside a patient’s body without cutting them open.

For this technique, radiographers use a computer to control the movement of the X-ray source and detectors. The computer processes the data before producing the image.

  • Magnetic resonance imaging (MRI)

Magnetic resonance imaging is a diagnostic imaging procedure. Radio waves and magnetic fields are used in an MRI to capture images of the anatomy and the physiological processes of the body.

  • Mammography 

Mammography is a medical imaging procedure that uses low-energy X-rays to capture images of breast tissues. It is used to examine the human breast for diagnosis and to detect abnormalities like breast cancer.

  • Fluoroscopy 

Fluoroscopy is another medical imaging technique known for its use of X-rays to capture real-time moving images of the body. 

A fluoroscopy procedure uses an X-ray beam that passes through the body part being examined. Images taken by the X-ray are projected on a monitor so that the body part and its motion can be viewed in detail.

Fluoroscopy is most commonly used in procedures, like gastrointestinal tract radiography, lumbar puncture, urological surgeries, and orthopedic surgeries. 

  • Nuclear medicine

Nuclear medicine is also one of radiologistsimaging modalities. It involves the application of short-acting radioactive substances in the body for diagnosis and treatment of diseases. 

  • Positron emission tomography (PET)

Positron emission tomography is a medical imaging technique that uses radioactive substances to monitor the human body’s metabolic processes.

A PET scan detects changes at the cellular level. This makes it useful in the early detection of various health issues.

  • Teleradiology 

Radiologists also rely on teleradiology or the transmission of radiological patient images. With teleradiology, sharing studies and new discoveries is easier for radiologists.

What Injuries and Diseases Can Radiology Detect?

Radiology can be used to diagnose a wide range of diseases and injuries.

A CT scan uses X-rays and a computer to capture images of the organs, bones, and other tissues. It can be used to detect stroke, pulmonary embolism, appendicitis, and bone fractures[8].

MRI machines are large, tube-shaped magnets that temporarily realign water molecules inside the body. 

Radiographers use radio waves to detect faint signals, which are used to form cross-sectional MRI images.

An MRI scan can detect aneurysms of cerebral vessels, eye and inner ear disorders, multiple sclerosis, spinal cord disorders, tumors, and brain injury caused by trauma[9].

A PET scan uses a radioactive drug or a tracer to detect diseases before it shows up on other imaging tests.

The radioactive drug may be injected, swallowed, or inhaled. A PET scan can evaluate and detect cancer, heart disease, and brain disorder[10].

Roles and Responsibilities of a Radiologist

Radiologists are medical professionals who use imaging technology to help referring physicians diagnose and treat diseases and injuries.

Before radiologists discuss the diagnosis with the referring doctor, they interpret and analyze the medical images.

By choosing the appropriate exam and directing radiology technologists in performing quality exams, radiologists serve as expert consultants to medical doctors.  

Radiologists not only analyze and report on images. They also recommend treatment and request additional tests when needed.

Radiologists can perform or instruct radiographers of diagnostic imaging procedures. They can also provide treatment to patients following diagnosis.

Diagnostic radiologists use several imaging procedures to view the body’s organs and assess or diagnose the patient’s condition.

Diagnostic radiologists can also specialize in the following subspecialties:

  • Breast imaging 
  • Cardiovascular radiology
  • Chest radiology
  • Emergency radiology
  • Gastrointestinal radiology 
  • Reproductive and urinary systems or genitourinary radiology
  • Head and neck radiology
  • Musculoskeletal radiology
  • Neuroradiology
  • Pediatric radiology 

Meanwhile, interventional radiologists are medical professionals who rely on image-guided, minimally invasive techniques to treat and diagnose medical problems.

Interventional radiologists guide medical instruments through small incisions in the body to reach tumors and to deliver treatments.

Radiology oncologists create and oversee the radiation therapy of cancer patients. 

The highly-trained doctors monitor cancer patients’ reactions to the therapy and adjust treatment to ensure the patients receive appropriate quality care. 

Radiation oncologists are trained in cancer medicine, in the safe use of radiation, and in managing the side effects of radiation.

How Does One Become a Radiologist?

After completing four years of undergraduate education, individuals interested in joining the radiological society have to take a year of clinical internship. 

Clinical practice is followed by four-years of medical school.

Applicants have to be a part of a ranking and matching system organized by the National Resident Matching Program before taking up a residency program

Residency programs for radiologists are accredited by the Accreditation Council for Graduate Medical Education.

Most residency graduates pursue a subspecialty fellowship. The following are some of the subspecialty fellowship the applicants can take:

  • Abdominal radiology
  • Body imaging/cross-sectional imaging
  • MR imaging
  • Cardiothoracic radiology 
  • Cardiovascular radiology
  • Emergency radiology
  • Musculoskeletal radiology
  • Neuroradiology
  • Nuclear radiology
  • Pediatric radiology
  • Vascular and interventional radiology 
  • Women’s imaging

Subspecialty Descriptions

Some diagnostic radiology subspecialties take more than a year to complete. A medical student taking the following subspecialties need specialized training and additional examination.

