MAGNETIC RESONANCE

IMAGING OF FOCAL HEPATIC

LESIONS

Presenter: MOZAMMIL RABBANI

Moderator: DR. DIPU BHUYAN

(ASSOCIATE PROFESSOR)

ANATOMY

Largest gland in the body weighing about 1.4kg in adult

Occupies right hypochondrium and part of epigastrium

Covered by peritonium except bare area on

posterosuperior surface, fossa for GB and IVC

Blood supply – Portal vein 80%, Hepatic artery 20%

Drained by three hepatic veins into IVC

SEGMENTAL ANATOMY

COUINAUD CLASSIFICATION

The Couinaud classification of liver anatomy divides the

liver into eight functionally independent segments.

Each segment has its own vascular inflow, outflow and

biliary drainage.

In the centre of each segment there is a branch of the

portal vein, hepatic artery and bile duct.

In the periphery of each segment there is vascular

outflow through the hepatic veins

Right hepatic vein divides the right lobe into anterior

and posterior segments.

Middle hepatic vein divides the liver into right and left

lobes (or right and left hemiliver). This plane runs from

the inferior vena cava to the gallbladder fossa.

The Falciform ligament divides the left lobe into a

medial- segment IV and a lateral part - segment II and

III.

The portal vein divides the liver into upper and lower

segments.

How to separate liver segments

on cross sectional imaging

MR IMAGING

Liver imaging is ideally done on a high field

system(>1.0 T) with fast gradients. Phased

array multicoils are used which provide high

signal to noise ratio.

Fast gradient echo sequences such as

FLASH is generally used to obtain T1

weighted sequences.

Echo-train sequences such as turbo spin

echo is used for T2 weighted images

Fat suppression is frequently used with these echo-train sequences because fat has very high signal intensity on these images.

T1 weighted 2D gradient echo sequences are used to perform post contrast imaging of liver.

The liver parenchyma appears homogenous on both T1 and T2 weighted scans.

The liver shows moderate signal intensity on T1W images, similar to pancreas but brighter than spleen and kidneys.

T2W scans the liver appears dark and has low signal intensity and has signal intensity less than that of spleen.

POST CONTRAST: TRIPHASIC

STUDY

The three phases of enhancement are based on the

location of gadolinium enhancement within the various

hepatic vessels.

The arterial dominant phase ---contrast material is

present in the arteries and in the main portal vein but not

in the hepatic veins.

The portal venous phase ---contrast material in the

arteries as well as in the portal and hepatic veins.

The delayed phase --- 2–3 min after contrast

administration.

In the arterial dominant phase --

hypervascular lesion ---if its enhancement is greater

than that of liver parenchyma

hypovascular lesion ---if its enhancement is less than

or equal to that of the liver parenchyma.

MR imaging contrast agents

MR contrast agents are currently used to accentuate

the difference in signal intensity between the liver

lesions and adjacent normal tissue and to highlight

different enhancement patterns.

According to biodistribution, the contrast agents are

divided into three categories

1. Extracellular contrast agents

2. Hepatobiliary contrast agents

3. Resticuloendothelial system targeted contrast agents

Extracellular contrast agents are hydrophilic, small

molecular gadolinium chelates. Gd-DTPA , Gd-DOTA

and the more recent non-ionic agents such as

gadodiamide ,gadobutrol and gadoteridol provide

information on vascularization and perfusion similar to

that of iodinated contrast media at CT examination.

Using breath-hold T1W GRE sequences , a dynamic

contrast enhanced study of liver is performed during the

arterial phase(20-30 sec after injection) , portal venous

phase (70-80 sec after injection) and the delayed

phase (2-3 min after injection).

Hepatobiliary agents are either only hepatocyte

selective ,such as mangafodipir trisodium (Mn-DPDP)

or are Gd chelates(gadobenate dimeglumine GD-

BOPTA and Gd-ethoxybenzyl Gd-EOB that are

distributed in the extracellular space and also

hepatocyte selective.

Mn-DPDP is injected at the dose of 0.5 mmol/kg as a

slow intravenous infusion and maximum liver

enhancement is observed within 15-20 minutes of

infusion,.

