Page 14 - Read Online

Castán et al. Radiology of hepatocarcinoma in non-cirrhotic patients

diagnosed as HCC directly with one imaging test with between the different causes of cirrhosis. However,
typical findings, if there is early enhancement and hypertrophy of the lateral segments, accompanied by
late washing; (2) nodules from 1 to 2 cm require two atrophy of the right and the left medial lobe segments,
different techniques for diagnosis with typical findings; occurs frequently in patients with cirrhosis induced by
and (3) nodules < 1 cm should be followed by US every virus. On the other hand, caudate lobe hypertrophy is
[3]
4 months during the first year and then every 6 months. usually associated with alcoholic cirrhosis. Several
studies have evaluated the ratio between the width
In nodules between 1 and 2 cm, the AASLD in its of the caudate lobe and the right lobe (C/RL) as an
latest update (2010) [21] establish the criteria for a indicator of cirrhosis. Awaya et al. [22] considered a value
single positive test. However, the EASL does not of C/RL > 0.65 indicative of cirrhosis. The specificity
recommend following this approach in the absence is high (> 90%), but with low sensitivity (43-80%),
of prospective studies to support it. Both guidelines indicating that the quotient C/RL is a useful measure if
recommend the use of CT or MRI and limit the abnormal. [23-25]
use of CEUS. As described in previous sections,
intravascular contrast distribution means that in Heterogeneous echostructure and multinodular
some cases the behavior of the lesion is not typical appearance are frequent observations in chronic liver
or obtains false positives in CC. In case of uncertain disease. However, its assessment mainly in the initial
[26]
diagnosis, biopsy of the lesion is required. stages has much variability. The presence of irregular
and nodular surface contour of the liver is considered
RADIOLOGICAL ASSESSMENT OF CIRRHOTIC to be a sign of cirrhosis. This alteration is secondary to
LIVER COMPARED TO HEALTHY LIVER the presence of fibrosis and regeneration nodes. This
sign is easily visible in the presence of ascites, which
In the assessment by imaging techniques of patients allows a better evaluation of liver surface through
without known cirrhosis three questions must be the liquid (88% sensitivity, 82-95% specificity). [27] In
considered: first, differentiating between healthy absence of ascites it is advisable to judge the previous
and cirrhotic liver; second, determining if there are liver surface by high frequency probes (7.5 MHz),
morphological differences or behavior in HCC that increasing the sensitivity in detecting this pattern. Its
occur in cirrhotic liver versus healthy liver; and existence is associated with macronodular cirrhosis.
third, analyzing the management and differential
diagnosis according to these characteristics with other Fibrosis of liver parenchyma can alter the morphology
tumors that may be seen in healthy liver, with similar of the hepatic veins, with alteration in distensibility,
radiological characteristics as HCC. causing luminal narrowing because the walls of the
hepatic veins are thin. In advanced cases, alteration of
Chronic liver disease, regardless of its etiology, leads venous flow is observed using Doppler-US, with loss of
to progressive development of liver fibrosis and then the triphase morphology of the wave flow in the hepatic
to the final and irreversible stage of cirrhosis. The veins (this condition is called “portalization”). Depending
gross morphological changes that occur in cirrhotic on the degree of fibrosis, intrahepatic arterial branches
livers are easily detectable with any current imaging may be elongated with tortuous appearance with a
techniques. In recent years, new imaging methods, “corkscrew” morphology, due to the distortion of the
from liver elastography of transition to modern underlying liver parenchyma architecture. The wave of
diffusion techniques and MRI elastography, have been the hepatic artery also shows an altered dynamic, with
developed to assess liver fibrosis with the intention increase of speed secondary to the lower flow of the
of making a diagnosis at an early stage that allows portal vein.
an active treatment for incipient liver fibrosis. In this
article we review the spectrum of chronic liver disease Another important sign in patients with cirrhosis is
findings in different imaging techniques. detection of portal hypertension. Increased resistance
of portal venous blood flow causes increased portal,
US is usually the first technique used and can detect mesenteric and splenic vein caliber. Thus, the
liver cirrhosis and its complications. In the first phase existence of a diameter greater than 13 mm has a
of cirrhosis liver can be enlarged, whereas in advanced sensitivity of 42% and a specificity of 90% for the
stages the liver is usually small with atrophy of the right diagnosis of portal hypertension. [28] The increase of
lobe (predominantly anterior segment) and the medial less than 20% in the diameter of the portal vein with
segment of the left lobe, and relative enlargement of deep inspiration is another sign of portal hypertension,
lateral segments of the left, caudate or both lobes. The with a sensitivity of 80% and a specificity of 100%. [29]
morphological patterns of chronic liver disease overlap However, the difficulty in assessing this measurement

6 Hepatoma Research ¦ Volume 3 ¦ January 12, 2017