evaluation of doppler ultrasound for renal … of doppler ultrasound for renal transplant evaluation...

Evaluation of Doppler ultrasound for renal transplant evaluationfor renal transplant evaluation

ARRS meeting2011‐05‐03

F Edward Boas, Terry Desser and Aya KamayaTerry Desser, and Aya Kamaya

Stanford Hospital

Disclosure of commercial interestDisclosure of commercial interest

Neither I nor my immediate family membersNeither I nor my immediate family members have a financial relationship with a commercial organization that may have acommercial organization that may have a direct or indirect interest in the content.

DiagnosesDiagnoses

Diagnosis Number of patients1. Normal, with creatinine ≤ 1.5 72. Delayed graft function post‐operatively 63 Acute rejection 83. Acute rejection 84. Chronic rejection, transplant

glomerulopathy, or drug toxicity, i i 1 5

5

creatinine > 1.55. Hydronephrosis 56. Renal vein thrombosis 27. Other 14Total 47

Resistive index = (V –V i )/VResistive index (Vmax Vmin)/Vmax

yow

velocit

Fl

V V iTime

Vmax Vmin

Resistive indexResistive indexSensitivity 38% for acute rejectionSpecificity 63%

30%

35%

40%Normal (0.71 ± 0.11)

Acute rejection (0.77 ± 0.11)

Other

20%

25%

30%

10%

15% Acute rejectionDelayed graft functionRenal vein thrombosis

0%

5%

<0.7 0.70 – 0.79 0.80 – 0.89 0.90 – 0.99 ≥1<0.7 0.70 0.79 0.80 0.89 0.90 0.99 ≥1Resistive index

Mid renal artery velocity waveformMid renal artery velocity waveform

Velocity waveformsVelocity waveforms

30

15

20

25

w (m

l/s)

— Normal— Acute rejection

5

10

15

artery flow

‐10

‐5

00 0.2 0.4 0.6 0.8 1Re

nal

10Fraction of cardiac cycle

Velocity waveformsVelocity waveforms

30

15

20

25

w (m

l/s)

— Normal— Acute rejection— Delayed graft function— Chronic rejection

5

10

15

artery flow

Chronic rejection— Hydronephrosis— Renal vein thrombosis— Other

‐10

‐5

00 0.2 0.4 0.6 0.8 1Re

nal

10Fraction of cardiac cycle

Velocity waveforms (average)Velocity waveforms (average)20

15

ml/s) Normal

5

10

tery flow

(m

Acute rejection

00 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

in re

nal art

‐10

‐5Mai

Renal vein thrombosis

Fraction of cardiac cycle

Velocity waveforms (Average ± stdev)Velocity waveforms (Average ± stdev)20

Thick lines: average

15

ml/s) Normal

Thick lines: averageThin lines: one standard deviation

5

10

tery flow

(m

Acute rejection

00 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

in re

nal art

‐10

‐5Mai



Windkessel modelWindkessel model

lSystole

Pulsatile pump Continuous capillary flow

Image credits: Piotr Michał Jaworski (kidney) and User ZooFari on Wikipedia (heart). Creative Commons Attribution‐Share Alike 3.0 Unported license.

Windkessel modelWindkessel model

lDiastole

Pulsatile pump Continuous capillary flow

Image credits: Piotr Michał Jaworski (kidney) and User ZooFari on Wikipedia (heart). Creative Commons Attribution‐Share Alike 3.0 Unported license.

3‐element Windkessel model3 element Windkessel model

R1 Pre‐glomerular resistance (renal artery)

C Vascular compliance

R2 Post‐glomerular resistance (renal vein)

NormalNormal

High R1High R1

NormalNormal

High R2High R2

NormalNormal

Low CLow C

3‐element Windkessel model250 7

150

200

24

5

6

C

50

100

R 2

1

2

3

C

00 10 20 30

R1

00 10 20 30

R17

4

5

6 NormalAcute rejectionDelayed graft functionChronic rejection

1

2

3

C Chronic rejectionHydronephrosisRenal vein thrombosisOther

00 50 100 150 200 250

R2

3‐element Windkessel model250 7

150

200

24

5

6

C


50

100

R 2

1

2

3

C

00 10 20 30

R1

00 10 20 30

R17

4

5

6 NormalAcute rejectionDelayed graft functionChronic rejection

1

2

3

C Chronic rejectionHydronephrosisRenal vein thrombosisOther

00 50 100 150 200 250

R2

Doppler ultrasoundDoppler ultrasound

Acute rejection can’t be diagnosed using:Acute rejection can t be diagnosed using:

• resistive index (intra‐renal)

l l i• pre‐glomerular resistance

• post‐glomerular resistance

• vascular compliance

• the shape of the velocity waveform (mid renalthe shape of the velocity waveform (mid renal artery)

ConclusionsConclusions

• Doppler ultrasound of kidney transplants hasDoppler ultrasound of kidney transplants has limited value in diagnosing acute rejection.

• Resistive index > 0 9 is seen in acute rejection• Resistive index > 0.9 is seen in acute rejection, delayed graft function, and renal vein thrombosisthrombosis.

• The 3‐element Windkessel model can be used d i l i dto determine vascular resistance and

compliance.

Additional slidesAdditional slides


Resistive index is increased with:Resistive index is increased with:

• Increased R2 (post‐glomerular resistance)

d ( l l i )• Decreased R1 (pre‐glomerular resistance)

• Increased C (vascular compliance)

• Increased pulse pressure

• Increased heart rateIncreased heart rate

Principal component analysisPrincipal component analysis

Average waveform Principal components

12 0.25 Flow

Average waveform Principal components

6

8

10

w (m

l/s)

0.05

0.1

0.15

0.2

ml/s)

Biphasic pulsatilityTriphasic pulsatility

2

4

6

Flow

‐0.15

‐0.1

‐0.05

00 0.2 0.4 0.6 0.8 1

Flow

(m0

0 0.2 0.4 0.6 0.8 1

Fraction of cardiac cycle‐0.25

‐0.2


Principal component analysis

30

40

50

60

70

lsatility

0

5

10

15

20

ulsatility

‐10

0

10

20

‐50 0 50 100

Biph

asic pu

‐20

‐15

‐10

‐5‐50 0 50 100

riph

asic pu

‐30

‐20B

Flow

‐30

‐25Tr

Flow

20

0

5

10

15

20

ulsatility Normal

Acute rejectionDelayed graft functionChronic rejection

25

‐20

‐15

‐10

‐5‐50 0 50 100

Tripha

sic pu Chronic rejection

HydronephrosisRenal vein thrombosisOther

‐30

‐25T

Biphasic pulsatility

evaluation of doppler ultrasound for renal … of doppler ultrasound for renal transplant evaluation...

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