On post contrast images, most tumours of non

hepatocellular origin including metastasis , benign liver

cysts and hemangioma remains hypo intense relative to

enhanced liver parenchyma on T1W images.

RES contrast agents are superparamagnatic particles

of iron oxide(SPIO) , which produce loss of signal on

T2W images.

Kupffer cells take up more than 80% of these particles

allowing liver specific phase imaging 10 min after

injection.

Malignant focal lesions usually do not contain Kupffer

cells and therefore appear as bright nodules against the

markedly hypo intense liver parenchyma

Angiography

The high quality of images provided by cross sectional

imaging techniques has led to a dramatic change in the

indications for hepatic angiography.

This technique is now seldom used for diagnostic

purpose but is widely used for vascular interventions

used in the management of liver lesions.

Prior to the procedure, coagulation profile and serum

creatinine are obtained.

Angiography of liver is performed by selective injections

of the celiac axis and superior mesenteric artery or one

or more of their branches.

A 5 french right angle or reverse curve angle catheter

such as Cobra is used.

The volume of the contrast usd is about 20-30 cc

injected at the rate of 5-6 cc per second.

Visualization of portal venous system is done by

injecting the splenic artery or SMA coupled with

prolonged filming.

Positron emisson tomography

PET is an imaging modality that uses positron emitters

,such as flourine-18 to visualize the tissue, such as

cancers with increased glucose metabolism.

The most commonly used radiotracer for PET is 2-(18F)

fluoro-2 deoxy-d –glucose.

FDG-PET has been proved to be highly sensitive in

detecting hepatic metastases from various primaries.

The ability of FDG-PET quantitatively to establish

metabolic rates makes it a potential valuable tool for

monitoring response to the therapy.

For benign lesions like hemangioma , adenoma and

FNH , FDG-PET is not suitable.

PET has limited spatial resolution compared with CT

and MR imaging and the intrinsic heterogenous activity

in normal background liver limits the ability of FDG-PET

to show small malignant lesions.

Radionuclide Imaging

In this technique,hepatocyte and kupffer cells can be

investigated with Tc 99m labelled tracers.

Radiopharmaceuticals based on imidodiacetic acid(IDA)

are taken up by functioning hepatocytes ,excreted

unchanged in bile and not absorbed from gut.

Studies with IDA compounds allow imaging of

functioning liver prenchyma and also trace the flow of

bile in the ducts,gall bladder and bowel.

Labelled colloids demostrate the distribution of

functioning tissue by targeting the RE cells of liver,

spleen and bone marrow.

Mass lesions which contain no functioning RE cells(the

vast majority of pathologies) are shown as non-

functioning areas.

Applications

Application of hepatobiliary scintigraphy in liver disease

include the assessment of regional liver function

,demostration of bile leaks in liver trauma and the

differential diagnosis of hepatocellular tumours.

In differntiating benign hepatocellular tumours from

metastasis or primary malignancies,the radionuclide

imaging using IDA or labelled colloids is sufficiently

specific to allow biopsy to be avoided in the majority of

the cases.

CLASSIFICATION OF FOCAL

LESIONS

BENIGN TUMORS AND TUMOR LIKE

CONDITIONS

MALIGNANT TUMORS

CYSTS

INFECTIONS/ INFLAMMATION

TRAUMA

OTHERS

MALIGNANT LESIONS

Hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma

Metastasis

Lymphoma

Sarcomas ( Angiosarcoma, Mesenchymal sarcomas)

Intrahepatic Cholangicarcinoma

Hepatoblastoma

Biliary Cystadenocarcinoma

HEMANGIOMA

MC benign hepatic tumor

Tumor composed of multiple vascular channels lined by

a single layer of endothelial cells supported by a thin

fibrous stroma

Small-<3 cm, large- >3cm ,giant ->10 cm

M:F= 1:5

Most are asymptomatic, incidental findings on imaging

Hemangiomas are usually solitary but are multiple in

approximately 10% of cases. Their borders are clear, but

they are not encapsulated.

