WB Skeletal Imaging - motion artifact

Whole body bone scan obtained 2 hours following the intravenous injection of Tc99m MDP.

Older cameras used to perform whole body images by scanning at the right side of the body head-to-toe, moving the table and scanning the left side of the body toe-to-head. This often produced a zipper line done the middle of the body where the images were joined. If the patient moved or the camera and table were not properly aligned the images could result in separation of the images or mis-registration.

Newer systems have the ability for single-pass imaging, which eliminates the zipper and mis-registration problems. The single-pass technique although does not always allow for inclusion of the patients arms in the field of view.

On this particular image the patient noticeably moved their head from right to left resulting in the alien feature of a twin lobed cranium.

The practice of this institution was to perform a whole body posterior image with spot shots of the anterior skull chest, abdomen, and pelvis. 

Although this is older technology, newer camera do not require a double pass for the whole body image, I have always enjoyed the "alien" presence in this image..

Quality Control Troublshooting

We have three cameras in my department. I completed the first intrinsic flood (2million counts) when I noticed the uniformity on detector 2 was not good. I decided to move on to the next camera and come back to determine the problem, since the pattern was not typical of most non-uniformity problems.

The second camera demonstrated a similar, but more intense non-uniformity issue with detector 2. Coincidence... Now I had to determine the problem. I removed the source from the area and started a uniformity flood without a source to see if there was contamination in the area. A previous episode had a hot needle in a nearby sharps container. This time nothing was initially found.

I then checked my discarded gloves, which I Usually place on top of the collimator cart after placing the source and removing them...

In the first room my gloves were placed at the back of the collimator cart, so the activity on the glove was attenuated by the cart. In the second room, to which I carried my gloves (I dispose of them in the hot lab after completion of acquiring all morning uniformities) and had placed them at the front of the cart. Without the attenuation from the cart, the "extra" source is predominant in the acquired image...