3.5 - Nuclear Medicine cont.

omarys's version from 2017-05-23 20:53

Section 9.5

Question Answer
In a renogram curve, _____ should be definedROIs (regions of interest)
At the peak of the renogram curve, the RA material is in the _____cortex (after that filtration or secretion starts and the curve goes down)
How to dx hypertension due to renal artery stenosis?Captopril (ACEi) renogram
Cystography useful for dx ofhydroureteronephrosis (due to posterior urethral valve)
Congenital hydroureteronephrosis is usually due toUreterovesical junction obstruction
Can US determine if the dilatation is due to obstruction?No. It only dx-es dilatation and tells us the size of it.
The disadvantage of US and MRI in renal mapping is that they don't-provide information about the relative functioning (but MRI is excellent anatomically)
A diuretic renal scan is good because itdifferentiate obstructive from non-obstructive uropathy + gives info about relative function (the latter is NECESSARY for deciding upon surgery)
Other than cause peripheral vasoconstriction (>>hypertension), what does angiotensin II do?Stimulates adrenal to produce aldosterone >> salt-water retention >> increased blood volume >> hypertension (2 mechanisms for same end result)
Which arteries in the kidney does angiotensin II constrict?Efferent arterioles (thus maintaining normal GFR, which would have otherwise become reduced due to Afferent stenosis)
Administering captopril (ACEi) will have what effect on the GFR?Reduced (recall diagram; if the afferent arteriole is stenotic and the efferent is not constricted by angiotensin II, then the blood will go thru it rather than thru the glomerulus)
Given renal artery stenosis, if we use radioactive materials that undergo FILTRATION (e.g. DTPA), what will we see in the scan if the patient takes captopril?Reduced signal (because stenosis + LACK of angiotensin II = low GFR)

Section 9.75 - static scans (DMSA)

Question Answer
Tc-99m DMSA shows the renal ____cortex
T or F- DMSA is uptaken into proximal tubule cells and then secreted into lumen.FALSE. It only undergoes uptake. This is why this thing is a static scan...There's no secretion like in MAG3.
DMSA = gold standard for DMS, i.e. = Dysplasia, "M"yelonephritis, Scarring