Renal Nuclear Medicine Studies

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Renal Nuclear Medicine Studies

Vesicoureteral Reflux Scan

Draw ROIs around intrarenal collecting systems and bladder

Calculate the residual urine volume

Formula for calculating the residual volume (mL)= Voided volume (mL) x Residual counts/min

________________________________________________

Max counts/min - Residual counts/min

Abnormal: Activity in upper urinary tract during filling, at full capacity, and /or while voiding.

Normal: No reflux visualized. Nearly all of solution is voided from bladder.

Remove the patients foley catheter. Then measure the urine.

Take an immediate post-void static (120 sec)

Deflate the catheter balloon and have the patient void while taking a dynamic image (2sec/frame for 120sec)

Take a immediate static once the bladder is full (120sec)

If Reflux is seen, record the amount of saline that was infused

Fill the bladder until drip from the bag slows or the patient begins to void around the catheter.

To determine the max capacity of a patients bladder use the formula: (age+2) x 30= Volume instill (mL)

Prepare camera for dynamic 60sec fill. Then inject Tc99m sulfur colloid into the tubing connected to bladder catheter. Begin to fill bladder with saline and begin the dynamic image.

Place the foley catheter using aseptic technique. Inflate the balloon and tape to secure.

Prep 500mL saline bag and the Tc99m sulfur colloid

Prep the patient by having them void or by making sure they are in a clean diaper if an infant.

Views: Posterior, LPO, and RPO with bladder and kidneys on the FOV

Patient Position: Sitting if using the potty seat, or lying supine of the table

Tc99m- Sulfur Colloid

MOL: Compartmental localization with the flow of Urine

Route of Administration: Via Foley catheter tubing

Dose: .5-1mCi

Ancillary Equipment: IV pole and potty seat (if needed)

Post-Void: 120sec static image

Void: Dynamic 2sec/ frame for 120sec.

Data Set: 60 images

Pre-Void: 120sec static image

Data Set: 1 image

Bladder filling: Dynamic 5sec per frame for 60 sec.

Data Set: 12 images

Patient Prep.

Prepare a 500mL bag of saline

Have the patient void before the exam. If the patient is an infant, have them wear a clean diaper.

Obtain a written consent for catheterization

Thoroughly explain the procedure to both the patient and the parents

Place absorbent pads around the potty chair if it is going to be used

Indications: Evaluation and detection of vesicoureteral reflux (VUR)

Morphological Renal Imaging

Additional Patient Prep: If this is a pediatric patient, a parent must sign a informed consent for sedation to begin study

Processing: No processing, it is a qualitative study

Abnormal: To differentiate a Column of Bertin from a true mass, DMSA will show uptake and a mass will not have any uptake. If Acute Pyelonephritis is the issue it may appear as single or multiple defects resulting in decreased uptake.

Normal: A smooth renal contour. Uniform and equal tracer concentration

Inject the Chosen Rph, then wait 2hrs before imaging

Select the proper collimator

Parallel or Pinhole Collimator

• A Pinhole collimator is preferred for children

Place the patient supine and begin taking static images (approximately 3min per view)

A SPECT can also be done (Approximately 15-30min)

Views: Ant, Post, and an optional RAO,LAO,RPO,LPO

Position: Supine

Rph

Tc99m- DMSA or Tc99m- GH

Go to Radiopharmaceutical section for Dose, MOL, and ROA

SPECT: 180 Rotation with 40sec/stop for 40 Views

Statics

Pinhole Collimator: 100K counts per image

Parallel hole colimator: 500K counts per image

Data set:2-6 images

Matrix: 128x128

Energy: 140keV

Confirmation of suspected hypertrophic column of berlin

Adema or scarring from acute pyelonephritis

Renal with ACE

Optional Maneuvers

Some protocols give the patient lasix just like a diuretic scintigraphy to empty any pelvic retention

A baseline renal scintigraphy without ACE should be done either before the Scintigraphy with ACE, or it can be done 2-3 days post Ace renal scintigraphy

