Brain mass? if a pet scan slide of the head and neck that shows the scalp i.e. the brain, what do three circles mean with ctac 3.75 thick next to it mean as an annotation. is this a brain slide of 3 d dimensions or three separate tumors? i suppose you kn

I : I suggest you make an appointment with the doctor who ordered the pet scan to review the images and adults with him or her. Ctac stands for "attenuation correction ct". This is ct, or computed tomography part of the combined pet/ct scan. It is what show the anatomy meaning all the organs and structures in the body. The 3.75 just means how thick the cat scan slices are. Unless a special kind of pet/ct dcan was done specifically to evaluate for a brain tumor, it is actually quite rare for brain tumors to show up on regular pet scans and they are usually not easily seen on the ct component of the scan alone, especially if no IV contrast dye aw given in addition to the pet scan sugar tracer.

Need more info: Sorry, more information is needed to completely understand the question. Ctac means ct for attenuation correction - to make the pet data more accurate based on differences in density in the patient's body. Circles on the image generally are to measure things - the density on the ct image (measured in houndsfield units - 0 = water) or standard uptake value (suv), a measure of metabolism on pet.