renal scintigraphy n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Renal Scintigraphy PowerPoint Presentation
Download Presentation
Renal Scintigraphy

Loading in 2 Seconds...

play fullscreen
1 / 102

Renal Scintigraphy - PowerPoint PPT Presentation


  • 1380 Views
  • Uploaded on

Renal Scintigraphy. Materials for medical students. Helena Balon, MD Wm. Beaumont Hospital Royal Oak, Michigan Charles University 3rd School of Medicine Dept Nucl Med, Prague. Renal perfusion and function Obstruction (Lasix renal scan) Renovascular HTN (Captopril renal scan)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Renal Scintigraphy' - Audrey


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
renal scintigraphy

Renal Scintigraphy

Materials for medical students

Helena Balon, MD

Wm. Beaumont Hospital

Royal Oak, Michigan

Charles University

3rd School of Medicine

Dept Nucl Med, Prague

indications
Renal perfusion and function

Obstruction (Lasix renal scan)

Renovascular HTN (Captopril renal scan)

Infection (renal morphology scan)

Pre-surgical quantitation (nephrectomy)

Renal transplant

Congenital anomalies, masses (renal morphology scan)

Indications

Evaluation of:

renal function
Renal Function
  • Blood flow- 20% cardiac output to kidneys (1200 ml/min blood, 600 ml/min plasma)
  • Filtration - 20% renal plasma flow filtered by glomeruli (120 ml/min, 170 L/d)
  • Tubular secretion
  • Tubular reabsorption (1% ultrafiltrate - urine)
  • Endocrine functions
renal radiotracers excretion mechanisms
Renal RadiotracersExcretion Mechanisms

GF TS TFTc-99m DTPA >95%

Tc-99m MAG3 <5% 95%

I-131 OIH 20% 80%

Tc-99m GHA 40%-60% 20%

Tc-99m DMSAsome 60%

Semin NM Apr.92

renal radiopharmaceuticals
Renal Radiopharmaceuticals

Extract. fractionClearance

Tc-99m DTPA 20% 100-120 ml/min

Tc-99m MAG3 40-50% ~ 300 ml/min

I-131 OIH ~100% 500-600 ml/min

renal radiopharmaceuticals dosimetry
Renal RadiopharmaceuticalsDosimetry

DTPA MAG3 GHA DMSA I-131OIH rad/10 mCirad/5mCi rad/300µCi

Kidney 0.2 0.15 1.6 3.5 0.01

Bladder 2.85.1 2.7 0.3 0.3

EDE (rem) 0.3 0.4 0.4 0.3 0.03

choosing renal radiotracers
Perfusion MAG3, DTPA, GHA

Morphology DMSA, GHA

Obstruction MAG3, DTPA, OIH

Relative function All

GFR quantitation I-125 iothalamate,

Cr-51 EDTA, DTPA

ERPF quantitation MAG3, OIH

Choosing Renal Radiotracers

Clin. Question Agent

basic renal scintigraphy patient preparation
Basic Renal ScintigraphyPatientPreparation
  • Patient must be well hydrated
    • Give 5-10 ml/kg water (2-4 cups) 30-60 min. pre-injection
    • Can measure U - specific gravity (<1.015)
  • Void before injection
  • Void @ end of study

Int’l Consens. Comm.

Semin NM ‘99:146-159

basic renal scintigraphy acquisition
Basic Renal ScintigraphyAcquisition
  • Supine position preferred
  • Do not inject by straight stick
  • Flow (angiogram) : 2-3 sec / fr x 1 min
  • Dynamic: 15-30 sec / frame x 20-30 min

(display @ 1-3 min/frame)

basic renal scintigraphy acquisition cont d
Basic Renal ScintigraphyAcquisition (cont’d)
  • Obtain a 30-60 sec. image over injection site @ end of study
    • if infiltration >0.5% dose do not report clearance
  • Obtain post-void supine image of kidneys @ end of study

Taylor, SeminNM 4/99:102-127

international consensus committee recommendations for basic renogram
International Consensus Committee Recommendations for Basic Renogram
  • Tracer: MAG3, (DTPA)
    • Dose: 2 - 5 mCi adult, minimum 0.5 mCi peds
  • Pt. position: supine (motion, depth issues)
    • Include bladder, heart
  • Collimator: LEAP
  • Image over injection site

Int’l Consens. Comm.

