Medical imaging is a key part of diagnosing and monitoring many health conditions, but not all scans work the same way. Technologies like X-ray, fluoroscopy, ultrasound, CT, and MRI each use different methods to look inside the body, and each is best suited for answering specific medical questions.
Understanding the differences can help patients feel more comfortable and know what to expect during their visit.
The UAB Department of Radiology offers a full range of imaging services. These are the most commonly used exams.
X-rays
X-rays are often the first imaging test a patient receives. They use a small amount of radiation to produce quick images of the body, making them especially useful for detecting broken bones or evaluating the lungs and chest. Because they are fast and widely available, X-rays remain one of the most common imaging tools.
“X-ray imaging offers a fast, non-invasive look inside the body, providing doctors with insight to diagnose bone and other health issues,” said Elainea Smith, M.D., chief of X-ray.
Fluoroscopy
Fluoroscopy is similar to an X-ray but provides moving, real-time images. Instead of a single snapshot, it allows doctors to watch how structures inside the body function and move. It is often used to evaluate swallowing, digestion, or blood flow, and to help guide certain procedures.
“Fluoroscopy uses live action or video X-rays to provide a look inside your digestive system, including sometimes watching its function in real time,” said Elainea Smith, M.D., chief of fluoroscopy.
Ultrasound
Ultrasound uses sound waves to create real-time images inside the body. It is commonly used during pregnancy and to assess organs such as the liver, kidneys, and gallbladder. Because it does not use radiation and can show movement as it happens, ultrasound is both safe and versatile.
“Ultrasound is an extremely versatile imaging modality used both in radiology departments and at the bedside in clinic and emergency settings,” said Constantine Burgan, M.D., chief of ultrasound. “It allows for rapid, real-time diagnosis, especially when patients present with pain, as the exam can be tailored to their specific concern. While it serves as an excellent screening tool, it is also the modality of choice for many conditions.”
CT scans
CT scans, or computed tomography, build on X-ray technology to create detailed cross-sectional images of the body. By combining multiple images taken from different angles, CT allows physicians to see organs and structures more clearly. It is especially valuable in emergency situations, where speed and accuracy are critical.
“CT is an integral part of healthcare imaging as it can be performed rapidly and with a high level of anatomic and diagnostic accuracy, helping patients and clinicians obtain critical information and guiding the next steps of clinical management in a time-efficient manner,” said David Summerlin, M.D., chief of CT.
MRI scans
MRI, or magnetic resonance imaging, does not use radiation at all. Instead, it relies on magnets and radio waves to produce highly detailed images of soft tissues. This makes it particularly useful for evaluating the brain, spine, and joints. Although MRI exams take longer and require patients to remain still, they provide exceptional detail.
“We are pleased to offer the most advanced and customized MRI services to the patients in the Birmingham metropolitan area as well as the in the whole state of Alabama,” said Manoj Tanwar, M.D., chief of MRI. “Patients could seamlessly get a high-resolution MRI at one of their closest UAB imaging centers without worrying about any radiation exposure.”
While each imaging method works differently, they all serve the same purpose: helping care teams clearly see what is happening inside the body.
Most imaging exams are quick, safe, and painless. At UAB, radiology specialists carefully select the most appropriate imaging test for each patient while prioritizing safety, accuracy, and a supportive, patient-centered experience.