Tomosynthesis Useful for Spotting OA

Osteoarthritis diagnosis more accurate with tomosynthesis than X ray

(RxWiki News) Advances in technology have given us amazing ways to see inside a person's body. Using X-ray or MRI, doctors can diagnose patients without cutting into their bodies. Not all imaging techniques, though, are equal.

Tomosynthesis, an imaging technology used to spot breast cancer, may be better than X-ray imaging for diagnosing knee osteoarthritis.

"Get screened for arthritis if you have joint pain."

Osteoarthritis is often diagnosed using traditional X-ray, MRI, or CT images. However, each of these imaging techniques has its limitations.

With these limitations in mind, Daichi Hayashi, M.D., Ph.D., of Boston University School of Medicine, and colleagues set out to see if tomosynthesis could be a more accurate way to spot osteoarthritis in the knee.

People develop osteoarthritis, the most common type of arthritis, when the bone and tissues in the joints wear away over time. This "wear and tear" leads to joint pain and stiffness.

Dr. Hayashi and a team of researchers led by Ali Guermazi, M.D., Ph.D., also of Boston University School of Medicine, found that tomosynthesis is more accurate than X-ray at spotting the signs of wear and tear in knee joints.

X-ray imagining is used frequently to diagnose osteoarthritis. Yet, recent research has shown MRI to be more accurate than X-ray.

Even though MRI makes better quality images, it is costly.

CT scan is another useful tool for diagnosing osteoarthritis. However, CT scans put patients through higher doses of radiation than X-rays.

Through their research, Dr. Hayashi and colleagues found that tomosynthesis identified more osteophytes (bone spurs) and subchondral cysts (fluid-filled sacs inside the bone) in the knee joint, compared to normal X-ray imaging.

Tomosynthesis uses X-rays to create an image of the joint. Unlike X-rays, which create a two-dimensional image, tomosynthesis produces a series of slices at different depths, creating a three-dimensional image of the joint.

For their study, the researchers took images of 40 participants' knees using X-ray, tomosynthesis, and MRI. They took note of the osteophytes and subchondral cysts they found, and asked participants to rate their knee pain.

Regardless of whether patients had osteoarthritis or not, tomosynthesis improved the detection of osteophytes in the knee joint, compared to X-ray. Tomosynthesis was five to 29 percent more sensitive for detecting osteophytes and 11 to 50 percent more sensitive for detecting subchondral cysts.

According to Dr. Hayashi, "This study shows that images obtained through tomosynthesis are significantly better than those from X-rays and could potentially be a better diagnostic tool for knee osteoarthritis in patients with knee pain.

"While tomosynthesis has not been widely used in imaging of bones and joints to date, the results of our study show that using tomosynthesis to detect knee osteoarthritis can be effective," Dr. Hayashi concludes.

This research was supported by a grant to Dr. Guermazi from GE Healthcare.

The study appears online in the journal Radiology.

Review Date: 
April 10, 2012