Renal Oral Test out

clinical indications for a renal scan

• determining a blockage (mechanical vs stasis)

• renal artery stenosis

• kidney transplant evaluation

• urinary reflux

advantage of DTPA

cheaper than MAG3

Disadvantage of DTPA

not a high of a first pass extraction

Advantage of MAG3

can do imaging for GFR and tubular secretion

Disadvantage of MAG3

is more expensive

Advantage of DSMA

can do renal cortex imaging/stays stuck longer

Disadvantage of DSMA

not widely available

what will renal artery stenosis show on a captopril challenge

it will look normal on the first scan but abnormal on the second scan with the captopril

what is the MOA of captopril

ACE inhibitor

why is it important the patient is hydrated prior to the exam

it overall just improves the image but also prevents false positives

• dehydration can look like a blockage

how to perform a normal renal scan without lasix

• hydrate patient

• have the patient supine under camera

• flow for 1 min into 19 minutes of dynamic pictures

• post void

how does positioning the camera change for a transplant patient

it will be anterior due to the transplant location being the iliac fossa

explain the first part of a renogram

initial rise— arrival of the tracer (0-60 sec)

explain the second part of a renogram

ascending limb— the tracer is beginning to pool into the kidneys (nephrons)

explain the third part of a renogram

descending limb— tracer is draining and excreting from the kidney

what is an isotope and dose for vesicoureteral reflux

Tc-99m DTPA 1 mCi

what is the decay and storage process for urine contaminated pads

you want to contain it and place into long term storage for 10 half lives (60 days)

what is the dose and administration type of lasix

0.5 mg/kg (typically 40 mg)

why do we not bolus lasix

because it can affect not only the renal drainage but also be harmful to the patient like hypotension, hearing loss, etc

what is a normal renogram

the tracer should peak by 5 mins and 50% should be out by 20 min