Radiology Specialties: What are the Differences Between Diagnostic, Interventional, and Therapeutic Radiology?



A radiologist is a medical doctor specializing in imaging technologies to diagnose and treat various conditions. They use multiple types of imaging techniques, including x-ray, ultrasound, computed tomography (CT) scan, nuclear medicine scanning (PET/SPECT), magnetic resonance imaging (MRI), and angiography.

These advanced technologies provide radiologists with a unique insight into the body’s internal structures and systems. As a result, they can accurately diagnose diseases, injuries, and other medical conditions by studying and interpreting the images.

Diagnostic and interventional radiology are two important specialties within the field of radiography. Diagnostic radiology diagnoses diseases and injuries using imaging technologies, while interventional radiology involves performing procedures such as biopsies, catheterizations, and angiograms to diagnose and treat conditions. A third specialty, therapeutic radiology, specializes in radiation treatments for cancer and other medical conditions.

Continue reading as we explore the differences between the types of radiology.

Diagnostic Radiology

Diagnostic radiology aims to provide accurate diagnoses and effective treatment plans that lead to improved patient health outcomes.

Radiologists use diagnostic radiology to see the organs, tissues, and other structures inside the body, and to identify fractures, tumors, infections, and other conditions. Making accurate diagnoses based on these images requires precision, strict attention to detail, and comprehensive knowledge of anatomy and physiology.

Radiologists are also experts in determining the type of imaging study necessary for the patient’s condition or disease. Diagnostic techniques include:

  • Computed Tomography (CT Scan) —CT scans use X-rays to create images of the body from different angles.
  • Magnetic Resonance Imaging (MRI) — MRIs use a powerful magnetic field and radio waves to create detailed images of the body’s internal organs, bones, and soft tissues.
  • Magnetic Resonance Angiography (MRA) — MRA is a type of MRI used to diagnose and treat conditions that affect the blood vessels, such as aneurysms and peripheral artery disease.
  • Mammography —An X-ray technique used to detect abnormalities or cancer in the breast tissue.
  • X-Rays —X-rays are the oldest and simplest form of imaging. They use electromagnetic radiation to create images of the bones and other structures inside the body.
  • Ultrasound — Ultrasound uses sound waves to create images of the body’s internal structures.


Interventional radiology

Interventional radiology is a branch of radiology that uses imaging technology to diagnose and treat conditions. It’s minimally invasive because it doesn’t require the use of surgery. Instead, it uses imaging techniques to guide catheters and other instruments through the body to the area requiring attention.

Interventional radiology can be used to:

  • Diagnose vascular diseases such as aneurysms or peripheral artery disease
  • Embolize tumors to stop their growth
  • Insert stents for blocked arteries
  • Remove blood clots from veins or arteries
  • Ablate tumors without surgery
  • Place feeding tubes into the stomach through small incisions rather than open surgery
  • Perform biopsies to diagnose cancer and other conditions
  • Drain abscesses

Using imaging technologies before a procedure gives a greater understanding of anatomy, leading to improved treatment precision. This reduces potential side effects as only affected areas are targeted rather than a wider area which could affect healthy tissue. Furthermore, interventional techniques can offer a quicker diagnosis, allowing for earlier treatment and improving patient outcomes.

This field of radiology has grown in recent years due to its benefits over traditional open surgeries. In many cases, it’s much less traumatic for patients, requires shorter recovery times, carries less risk of complications, and can provide effective results.

Therapeutic radiology

Therapeutic radiology, also known as radiation oncology or therapy, is the specialty of using radiation to treat cancer and other conditions. It harnesses X-rays or other forms of ionizing radiation, such as gamma rays, to kill cancer cells and prevent them from returning or multiplying.

Radiation therapy can be given in different forms. External beam radiation is the most common form. It uses a machine to direct radiation from outside the body. However, internal radiation is sometimes used, which involves placing radioactive material near affected tissue inside the body, usually through an implant.

Therapeutic radiation can be used as a standalone treatment or in conjunction with other treatments, such as chemotherapy and surgery. It’s often used to shrink tumors before they are surgically removed or after surgery to ensure they don’t return. Sometimes, people have palliative radiation therapy to ease the effects of advanced cancers and improve their quality of life.