White Blood Cell Imaging

alkathryn's version from 2016-06-17 20:35


Question Answer
Two rphxs for WBC imagingIn-111 Oxine & Tc-99m Ceretec
WBC IndicationsLocalization of acute abscesses and infections, osteomyelitis, acute inflammatory disease, evaluation of prosthesis rejection, differentiation of pulmonary infiltrates
WBC ContraindicationsLeukopenia
Oxine dose500 uCi
Ceretec dose10-25 mCi
Ceretec AKAHMPAO or Exametazime
Oxine advantages over GaDoes not concentrate in the GI tract and 97% vs 64% specificity
Oxine disadvantagesrequires 50 mL of blood and 2-3 labeling procedures. Cannot image beyond 48 hours
Ceretec blood draw50-50 mL
MOL of WBCChemotaxis
Create goes to Extremeties
Key to blood drawStore facing up immediately so it can separate, cuts down time
% of WBCs tagged95
Patient prepnone specific, explain and verify
Oxine Imaging Times2-6 hours (acute infection), 24-48 hours
Oxine collimatorME
Ceretec Imaging Times1-4 hours, 24 hour delay (chronic infections)
Ceretec collimatorLE
WBC Imaging parametersWB 10 cm/min, Statics 800-1000Kcts/5-10 mins, SPECT ROI 20-30 sec/stop
Oxine Negative StudiesPulmonary uptake (up to 4 hours), liver spleen and bone marrow, no renal or GI activity
Ceretec Negative Studies Initial Lung, liver spleen uptake
Ceretec Negative Studies 1-2 hoursliver, spleen, bone marrow, bladder, kidney
Ceretec Negative Studies 4 hoursbowel activity, lung activity reduced
Ceretec Negative Studies 24 hoursbowel activity, other organs reduced
Will never see ___ on a bone scanspleen
Positive studiesareas of focal activity outside normal uptake, activity compared to liver
> Liver indicatesinfectious process
< Liver indicatesnoninfectious process
Photopenic meanslack of counts, cold
Which leg is always elevatedRight
Splenomegaly meansenlarged spleen--bigger than liver. no treatment
False Positivespneumonia, emphysema, PE, CHF, ulcers, hematomas, fractures, surgical wounds
Low white countdecreases sensitivity of test for detecting and localizing infections

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