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

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ABDOMINAL ULTRASOUND
A
B
Figure 11.13 Radiofrequency ablation (RFA). (A) The RF probe is introduced into the metastasis under intraoperative
ultrasound guidance. (B) The lesion is gradually ablated; the area of ablated tissue reflects the sound and can be seen
to increase in size progressively during the course of the therapy.
will demonstrate occult metastases, often in the
peritoneum.
Staging laparoscopy still cannot demonstrate
intrahepatic metastases, and the use of laparoscopic
ultrasound at this stage greatly increases the accuracy
of staging and influences the surgical decision.
23
Laparoscopic ultrasound is also useful in staging
patients with gastric cancer 24 and colorectal
cancer. 25 Curative resection of bowel cancer can
be performed with either open surgery or laparoscopic
resection. Laparoscopic ultrasound can be
used to examine the liver to confirm the absence
of metastases: this is particularly useful in a
laparoscopic resection as the surgeon is unable
to palpate the liver under these circumstances.
This laparoscopic approach reduces patient morbidity
when compared with open surgical exploration.
Figure 11.14 Laparoscopic ultrasound demonstrating
multiple liver metastases in a patient with carcinoma in
the tail of the pancreas.
ULTRASOUND CONTRAST AGENTS
IN THE ABDOMEN
Ultrasound contrast media have been well established
for cardiac imaging since the 1980s and the
first clinical use of such an agent was in 1968 and
involved the injection of saline to identify echoes
from the mitral valve. 26
These early contrast agents were composed of
relatively large (by today’s standards) microbubbles
of air in solution. They were unstable, shortlived
and the bubbles were too large to pass
through the capillary beds, hence their use exclusively
for cardiac ultrasound.