2. Solitary Liver Lesions
A) Benign Tumours
1.Cavernous Haemangioma
2.Adenoma
3.Focal nodular hyperplasia
4.Mesenchymal Hamartoma

3. B)Infections
1. Abscess
2.Echinococcus cyst
3.Infective pseudotumour
C)Trauma
1.Haematoma
2.Traumatic cyst

4. D) Malignant Tumours
1.Hepatocellular carcinoma
2.Metastasis
E) Other
1.Fatty change
2.Simple cyst

5. CAVERNOUS HAEMANGIOMA
Most common benign liver neoplasm.
Usually in women, rare in children.
Asymptomatic when small, mass effect when large.
May be isolated or multiple
Usually in the posterior segment of the right hepatic
lobe.
Usually less than 5 cm in diameter but can be very
large.

6. They typically remain stable in size but may
demonstrate growth.
Rarely haemorrhage may occur.
Pathologically, composed of many endothelium-lined
vascular spaces separated by fibrous septa.
Blood supply from the hepatic artery.

7. IMAGING FINDINGS
Ultrasound features
Well defined, rounded or ovoid hyperechoic lesion.
Homogeneous when small, heterogeneous due to
internal haemorrhage and necrosis when large.
No/ minimal flow on color Doppler u/s.

8. IMAGING FINDINGS
At unenhanced CT, a well defined hypodense lesion.
At contrast-enhanced CT, a characteristic pattern of
enhancement.
Nodular peripheral puddling of contrast on early-
phase images, followed by centripetal diffusion into
the centre.

9. Persistence of contrast on delayed images.
A central scar (if present) may not enhance, even on
delayed images.
Calcification within hemangiomas has been reported.

10. Spiral CT,contrast enhanced,arterial phase.well defined
rounded hypodense lesion with peripheral nodular puddling.

11. Spiral CT contrast enhanced, arterial phase, oval shaped hypodense
lesion with peripheral nodular contrast enhancement.

12. Delayed phase, central perfusion of contrast with persistence of contrast.

13. MR imaging
Hemangiomas usually appear hypointense and well
defined on T1-weighted images.
Demonstrate a marked hyperintensity that increases
with echo time on T2-weighted images .
After administration of contrast, same characteristic
pattern of enhancement as is seen at CT.

14. MRI T1W image, unenhanced, well defined rounded hypointense lesion in
right lobe.

16. T1 post contrast

17. T1 post contrast,nodular puddling with central non enhancing scar

18. Focal nodular hyperplasia
Second most common benign neoplasm of the liver
after hemangioma.
 Typically occurs in young women
 Asymptomatic, some may present with right upper
quadrant pain.
 Increased prevalence in women taking oral
contraceptives .

19. Composed of hepatocytes, Kupffer cells, primitive bile
ductules not connected with the biliary tree, and
blood vessels .
 A central fibrous scar containing a small
arteriovenous malformation may be present.
Usually less than 5 cm in diameter , may be multiple
and is often located near the liver surface.

20. IMAGING FEATURES
Ultrasound findings
Well defined mass of hypo, iso or hyperechogenicity.
Doppler U/S demonstrates high velocity flow within
the lesion.

21. At unenhanced CT,
appears homogeneous, well defined, and hypo to
isodense relative to the liver.
At contrast-enhanced CT, it exhibits a characteristic
pattern of enhancement.
Enhances brightly on early-phase images with
subsequent wash out.

22. On delayed scans, the mass may be isodense relative
to the liver and therefore imperceptible except for any
mass effect.
A central scar (if present) may demonstrate delayed
enhancement and may remain bright on subsequent
images due to delayed washout .

23. Contrast enhanced spiral CT arterial phase, well defined
heterogeneously enhancing oval lesion in left lobe with central non
enhancing scar.

24. Arterial phase contrast enhanced spiral CT,isodense lesion
displacing adjacent vessels, central non enhancing scar

25. Delayed scan, imperceptible lesion, persistantly enhancing central
scar.

26. At MR imaging,
Iso to hypointense on T1-weighted images and
hyperintense on T2-weighted images.
Demonstrates early arterial enhancement after
administration of contrast with rapid wash out.
However, the central scar shows delayed
enhancement with delayed wash out.

27. T1W MRI, axial cuts, contrast enhanced,arterial phase showing an oval shaped
brightly enhancing lesion in left lobe.

28. Delayed phase, lesion becoming isointense to normal liver

29. Hepatic abscess
Localized collections of necrotic inflammatory tissue
caused by bacterial, parasitic or fungal agents
In developing countries, parasitic abscesses are most
common, including
amoebae
echinococcus
protozoa
helminths

30. In developed countries, bacterial abscesses are most
common, usually in association with a co-morbidity
such as:
Abdominal sepsis
Immunocompromised
Diabetes mellitus
HIV/AIDS
Elderly
Chemotherapy / transplant recipients
Malignancy

31. Trauma
ERCP
Cryptogenic

32. Most common bacterial agents are
Gram negative and gram positive organisms
Escherichia coli,Klebsiella pneumoniae,bacteroides
anaerobic streptococci,enterococci
Typical presentation is of right upper quadrant pain,
fever and jaundice.
Anorexia, malaise and weight loss are also frequently
seen.

