Diagnostic ultrasound ( PDFDrive )

1008 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
A
B
C
FIG. 27.67 Graft or Arteriovenous Fistula (AVF) Draining
Vein Stenosis Assessment Using Color and Spectral
Doppler With Peak Systolic Velocity (PSV) Measurement.
(A) Visual narrowing in draining vein greater than 2 cm
downstream from anastomotic stenosis (therefore draining
vein stenosis, not juxta-anastomotic stenosis). (B) PSV
measurement of area of greatest narrowing is 8.5 m/sec. (C)
PSV 2 cm upstream from draining vein stenosis is 3.4 m/sec
for a PSV gradient of >2 : 1, with visual narrowing, consistent
with at least 50% stenosis.
A
B
C
FIG. 27.68 Graft Venous Anastomotic Stenosis. (A)
Gray-scale image shows signiicant narrowing at thigh graft–
common femoral vein anastomosis. (B) Venous anastomosis
peak systolic velocity (PSV) measures 6.1 m/sec in greatest
jet. (C) PSV measurement within the graft 2 cm upstream
from the venous anastomosis is 2.53 m/sec, for a PSV ratio
>2 : 1, and concordant with visual narrowing, consistent with
at least 50% stenosis. See also Video 27.29.