As the hemangioma grows, various degenerative

changes are seen in its center, including old and new

thrombus formation, necrosis, scarring, hemorrhage,

and calcification.When degeneration and fibrous

changes become more prominent, the lesion is referred

to as a sclerosed hemangioma

To diagnose Hemangioma, 3 conditions have to be

fulfilled :

1. Enhancement equal or more than the Aorta

2. Enhancement persists on delayed imaging

3. Appears in a globular or nodular in discontinuous

fashion

T1-hypointense

T2- Significantly hyperintense ( light bulb )

T1 with IV Gd – DTPA shows enhancement similar to

that seen on CT examination.

HAEMANGIOMA-MRI

Rapidly filling hemangiomas are not very frequent (16%

of all hemangiomas). However, rapid filling seems to

occur significantly more often in small hemangiomas

(42% of hemangiomas .

MR imaging show a particular enhancement pattern:

immediate homogeneous enhancement.

D/D- hypervacular mets hemangioma remain

hyperintense on delayed scans whereas mets are

hypointense on delayed scans.

Nuclear Scintigraphy

Tagged RBC blood pool scans are virtually diagnostic with defect on early scans and prolonged and persistent filling in, on delayed scans

Many vascular tumors like HCC, adenoma, FNH may have a persistent uptake but in the early scans have uptake rather than defect

Angiography

Early pooling of

contrast in the late

arterial phase

Contrast retained well

beyond venous phase

-cotton wool

appearance

Angio- important when

coexist with metastasis

as differentiation is

important when

planning resection

FOCAL NODULAR

HYPERPLASIA(FNH)

Tumor like condition characterized by a central stellatefibro vascular scar with surrounding nodules of hyperplastic hepatocytes, Kupffer cells and small bile ductules

Vessels present in the central stellate scar

Usually smaller than 5cm

2nd MC benign liver tumor

MC in women

Age- 20-40yrs

Calcification, necrosis and haemorrhage are extremely rare, as even large FNH lesions do not usually outgrow their blood supply.

Both Kupffer cell activity and the central scar have been used to characterize FNH,

The histologically important distinguishing features are the lack of normal architecture with absent portal tracts and no connecting bile duct drainage.

If vessels radiating from the central scar to the

periphery of the tumor are visualized, a near-definitive

diagnosis of FNH can be made.

This spoke-wheel pattern is most sensitively delineated

by contrast-enhanced ultrasonography.

The central scar is not a specific finding of FNH and can

be seen in a variety of other focal liver lesions such as

giant hemangiomas and HCCs.

The central scar in giant hemangiomas is typically larger

and brighter on T2-weighted images. In addition, the

lesions have homogeneous high signal intensity on T2-

weighted images and show peripheral nodular

enhancement in most cases.

Some HCCs may contain a central scar, the central scar

in HCC shows low signal intensity on T2- and T1-

weighted images and does not enhance much on

contrast-enhanced images.

MRI

T1-iso to hypointense, scar is hypointense

T2-iso to hyperintense, scar is hyperintense

Gd-DTPA-

Early-homogeneous enhancement of FNH

Late-enhancement of scar

T2 with SPIO ( coated crystalline particles taken up by phagocytes), uniform decrease in intensity throughout liver due to T2 signal loss.

Nuclear Scintigraphy

Sulfur colloid-due to presence of Kupffer cells, uptake in

60%

Hepatobiliary scans-HIDA-uptake and excretion due to

presence of biliary ductules

Angiography

Hypervascular mass possessing a centrifugal

or spoke wheel pattern of vascular supply.

HEPATOCELLULAR ADENOMA

Rare benign tumour

M.C in women of child bearing age

Four times high risk with OCP’s

Usually solitary, 8- 15 cm in size

Contains fat and glycogen

Associated with GSD type I, when multiple lesions are

present

Tumor composed of fatty hepatocytes arranged in cords

that occasionally form bile.

Vascular lesions composed mainly hepatocytes with no

portal tracts or bile ducts.

Thrombosis, necrosis, hemorrhage is common

Can rupture leading to hemoperitonium

Small, but definite risk (1%) of malignant change

Hence surgical resection is usually preferred.

T1-heterogeneous

with increased signal areas due to fat and

hemorrhage

T2- heterogeneous appearance

1/3 rd have rim which is hypointense on T1 and T2

Gadolinium enhanced MRI – Heterogenous

enhancement in the arterial phase but rapidly fades on

subsequent images.

