Infection/inflammation GW Flashcards
RP for chronic cases
Ga67
RP for acute cases
Tc99m exametazime HMPAO WBCs
In111 WBCs
Indications for Ga67 imaging
Source of FUO
Osteomyelitis
Lung infection
Inflammatory processes (sarcoidosis)
Ga67 dose
4-6 mCi
-depending on pathology
-up to 9 mCi for large patients
Injection to imaging time for Ga67
4-72 hours
When is bowel activity at minimum with Ga67
Earlier imaging
How many photon energies does Ga67 have
4
93, 184, 296, 388
93 is most abundant
What to remember about imaging time with Ga67
If camera can do multiple photo peaks, this will decrease imaging time
-this is actually the same case with In111 because it has 2 photopeaks
Most prominent organ on Ga67 imaging
Liver
When are kidneys seen on Ga67 imaging
First 48 hours
-if imaged during this time, pt must void first
- if it persists, indicates disease
Kidneys excrete 20-30% of the dose during the first 24 hours
What increases Ga67 uptake
Blood transfusions
Chemo
Iron therapy
Recent trauma
Ga67 excretion
First 48 hours: renally
After 48 hours: GI tract
Prep for Ga67
Bowel prep: laxatives or enema
Contraindications for bowel prep for Ga67
Pts who are acutely ill or cannot retain solid foods
Best RP for imaging abdomen
In111 labeled WBCs
Indications for In111 WBCs
Source of FUO
Inflammatory bowel disease
Osteomyelitis
Medicines that can lower WBC tagging
Steroids
Aspirin
Antibiotics
How long after labeling WBCs should they be administered
1-2 hours to ensure maximum cell viability
When is imaging performed for In111 WBCs
1-4 hours or
16-30 hours
Simultaneous dual tracer for osteomyelitis
In111 WBCs with 99mTc MDP
- must use different photopeaks ro differentiate the low energy tech photons from the In111 photons
Most intense organ uptake for in111
Spleen
99mTc labeled WBCs indications are similar to In111 but may be more sensitive for
Detecting inflammation or ischemia in small bowel and detecting acute osteomyelitis
WBC and bone marrow imaging combined RPs
In111 WBCs 0.3-1 mCi
99mTc Sulfur colloid 10 mCi
Injection to imaging time for WBC/bone marrow
SC - 30 minutes
In111 - 24 hours
Must use freshly prepared SC for bone marrow imaging because
<2 hours old
Old SC can result in persistent blood pool and bladder activity
When is imaging preformed with SC/in111 WBCs
Can be preformed at the same time
Or SC imaging can be preformed immediately after WBC imaging
