Q.All are
true regarding hepatocellular carcinoma except
a.result of
defferentiation through regenerative nodules to dysplastic nodules to HCC
b.regenerative
nodules and dysplastic nodules are predominantly supplied by portal vein
c.HCC is
solely supplied by abnormal ,unpaired hepatic arteries
d.HCC
doesnot have portal blood supply
e.HCC is
commonly diagnosed on basis of histological confirmation
ANS---e
Hepatocellular
carcinoma differs from most malignancies because it is commonly diagnosed on
the basis of imaging features alone, without histologic confirmation
4.All are
true regarding AASLD recommendation of HCC except
a.US
surveillace every 6 months in cirrhosis patients
b.new
nodules > 1cm is suspicious of HCC
b.nodules
stable for 2yrs should undergo routine surveillance
d.suspicious
nodules require further investigation by Multiphasic CT/MRI
e.arterial
phase washout
ANS.---e
Portal
veinous or delayed washout is seen in HCC
Q.All are
true regading AASLD criteria for diagnosis of HCC in cirrhosis
a.use of
multiphasic CT/MRI
b.arterial
hyperattenuation of lesion
c.portal
venous phase hypoattenation of thelesion
d.delayed
phase hyperatenuation of the lesion
e.portal
veous phase /delayed phase washout
ANS.---d
---The radiologic diagnosis of hepatocellular carcinoma can be made at
either CT or MR imaging, provided that a multiphasic contrast material–enhanced
study is used.
----Characteristically, hepatocellular carcinoma enhances during the
arterial phase because of its blood supply from abnormal hepatic arteries.
Contrast medium in the surrounding liver parenchyma is diluted during this
phase because the parenchymal blood supply arises mostly from the portal veins,
which are not yet opacified.
-----In the portal venous phase, the surrounding liver
parenchyma becomes relatively hyperattenuated and the lesion is perceived to be
hypoattenuated because of its lack of portal venous supply. This appearance is
the so-called washout effect. Occasionally, washout is evident only during a
delayed phase sequence.
------ Thus, a four-phase imaging study is required:
non–contrast-enhanced phase, arterial phase, portal venous phase, and delayed
phase
----- Images should be acquired in four
phases: non–contrast-enhanced phase (before the injection of contrast
material), late arterial phase (about 20 seconds after the injection), portal
venous phase (50 seconds after the injection), and delayed phase (>120 seconds
after the injection).
-----The optimal timing for image acquisition in the delayed
phase is debated, varying between 2 and 15 minutes after contrast material
injection.
------Contrast-enhanced US studies have shown that approximately 90% of
hepatocellular carcinomas demonstrate washout by 5 minutes after injection of
the microbubble contrast agent . Use of a 5-minute delay may be the practical
choice for the timing of the delayed phase.
-----Precontrast and dynamic postcontrast
T1-weighted three-dimensional fat-suppressed gradient-echo sequences are
required, in addition to T2 (with and without fat saturation) and T1 in-phase
and opposed-phase imaging. Timing of the dynamic contrast-enhanced sequences is
the same as that used for the CT examination. Emphasis on precise
breath-holding is extremely important.
-----Systematic review has shown that MR imaging
is more sensitive than CT in the diagnosis of hepatocellular carcinoma (81% vs
68%)
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