The Art of Radiology

CT OF THE LIVER

Helical CT application of the liver include

SIZE OF THE LIVER

15cm

LIVER DENSITY

Principles of Hepatic Contrast Enhancement

Non- contrast scan

Single phase CECT

Dual- phase CECT

TRIPHASIC CYCLE

PVP

Equilibrium phase

(C,D )corresponding PVP images obtained 40 seconds later show substantial hepatic parenchymal enhancement due to influx of

enhanced blood via the portal vein (arrows)

Homogenous hypervascularOnly arterial phase enhancment

Homogenous hypovascularPorto-venous

Only arterial Porto-venous enhancment

Heterogenous PatterenHyper or hypo

DELAYED ENHANCMENT

RING enhancment

Abscess

NODULAR ENHANCMENT

NO ENHANCMENT

MULTIPLE LIVER LESION

CT scan of the abdomen reveals multiple abscess cavitieswithin the liver (arrow) and spleen (arrowheads).

(hepatosplenomegally)

CALCIFICATION

Capsule

Fat

Hemorrhage

HCC

CT

[arterial phase]

HEPATOCELLULAR CARCINOMA

PATTEREN OF ENHANCMENTOF HCC

Hepatocellular carcinoma. Spiral CT shows two masses, with hyperattenuation of the small mass in the right lobe, large mass

demonstrates less enhancement than the small one

HCC AT HAP

HCC AT HAP

HCC AT HAP

HCC AT PVP

HCC AT HAP

HCC AT PVP

HCC AT HAP

HCC AT PVP

HCC AT HAP

HCC AT PVP

Portal node

This abdominal CT scan in axial view demonstrates a large mass that occupies most of the posterior right lobe of the liver. This is an hepatocellular

carcinoma. These cancers can appear as one large mass, or there may be small surrounding satellite nodules, or multifocal masses. The serum alpha-

fetoprotein (AFP) is often elevated with hepatocellular carcinoma

This abdominal CT scan reveals an hepatocellular carcinoma, with areas of less attenuation from extensive tumor necrosis, involving the inferior margin of the right

lobe of the liver. In the view above, this carcinoma has invaded through the liver capsule and extended to the abdominal wall. Note the presence of ascitic fluid as well. Hepatocellular carcinomas that rupture through the liver capsule may also produce a

hemoperitoneum

Figure 2a. Hepatitis C and HCC that was not prospectively diagnosed at triphasic contrast-enhanced helical CT in a 57-year-old man. (a) Transverse

nonenhanced CT image shows cirrhotic liver without an contrast

HCC AT HAP

C-HCC AT PVP

HEPATOMA IN CIRRHOTIC LIVERCT FINDINGS

Hepatitis C, alcohol-related liver disease, and HCC that was prospectively diagnosed at triphasic contrast-enhanced helical CT in a 45-year-old man. (a) Transverse nonenhanced CT image

shows nodular cirrhotic liverhypodense lesion

Same case show enhancement at HAP

C-hypodense at PVP

CT scan of the upper abdomen showing an widespread (disseminated) carcinoma of the liver (hepato cellular carcinoma). The liver is the large organ on the left side

of the picture. Note the

Cystic hepatocellular carcinoma. (b) Arterial-phase contrast-enhanced CT scan obtained in a 55-year-old man shows indirect signs of liver cirrhosis: atrophy of the

right hepatic lobe, hypertrophy of the caudate lobe, contour irregularities, and ascites. In addition, an

Focal nodular hyperplasia FNH

Focal nodular hyperplasia FNH Imaging

Focal nodular hyperplasia (FNH)

Focal nodular hyperplasia. A: Unenhanced CT image shows a slightly hypoattenuating mass (arrow heads) with a small central lower attenuation

scar (open arrow).

B: The mass enhances homogenously, except for the Scar .

2A-Typical CT findings of focal nodular hyperplasia in 30-year-old woman. Unenhanced CT scan shows lesion in left lobe of liver

(arrowheads), which is slightly hypodense to remainder of liver. Note more hypodense central scar (arrow).

2B Arterial phase contrast-enhanced CT scan shows strong homogeneous enhancement of lesion, caused by arterial vascular supply.Note focal central

area of low attenuation, representing central scar

Contrast-enhanced CT scan during the portal venous phase shows lesion being slightly hypoattenuating compared with surrounding liver because of

rapid contrast material washout

2D-Typical CT findings of focal nodular hyperplasia in 30-year-old woman. Delayed phase contrast-enhanced CT scan shows

persistent enhancement of central scar (arrowhead).

FNH AT ARTERIAL PHASE

DELAYED SCAN

FNH AT HAP

FNH HAP

FNH AT PVP

HAP

Multiplicity of lesions Multiple focal nodular hyperplasias in 28-year-old woman. Contrast-enhanced CT scan during arterial phase shows multiple hypervascular lesions disseminated

throughout liver

1a. Transverse CT scans obtained in a 41-year-old woman with FNH.

a) Section obtained during the hepatic arterial phase shows a round mass that demonstrates intense homogeneous enhancement with a smooth

margin and a small central scar (arrow

1b.). Section obtained during the portal venous phase at the same level. The mass (solid arrows) is isoattenuating with the normal hepatic parenchyma and can be

identified by the scar (open arrow) that has decreased in size due to partial enhancement

2c. Images obtained in an 18-year-old woman with fibrolamellar HCC. (a) Unenhanced transverse CT scan demonstrates a large, heterogeneous

hypoattenuating mass that replaces most of the left hepatic lobe. The central scar is not well seen, but there are central coarse calcifications (arrow) .

2c. Images obtained in an 18-year-old woman with fibrolamellar HCC. (b) Hepatic arterial phase image obtained at the same level shows

heterogeneous intense enhancement of the same mass (open arrows). There are two satellite lesions (solid white arrows), and the surface lobulation,

central scar (solid black arrow), and calcifications within the scar are seen more clearly .

3b. Transverse CT scans obtained in a 67-year-old man with a large hemangioma. (a) Section obtained during the hepatic arterial phase shows a large lobulated mass (solid arrows) that replaces the right hepatic lobe and demonstrates nodular enhancement

(open arrows) that is isoattenuating with the aorta. There is an irregular, cleftlike, central hypoattenuating scar

3b. Transverse CT scans obtained in a 67-year-old man with a large hemangioma.. (b) Section obtained during the portal venous phase at the same level shows more nodular enhancement of the mass, which is still isoattenuating with the aorta. The irregular, elongated, hypoattenuating

central scar (arrow) is seen more clearly with the increase in lesion enhancement

HEPATIC ADENOMA

hepatic adenoma

Fig. 3A. —44-year-old woman with hepatocellular adenoma (straight arrow) in right liver lobe (subcapsular). Arterial phase CT scan shows lesion is slightly

hyperdense and shows feeding artery (curved arrow)

b

ADENOMA

ADENOMA

HAP PVP

REGENERATING NODULES AT HAP

REGENERATING NODULES AT PVP

Case 2

Case 3