Nukes bones

Question 1

MDP mechanism of action

Answer 1

chemisorption incorporated into the bone matrix in hydroxyapatite

Question 2

what happens if not enough stannous ion is in your MDP kit?

Answer 2

oxidation of Tc-99m –> free tech

Question 3

what happens if you pull air into the syringe right before injecting Tc99m-MDP?

Answer 3

oxygen gets in –> oxidation –> free tech

Question 4

What happens if water gets into you Tc-MDP solution?

Answer 4

water –> tin colloid AND Tc-99m dioxide –> these are large clumps of stuff –> goes to RES ( liver, spleen, bone marrow)

Question 5

what happens if you forget stannous ion in the MDP kit?

Answer 5

stannous ion (tin) is the reducing agent. If no stannous ion –> Free Tc

Question 6

Answer 6

Free Tc

Question 7

Answer 7

Wrong window. Window set too low for Tc-99m MDP.

If set too low, for example set to only accept Thallium keV range (70-80 keV) –> camera will exclude everything >80 keV –> you completely exclude Tc-99m 140 keV gamma ray –> only really imaging the scatter

Question 8

Soccer player with lots of trauma to the thigh. Next step?

Answer 8

get more imaging - CT or XR to further evaluate possible myositis ossifcans

Question 9

What additional imaging do you want?

Answer 9

CT Chest

Question 10

Two main causes of hot kidneys on MDP?

Answer 10

1. Chemotherapy
2. urinary obstruction

Question 11

Answer 11

autoinfarcted spleen in Sickle Cell Disease

Question 12

Answer 12

Question 13

Answer 13

osteosarcoma in a kid

hot uptake in the metaphysis of a kid

Question 14

painful scoliosis

Answer 14

osteoid osteoma in the posterior elements

Question 15

Answer 15

Enchondroma

Question 16

Answer 16

Question 17

Answer 17

Paget’s

Question 18

Answer 18

aseptic loosening in a hip prothesis. uptake at wiggle points at the distal part of the femoral component and at the lesser trochanter

Question 19

Answer 19

Question 20

how long do you have to be on bisphosphonates before you get insuffiency fractures?

Answer 20

4 years

Question 21

When is the best time to use a bone scan to evaluate for an occult fracture with an MDP bone scan?

Answer 21

At three days

Question 22

Answer 22

sacral insufficiency fracture

Question 23

Answer 23

Flair phenomenon. gets worse then better

Question 24

Answer 24

osteomyelitis

progressively hotter on 3 phase bone scan

Question 25

Answer 25

Question 26

Answer 26

Question 27

Answer 27

cellulitis

cellulitis is only two phase

Question 28

Answer 28

Reflex sympathetic dystrophy (complex regional pain syndrome)

UNILATERAL periarticular uptake on delayed imaging

Question 29

A diabetic patient presents with calcaneal ulcer, pain and leukocytosis. What may be useful on bone scan if osteomyelitis is suspected?

Answer 29

4th phase imaging at 24 hr

Diabetic and vasculopathic patients pose a difficult problem for skeletal scintigraphic evaluation of the feet. The small vessel disease and overall poor circulation do not allow enough time for the radiotracer to be delivered and taken up by the osseous structures and cleared by the soft tissues. One protocol that can be instituted is the use of 4th-phase imaging. This involves a 24-hour image being acquired to allow for greatest osseous uptake and soft tissue clearance. Plantar, posterior, or lateral views would best image the calcaneus.

Question 30

what are the parameters for using strontium

Answer 30

WBC counts >2400 and platelets >60K. renal function

Question 31

How do you treat brown fat?

Answer 31

warm up with blanklets or beta blockers