bone scans a&p

indications for bone scans

fractures, trauma, metabolic disorders, bone pain, assess prosthetic, AVN, staging and restaging

tumors

breast, lung, thyroid, kidney, prostate, multiple myeloma

normal adult findings

kidney, bladder, SI joints, thyroid cartilage, frontal and parasagittal sinuses, acromioclavicular joints, scapular tips

normal pediatric findings

cranial sutures, growth plates,

other views for excessive bladder activity

SPECT, TOD, LATS, obliques

pagets disease

osteoclasts more active than osteoblasts, irregular/mosaic patterns, affects skull, hip, pelvis, legs and spine

Erdheim-Chester disease

only in long bones, symmetric uptake in long bones

AVN

cold area, later will appear as doughnut, common at joints of long bones

where does radiotracer go during bone scan

soft tissues first then bone

excessive soft tissue uptake can be due to

poor tracer clearance from blood, diabetes

counts for head

750 kcounts

counts for hands and feet

250 kcounts

counts for thorax

1000 k counts

counts for abdomen

1000 kcounts

counts for knees

450 kcounts

dose for Tc99m

10-20 mCi

what are the uptake percentages for Tc99m

50%bone 50% renal

what are the 3 phases for bone imaging

blood, pool, delayed

what does the flow phase look at

blood

what does the pool phase look at

tissue

what does delayed phase look at

bone

indications for 3 phase bone scan

infection/inflammation, bone pain, stress fractures

artifacts

attenuation (arm shield), motion, contamination, gloving, injection site/ infiltration with lymph node uptake, soft tissue uptake, wrong peak, bad tracer