  • Hospice and Palliative Medicine

Hospice and palliative medicine requires medical professionals with special knowledge and skills to relieve the suffering experienced by patients with life-limiting illnesses.

Along with an interdisciplinary hospice or palliative care team, specialists have to maximize the patients’ quality of life and address their physical, psychological, social, and spiritual needs.

  • Neuroradiology 

Neuroradiology needs specialists who diagnose and treat disorders of the brain, sinuses, spine, spinal cord, neck, and the central nervous system. 

Medical professionals with a neuroradiology subspecialty treat aging and degenerative diseases, cerebrovascular diseases, seizure disorders, cancer, stroke, and trauma.

For this specialty, medical students undergo an additional one year of fellowship training and one more year of practice or additional approved training.

  • Nuclear Radiology 

Nuclear radiology specialists use tracer quantities of radionuclides or radiopharmaceuticals to collect physiological data.

The specialists use the data to diagnose and treat benign and malignant conditions in adults and children. 

  • Pain Medicine 

Pain medicine specialists treat patients experiencing acute, chronic, or cancer pain. One more year of fellowship training is needed for medical professionals under this specialty.

  • Pediatric Radiology 

Pediatric radiology uses imaging and interventional procedures to diagnose and manage various congenital abnormalities and diseases particular to infants and children.

Individuals taking this subspecialty need two additional years of training. This includes one year of a fellowship and another year for practice or additional approved training.

Following the American Board of Radiology requirements, students have to pass the core exam and certifying exam before becoming a board-certified radiologist.

The American Osteopathic Board of Radiology awards board certification to doctors of osteopathic medicines who specialize in radiology.

The Radiological Society of North America (RSNA) helps physicians receive their certifications by offering high-quality educational resources, including continuing education credits.

The Beginning of Radiology

Radiology began with Wilhelm Conrad Röntgen’s discovery of X-rays in Germany.

On November 8, 1985, Röntgen, a mechanical engineer, developed an energized, lightproof cathode ray tube that glows when placed a couple of feet away from a fluorescent screen.

The engineer discovered that the screen was responding to unknown rays transmitted throughout the room, which he called X-rays

After his experiment, other people began to develop radiographic images that started as a burst of ionizing radiation and created a contrast image on film.


Radiology is a field of medicine that relies on medical imaging to diagnose diseases and deliver treatment.

Radiology is important because healthcare professionals from every sector of the medical field rely on radiology for diagnosis and treatment.

Radiologists are medical professionals who use imaging technology to help physicians diagnose and treat various medical issues. 

These professionals undergo extensive medical training before they receive certification to practice radiology.

  1. Katsanos, K., Ahmad, F., Dourado, R., Sabharwal, T., & Adam, A. (2009). Interventional radiology in the elderly. Clinical Interventions in Aging, 4: 1-15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2685220/
  2. Elson, D., & Guang-Zhong, Y. (2010). The Principles and Role of Medical Imaging in Surgery. Key Topics in Surgical Research and Methodology, 529-543. https://doi.org/10.1007/978-3-540-71915-1_39
  3. Barnacle, A. (2014). Interventional radiology in infancy. Early Human Development, 787-790. https://pubmed.ncbi.nlm.nih.gov/25260962/
  4. Guglielmi, G., & Nasuto, M. (2017). Emergency and Trauma in MSK Radiology. Seminars in Musculoskeletal Radiology, 165-166. https://doi.org/10.1055/s-0037-1603352
  5. Kumar, R., Basu, S., Torigian, D., Anand, V., Zhuang, H., & Alavi, A. (2008). Role of Modern Imaging Techniques for Diagnosis of Infection in the Era of 18F-Fluorodeoxyglucose Positron Emission Tomography. Clinical Microbiology Reviews, 209-224. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2223836/
  6. Baskar, R., Lee, K., Yeo, R., Yeoh, K. (2012). Cancer and Radiation Therapy: Current Advances and Future Directions. International Journal of Medical Sciences, 193-199. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3298009/
  7. National Cancer Institute. Radiation Therapy Side Effects. (2018). Retrieved from https://www.cancer.gov/about-cancer/treatment/types/radiation-therapy/side-effects
  8. New York University. Common Conditions. Retrieved from https://med.nyu.edu/radiology/about-us/subspecialties/emergency-radiology/our-services/common-conditions
  9. Mayo Clinic. MRI. (2019). Retrieved from https://www.mayoclinic.org/tests-procedures/mri/about/pac-20384768
  10.  Mayo Clinic. Positron emission tomography scan. (2019) Retrieved from https://www.mayoclinic.org/tests-procedures/pet-scan/about/pac-20385078#:~:text=PET%20scans%20of%20the%20brain%20for%20Alzheimer’s%20disease,-A%20PET%20scan&text=A%20positron%20emission%20tomography%20(PET,up%20on%20other%20imaging%20tests.
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