Processing: Renogram

Abnormal: Asymmetric curve, low uptake, little to no excretion from kidneys, bladder activity does not increase

Normal: Symmetric curve, prompt kidney uptake, Decreased kidney activity to T1/2 at 8-12min mark, bladder activity increases as the kidneys excrete

Views: Posterior with both kidneys and bladder in the FOV

Patient position: Supine

Get the Baseline BP

Give the patient the chosen ACE inhibitor and wait the designated time

If captopril wait 1 hr. before Rph injection and take BP every 15 min

If Enalaprilat wait 10 min before Rph injection

Inject the chosen Rph and begin the flow immediatly (2min)

Begin the Dynamic immediately after flow (20-30min)

Take the patient final BP

RPh/ Interventional pharmaceuticals

Interventional Pharmaceuticals

Enalaprilat: 40ug/kg

Administered via IV

Wait 10 min before the injection of Rph

Captopril: 25-50 mg

Pill is crushed up and added to water

Administered PO

Must be given 1HR prior to Rph injection

Rph: 5-10 mCi of Tc99m-DTPA or Tc99m-MAG3 (MAG3 is the preferred RPH)

Refer to Radiopharmaceutical section for MOA, and MOL

Number of images

Dynamic: 30sec/frame for 20-30 min

Data set: 40-60 images

Data acquisition

Energy:140 keV

Additional Contraindications

Stop taking ACE inhibitors/diuretics 4 days prior to exam

Patient was not NPO for at least 4 hrs

Obtain a baseline BP and start an IV

NPO 4-6 Hrs before exam

To assess if patients hypertension is related to possible RAS (renal artery stenosis: the narrowing of one or more arteries that carry blood to your kidneys.)

Diuretic Renal Imaging

Additional Patient Prep

Stop taking diuretics 4 days prior to exam

Abnormal: Asymmetric curve, No excretion from the kidneys/ no filling of the bladder, and slow activity increase in kidneys

Normal: Symmetric curve, excretion begins 2-3 min post Lasix injections, and the bladder curve increases post Lasix injection.

Processing

Imaging

Procedure

Bolus Injection of Rph

Immediately begin the flow imaging

Begin Dynamic imaging immediately after the flow. (20min)

Once the dynamic has been going for 20min, Inject the Lasix (40mg for an adult)

Some protocols have the patient void before the Lasix injection.

The Lasix is a slow injection over a 1-2 min period

Continue dynamic for 20min

Have the patient void and then do a post void static. The patient can either be is the supine position or upright with there back to the detector.

Patient Position

Supine

Some protocols may want the patient to be in an upright position with there back to the camera. This is mostly for post void imaging.

Views

Posterior with both kidneys and bladder within the FOV

If the patient has had a renal transplant than images should be acquired in the anterior view

Rph/Interventional pharmaceuticals

Lasix: 40 mg

If a pediatric patient dose is 1mg/kg with a max of 40mg

Tc99m-MAG3 is the preferred Rph

Go to the descriptions of the Rph for dose, MOL, and MOA

Data Analysis

Number of Images

Dynamic: 30 sec/frame for 20 min

Data set: 40 images

Flow: 2sec/frame for 2 min

Matrix

Data Acquisition

Energy: 140 keV

Dynamic/Flow and Static

Evaluate renal function and urodynamics

To distinguish between obstructive hydronephrosis and non-obstructive collecting system dilation

Radiopharmaceuticals

Morphological Radiopharmaceuticals (AKA cortical agents)

Agents that are rapidly taken up by the kidneys, BUT use more complex mechanisms that involve ERPF, GFR, Tubular secretion, AND tubular resorption

Tc99m- DMSA

AKA: Succimer

Dose:

• Adult: 5mCi
• Pediatric: 55uCi/kg; minimum of 500 uCi

Administered via IV

34% is retained by the renal cortex

MOL: Tubular binding

Tc99m-glucoheptonate

No longer used in the US

5-10% retention by the renal cortex

Dose: 10-15mCi

ROA: IV

MOL: Glomerular filtration and tubular secretion

Functional Radiopharmaceuticals

These are rapidly taken up and excreted by the kidneys by a single, simple physiological mechanism (i.e. ERPF or GFR)

