Renal Imaging & Rphxs

alkathryn's version from 2016-08-01 04:03


Question Answer
Functional rphxsMAG3 and DTPA
Anatomical rphxsDMSA
Morphologicscars and damage to kidneys (anatomy/DMSA)
MAG3 akaMertiatide or Mercaptoacetylglyclylgylglycine
MAG3 dose3-10 mCi
MAG3 used to determineERPF
ERPF akaEffective renal plasma flow
MAG3 can showflow and function
MAG3 imaging time<30 minutes
MAG3 MOLTubular secretion -- 90% urine secrete, 10% glomerular filtration
DTPA akaPentetate or diethylenetriaminepentaacetic acid
DTPA dose3-15 mCi
DTPA used to determineGFR
DTPA also used to determineobstruction of collecting system
DTPA MOLglomerular filtration
MAG3 cannot be used forGFR - only 10% glom. filtrration
DMSA akaSusciter or dimercaptosuccinic acid
DMSA imagesrenal cortex (strictly structure)
DMSA is best to evalrenal parenchyma
DMSA imaging time3-4 hours post injection
DTPA imaging timewithin 1 hour of prep
DMSA won't seecollecting system
DMSA dose1-6 mCi
DMSA critical and whykidneys, because it sits there
Renal cortical imaging indicationsacute pyelonephritis, scarring, masses, ectopic/solitary tissue, iodine allergies
Patient prep for DMSAhydrate and void prior, reference points
Normal DMSA resultssymmetric activity to each kidney on both dynamics and statics
Abnormal DMSA resultsasymmetrical perfusion, acute pyelonephritis, hydronephrosis, cysts, neoplasm, trauma
Function can be used to determine bothabsolute and relative renal function
Absolute akacomplete
Relative renal function akaestimate
Relative renal function is calculated by usingan early image of the kidneys
Function indicationperfusion/function, patency/obstruction, ATN, renal transplants, renal HTN
Renogram is atime versus activity curve
Clearance of rphx depends onhydration, blood flow, and function
Peaks occurs at2-5 minutes
GFR*120-125 ml/min
GFR uses rphxDTPA
GFR is thevolume of plasma filtrate produced every minute in glomeruli of the kidneys
DTPA GFR dose3 mCi bolus
DTPA function dose5-15 mCi bolus
DTPA is an estimate ofGFR (relative)
Camera methodmeasuring the plasma clearance after a single bolus
Only way to get absolute GFR is todraw blood
Gates method dose3 mCi
Gates method stepspre syringe count, image for 6-10 mins, post syringe count, blood sample 60-180 mins post in
Draw ROI aroundboth kidneys and background
increased liver and spleen activity indicatesrenal failure
MAG3 dose3-10 mCi
EPRF*370 ml/min
MAG3 processingdraw ROI around kidneys, bladder, aorta, and background
MAG3/eprf determinesflow and function
MAG3 imagingdynamic 20-30 mins
Transplant imaging doneanteriorly

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