Categorieën: Alle - pregnancy - equipment - imaging - preparation

door April Saldana 3 jaren geleden

177

Genitourinary System

Renal imaging involves specific preparations and considerations to ensure accurate results, particularly in the context of morphological and functional assessments. Patients need to be well-hydrated and should void their bladder before imaging.

Genitourinary System

Genitourinary System

RADIONUCLIDE CYSTOGRAPHY

voided (ml)x Residual counts/minutes over Max counts/min-Residual counts/minutes

-Patient to void before procedure -Inject tracer mixed with saline into the tubing of the catheter -Fill bladder to max fill limit -Monitor P-scope carefully to view reflux, if reflux is visualized make note of amount of saline used at that time -Image full bladder -Deflate folley balloon and proceed to take post void images -Record the amount of urine output -Determine residual bladder volume

120 second immediate posterior void static image

Full Bladder Phase: 120 second immediate static of posterior and right/left posterior obliques

Filling Phase: Dynamic at 5 seconds for 1 minutes

Use Max Filling Formula to determine how much to fill the bladder: (age+2)x30= volume of bladder in mL

-Hand 500mL bag of normal saline at least 25cm above table

Patient Position: SUPINE with camera posterior or sitting with back and pelvis against camera
99mTc-Sulfur Colloid 99mTc-DTPA 99mTc-Pertechnetate

Tracer is injected into the tubing connected to the catheter

Method of Administration: Catheter

Dose: 0.5-1.0mCi

-Cover imaging table with absorbent paper -Patient to void before imaging -Written consent for catherization -Keep track of amount of saline from start to finish
Pregnancy
Evaluation and detection of vesicoureteral reflux (VUR)

MORPHOLOGICAL RENAL IMAGING

-Patient needs to void before imaging -Patient to be imaged 2-4 hours after injection

Static Images: Posterior, RAO, LAO, RPO, LPO -500K total counts per image -Pinhole- 100K or 5 minutes

Patient Position: SUPINE with kidneys in field of view
-Single or dual head gamma camera -Full field view for adults -Zoom field of view for pediatrics -Low energy all purpose (LEAP) collimator -OPTIONAL: Pinhole Collimator
99mTc-GH (Gluceptate)

Secreted by glomerular filtration and tubular secretion

99mTc-DMSA (Dimercaptosuccinic Acid)

-Taken up in renal cortex

Dose: 5mCi (adults) 50uCi/kg (children)

-Well hydrated -Void prior to imaging -IV
Pregnancy Patient movement
Detection of pyelonephritis Differentiation of renal mass from normal variant

ACE INHIBITOR

A baseline renal scan needs to be performed before or after ACE scan to compare.

Final blood pressure taken (must be 70% of baseline blood pressure)

Blood Pressure taken every 15 minutes for 1 hour when given Captopril

25-50mg of Captopril given 1 hour before Tc99m or 40ug/kg of Enalaprilat given 10-15 minutes prior to Tc99m

ACE Inhibitors

ENALAPRILAT

10-15 minutes prior to radiopharmaceutical

40ug/kg in 10mL saline given over 3-5 minutes

CAPTOPRIL

Blood Pressure to be taken ever 15 minutes for 1 hour

1 hour prior to radiopharmaceutical injection

25-50mg pill given orally

Discontinue diuretics, ACE inhibitors, A2 receptors blockers- 4 DAYS PRIOR TO STUDY
NPO 4 to 6 hours prior to study
Patient to void before imaging
diuretics, ACE inhibitors
Determination of renal vascular retention

DIURETIC

Continue Dynamic acquisition for 20-30 minutes post furosemide injection

Diuretic: 40mg of Furosemide, injected slowly in IV at 20-30 minutes

Radiopharmaceutical and Interventional Pharmaceutical
Furosemide (LASIX)

Given 20-30 minutes post radiopharmaceutical

Pediatrics: 1mg/kg max dose of 40mg

Adult Dose: 40mg IV injection

99mTc- MAG3

-Excreted by tubular secretion -Rapid Plasma Clearance -Measures Effective Renal Plasma Flow (ERPF)

Dose: 10-15mCi

Serum creatine obtained
Well hydrated
Diagnose or exclude urinary tract obstruction

FUNCTIONAL RENAL IMAGING

Imaging
Processing

Renogram (time activity curve)

Region of interests (ROIs) are drawn around each kidney. Also, background regions are drawn (be careful to draw within body not outside the body), and also an aorta ROI is drawn around the aorta.

Procedure

Post Void: Posterior Static acquisition- 2 minutes

Function: Dynamic acquisition- 1 minute per frame for 30 minutes.

FLOW: Bolus Injection, 3 sec/frame for 1 min

Patient Position: SUPINE with kidneys and bladder in field of view. Dose is used to measure that xiphoid process, pelvis/bladder and sides of body are with in field of view
Radiopharmaceutical
Equipment

-Single or dual head gamma camera -Full field view for adults -Zoom field of view for pediatrics -Low energy all purpose (LEAP) collimator

99mTc-DTPA

-Glomerular filtration agent -Measures Glomerular Filtration Rate

99mTc-MAG3

-Excreted by tubular secretion -Rapid Plasma Clearance -Measures Effective Renal Plasma Flow (ERPF)

Method of Administration: Intravenously

Dose: 10-20mCi

Patient Preparation
Start IV
Patient to void their bladder before imaging
Well hydrated-orally or intravenously
Contraindications
Diuretics
Dehydration
Assess renal function and urodynamics
Indications