Nuclear Genitourinary
Studies
Functional Renal
Imaging
Indications
Assess split renal function for native kidneys
Evaluate blood flow and function of renal transplant
Assess cause for acute renal failure or UPJ obstruction
Assess for RAS or urinary reflux and scarring
Address renal function in infants with hydronephrosis
Postsurgical renal function assessment after pyeloplasty
Contraindications
Pregnancy or breastfeeding
Recent nuclear medicine studies
Radiopharmaceutical
Administration
Intravenous, bolus
Large antecubital vein preferred
Tc99m - DTPA
Functional glomerular agent
MOL: Glomerular filtration
Dose
Adult: 10-20 mCi
Pediatric: 200 uCi/kg
Minimum 2 mCi
Target organ: Kidneys
Critical organ: Bladder
Tc99m - MAG 3
Functional, effective renal plasma flow agent
MOL: Tubular reabsorption/Glomerular filtration
Dose
Adult: 10-20 mCi
Pediatric: 100 uCi/kg
Minimum 1 mCi
Target organ: Kidneys
Critical organ: Bladder
Energy
140 keV
Patient Preparation
Well hydrated
Bladder emptied immediately before imaging
IV placement
Imaging
Patient Positioning
Supine
Use dose to mark sternal notch in top 1/3 of image and bladder in bottom 1/3 of image. Use dose to ensure patients left and right sides are in the image
Procedure
Flow: Dynamic acquisition
30 frames x 2 s/frame
Function: Dynamic acquisition
19 minutes of 20 s/frame; compressed to 1 min/frame
Post Void: Posterior static acquisition
2 minutes
TOTAL TIME: 22 MINUTES
Equipment
Single or dual head gamma camera
Posterior imaging for native kidneys
Anterior imaging for renal transplants
Full FOV for adults
Zoom FOV for pediatrics
LEAP collimator
Processing Images
ROI's drawn around kidneys, abdominal aorta and background
Quantitative analysis - relative renal function
Results
Normal
reasonably symmetric
kidney activity peaking at 3-5 minutes and decreased to less than 50% by 20 minutes
Abnormal
asymmetric
retention of activity in the kidneys
Renal Scintigraphy with ACE Inhibitor
Indications
High Blood Pressure of unknown origin
Renal Artery Stenosis
Renal Hypertension
Contraindications
No diuretics onboard
No ACE inhibitors onboard
Radiopharmaceuticals
Tc99m MAG-3
Dose
Adult: 5-10 mCi I.V.
Pediatric: 0.15 mCi/kg
Minimum: 1mCi
Maximum: 4mCi
Target Organ: Kidneys
Critical Organ: Bladder Wall
Tc99m DTPA
Dose
Adult: 5-10 mCi I.V.
Critical Organ: Bladder Wall
Target Organ: Kindeys
Tc99m
Energy: 140 keV
Interventional Pharmaceuticals
Captopril
Dose: 50mg
Crushed and dissolved in water
P.O.
Pediatric dose: 0.5 mg/kg
Maximum: 25mg
Given 1 hour before injection of radiopharmaceutical
Enalapirlat
Dose: 40ug/kg
I.V. over 3-5 minutes
Patient Preparation
Fasting
4 hours fasting
Well hydrated
Void before imaging
I.V. placement
Imaging
Patient Positioning
Supine
Procedure
Monitor patients blood pressure before administration of ACE inhibitor and every 15 minutes after for 1 hour
monitoring for hypotension
Flow: Dynamic Acquisition
2-4 seconds/frame
60-120 seconds
Serial Dynamic images
1-2 minutes/frame
20-30 minutes
Obtain pre-void and post-void images
suspected ureteral obstruction
Equipment
Single or dual head camera
Posterior imaging
Full FOV
LEAP collimator
Processing
Renogram Curve Analysis
ROI's
cortical regions of the kidneys
Background subtraction
Results
Abnormal
Decreased renal uptake in one or both kidneys
prolonged renal parenchymal transit
Time to Peak activity decrease
Kidney Function decrease
Morphological Renal Imaging
Indications
Adema
Scarring from acute pyelonephritis
pyelonephritis is usually results from reflux of infected urine
Confirmation of suspected hypertrophied column of Bertin
Contraindications
patient movement
pregnancy
not an absolute, risk-to-benefit ratio must be considered
Radiopharmaceutical
Tc99m DMSA
Tc99m dimercaptosuccinic
7 RADS to the renal cortex
Highest patient radiation dose of all renal imaging agents
Taken up by renal cortex (proximal convoluted tubule) MOL tubular binding
90% binds to plasma proteins, preventing significant glomerular filtration
25-50% of dose is in kidney in 1 hour and increases with time
Approx 16% will be in the urine in 3 hours after inj.
