Joint pain is a common problem. Often it is transient and resolves on its own. However, when it persists, x-rays or more advanced imaging can help make a correct diagnosis.
Arthritis can be one cause of persistent joint pain or pain in multiple joints. X-rays are often a good tool for determining if arthritis exists and, specifically, what type. Common types of arthritis include rheumatoid arthritis, psoriatic arthritis, and osteoarthritis. Several less common types of arthritis also occur with regular frequency. It is important to make the correct diagnosis since the treatment varies per arthritis condition. When multiple joints are involved, a survey of the joints is often helpful to confirm the diagnosis and to establish a baseline by which future studies can be compared. This serves as a means of determining how responsive a patient is to the recommended treatment.
Bright white areas represent inflammation in this wrist MRI.
In the past, treatment options for arthritis have been limited. Today, newer effective “biologic” medications are now widely available. As with any medication, there are potential adverse reactions and the cost of prescribed drugs can also be prohibitive. The potential adverse side effects of these medications can also be diminished by adjusting the dose. An MRI can help determine a proper dosing amount. For these reasons, it is vitally important to secure a correct diagnosis.
At Wake Radiology, we take all of this into account. We do our very best to capture the needed image the first time and your joint images are interpreted by trained specialists in orthopedic and sports imaging.
An x-ray is not the only type of medical imaging that can assist with diagnosing arthritis. In fact, other tools – like MRI and CT – can be more effective.
Early in the disease process, x-rays may look normal with elements so subtle that a diagnosis can be difficult. In these cases, more sophisticated imaging may be necessary, especially MRI. An MRI can often expose earlier changes in the bones, in addition to soft tissue abnormalities associated with arthritis such as:
- Joint capsule thickening or inflammation
- Bone marrow edema (swelling), and
- Inflammation of the tendon and tendon sheaths.
The additional cost of the MRI, over an x-ray, can be justified in that a correct diagnosis will get the patient started on the appropriate treatment plan sooner. Also, follow-up MR imaging can quickly and accurately determine if the treatment is having its desired effect, potentially saving thousands of dollars and months of treatment with expensive drugs.
MRI is also useful to characterize the extent of the arthritis and potential need for steroid injections for pain or joint replacements. If a replacement is needed, MRI is sometimes used to customize the type of hardware needed. Finally, MRI is used extensively to exclude other causes of pain apart from arthritis including tendonitis and tendon tears, ligament injuries, muscle strains, bursitis, tumors, or even subtle fractures – all of which are not detectable on x-rays.
A CT scan can be a useful imaging tool when MRI is not possible. For example, a CT is a good option if the patient has an incompatible pacemaker or is not physically able to get into the machine. A nuclear medicine bone scan is also a very sensitive test for determining if the patient’s cause of pain is bone-related and possibly due to arthritis, but is not recommended in making specific diagnoses.
If you are suffering from joint pain or arthritis, talk with your doctor to determine if you are someone who may benefit from a steroid injection for pain relief. Selectively injected joints can dramatically decrease pain for months. Some joint injections benefit from being conducted under fluoroscopic, CT or ultrasound guidance as this helps ensure the accurate delivery of medicine to the joint. At Wake Radiology, we routinely inject hip, shoulder and knee joints as well as the small joints of the feet and ankles, but any joint can be accessed. While not a cure for damaged joints, steroid injections will, in most cases, relieve pain due to inflammation.
We encourage you to talk with your doctor about how medical imaging could assist in how you treat your joint pain or arthritis.
Imaging tools play an important role in diagnosing certain types of joint pain.
If you wake up with stiff, achy joints that interfere with your ability to move freely, it’s probably a good idea to get them checked out. Maybe you have trouble typing or texting. Or maybe buttoning your shirt has become more challenging. You might even notice your knees creaking, crackling, or popping when you get out of bed in the morning. According to Meera Subash, M.D., a rheumatologist with McGovern Medical School at UTHealth in Houston, TX, if you’re having any of those symptoms, your first stop should be your primary care provider.
Your doctor will ask about your symptoms, examine your ailing joints, and often order x-rays. Why? X-rays can help your provider sort out whether the pain you are feeling is related to issues with your bones or joints, as in the case of rheumatoid arthritis (RA), osteoarthritis (OA), or some other joint-related ailment. “In many cases, the PCP will order x-rays of the hands, wrist, and feet even before referring patients to rheumatology,” says Dr. Subash.
Here, we asked the experts for the lowdown on how x-rays may be used to diagnose and treat rheumatoid arthritis.
What Is RA?
