9%20ECOGRAFIA%20ABDOMINAL%20COMO%20CUANDO%20DONDE

208
ABDOMINAL ULTRASOUND
A
B
Figure 8.10 (A) LS through the epigastrium
demonstrating a gastric carcinoma (arrows). (B) TS
through the epigastrium demonstrating a gastric
carcinoma (arrows). (C) Gastric carcinoma,
presenting with altered liver function tests (LFTs).
The patient had multiple liver metastases.
C
subsequent weight loss. Patients frequently undergo
a number of comparatively invasive investigations
before a diagnosis is reached, and this delay increases
the mortality and morbidity of the condition. 17,18
Treatment involves restoring the blood flow via
angioplasty or surgery and, if necessary, resecting
segments of necrosed bowel.
Atherosclerosis may be demonstrated in the
SMA in a number of cases. Signs of occlusion or
stenosis of the SMA may be identified with colour
or power Doppler 19 as a filling defect within the
lumen of the vessel. However, significant stenoses
have been diagnosed with Doppler in a relatively
high percentage (18%) of the asymptomatic, elderly
population. The finding of a stenosis on ultrasound,
therefore, is an indication for further
imaging in symptomatic patients, rather than an
absolute indicator of mesenteric ischaemia. 20
In a normal patient, the response of the SMA to
food can be demonstrated as an increase in end
diastolic flow velocities (Fig. 8.12).
Mesenteric compromise has also been associated
with an abnormal postprandial response;
Doppler waveforms of the SMA have decreased
peak systolic and end diastolic velocities after
food. 21
None of these ultrasound signs and appearances
are specific for mesenteric ischaemia; the mesentery
is supplied by three arteries which cannot all
be evaluated with ultrasound and, in addition,
numerous other conditions are associated with
altered SMA Doppler resistance, including inflam-