Diagnostic ultrasound ( PDFDrive )

CHAPTER 18 Organ Transplantation 655
A B C
D
E
F
G
H
I
FIG. 18.37 Renal Transplant-Related Infections. (A) Uroepithelial thickening. Sagittal sonogram shows mild uroepithelial thickening (arrowheads).
(B) Sagittal scan shows mild uroepithelial thickening (arrows) surrounding a mildly dilated collecting system with internal echoes, secondary to
early pyonephrosis. (C) Transverse sonogram shows moderate to severe uroepithelial thickening (arrow), which can be misinterpreted as a mass
in the renal pelvis. (D)-(F) Focal pyelonephritis. (D) Sagittal sonogram shows subtle, focal echogenic region in the upper-pole cortex (arrowheads).
(E) Intraparenchymal phlegmon appearing as a hypoechoic mass within the renal cortex (arrows). (F) On color Doppler, the phlegmon seen in
image (E) is vascular. (G) and (H) Diffuse pyelonephritis. (G) Transverse sonogram shows a generous kidney with echogenic granular renal
cortex, surrounded by inlamed echogenic perinephric fat (F). (H) Corresponding CT shows inlamed fat (F) as perinephric streaking. (I) Emphysematous
pyelonephritis. Sagittal sonogram shows air (arrows) within collecting system, appearing as bright, echogenic linear foci with distal dirty
shadowing.
On Doppler sonography, the infarcted region appears as a wedgeshaped
area devoid of low on color or spectral interrogation. 57
Interpretation of the gray-scale and Doppler indings should not
be inluenced by urine output of the allograt or laboratory data,
because segmental infarction may occur in the presence of
preserved renal function.
he absence of blood low on Doppler interrogation in the
kidney parenchyma may be observed in conditions other than
arterial thrombosis, including hyperacute rejection and renal
vein thrombosis. In these conditions, however, the main renal
artery is patent on spectral Doppler ultrasound and may exhibit
reversal of diastolic low. 44
Renal Artery Stenosis
Renal artery stenosis, the most common vascular complication
of transplantation, occurs in up to 10% of patients within the
irst year, is more frequent in living donor allograts compared
with cadaveric allograts, and should be suspected in cases of
severe hypertension refractory to medical therapy. Transplants
with multiple renal arteries are now being used more frequently