Dose
Adult: 5 mCi
10 mCI will give a higher dosimetry dose, but gives better image quality due to increased counts
Child: 50uCi/kg
Webster's rule for pediatric dose: [age + 1] / [Age + 7] x adult dose
Administration
Intravenous
Tc9m GH Gluceptate
Dose
Adult: 10-15 mCi
Child: 200 uCi/kg
Must be stored in the refrigerator
Secreted by Glomerular filtration and tubular secretion
Renal clearance is approximately 50% at 3 hours
Permits visualization of renal blood flow and imaging of the renal cortex
Patient Preparation
I.V. placement
Well Hydrated
void before imaging
Imaging
Positioning
Supine
include kidneys and bladder
Equipment
LFOV gamma camera
parallel hole collimator for differential calculation
Pinhole collimator for cortical images
prone preferred
SPECT: single, dual or triple head
Images
500k counts for each image
5 images total
Data Acquisition
140 keV, 20% winodw
Procedure
Static images
2 hours post injection
Posterior/ RAO/LAO/RPO/LPO with kidney in center of FOV
Results
Normal
smooth renal contour
equal distribution in each kidney
Abnormal
Acute pyelonephritis
single or multiple defects resulting in decreased uptake
Differentiate column of Bertin from mass
uptake in the column of Bertin, but not in a mass caused by tumor
Diuretic Renal Imaging
Interventional Pharmaceutical
Furosemide
Dose: 20-80mg I.V.
Pediatric dose: 1 mg/kg (Max 40 mg)
Contraindications
Dehydration
Indications
Renal obstructive neuropathy
Hydronephrosis
Radiopharmaceuticals
SAME AS FUNCTIONAL RENAL IMAGING
Patient Prep
SAME AS FUNCTIONAL RENAL IMAGING
Imaging
Positioning
See Functional Renal Imaging
Equipment
See Functional Renal Imaging
Processing
See Functional Renal Imaging
Generate Time Activity Curve
Procedure
Flow
30 frames x 2 seconds/frame
Dynamic
1-2 minutes/frame 20-30 minutes
Lasix
Administer over 1-2 minutes by IV at 20 minutes
note frame number at time of administration
Pre void and post void images of kidney and bladder
Vesicoureteral Reflux Study
Indications
Evaluation and detection of vesicoureteral reflux (VUR)
Patient Preparation
Explain procedure to patient
void prior to exam
consent for catheterization
foley catheterization placement
aseptic technique
inflate, balloon, tape to secure
note amount of saline at start and finish
Radiopharmaceutical
Tc99m pertechnetate
Tc99m DTPA
Tc99m Sulfur Colloid
Dose: 0.5-1.0 mCi
Administration
indwelling bladder catheter
MOL: compartmental with flow of urine
Critical organ: bladder (18-27 mrads/mCi)
Imaging
patient positioning
sitting or supine
bladder and kidneys in FOV
Posterior
Procedure
image 5 sec/frame for 60 seconds
inject tracer into tubing connected to bladder catheter
Filling phase
fill bladder to max capacity (age + 2) x 30 =volume instill [ml]
fill until drip slows or voids around catheter
monitor p-scope for signs of reflux (any activity above the bladder)
if reflux is seen, record amount of saline was infused at that time
once bladder is full, take 120 second immediate statics of posterior and L/R posterior obliques
Voiding phase
Take 120 second immediate post void static and record CPM
place patient sitting on potty chair with camera posterior
deflate foley and have patient void
measure urine output
Results
Total bladder volume residual post void volume and bladder volume at initiation of reflux can be measured
residual bladder volume [ml]= voided volume [ml] x residual counts/min
Divided by max counts/min - residual counts/min
Normal
no reflux visualized
all or nearly all solution voided from bladder
abnormal
activity in upper urinary tracts during filling, at full capacity, and/or while voiding