Imaging of liver lesions....
Malignant lesions of the liver
Hepatocellular Carcinoma
It can be solitary, multifocal or diffuse
Ultrasound- It appears as a discrete lesion, either solid or multiple.
Small tumor ie (<3cm) are hypoechoic where as larger sized tumors are hyperechoic.
Ultrasound has a very low sensitivity in differentiating a regenerating nodule from a tumor.
Presence of hypoechoic rim helps in differentiating a hepatocellular carcinoma from haemangioma.
Invasion of portal vein and hepatic vein may be seen.
Colour Doppler - It shows an arterial flow pattern in the thrombus.
Contrast Enhanced Ultrasound-- Shows Rapid peak enhancement in the arterial phase and (increased echogenicity) and washout (hypoechogenity) in the venous phase.
CT Scan- Non enhanced CECT shows- solitary or multiple low attenuating lesion
Arterial phase- Intense enhancement through out the tumor with hypodense rim
Venous phase- Rapid washout of contrast and lesion becomes hypodense to isodense
Delayed Images - show the capsule and fibrous septa as hyperdense.
MRI Hypointense on T1W
Hyperintense on T2W
Fibrolamellar hepatocellular carcinoma
Major clue to the diagnosis is central scarring and central stellate calcification.
Ultrasound- Lobulated heterogenous, hyperehoic mass
Scar is hyperechoic non shadowing area
CT scan --Well defined hypodense lesion
Stellate calcification seen in 50-60%
It shows hetergenous enhancement on arterial and portal venous phase and washout in delayed phase.
MRI - Hypointense on T1w and hyperintense on T2w