Hepatocellular adenomas imaged with CT, lipid

deposition seen in only 7% of lesions. In contrast, 35%–

77% of adenomas demonstrate steatosis at chemical

shift MR imaging

) Axial in-phase T1-weighted GRE image shows a large, hypointense mass in the right hepatic

Nuclear scintigraphy

Sulfur colloid-Very few kupffer cells hence uptake in only 20%

Hepato biliary agents HIDA scans-uptake due to hepatocytes but no excretion due to lack of bile ductules

Nodular Regenerative Hyperplasia

Presence of diffuse, multiple regenerative nodules, not associated with fibrosis

Multiple nodules varying in size from few mm to cms on the liver surface

Rare condition.

Usually associated with portal hypertension and portal vein thrombosis

MRI

T1- Hyperintese

T2- Hypointense

Nuclear scintigraphy: Abnormal hepatocytes with kupfercells, hence uptake of Tc 99m sulfur colloid

Mesenchymal Hamartoma

<2 years, 7 % of childhood tumors

Benign cystic developmental lesions

Gelatinous mesenchymal tissue

Large – 15 cms or more

Mass effect – Respiratory distress and lower limb edema

T1 – hypointensity. T2 – slightly hyperintense

Angiomyolipoma

10% of patients with tuberous sclerosis & renal angiolipomas have hepatic fatty tumors either lipoma, angiomyolipoma.

MR

◦ Fat is high signal on T1 & T2

◦ MR with fat Suppression-same lesions are hypointense

Infantile Hemangioendothelioma

M/c liver tumor for first 6 months. Vascular tumor derived from endothelial cells that

proliferate and form vascular channels Solitary or multinodular. Nodules from few mm to

15cm or more Hemorrhage, fibrosis, thrombosis, calcification are

common 90% discovered in first 6months. F>M, appearance similar to multiple

hemangiomas Hepatomegaly, CHF due to AV shunts,

thrombocytopenia caused by trapping of platelets Occasional rupture- hemoperitoneum

MRI

Heterogenous appearance on both T1 & T2WI because

of presence of necrosis , hemorrahage and fibrosis.

Peripheral enhancement and central fillin is noted after

administration of gadolinium.

Simple Cyst

Arise from bile duct epithelium ,lined by cuboidal

epithelium. Multiple cysts as part of ADPKD and Caroli

disease .

Hepatic cysts appear markedly hypointense on T1-

weighted MR images and markedly hyperintense on T2-

weighted images.

Hepatic cysts have well-defined margins and are usually

oval or round. The presence of thick walls or enhancing

internal components suggests the diagnosis of hepatic

abscess or neoplasm rather than a simple cyst.

When haemorrhage or inflammation occurs in the centre

of these cysts, the signal intensity on MRI undergoes a

variety of changes. Such lesions are referred to as

complicated cysts

Biliary Hamartoma

Bile duct hamartomas, also called von Meyenburg

complexes, are uncommon benign biliary malformations.

asymptomatic and are typically discovered incidentally.

Bile duct hamartomas are usually less than 1 cm in

diameter and are often numerous.

MRI

T1- hypo

T2 – hyper.

contrast-enhanced images- no internal enhancement

Focal Hepatic Steatosis

Focal steatosis is often easily recognized on

the basis of the typical periligamentous or

periportal location, and the presence of

nondistorted, traversing blood vessels.

Patchy focal fat deposition or sparing may be

mistaken for an infiltrative neoplasm.

Focal Hepatic Infections

HYDATID DISEASE

PYOGENIC ABSCESS

AMOEBIC ABSCESS

CANDIDIASIS

Hydatid Cyst

Caused by Echinococcus

Right lobe of liver is most commonly involved.

Cyst structure-

PERICYST: Dense connective tissue capsule

around the cyst

ECTOCYST: Middle laminated layer

ENDOCYST: Inner germinal layer that gives rise

to brood capsules

Demonstrates pericyst, the matrix & daughter cysts.

Pericyst- Hypointense rim on both T1 & T2 WI.

Hydatid matrix – Hypointense on T1WI & markedly hyperintense on T2WI.

Daughter cysts- slightly hypointense when compared to matrix on T2WI.

Precetti S et al 2007 classified Hydatid disease into four

types on the basis of their radiologic appearance.

