Diagnostic ultrasound ( PDFDrive )

CHAPTER 18 Organ Transplantation 665
A
B
C
D
FIG. 18.49 Harmonic Imaging in Two Patients. (A) Sagittal fundamental image shows barely detectable stones (arrows) and a dilated collecting
system. (B) Harmonic image shows improved resolution of stones (arrows), now seen associated with distal acoustic shadowing, within anechoic
dilated collecting system. (C) Fundamental image shows cortical cyst (arrowhead) with internal echoes and minimal through transmission. (D)
Harmonic image shows cyst (arrowhead) to be anechoic and simple, now associated with an appropriate amount of through transmission.
hematoma, urinoma, lymphocele, and abscess. he ultrasound
appearances of these peritransplant collections are oten nonspeciic,
and clinical indings are warranted to determine their
cause. However, the presence of air within a perirenal collection,
without a history of recent percutaneous intervention, is highly
suggestive of an abscess. he size and location of each collection
should be documented on baseline scans because an increase in
size may indicate the need for surgical intervention.
Postoperative hematomas are variable in size but are oten
small, perirenal in location, and insigniicant clinically and oten
resolve spontaneously. 68 heir ultrasound appearance depends
on the age of the collection. An acute hematoma will appear as
an echogenic heterogeneous solid mass. With time the hematoma
will liquefy, becoming a complex luid collection with internal
echoes, strands, or pseudoseptations. Postbiopsy hematomas have
a morphology similar to that of their postoperative counterparts
(Figs. 18.55 and 18.56).
Urine leaks, or urinomas, have been reported in up to 6%
of renal transplants and occur within the irst 2 weeks ater
surgery. 44 hey are usually secondary to either anastomotic leaks
or ureteric ischemia. Rarely, urinomas can result from high-grade
collecting system obstruction (Fig. 18.57). On sonography,
urinomas are well deined and anechoic, may be associated with
hydronephrosis, and in some cases can increase rapidly in size. 57
Large urine leaks may result in widespread extravasation and
gross intraperitoneal urinary ascites.
Lymphoceles result from surgical disruption of the iliac
lymphatics and have been reported in up to 20% of patients.
hey most oten occur 4 to 8 weeks ater surgery but may develop
years ater transplantation. Although most are discovered