Chapter 14 - Abdominal vessels Flashcards
Renal aortic ratio (RAR) calculation and normal values
Renal artery PSV / Aortic PSV
Normal < 3.5
Abnormal > 3.5 = 60% stenosis
When is RAR not accurate
1) Presence of aortic aneurysm
2) PSV of aorta outside of 40-90 cm/sec
Renal PSV value suggestive of disease
> 180 cm/s with poststenotic turbulence
Suggestive 60% stenosis
Signs other than velocity to suggest significant renal artery stenosis
1) diameter reduction of 60%
2) poststenotic turbulence
3) spectral broadening
Normal kidney length
10-12 cm
End diastolic ratio of kidney
AKA parenchyma resistance ratio (PRR) or diastolic/systolic ratio
End-diastolic velocity / peak systolic velocity
Normal > 0.2
Abnormal < 0.2
Pourcelot’s ratio
AKA resistive index (RI)
PSV - EDV / PSV
Normal < 0.7
Abnormal > 0.7
Renal resistive index value
RRIV = RI = 1 - PRR
< 0.75 suggest improvement in blood pressure and renal function after correction of renal artery stenosis
> 0.75 suggest no improvement
Acceleration time for renal artery
Time interval from onset of systole to initial peak
60% stenosis if AT > 100 ms
Acceleration index of renal artery (AI)
Slope of doppler velocity waveform
Change in velocity between onset of systole and systolic peak divided by AT
60% stenosis if AI < 291 cm/s^2
Celiac artery stenosis > 70% duplex criteria
PSV > 200cm/s
SMA stenosis > 70% duplex criteria
fasting PSV > 275 cm/s
Celiac artery stenosis > 50% duplex criteria
EDV > 55 cm/s
SMA stenosis > 50% duplex criteria
EDV > 45 cm/s
Normal PSV of SMA and Celiac
SMA 110-177 cm/s
Celiac 50-160 cm/s
SMA preprandial vs postprandial
PSV and EDV increases postprandial
Flow reversal in preprandial is lost after feeding
Median arcuate ligament syndrome inspiration vs expiration
Inspiration has improved flow
Expiration has worse stenosis with audible bruit and color bruit
Normal portal vein size
< 1-1.5 cm
B mode signs of renal transplant rejection
1) increase renal transplant size
2) increased cortical echogenicity
3) hypoechoic regions in the parenchyma