Semin NM ‘99:146-159

relative uptake
Relative uptake
  • Contribution of each kidney to the total fct

net cts in Lt ROI

% Lt kid = --------------------------------------- x 100%

net cts Lt + net cts Rt ROI

    • Normal 50/50 - 56/44
    • Borderline 57/43 - 59/41
    • Abnormal > 60/40

Taylor, SeminNM Apr 99

basic renal scintigraphy processing
Basic Renal ScintigraphyProcessing
  • Time to peak
    • Best from cortical ROI
    • Normal < 5 min
  • Residual Cortical Activity (RCA20 or 30)
    • Ratio of cts @ 20 or 30 min / peak cts
    • Use cortical ROI
    • Normal RCA20 for MAG3 < 0.3
  • Residual Urine Volume
    • (post-void cts x void. vol)  (pre-void cts - post void cts)
slide18

DTPA flow + scan

GFR = 29 ml/’

Creat = 2.0

L= 33%

R= 67%

renogram phases
Renogram Phases
  • I. Vascular phase (flow study): Ao-to-Kid ~ 3”
  • II. Parenchymal phase (kidney-to-bkg): Tpeak < 5’
  • III. Washout (excretory) phase
evaluation of hydronephrosis
Evaluation of Hydronephrosis

Diuretic (Lasix) Renal Scan

obstruction
Obstruction

Obstruction to urine outflow leads to obstructive uropathy(hydronephrosis, hydroureter) andmay lead to obstructive nephropathy(loss of renal function)

diuretic renal scan principle
Diuretic Renal ScanPrinciple
  • Hydronephrosis - tracer pooling in dilated renal pelvis
  • Lasix induces increased urine flow
  • If obstructed >>> will not wash out
  • If dilated, non-obstructed >>> will wash out
  • Can quantitate rate of washout (T1/2)
diuretic renal scan indications
Diuretic Renal ScanIndications
  • Evaluate functional significance of hydronephrosis
  • Determine need for surgery
    • obstructive hydronephrosis - surgical Rx
    • non-obstructive hydronephrosis - medical Rx
  • Monitor effect of therapy
diuretic renal scan requirements
Diuretic Renal ScanRequirements
  • Rapidly cleared tracer
  • Well hydrated patient
  • Good renal function
diuretic renal scan procedure
Diuretic Renal ScanProcedure
  • Pt. preparation:
    • prehydration adults - oral or 360ml/m2 iv over 30’ peds - 10-15 ml/kg D5 0.3-0.45%NS
    • void before injection
    • bladder catheterization ?
diuretic renal scan procedure cont d
Diuretic Renal ScanProcedure (cont’d)
  • Tracers: Tc-99m MAG3 5-10 mCi (preferred over DTPA)
  • Acquisition: supine until pelvis full (can switch to sitting post- Lasix)
  • Flow (angiogram) : 2-3 sec / fr x 1 min
  • Dynamic: 15-30 sec / frame x 20-30 min
diuretic renal scan procedure cont d1
Diuretic Renal ScanProcedure (cont’d)
  • Void before Lasix
  • Lasix: 40mg adult, 1mg/kg child iv @ ~10-20 min (when pelvis full)or @ -15min (“F-15” method)
  • Acquisition for 30 min post Lasix
  • Assess adequacy of diuresis
    • Measure voided volume
    • Adults produce ~200-300 ml urine post-Lasix
diuretic renal scan procedure cont d2
Diuretic Renal ScanProcedure (cont’d)
  • Don’t give Lasix if
    • Collecting system still filling
    • Collecting system not full by 60 min
    • Collecting system drains spontaneously
    • Poor ipsilateral fct (< 20%)
no upj obstruction
No UPJ obstruction

T1/2

R = 6’

L = 2’

pre lasix1
Pre-Lasix

10 y/o M

rt upj obstruction
Rt UPJ obstruction

T1/2

R = N/A

F/U - nephrostomy tube placed

slide39

Lt hydronephrosis

3-wk old baby

3164897

rt upj obstruction1
Rt UPJ obstruction

T1/2

R = N/A

F/U - nephrostomy tube placed

diuretic renal scan processing
Diuretic Renal ScanProcessing
  • ROI placement
    • around whole kidney or
    • around dilated renal collecting system
  • T/A curve
  • T1/2
    • from Lasix injection vs. from diuretic response
    • linear vs. exponential fit of washout curve
diuretic renal scan washout diuretic response
Diuretic Renal ScanWashout(diuretic response)