RA is a progressive and treatable disease that affects an estimated 1.3 million Americans. Unlike its more common cousin, OA, RA is not related to repetitive use or wear and tear. Instead, it’s an autoimmune disease that causes your body to inadvertently turn on itself.
With RA, your body attempts to fight off a perceived invader, some of which resemble molecules that naturally occur in your joints, explains Larry Burk, M.D., a holistic musculoskeletal radiologist in Durham, NC, and former associate professor of radiology at Duke University Medical Center. The end result: Your body begins attacking its own joints, which causes pain and limited mobility.
RA typically affects the joints in the hands, wrists, and feet, but later stages of the disease can involve larger joints, too. While there’s no cure for RA, a variety of medications can help slow the disease process and ease the pain. The earlier patients are diagnosed and treated, the better the outcome.
Why X-Rays for Detecting RA?
X-rays are accessible, inexpensive, and effective. In fact, experts agree, x-rays play a key role in diagnosing and monitoring RA. “With x-rays, you can see changes in the cartilage and the joints, sometimes even when the blood work comes back normal,” says Rashmi Magnati, M.D., an assistant professor and interim section chief of immunology, allergy, and rheumatology at Baylor College of Medicine in Houston, TX. “In later stage disease, we also tend to see bony erosions on x-ray.”
True, x-rays use a form of radiation called ionizing radiation that is dangerous to the human body in large doses. But with RA, techs typically focus images on the hands, feet, and occasionally the knees and hips, so none of your vital organs are exposed to the radiation.
Want some numbers? A single x-ray of the joints and limbs has a radiation dose of only 6 millirem (mrem), while the average annual radiation dose from natural background sources (the amount you are exposed to from everyday living) hovers around 300 mrem, according to the Environmental Protection Agency.
Rheumatoid Arthritis Hand X-Ray
What Do Doctors Look for on X-Ray?
X-rays are quick, painless, and they highlight the bones and soft tissue in white on imaging. With those features illuminated, doctors can hone in on key signs of RA:
Soft tissue swelling
Bony erosions
Narrowing of the joint
Thinning of the cartilage
Thinning of the bones near the joints
If the diagnosis still isn’t clear, doctors may order an ultrasound or MRI. Ultrasound may help identify fluid in the joint and inflammation, but it’s also a subjective exam. “I might see evidence of RA on ultrasound, but my colleague might not see it,” Dr. Magnati says. “So when we're trying to establish a diagnosis in very early stage disease and x-rays look normal, I’ll order an MRI.”
Research suggests that MRI is a highly sensitive test that can detect bone erosions up to three years before they’re visible on conventional x-rays. While x-rays continue to be important for the diagnosis and management of RA, MRI is emerging as the imaging exam of choice when the diagnosis isn’t clear-cut.
Which Body Parts Are X-Rayed?
RA begins as a peripheral disease that has a strong affinity for the hands. Plus, since there are more joints in the hands than any other region of the body, doctors often order x-ray images of the hands first—then the feet.
“There are more than 30 joints in the hands, so getting x-rays of the hands provides a very good diagnostic yield,” says Dr. Magnati. If the x-rays show bone erosions and narrowing of the joints at the base of your fingers near the palm, the knuckles, and the uppermost joint of the thumb (the metacarpophalangeal, proximal interphalangeal, and thumb interphalangeal joints respectively), that’s classic RA.
RA tends to affect joints in pairs, so doctors typically order x-rays of both hands and both feet (or both knees, shoulders, and hips in advanced disease). “The other area that can be involved in RA is the neck, where the spine connects to the skull,” says Dr. Burk.
How Do Doctors Use X-Rays to Monitor RA?
For clinicians, x-rays are an invaluable tool to diagnose RA when patients’ lab results are elusive. After diagnosis, doctors use x-rays to monitor how patients are responding to treatment and guide treatment decisions.
In fact, clinicians often rely on x-rays to decide whether to intensify treatment or change medication. “With certain disease-modifying anti-rheumatic drugs like methotrexate, x-ray imaging may show some of the hallmark changes of RA reverse over time,” says Dr. Maganti.
So if you regularly struggle to open the marinara jar, or your fingertips can’t quite text in the same rapid-fire way they once did, see your primary care provider. The only way to really know whether your woes are due to regular wear and tear or something more is if you get a complete workup, which usually includes x-rays.
Meet Our Writer
Amy Paturel, M.S., M.P.H.
Amy Paturel, M.S., M.P.H. is a health and science writer and essay writing teacher in Southern California. You can find her work in The New York Times, The Washington Post, Discover Magazine, Good Housekeeping, AARP