Learning objectives
The purpose of this educational exhibit is to:
To discuss etiopathogenesis and common organs infested by Echinococcosis.
To demonstrate various imaging appearances of hydatid disease in different parts of the body using CT and MRI as imaging modalities.
Background
Hydatid disease is a parasitic infection,
tapeworm is causative factor,
genus Echinococcus.
The larval cestode of the phylum Platyhelminthes causes echinococcosis.
Caused by 4 species of Echinococcus,
3 of these are of importance,
they are
Echinococcus granulosis,
causing cystic echinococcosis,
most common type;
Echinococcus multilocularis,
causing alveolar echinococcosis,
rare but is very virulent;
Echinococcus vogeli,
rarest.
It is endemic in many parts of world,
in tropical countries.
The life cycle of echinococcosis,
has 2 hosts ,
one definitive and other intermediate host,
humans are accidental...
Findings and procedure details
Radiological classification of hydatid cyst:
Sites of involvement(5)
Liver:
Liver is the most commonly affected organ (68 to 75% of cases),
with the right lobe being the most frequently involved portion.
Imaging findings in hepatic HD depend on the stage of cyst growth
Complications such as rupture into the biliary tree or transdiaphragmatic migration to involve the thoracic cavity can occur.
LUNG:
Pulmonary lesions can be primary or secondary to intrathoracic rupture of a hepatic hydatid cyst.
It can also involve the pleural cavity,
mediastinum...
Conclusion
Hydatid disease is a dynamic entity with varying imaging appearances.It can arise in any part of the body.
Familiarity with imaging findings,
especially in endemic countries,
provides important advantages in making the diagnosis.
Despite the characteristic imaging findings,
hydatid disease in unusual anatomic locations may make diagnosis difficult.
Hence,
hydatid cyst should be kept in mind when a cystic lesion is encountered anywhere in the body.
Hydatid disease should be identified radiologically before its rupture to prevent complications.
References
Mehmet atalar,
Hydatid cyst: A pictorial review of radiological appearances.
Journal of clinical and analytical medicine,
2011; 81-85
Beggs I,
The radiology of hydatid disease.
AJR Am J Roentgenol 1985; 145: 639-648.
Engin G,
Acunas B,
Rozanes I,
Acunas G.
Hydatid disese with unusual localization,
EurRadiol 2000; 10 : 1904-1912.
Oedrosa I,
Saiz A,
Arrazola J.
Hydatid disease: Radiologic and pathologic features and complications.
Radiographics 2000; 20: 795-8
Eckert J,
Gemmell MA,
Meslin FX,
Pawlowski ZS: WHO/OIE manual on echinococcosis in humans and animals: a...