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ABDOMINAL ULTRASOUND
Figure 4.13 A calcified granuloma demonstrates
acoustic shadowing.
Figure 4.15 The mass effect: an isoechoic lesion
(arrows), confirmed on CT, is recognized because of the
adjacent deviation of the portal and hepatic venous
radicles.
Figure 4.14 Considerable deposits of calcification are
seen in the liver in this patient with nephrotic syndrome.
Metastases
The liver is one of the most common sites to which
malignant tumours metastasize. Secondary deposits
are usually blood-borne, spreading to the liver via
the portal venous system (for example in the case of
gastrointestinal malignancies), or hepatic artery (for
example lung or breast primaries), or spread via the
lymphatic system. Some spread along the peritoneal
surfaces, for example ovarian carcinoma. This
demonstrates an initial invasion of the subserosal
surfaces of the liver (Fig. 4.16A), as opposed to the
more central distribution seen with a haematogenous
spread (Fig. 4.16B). The former, peripheral
pattern is more easily missed on ultrasound because
small deposits are often obscured by near-field artefact
or rib shadows. It is therefore advisable for the
operator to be aware of the possible pattern of
spread when searching for liver metastases.
Ultrasound appearances
The acoustic appearances of liver secondaries are
extremely variable (Fig. 4.16). When compared
with normal surrounding liver parenchyma, metastases
may be hyperechoic, hypoechoic, isoechoic or
of mixed pattern. Sadly, it is not possible to char-