33. RADIOGRAPHIC FEATURES
As a general rule, bacterial and fungal abscesses are often
multiple, whereas amoebic abscesses are more frequently
single.
Amoebic abscesses are more common in a sub-
diaphragmatic location
Are more likely to spread through the diaphragm and into
the chest.
Amoebic abscess is more likely to be round or ovoid,
hyporeflective with fine level echoes.

34. Ultrasound Findings
Pyogenic abscesses are typically poorly demarcated with a
variable appearance, ranging from predominantly
hypoechoic to hyperechoic.
Hyporeflective and irregular wall.
Internal contents may show debris, fluid levels and
septations.
Gas bubbles may also be present.
Doppler will demonstrate absence of flow.

35. Amoebic abscesses are typically single
Peripherally located
Well defined round or ovoid mass
With fine low level internal echoes.

38. CT Scan
Variable in appearance.
In general, appears as peripherally enhancing,
centrally low density lesion.
Occasionally they appear solid, or contain gas.

39. Oval shaped hypodense lesion with peripherally enhancing irregular rim.

41. MRI
T1
Heterogeneous
Usually hypointense centrally
May be slightly hyperintense in fugal abscess
Enhancement of the capsule, although this may be
absent in immunocompromised patients
Multiple septations may be present
T2 - tends to have hyperintense signal.

42. Hydatid cyst
Hydatid disease is a worldwide zoonosis produced by
the larval stage of the Echinococcus tapeworm
The two main types of hydatid disease are caused
by E granulosus and E multilocularis.
Definitive host is dog.
Human becomes the intermediate host when comes
in contact with definitive host.

43. The right lobe is the most frequently involved
Imaging findings depend on the stage of cyst growth
whether the cyst is unilocular
contains daughter cysts
is partially calcified,
or is completely calcified [dead]

44. Ultrasound findings
US is the most sensitive modality for the detection of
membranes, septa, and hydatid sand within the cyst.
Simple cyst appears as well defined anechoic lesion
with posterior acoustic enhancement.

45. Echogenic foci due to hydatid sand may be seen within
the lesion by repositioning the patient.
Quickly fall to the most dependent part of the cavity
without forming visible strata—snow storm sign.
Detachment of the endocyst from the pericyst-- “floating
membranes”.
Complete detachment of the membranes inside the cyst-
water lily sign.

46. Multivesicular cysts manifest as well-defined fluid
collections in a honeycomb pattern with multiple septa.
Membranes may appear within the matrix as serpentine
linear structures.
Calcification seen in 20%–30% of cases.
Usually manifests with a curvilinear or ringlike pattern.
Or dense calcification of all components during healing
phase.

47. Zoomed imaged, well defined oval shaped heterogeneous lesion with internal echoes.
Internal echogenic serpentine structures—collapased membranes.

49. CT Scan findings
Indicated when U/S fails due to:
Patient-related difficulties (e.g, obesity, excessive
intestinal gas, abdominal wall deformities, previous
surgery) or
Disease complications.
CT may display the same findings as U/S.

50. Cyst fluid usually demonstrates water attenuation (3–30
HU).
Calcification of the cyst wall or internal septa is easily
detected at CT.
Typically has a high-attenuation wall at unenhanced CT
even without calcification.
Detachment of the membranes is visualized as linear areas
of increased attenuation within the cyst.

51. Hydatid cyst with collapsed parasitic membranes. Unenhanced CT scan shows a circular
area of increased attenuation within the cyst representing detached membranes

53. MRI Findings
A well defined hypointense lesion on T 1 and
hyperintense on T2 W images.
A characteristic sign of hydatid disease is a low-
signal-intensity rim on T2-weighted images,
represents the collagen rich outer layer of the hydatid
cyst.
Collapsed parasitic membranes appear as twisted
linear structures within the cyst.

54. Noncalcified hydatid cysts.
Axial T1-W MRI.two large cystic lesions
in the right hepatic lobe. Anterior cyst
has high SI(reduction in the water
content of the fluid).Several
round,nodular,low SI lesions--daughter
cysts.Mother cyst has a characteristic
low SI rim.
Posterior cyst has homogeneous low SI
with a double ring.hypointense outer
ring– pericyst,partially “wrinkled,”
intermediate SI inner ring--
incompletely detached membranes

55. THANKS