Table 1

ClassificationVelocity (cm/sec)Image characteristics

NormalMid graft PSV > 150 cm/secNo visible narrowing
Distended outflow veins
Anastamosis PSV > 300 cm/sec, chaotic, disorganized flowAneurysms, puncture sites, perigraft
fluid may be visible

Moderate stenosisRatio of PSV at stenosis to PSV at 2 cmDecrease in lumen diameter
beyond anastamosis if normal-appearing <3Echogenic narrowing
Wall abnormalities

Severe stenosisMarked velocity acceleration at stenotic areaIntraluminal echogenicity < 2 mm
lumen >50% diameter reduction
Ratio of PSV at stenosis to PSV at 2 cmMarked reduction in lumen
beyond anastamosis if normal-appearing >3diameter with color doppler

Inflow StenosisPeak systolic velocities will increase at the site ofIntraluminal echogenicity
stenosis with monophasic and diminished< 2 mm lumen at velocity acceleration
waveforms distal
Flow acceleration with graft compression at
outflow anastamosis

Outflow stenosisMid graft PSV < 100 cm/sIntraluminal echogenicity
Distal vein > 300 cm/sec< 2 mm lumen velocity acceleration
Velocity at the proximal anastamosis will diminishProminent collateral veins around outflow
in proportion to severity of venous outflow stenosis

OcclusionNo doppler signalIntraluminal echogenicity
Graft walls appear collapsed
Occluded vein may not be visible