T1/2time required for 50% tracer to leave the dilated unit i.e. time required for activity to fall

to 50% of peak

t 1 2 washout
T1/2 washout

cts

100%

50%

T1/2 min

t 1 2 value
T1/2 value
  • Variables influencing T1/2 value:
    • Tracer
    • State of hydration
    • Volume of dilated pelvis
    • Bladder catheterization
    • Dose of Lasix
    • Renal function (response to Lasix)
    • ROI (kidney vs. pelvis)
    • T1/2 calculation (from inj. vs. response, curve fit)
t 1 2
T1/2
  • Normal < 10 min
  • Obstructed > 20 min
  • Indeterminate 10 - 20 min
  • Best to obtain own normals for each institution, depending on protocol used
diuretic renal scan interpretation
Diuretic Renal ScanInterpretation
  • Interpret whole study, not T1/2 alone
  • Visual (dynamic images)
  • Washout curve shape (concave vs. convex)
  • T1/2
diuretic renal scan pitfalls
Diuretic Renal ScanPitfalls
  • False positive for obstruction
    • Distended bladder
    • Gross hydronephrosis

T(transit time) = V (volume) F (flow)

    • Poorly functioning / immature kidney
    • Dehydration
  • False negative
    • Low grade obstruction
    • Poorly functioning / immature kidney
effect of catheterization 1
Effect of catheterization (1)

full bladder,no catheter

effect of catheterization 2
Effect of catheterization (2)

with catheter in bladder

effect of catheterization 3
Effect of catheterization (3)

without catheter

with catheter

f minus 15 diuretic renogram
“F minus 15” Diuretic Renogram
  • Furosemide (Lasix) injected 15 min before radiopharmaceutical
  • Rationale: kidney in maximal diuresis,under maximal stress
  • Some equivocals will become clearly positive, some clearly negative

English, Br JUrol 1987:10-14Upsdell, Br JUrol 1992:126-132

evaluation of renovascular hypertension
Evaluation of Renovascular Hypertension

Captopril Renal Scan (ACEI Renography)

renovascular disease
Renovascular Disease
  • Renal artery stenosis (RAS)
  • Ischemic nephropathy
  • Renovascular hypertension (RVH)

RAS  RVH

renovascular hypertension
Renovascular Hypertension
  • Caused by renal hypoperfusion
    • Atherosclerosis
    • Fibromuscular dysplasia
  • Mediated by renin - AT - aldosterone system
  • Potentially curable by renal revascularization
renovascular hypertension1
Renovascular Hypertension
  • Prevalence
    • <1% unselected population with HTN
  • Clinical features
    • Abrupt onset HTN in child, adult < 30 or > 50y
    • Severe HTN resistant to medical Rx
    • Unexplained or post-ACEI impairment in ren fct
    • HTN + abdominal bruits

If these present - moderate risk of RVH (20-30%)

renin angiotensin system
Renin-Angiotensin System

RAS

Angiotensinogen

Renin

Angiotensin I

Captopril

ACE

Angiotensin II

Aldosterone Vasoconstriction

HTN

diagnosis of ras
Diagnosis of RAS
  • Gold std: angiography
  • Initial non-invasive tests:
    • ACEI renography
    • Duplex sonography
  • Other tests:
    • MRA - insensitive for distal / segmental RAS
    • Captopril test (PRA post-C.) - low sensitivity
    • Renal vein renin levels
slide62

ACEI Renography Patient Preparation

  • Off ACEI & ATII receptor blockers x 3-7 days
  • Off diuretics x 5-7d
  • No solid food x 4 hrs
  • Patient well hydrated
    • 10 ml/kg water 30-60 min pre- and during test
  • ACEI
    • Captopril 25-50 mg po (crushed), 1 hr pre-scan
    • Enalaprilat 40 µg/kg iv (2.5 mg max), 15 min pre-scan
    • Monitor BP q 15 min
acei renography procedure
ACEI RenographyProcedure
  • Tracer: Tc-99m MAG3 (or DTPA)
  • Protocol: 1 day vs. 2 day test
    • 1 day test: baseline scan (1-2 mCi) followed by post-Capto scan (8-10 mCi)
    • 2 day test: post-Capto scan, only if abnormal >> baseline
  • Acquisition: flow & dynamic x 20-30 min.
acei renography processing
ACEI RenographyProcessing
  • Relative renal uptake (bkg corrected)
  • Time to peak (Tp) - from cortical ROI
    • normal < 5 min
  • RCA20 (20 min/peak ratio) - from cortical ROI
    • normal < 0.3
acei renography diagnostic criteria
ACEI RenographyDiagnostic Criteria
  • MAG3:ipsilateral parenchymal retention p.C.
    • change in renogram curve by  1 grade
    • RCA20 increase by  15% (e.g. from 30% to 45%)
    • Tp increase by  2 min or 40% (e.g. from 5 to 7’)
  • DTPA: ipsilateral decreased uptake
    • Decrease in relative uptake  10% (e.g.from 50/50 to 40/60), change of 5-9% - intermediate
    • change in renogram curve by  2 grades