Tubular Agents

Tc99m-MAG3

Dose:

• Adult: 10-20 mCi
• Pediatrics: 100 uCi/kg; minimum 1 mCi

Administered via IV

MOL: binds to RBC

Clearance 100% via tubular secretion

Used to measure ERPF

Recommended in pts with decreased renal function and infants

High first pass ratio

High target to background ratio

Great image quality, low radiation dose

I-131 Hippuran

Dose:

• Adult: .025-.2mCi
• Pediatrics: Not used in pediatrics

Administered via IV

MOL: ion exchange

No longer available in the US due to the high radiation dosage and low image quality

Used to measure ERPF

High first pass extraction: almost all of the radiation delivered to the kidneys remains in the kidneys.

Near total tubal secretion

High target to background ratio

Glomerular Agents

Tc99m-DTPA

Dose:

• Adult: 10-20 mCi
• Pediatric: 200uCi/kg; minimum 2mCi

Administered via IV

MOL: Inulin analog

Excreted 100% via glomerular filtration within 2 hrs.

Assess renal blood flow, function, drainage of the pelvicalyceal systems

Measures GFR

Readily available

Great image quality, low radiation dose to patient

I-125 Iothalamate

Dose:

• Adult: 80 uCi
• Pediatric: 1uCi/kg; minimum 10 uCi

Administered via IV

MOL: simple/passive diffusion

AKA: Glofil

Measurement of GFR

Poor image quality

Contraindications

Patient is unable to remain still

Dehydrated

Currently taking Diuretics

A recent renal arteriogram with contrast

Pregnancy/Breastfeeding

Patient Prep

Detailed Patient History

Do you still have both of your kidneys?

Previous transplant?

Also look in patients records for:

• previous imaging done to see kidney location/size
• creatinine levels (high number may indicate kidney failure)

If the patient has a nephrostomy, check the order to see if the tube should be clamped or not.

Make sure patient has not had a recent renal arteriogram with contrast.

Patient needs to void before scan and those who cannot void bladder need a urinary catheter

Start IV

Adequately hydrated

Oral hydration of 20 ounces (App. 3 cups an Hr. before imaging) or IV hydration of 250 ml prior to images

Equipment and Parameters

IV Supplies

Single or Dual head gamma camera

LEAP collimator

Zoom FOV for pediatrics

Typically a zoom of 2

Full FOV for adults

Basic Renal Scan (Functional renal imaging)

Indications

Evaluation of renal perfusion and function, and collecting system patency information

Interpretation

Abnormal: more uptake in one kidney than the other. A lower excretion rate. Asymmetric curve

Normal: the curve for each kidney should be reasonably symmetric with prompt uptake and a peak between the first 3-5 min. A decreased slope of less than 50% at the 20 min mark.

If MAG3 was used then a ERPF of 600 mL/min is normal

If DTPA was used then a GFR of 120 mL/min is normal

Processing:

Renogram

A renogram is a time-activity curve that provides a graphic representation of the uptake and excretion of a rph.

Draw ROI around the aorta, bladder, both kidneys, and a background below each kidney

This creates the information to make the renogram

Imaging:

Procedure:

Bolus inj.

Immediately begin flow

Begin the dynamic function image after flow

Have the patient void then do the post void image standing with back to detector

Views: Posterior (anterior if patient has had a renal transplant)

Patient Position: -Supine (can be standing for post void) -Sternal notch to include both kidneys, inferior bladder in FOV

RPH

Tc99m-MAG3 or Tc99m-DTPA

Look at Rph section for dose amount MOA and MOL

Instrumentation

Data analysis

Number of images:

Static: 2min

Data set: 1

Dynamic: 30sec/frame for 30 min

Data set: 60 images

Flow: 2sec/frame for 1-2min

Data set: 30-60 images

Matrix:

Dynamic: 256x256

Flow: 128x128

Data Acqusition

Energy peak: 140keV

Window: 20%

Dynamic/flow and static