Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

Chapter One Introduction 21
Fig. 1-15 Longitudinal sonogram of
the urinary bladder of a dog. There
are many echoes within the bladder
lumen. These are the result of reverberation
or electronic noise artifacts.
These artifacts add echoes to the
normally anechoic urine and could
be misinterpreted as echogenic cellular
material within the urinary
bladder.
A
B
Fig. 1-16 Longitudinal (A and B)
and transverse (C and D) sonograms
of the urinary bladder of a 4-yearold
female mixed breed dog with a
2-week history of vomiting and diarrhea.
In the longitudinal sonograms
there is a hyperechoic area that
appears to be within the dorsal
aspect of the urinary bladder. In the
transverse sonograms this hyperechoic
area is identified as the colon,
which is indenting the dorsolateral
aspect of the bladder. This creates a
beam-width or slice-thickness artifact
because, due to the width of the
ultrasound beam, a portion of the
colon is included along with the urinary
bladder when the longitudinal
sonogram was obtained.
C
D
DEVELOPING A DIFFERENTIAL DIAGNOSIS
After an abnormality has been identified radiographically or ultrasonographically using
the features described in this chapter, a list of differential diagnoses should be established.
This list should include all possible causes of the described radiographic or