CDI Miami | Tuesday March 24, 2015

PET/MRI Better Than PET/CT for Foot Pain?

It’s true, according to a new study published in The Journal of Nuclear Medicince. This study evaluated 13 men and woman who had complaints of foot pain without a clear cause. The images from the PET scan combined with an MRI were significantly clearer than those combined with the CT scan.

“In our study, 18F-fluoride PET/MR[I] provided more diagnostic information at a higher diagnostic certainty compared to 18F-fluoride PET/CT in patients with foot pain of unclear cause,” co-author Isabel Rauscher, said in a release. “Besides information on bone metabolism, it provides additional diagnostic relevant findings from soft-tissue and bone marrow pathology (eg, bone marrow edema, ganglion cysts, or tenosynovitis) compared to PET/CT.”

How a PET Scan Works

Positron emission tomography, also called a PET scan, falls under a branch of diagnostic imaging called nuclear medicine. Nuclear medicine uses an injectable radioactive tracer to build a 3D image. The tracer has the equivalent radiation of an x-ray. A PET scan measures important body functions, such as blood flow, oxygen use, and metabolism, to help doctors evaluate how well organs and tissues are functioning. When combined with either computed tomography (CT) or magnetic resonance imaging (MRI), doctors can create special fused images that enable them to the problem more clearly than either image by itself. For example, a CT scan provides excellent anatomical information, so a PET scan combined with a CT scan can map the exact location and function of any given area.

There are some that argue, and this study seems to reinforce, that the newer PET/MRI combination allows for better quality. MRI offers, compared to CT, better contrast among soft tissues as well as functional imaging capabilities. Additionally, as the study noted, the PET/MRI combination exposed patients to lower doses of radiation.

PET MRI of Foot

Fused PET and MRI of a patient with diabetic foot and suspected bone infection. Source: Clinical Mircrobiology Reviews

Even relatively mild foot pain can be quite debilitating. It is usually safe to try simple home remedies for a while. If your foot pain has been persistent and does not improve for several weeks without cause, then it’s time to see your doctor.