Muscle Uptake on MDP Bone Scan

This is an interesting scan, because not often do we come across muscle uptake in our bone scans.  For the most part we shouldn't see muscle uptake at all, however it is not uncommon, and there has been several journaled articles relating to this fact.  Having "googled" the topic, it appears that there are several conditions that can cause this extra osseous uptake.  There has also even been one case in which exercise prior to the bone scan has caused muscle uptake.

On a quick note, here are some interesting articles (Radionuclide Bone Imaging:  An Illustrative Review) in regards to screening pathological conditions and as well Nonosseous, Nonurologic Uptake on Bone Scintigraphy:  Atlas and Analysis that provides some of the pathways in which Tc99m MDP are involved with non osseous uptake.

With this patient here, you can see if you expand the image, that there are diffuse muscle and soft tissue uptake throughout the body:  hip flexors, quadriceps, calf muscles, deltoids, triceps  and breast tissue.  The patient had been suffering from left sided flank pain and had undergone several examinations to determine the nature of the pain.  This person also has had a previous liver transplant and heart transplant as the result of being diagnosed with glycogen storage disease (GSD) type IIIA at an early age.  We are not really sure how the Tc99m MDP got into the muscles and other soft tissues, but conditions such as polymyositis, myositis ossificans or amyloidosis can cause this appearance.  However there are a slew of conditions that can also cause this, some of which may be pathological in nature whereas other may be more technical, like too much reduced hydrolyzed in the radiopharmaceutical.

In the end, the left sided flank pain may have been attributed to a 12th rib fracture, as noted on the bone scan.  A SPECT acquisition was also performed to determine the location.  Furthermore in the final report, the diffuse uptake in soft tissue was discussed with the referring physician about the possibility of an underlying myositis or anasarca.