Diagnostic ultrasound ( PDFDrive )

CHAPTER 18 Organ Transplantation 661
A
B
C
D
FIG. 18.44 Mimickers of Renal Artery Stenosis. (A) Abrupt turn in renal artery. On color Doppler ultrasound, aliasing is identiied in this
region (arrow), with peak systolic velocities of 429 cm/sec on spectral Doppler. (B)-(D) Misaligned angle correction. (B) Initial spectral Doppler
shows elevated renal artery anastomotic velocity of 298 cm/sec. This elevated velocity reading is artifactual because the spectral angle correction
is not aligned with the direction of the renal artery. (C) Follow-up spectral Doppler ultrasound shows a normal renal artery velocity of 189 cm/sec,
with appropriate angle correction in the direction of the artery. (D) Renal angiogram conirms a normal renal artery (arrows) with no evidence of
stenosis.
such as the renal collecting system for regions of subtle
dilation, and the presence of small intraluminal stones
(Fig. 18.49).
Mild pelvicaliectasis may be secondary to nonobstructive
causes such as overhydration, decreased ureteric tone (from
denervation of transplant), and ureteric-vesical relux or can
occur transiently in the immediate postoperative period from
perianastomotic edema. 45,68 In addition, multiple parapelvic cysts
can mimic a dilated collecting system (Fig. 18.50).
Arteriovenous Malformations and
Pseudoaneurysms
Intraparenchymal arteriovenous malformations (AVMs) result
from vascular trauma to both artery and vein during percutaneous
biopsies and are usually asymptomatic with few clinical sequelae.
Because most of these are small and resolve spontaneously, the
incidence of posttransplant AVMs is unknown, although rates
of 1% to 18% have been reported. In rare cases, large AVMs may
manifest with bleeding, high-output cardiac failure, or decreased