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148
ABDOMINAL ULTRASOUND
from other possible cystic masses near the splenic
hilum, such as pancreatic pseudocysts.
They are usually asymptomatic and are associated
with pregnancy or liver disease with portal hypertension.
Surgical resection or ligation is performed
to prevent rupture, although smaller aneurysms
may be safely monitored with ultrasound. 12
Pseudoaneurysm
Pseudoaneurysm in the spleen occurs in a minority
of cases following splenic trauma. An echo-free or
‘cystic’ area may be observed, which demonstrates
flow on colour Doppler.
In rare cases, pseudoaneurysm is also a complication
of splenic infarct, inflitration of the spleen
by malignancy, inflammatory disease such as pancreatitis,
or infection 13 and usually occurs in association
with non-traumatic splenic rupture.
normal lymph nodes can be demonstrated in the
hepatoduodenal ligament at the porta hepatis (Fig.
6.9A), particularly in younger patients. 14
The search for lymphadenopathy should include
the para-aortic and paracaval regions, the splanchnic
vessels and epigastric regions, and the renal hila
(Fig. 6.9). Ultrasound has a low sensitivity for
demonstrating lymphadenopathy, in the retroperi-
Splenic trauma
(See also Chapter 10.) Splenic laceration may be
particularly difficult to detect on ultrasound, particularly
in the immediate post-trauma phase. The
presence of free fluid in the abdomen of a trauma
victim should alert the sonographer to the strong
possibility of organ injury. The laceration may
appear as a subtle, hyperechoic line within the
spleen immediately after the injury. A frank area of
haemorrhage, easily identifiable on ultrasound,
may not develop until later.
CT is normally performed following the identification
of free fluid on ultrasound in order to
assess the extent of organ injury. Intrasplenic
pseudoaneurysm is a recognized, but rare complication
of splenic trauma, which can be demonstrated
on colour Doppler.
In rare cases, spontaneous splenic rupture may
be encountered, most usually associated with massive
splenomegaly of the sort seen in infectious
mononucleosis.
A
PORTA
GB
IVC
s
LYMPHATICS
Traditionally, normal lymph nodes are difficult or
impossible to demonstrate on ultrasound. However,
with good-resolution equipment, and using a suitable
acoustic window, such as normal liver tissue,
B
Figure 6.9 (A) Normal lymph nodes at the porta.
(B) Lymphadenopathy in the epigastrium (arrows) can be
seen anterior to the inferior vena cava (IVC).
(Continued)