Type Ⅰ: Simple cyst

Type Ⅱ: Cyst with daughter cysts and matrix

Type Ⅲ: Calcified cyst

Type Ⅳ

Hydatid complications include rupture and superinfec-

tion

A solitary type cyst may be difficult to distinguish from a

simple epithelial cyst. The hydatid cysts are

hyperintense on DWI, whereas none of the simple cysts

show significant hyperintensity. The mean ADCs of the

hydatid cysts is significantly lower (2.5 × 10-3 ± 0.9) than

that of the simple cysts(3.5 × 10-3 ± 0.5)

Complications

Rupture and superinfections

Rupture can be:

1. Contained type: only endocyst ruptures & cyst

contents confined by pericyst

2. Communicating type : when cyst contents escape into

biliary or bronchial radicles that are incorporated into

pericyst

3. Direct type:when both endo & pericyst tear & spill

contents into pleural, peritoneal or pericardial cavities

Biliary Communications:

Direct sign: Visualisation of cyst wall defect or

a communication between the cyst and biliary

radicle.

Indirect sign: Fluid levels and signal intensity

changes.

Pyogenic Abscess

ETIOLOGY.

50% caused by anaerobic, mixed anaerobic-aerobic

E. coli- MC in adults

Staph- MC in children

PATHOGENESIS

1. Biliary- MC because of ascending cholangitis from benign or malignant biliary obstructions.

2. Portal vein - abscesses of biliary origin are often multiple , whereas from portal vein source are often solitary.

3. Hepatic art

4. Direct from adj organs

MRI

T1-Hypo

T2-Hyper

DWI: tends to to have high signal within the abscess

cavity

ADC: tends to have low signal within the abscess cavity

Gd-DTPA-rim enhancement which persist in thickness and intensity over time.

Perilesional edema -hyper on T2 seen in 1/3 & diff from cysts & hemangiomas

Differentiating hepatic abscess

from malignant mimickers

No hepatic abscesses shows peripheral washout on 3-

min late phase compared with malignant tumors.

Both shows hyperintense rims on DWI, but abscesses

have rims with high ADC values compared with one

malignant tumor.

Mean ADC values of abscesses (1.47 × 10-3 mm2 /s) is

significantly higher than malignancies (0.68 × 10-

3 mm2 /s ).

Amoebic Liver Disease

Caused by E.histolytica

Mostly solitary

MC in right lobe

After intestinal infection is established, amoeba is carried to the liver by the portal vein.

Centrally the cavity is filled by a thick fluid that resembles anchovy paste.

MR

Hypo-T1

Hyper-T2

T2-edema

They are difficult to differentiate from other liver

abscesses. They generally tend to be round or oval in

shapes in 82 verses 60% of pyogenic abscesses.

Hepatic Candiasis

Uncommon ,caused by candid species

Seen in immuno compromised patients

Candida species may evoke

- little or no inflammatory response.

- cause the usual suppurative response

- occasionally produce granulomas

MRI

Untreated nodules

1. Rounded lesions less than 1 cm in diameter

2. Minimally hypointense on T1-weighted and gadolinium-enhanced images and markedly hyperintense on T2-weighted images .

In the subacute presentation after treatment

1. Lesions appear mildly to moderately hyperintense on T1- and T2-weighted images and demonstrate enhancement on gadolinium-enhanced images.

2. A dark ring is usually seen around these lesions with all sequences.

MALIGNANT LESIONS

Hepatocellular Carcinoma

MC primary malignant tumor of liver

Can develop in Cirrhotic and Non-Cirrhotic liver

Wide geographical variation in incidence

Present with - dull pain, fever, malaise, jaundice

Elevated AFP values

Hepatitis (B& C) and cirrhosis (particularly post necrotic & haemochromotosis)-main risk factors. Others are aflotoxins, steroids

THREE MAJOR PATTERNS

1. Large solitary mass

Associated with massive necrosis and hemorrhage

2. Multifocal/nodular

Multiple, well demarcated nodules similar to

metastasis

3. Diffuse infiltrative

Multiple small foci through out liver

Highly vascular and receives blood supply from the hepatic artery.

Vascular invasion of the Portal vein is more common than the hepatic vein.

