Diagnostic ultrasound ( PDFDrive )

CHAPTER 9 The Kidney and Urinary Tract 367
A
B
FIG. 9.81. Renal Infarct. (A) Transverse power Doppler sonogram shows an avascular slightly echogenic “lesion.” (B) Corresponding CT
angiogram shows an acute right upper-pole renal infarct and focal clot within mid right renal artery. (Courtesy of William Middleton, MD. Mallinckrodt
Institute of Radiology, St. Louis Missouri.)
FIG. 9.82 Renal Arteriovenous Malformation
(AVM). Top: Left image, Normal sagittal
sonogram of the kidney. Right image, Focus
of color aliasing (arrow). Middle: Spectral
waveform shows a high-velocity draining vein.
Bottom: Spectral wave form shows an arterial
signal from within the AVM. Note high-velocity,
low “resistance” low (RI = 0.46).
small, abnormal vessels. Gray-scale sonography may reveal no
abnormality. he addition of duplex and color Doppler imaging
has been helpful in deining these lesions. 275 Duplex Doppler
demonstrates increased low velocity, a decreased RI (0.3-0.4),
and turbulent diastolic low in the arterial limb. Arterial pulsations
in the draining vein are also observed. Spectral broadening is
present. Color Doppler sonography may demonstrate a tangle
of tortuous vessels with multiple colors, indicative of the haphazard
orientation and turbulent low within the malformation (Fig.
9.82).