Consens. report JNM ‘96:1876Semin NM 4/99:128-145

acei renography interpretation
ACEI RenographyInterpretation
  • High probability RVH (>90%)
    • Marked C-induced change
  • Low probability RVH (<10%)
    • Normal Captopril scan
    • Abnormal baseline, improved p-C.
    • Type I curve - pre- and post-C.
  • Intermediate probability RVH
    • Abnl baseline, no change p-C.
acei renography1
ACEI Renography
  • In normal renal function - sens/spec ~ 90%
  • In poor renal fct / ischemic nephropathy, ACEI renography often indeterminate >>> do MRA, Duplex US, angio
evaluation of renal infection
Evaluation of Renal Infection

Renal Morphology Scan (Renal Cortical Scintigraphy)

slide79
UTI

VUR

risk factor for PN,

not all pts w PN have VUR

PN may lead to scarring >>> ESRD, HTN

early Dx and Rx necessary

Clinical & laboratory Dx of renal involvement in UTI unreliable

renal cortical scintigraphy indications
Renal Cortical ScintigraphyIndications

Determine involvement of upper tract (kidney) in acute UTI (acute pyelonephritis)

Detect cortical scarring (chronic pyelonephr.)

Follow-up post Rx

renal cortical scintigraphy procedure
Renal Cortical ScintigraphyProcedure

Tracers

Tc-99m DMSA

Tc-99m GHA

Acquisition

2-4 hrs post-injection

parallel hole posterior

pinhole post. + post. oblique (or SPECT)

Processing: relative fct

renal cortical scintigraphy interpretation
Renal Cortical ScintigraphyInterpretation

Acute PN

single or multiple “cold” defects

renal contour not distorted

diffuse decreased uptake

diffusely enlarged kidney or focal bulging

Chronic PN

volume loss, cortical thinning

defects with sharp edges

Differentiation of AcPN vs. ChPN unreliable

renal cortical scintigraphy cold defect
Renal Cortical Scintigraphy“Cold Defect “

Acute or chronic PN

Hydronephrosis

Cyst

Tumors

Trauma (contusion, laceration, rupture, hematoma)

Infarct

slide85

Normal DMSA

pinhole

LPO RPO

acute pyelonephritis dmsa
Acute pyelonephritisDMSA

post L

postR

LEAP

LPO pinhole

RPO

renal cortical scintigraphy congenital anomalies
Renal Cortical ScintigraphyCongenital Anomalies

Agenesis

Ectopy

Fusion (horseshoe, crossed fused ectopia)

Polycystic kidney

Multicystic dysplastic kidney

Pseudomasses (fetal lobulation, hypertrophic column of Bertin)

dmsa horseshoe kidney
DMSAhorseshoe kidney

parallel pinhole

indications1
Indications
  • Evaluation of children with recurrent UTI
    • 30-50% have VUR
  • F/U after initial VCUG
  • Assess effect of therapy / surgery
  • Screening of siblings of reflux pts.
methods
Tc-99m S.C. or TcO4

via Foley

can do at any age

VUR during filling

catheterization

Tc-99m DTPA or Tc-99m MAG3

i.v.

no catheter

info on kidneys

need pt cooperation

need good renal fct

Methods

DirectIndirect

Advant.

Disadv.

direct cystography
Direct Cystography
  • 1 mCi S.C. in saline via Foley
  • Fill bladder until reversal of flow
    • (bladder capacity = (age+2) x 30
  • Continuous imaging during filling & voiding
  • Post void image
  • Record
    • volume instilled
    • volume voided
    • pre- and post- void cts
rn cystogram vs vcug
Lower radiation dose(5 vs 300 mrad to ovary)

Smaller amount of reflux detectable

Quantitation of post-void residual volume

Cannot detect distal ureteral reflux

No anatomic detail

Grading difficult

RN Cystogram vs. VCUG

AdvantagesDisadvantages

normal cystogram
Normal cystogram

filling voiding post-void

post void residual volume
Post void residual volume

voided vol x post-void cts pre-void cts - post void cts

RV =