Vascular invasion is a typical feature of HCC but tends to occur in larger lesions, which can cause portal vein invasion and thrombosis.

The hyperintenense signal on T2WI is highly suggestive of tumor thrombosis. The malignant thrombus also causes portal vein dilatation (>23 mm)where as bland thrombus rarely does. Identification is important because malignant thrombus is a contraindication to liver transplantation.

HCC-MRI

T1WI- Hypointense

T2WI- Hyperintense

Capsule - hypointense on T1W and Hyperintense on

T2W

Post contrast- Intensely enhance on arterial phase,

wash out of tumor signal below liver at 2min with late

enhancemnt of pseudocapsule.

In contradistinction to the uniform fat deposition in

adenomas, fat deposition in HCCs is usually patchy.

Macroscopic fat within HCC is well demonstrated on CT

scans.

The term transient hepatic intensity difference (THID), a

modification of the CT term transient hepatic attenuation

difference, is also used to describe peritumoral

enhancement, which is seen around HCC as an area of

hypervascularity in the arterial phase.

In the cirrhotic liver if the lesion demonstrates

characteristic features of hepatocellular carcinoma—that

is, arterial phase hyperenhancement and portal venous

or delayed phase washout—with a single modality, the

diagnosis can be made and no further investigation is

required.

Focal Nodule In a Cirrhotic Liver

Regenerating nodule

Hypointense on T1WI, T2WI, similar enhancement to rest of liver.

Dysplastic nodule

Hyperintense on T1WI, Hypointense on T2WI due to iron accumulation ( siderotic nodule). Variable enhancement

HCC

Hypointense on T1WI, Hyperintense on T2WI

Enhances on arterial phase with washout of tumoursignal below liver at 2 min post contrast.

Peripheral pseudocapsule may enhance

Role of DWI in the characterization of

hepatocellular carcinomas and dysplastic

nodules in cirrhotic liver.

HCC have slightly high or strongly high SI on

DWI, where as DNs have iso-SI or low SI. The

mean (SD) ADC and ADC ratio (lesion to

liver)for HCCs (1.28 x 10 [0.25] mm/s and 0.88

[0.15], respectively) is significantly lower than

those for DNs (1.53 x 10 [0.33] mm/s and 1.00

[0.08], respectively).

Regenerating nodules

Dysplastic nodules. Axial

unenhanced

enhanced (b) 3D GRE T1

weighted VIBE MR

images show multiple small

focal lesions representing

dysplastic nodules. The lesions

exhibit high signal intensity on

both images and no

enhancement after contrast

material administration. On

axial T2

shown),

the lesions demonstrated low

signal intensity.

NUCLEAR SCINTIGRAPHY

Sulfur colloid- Heterogeneous uptake. Defect with

prominent left lobe & caudate lobe in cirrhosis

HIDA-50% uptake due to ability of neoplastic

hepatocytes to produce bile

ANGIO

Tumor blush due to presence of neovascularity and

shunts.

If extension into veins → threads & streaks pattern can

be seen

Fibrolamellar Ca

Solitary, lobulated,well defined tumor containing a central fibrous scar.

Younger age,5-35yrs

M:F=1:1

Non-cirrhotic, No increase in AFP

Relatively good prognosis, mean survival-60 months(HCC-6mo)

Hemorrhage and necrosis are rare.

Central stellate calcification in 55% cases.

MRI

T1- iso-hypo, T2- iso-hyper

Scar is hypo on T1 & T2 (fibrous nature)

(DD –FNH scar hyperintense on T2w)

Intrahepatic CholangioCarcinoma

2nd MC primary liver malignancy

M>F ,usually in 60’s

Tumor arising from biliary duct epithelium & tends to spread by local infiltration, accounts for 10% of all cholangio Ca

Three types

1.Mass forming

2.Periductal infilrating

3. Intraductal growing

Cholangio ca - MRI

T1-hypointense

T2-hyperintense +/-central hypo due to scar

CE-(>4cm)-peripheral enhancement which progresses towards center and spares scar

CE-(2-4cm)-enhances homogeneously

There are no specific imaging feature of ICCA that truly

distuinguishes it from HCC & metastsis.

Capsular retraction and biliary dilatation adjacent to the

mass are highly suggestive of ICCA.

