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
