mage 1
fluid is homogeneously
echogenic
and
may
6 5
when haematological
and biochemical
is not
that ultrasonography
is more 8).
accurate for detecting
appear
to swirl analysis
(haemoabdomen;
Image
readily available.
strangulating
lesions
of
the
small
intestine than per-
7
Heterogeneous
fluid
is
usually
consistent
with
rectum evaluation.
3
splenic window
– place the probe
Ultrasonographic
approaches
7th intercostal space (or paralumbar
intestinal
rupture.
A complete abdominal evaluation involves systematic
Equipment
at the level between the dorsal and
imaging
abdomen, typically by dividing the
A low frequency (2-5MHz) curvilinear transducer (probe)
third of the
left side of
of the
the entire
abdomen.
kidney should
be visualised
deep
left and
right sides
into to three regions; the paralumbar
is ideal, it will allow penetration of up to 30cm depth and
en (Image fossa,
4). Obstruction
of the intercostal
view
the 5th-17th
spaces and ventrum. A
offers a wide field of view. A higher frequency and/or
left kidney by large colon indicates
limited
evaluation
of
the
ventrum
for
strangulating
small
linear transducer e.g. a rectal probe will provide limited
plenic entrapment (Image 5), although
intestinal
lesions
and
the
left
caudal
intercostal
spaces
penetration (typically Image
<12cm) 3 and a narrower field of
ommended to pair these findings with
Duodenal window – place the probe
um examination
(Scharner et al. entrapment
2002).
for nephrosplenic
can
be
performed
in
view
but
can
still
provide
important information and
in the 14-15th intercostal space at the
colicking horses (le Jeune and Whitcombe
2014).
guide third
the decision-making process.
level between
the Busoni
middle to dorsal
on the right the
side diagnostic
of the abdomen. The liver,
et al. (2011) described and evaluated
right dorsal colon (RDC) are
Right middle third – move the probe
accuracy of Fast Localised duodenum
Abdominal and
Sonography
Patient preparation
visible (Image 6). The RDC is characterised
systematically around the middle one
of Horses, a ‘FLASH’ protocol by in a horses
referred
with Wall
The
hair coat of third
the of regions
to be scanned
should
be
large, smooth
curvature.
thickness
the abdomen.
The caecum
occupies
colic. This focused trans-abdominal
(and
therefore non-
of dirt (removed
by
brushing)
and
isopropyl
alcohol
of >4mm
is considered
abnormal, free
especially
the dorsal right paralumbar fossa and the
if irregularly
(Image
apex
extends so to that
the the
ventral
Small
invasive) ultrasonographic approach
was thickened
designed
for 7). should be applied
liberally
coat abdomen.
is saturated.
pockets
of peritoneal
(hypoechoic)
can
clinicians with basic ultrasonography experience, for
Hair clipping is not
usually
required fluid
unless
the hair coat
be a normal finding and assessment of quantity
the quick detection of major abdominal abnormalities
is especially thick,
or if the horse is obese. Acoustic
is subjective and difficult. Haemorrhagic
requiring surgical intervention.
contact gel can
be
to the echogenic
probe to and
further
fluid is applied
homogeneously
may
improve contact.
Abdominal
is usually
well
appear
to swirl ultrasound
(haemoabdomen;
Image
8).
mage 4
Heterogeneous fluid is usually consistent with
Five inexperienced clinicians were trained to perform
tolerated.
intestinal rupture.
the FLASH protocol in which the abdomen is divided
5
6
into seven regions. Thirty-six horses were included in
the prospective study and the results of the FLASH
evaluations were compared with serial clinical
examination parameters, surgical Image
versus 6 non-surgical
outcomes, and where available, post-mortem findings.
The examination took approximately 10 minutes and
yielded good to excellent sensitivity (80%), specificity
(96%), positive predictive value (PPV; 89%) and negative
predictive value (NPV; 93%). In an earlier retrospective
mage 5
study by Klohnen et al. (1996) transabdominal
ultrasonography performed in horses with small
intestinal strangulation had 100% sensitivity, specificity,
PPV
NPV.
the same
4 study, per-rectum palpation
ddle third
– and
move
the In probe
tically around
third
had the
only middle
50% one
sensitivity
but 98% specificity, revealing
Image 8
Conclusions
Transcutaneus abdominal ultrasonography is a
potentially valuable tool in the evaluation of the equine
acute abdomen and can help with the identification of
lesions which require rapid surgical intervention.
7
Cranial Ventral Thorax – place the probe
Image 8
in the intercostal space immediately caudal
to the right triceps muscle, ventrally to visualise
Cranial Ventral Thorax – place the probe 7
in the intercostal
space immediately caudal
the
cranioventral abdomen, including
the liver.
bdomen. Assessment of small
intestinal
nd presence of gas filled colon can be
d in this position.
Image 7
to the right triceps muscle, ventrally to visualise
the cranioventral abdomen, including the liver.
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