Lesion > 4 cm show thick peripheral enhancement with

centripetal progression , like hemangioma but portal vein

invasion, bile duct dilatation, and patchy restricted

diffusion favors ICCA.

Metastasis

Mets are the most common cause of malignant focal lesions out numbering primary by 18:1

MC site of mets is Lymph Node, 2nd is liver

Colon-42%

Stomach-23%

Pancreas-21%

Breast -14%

Lung –13%

MRI

T1 – usually hypointense. Mucin, hemorrhage, fat and melanin appear hyperintense

T2 – hyperintense

The peripheral ring pattern is considered a specific enhancement pattern for liver metastases butobservedmore frequently in hypervascular metastases, particularly in neuroendocrine and carcinoid tumors

.

. Classically, metastases from colon carcinoma, bladder

carcinoma, prostate carcinoma, and pulmonary

carcinoma have been considered hypovascular, and

those from thyroid carcinoma, carcinoid tumor,

neuroendocrine tumor, and renal cell carcinoma have

been considered hypervascular

Metastatic liver cancer forms nodules as a rule, and their

distribution and size vary to some extent according to

the type of underlying malignancy.

For example, liver metastases from pancreatic cancer

are usually small and uniform and are distributed

throughout the liver, whereas those from gallbladder

cancer tend to cluster in the gallbladder fossa

Cystadenoma&Cystadenoma Ca

Rare & represent only 5% of all intra hepatic cysts of bile duct origin

Usually in middle aged women

Same disease with cyst adenoma transforming into

Cystadeno Ca

Cystadenomas are typically large and multilocular.

MRT1- low intensity

T2- high intensity

Variable intensity on both T1 and T2 images depend on

presence of solid components, hemorrhage and protein

content and helps in diff from other cystic diseases.

Hepatoblastoma

MC primary liver neoplasm under the age of 3 years.( esp b/w18-24 months)

3rd MC abdominal tumor in childhood

MC in males

Increased serum AFP

Aggressive-lung mets usually at time of diagnosis

MRI

T1-hypo + areas of hyper (hemorrhage)

T2-hyper + areas of linear hypo (septae)

Role of DW-MRI in evaluation of

hepatic focal lesions

The lowest ADCs are found in metastases, CCA and

HCCs and the highest values are found in

hemangiomas. The difference between the mean ADC

values of benign and malignant lesions was significant.

No significant differences in ADC values among the

different benign lesions or among the different malignant

lesions at both sequences.

Female

patient aged

55 year

presented

with

jaundice,

epigastric

pain and

epigastric

swelling

with past

history of

cancer

colon

resection.

mean ADC

value = 0.9

× 10−3 s/mm2.

Male

patient

aged

66 year

with liver

cirrhosis

presented

with

clinically

palpable

epigastric

swelling.

mean ADC

value = 1.1

2 × 10−3 m

m2/s

Male patient

aged 55 years

presented with

obstructive

jaundice. mean

ADC

value = 1.2 × 1

0−3 s/mm2

Female patient

aged 51 year,

presented with

hyperechoic left

hepatic lobe focal

lesion during US

checkup. mean

ADC

value = 2.9 × 10−3 s

/mm2

Advanced and emerging modalities

Patient with hepatic

adenoma. A, T2

MR image (A) shows

hyperintense

adenoma (arrow) in right

lobe of liver. B,

Gadolinium

image shows intense

arterial phase

enhancement (arrow). C,

Axial MR

wave image shows good

illumination of

(circle). Waves in

have slightly longer

wavelength than those in

surrounding normal liver

parenchyma. D,

Elastogram

interest corresponding to

colon cancer A, T2

image shows single

hyperintense

in periphery of right lobe of

liver. B, Wave image shows

prolongation of shear wave

through

compared with surrounding

normal liver parenchyma. C,

Elastogram

(arrow) as hot spot with

stiffness value of 6.2

suggestive of malignant

tumor

confirmed at surgery to be

metastasis from colon

cancer.

Conclusion

Dynamic contrast-enhanced MR imaging is excellent for

the evaluation of various focal hepatic lesions. A

comprehensive MR imaging examination can be used to

diagnose or at least narrow the differential diagnosis for

most of these lesions.