Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

384 Small Animal Radiolo g y and Ultrasono graphy
Fig. 3-159 Longitudinal sonograms
of the right kidney of a 16-year-old
spayed female Doberman Pinscher
with a history of anorexia and vomiting
for 2 weeks. The dog had a mass
on the right rear foot. There is a heteroechoic
mass associated with the
renal cortex at the cranial aspect of
the right kidney (arrows). This represents
a renal tumor. Diagnosis:
Metastatic melanoma.
Fig. 3-160 Longitudinal sonograms
of the left kidney of a 10-year-old
male Rottweiler with a history of
anorexia, vomiting, and hematuria
of 3 weeks duration. The renal architecture
is totally obliterated and
replaced by multiple hypoechoic,
somewhat oval-shaped lesions. This
is indicative of renal neoplasia.
Diagnosis: Metastatic carcinoma.
Fig. 3-161 Longitudinal sonograms
of the left kidney of a 3-year-old castrated
male cat with a history of
episodic hind limb paresis. There is a
focal hyperechoic lesion at the corticomedullary
junction in the cranial
pole of the kidney (arrows). This
most likely represents a renal infarct
or focal area of infection. Diagnosis:
Renal infarct secondary to hypertrophic
cardiomyopathy.
hyperechoic linear bands that stretch from the renal pelvis to the renal cortex (Fig.
3-164). Pyonephrosis may produce renal pelvic dilation, which appears similar to
hydronephrosis. The fluid usually will be more echogenic, and the complex, cellular
nature of the fluid often can be recognized by the motion of the cells within the purulent
material contained in the renal pelvis. Aspiration of the renal pelvis using ultrasonographic
guidance will provide a definitive diagnosis. Intrarenal cysts are anechoic,
usually round, vary in size, may be septated, and are located within the renal
parenchyma away from the renal pelvis. It is important to identify the cyst in both longitudinal
and transverse planes in order to be certain it is in the kidney. The cysts may
be single or multiple, large or small, and may protrude from the renal cortex or be
located completely within the renal parenchyma (Fig. 3-165). Some tumors and
abscesses appear cavitated (loosely termed cystic) while some cysts contain echogenic
material that may create the illusion that they are solid. 475,481,484 Aspiration or biopsy
may be required for a definitive diagnosis.