Ligma Bones

How much of the bone is inorganic?

45%

How much of the bone is H2O?

20-30%

How much of the bone is organic?

30%

what are some questions to ask about patient history?

- Hx of fractures and/or trauma - Hx current symptoms - Hx of recent nuc med scans - Hx of therapies or surgeries - Hx of renal abnormalities

factors determining uptake

- bone remodeling - growth - capillary and membrane permeability

what are the steps of a normal bone scan?

- confirm patient and explain exam - inject 20-30 mCi of RPx (mark injection site) - wait 2-3 hours - make sure patient urinates - make sure they remove metal and things from pockets - whole body scan or SPECT scan - static images of oblique views of head and chest

what are the steps of a three-phase bone scan

- confirm patient explain exam - inject 20-30 mCi RPx - acquire blood flow image (dynamic video) - pooling image (static) - wait 2-3 hrs delayed tissue image (static) - optional whole body scan

what are causes of superscans?

- metastatic disease - pagets disease - hyperparathyroidism - osteomalacia

what is fibrous dysplasia?

- overgrown fibrous tissue - sites of increased uptake

what are the steps of bone marrow imaging

-explain patient procedure and confirm patient -inject Tc sulfur colloid (specific uptake in only bone marrow) -wait 5-10 minutes -take static image of bone marrow (should show displacement if there is an infection)

how does cellulitis present itself in a bone scan?

-increased uptake in soft tissue -only shows up in the first two images of a three phase bone scan

How does avascular necrosis present itself in a bone scan?

-should see a cold center of bone surrounded by increased uptake - may not show up on x-ray for up to 6 months

what is metastatic disease?

a form of late stage cancer that has the original cancer site plus multiple mets throughout the body

how would a fracture present itself in a bone scan?

a single hot spot of increased uptake that can show for up to 2 years

what is loosening

an issue with a prosthetic where is starts to move around and rub against the bones causing damage

what is hyperostosis frontalis interna?

bilateral increase in activity in the frontal skull; most common in bitches

what is the critical organ for bone scans?

bladder

what is the purpose of osteoblasts?

bone formation

what is shoulder-hand syndrome

burning pain, stiffness in hand, sensitivity to cold (do not know what it is caused by)

what causes arthritis?

cartilage wears down from aging

what causes Paget's disease?

caused by the excessive breakdown and formation of bone

how does HPO present on bone scan

center of bone is cold and outside is hot

what is diabetic feet?

disease due to chronic effects of diabetes

What is osteomyelitis?

disease in bone and soft tissue

what is cellulitis?

disease in tissue or muscle

how do diabetic feet present itself in bone scans?

feet and toes present as hot in all three phases of bone scans (hot dogs)

how does Legg-perthes present itself in a scan?

growth plates appear cold

what is HPO

healing of the cortical surface of the bone; common in long bones only

what does HPO stand for

hypertrophic pulmonary osteoarthropathy

how does hyperostosis frontalis interna appear in a bone scan?

increased activity in the frontal skull (dark)

how does shoulder-hand present

increased uptake in extremities

how does arthritis present itself in a bone scan?

increased uptake in joints

what is MDP?

known as medronate; a less expensive RPx of Tc99m

what is HDP?

known as oxidronate; cheaper, clears from the blood faster, more uptake; most commonly used

what is a superscan?

little tissue uptake, no renal activity, and early uptake in bones

what are osteocytes?

mature bone cells

how would metastatic disease present itself in a bone scan?

multiple hot spots in bones; most are in the axial skeleton (80%)

how does loosening show up on 3 phase-scans

normal flow and pool imaging increased uptake on delays

What causes avascular necrosis?

occurs as a result of fractures, metabolic disorders, and embolisms

how does Paget's disease present itself in a scan?

presents whole bones as hot; bow-legged

what is Legg-perthes disease?

problems with blood supply to the femoral epiphysis that leads to bone necrosis

What is TNT (target to non-target) for?

ratio of RPx uptake in bone to blood

how does osteomyelitis present itself in a bone scan?

shows up hot in all three phases of the bone scan

what does TNT stand for?

target to non-target ratio

what is the purpose of osteoclasts?

to break down bone

why would we use gallium to look at diabetic feet?

to show the presence of infection in toes

how does fibrous dysplasia present itself in a bone scan?

usually has lesions on the skull, face, and long bones