Cirrhosis.

HISTORY: Known cirrhosis, screening ultrasound performed to rule out hepatoma.

FINDINGS: Image 1 is a transverse scan of the right lobe of the liver

demonstrating a very subtle area of focal increased echogenicity

anteriorly near the liver capsule (arrow).  There is very subtle

refractive edge shadowing.  Images 2 and 3 are high-resolution, linear-

array scans of the liver capsule demonstrating a 1 cm echogenic lesion

(arrows) just below the liver capsule with refractive edge shadowing.

Image 4 is a black and white depiction of a color Doppler scan

demonstrating increased vascularity within the lesion.  Image 5 was

obtained during a percutaneous fine-needle aspiration biopsy of the

lesion.  Notice the linear bright echo within the center of the lesion

(arrowhead) representing the needle tip.

Images 6-8 are taken from an MRI scan.  Image 6 is a T1-weighted

sequence, Image 7 is a T2-weighted fast spin-echo sequence, and

Image 8 is a gadolinium-enhanced, T1-weighted multiplanar spoiled

GRASS sequence.  Even in retrospect the lesion is virtually impossible

to identify on the MRI.

The patient was then treated with percutaneous alcohol ablation of the

lesion.  Notice on Image 9 that the lesion is markedly echogenic due to

the alcohol dispersion within the lesion.  Similarly increased

echogenicity is noted within the lesion on Image 10.

One week following the ablation, a follow-up sonogram (Images 11 and 12)

demonstrates that the lesion is smaller in size and now hypoechoic

rather than echogenic.  A color Doppler sonogram post ablation (Image

12) demonstrates no intrinsic vascularity within the lesion.

DIAGNOSIS: Small hepatocellular carcinoma detected by high-resolution

linear ultrasound.  Successful percutaneous ablation with alcohol

injection.

DISCUSSION: Standard 3.5 MHz and 5.0 MHz abdominal transducers

failed to optimally image superficial hepatic lesions.  In this patient

high-resolution linear array scans were essential to diagnose the small

lesion just beneath the liver capsule.  Had this not been performed, the

lesion would have been missed as the standard abdominal ultrasound and

MRI were, even in retrospect, unrevealing.  Edge shadows are indicative

of space-occupying masses of the liver.  They are typically seen with

malignant lesions such as metastasis and hepatocellular carcinoma.

Intrinsic vascularity within a focal lesion is highly suspicious for

hepatocellular carcinoma.  However, this finding is not specific for

hepatoma.  Some benign lesions, such as focal nodule hyperplasia, also

have significant intrinsic vascularity.  Metastases tend to have

peripheral vascularity (the "detour sign") due to displaced vessels.

Alcohol ablation has been used for several years to treat poor operative

candidates with small hepatocellular carcinomas (e.g., less than 3 cm).

Clinical follow up demonstrates improved survival compared to control

groups.  The technical difficulties relate to leakage of alcohol along

the needle track into the peritoneal cavity (which can be avoided by

having a normal "cuff" of liver surrounding the needle track).  Other

problems include the fact that there may be incomplete necrosis due to

poor diffusion of the alcohol through the entire lesion.  Recent work

suggests that PET scanning may be very valuable in assessing the

viability of a tumor after alcohol ablation.