Radiological manifestations of hydatid disease and its complications

Abstract

Hydatid disease (HD) is endemic in many parts of the world. HD can affect virtually any organ system in body and should be kept as differential diagnosis of cystic lesion. HD is mostly asymptomatic; however, it demonstrates a variety of characteristic imaging findings depending on the site of involvement, stage of growth, mass effect, complications, or hematogenous spread, which helps in diagnosis. Radiography, ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI) are commonly used imaging modalities. Radiography is helpful in chest and for demonstrating calcification. USG demonstrates characteristic findings such as cystic nature, daughter vesicles, membranes, septa, and hydatid sand. CT and MRI are modalities of choice for number, size, anatomic location, identification of local complications, and systemic spread. CT is, especially helpful for osseous involvement, and MRI is better for biliary and neurological involvement. Knowledge of these imaging findings helps in early diagnosis and timely initiation of appropriate therapy.

Keywords: Computed tomography; hydatid disease; magnetic resonance imaging; ultrasonography.

Figure 1

Contrast-enhanced computed tomography of abdomen in two different patients show unenhanced hypodense mass with well-defined borders and no internal architecture without (a) or with septa (arrow) (b) -Type I hydatid cysts

Figure 2

Contrast-enhanced computed tomography of abdomen shows Type II liver hydatid cysts with multiple irregularly shaped daughter cysts that occupy almost the entire volume of the mother cyst – “rosette appearance”

Figure 3

Ultrasound (a), magnetic resonance imaging axial T2-weighted (b) and magnetic resonance cholangiopancreatography (c) images show heterogeneous soft tissue lesion with internal membranes (arrow), few calcifications and daughter cysts (arrow head) causing mild intrahepatic biliary radical prominence due to mass effect

Figure 4

Magnetic resonance imaging of abdomen T2-weighted axial image shows liver hydatid with multiple peripherally arranged brood capsules (arrow head) and hypointense pericyst

Figure 5

Contrast-enhanced computed tomography of abdomen shows calcified Type IIc (arrow head) and III (arrow) hydatid cysts showing calcification of wall, internal matrix, and membranes

Figure 6

Contrast-enhanced computed tomography abdomen shows contained rupture of liver hydatid cyst with “floating membrane sign” (arrow) produced by detachment of the germinal membrane of the endocyst

Figure 7

X-ray chest (a) and contrast-enhanced computed tomography of abdomen (b) show partially-calcified liver hydatid cyst with intracystic air and right pleural effusion, suggesting super-infection and rupture into the thoracic cavity

Figure 8

Contrast-enhanced computed tomography of abdomen shows Type II liver hydatids with multiple daughter cysts (arrows)

Figure 9

Contrast-enhanced computed tomography of abdomen shows communicating rupture of liver hydatid into surrounding hepatic parenchyma and sub-capsular hepatic space (arrow)

Figure 10

Contrast-enhanced computed tomography abdomen: Sequential axial (a and b) and reconstructed coronal (c) images show intrabiliary rupture of liver hydatid cyst visualized as dilated biliary system with intraluminal daughter vesicles and membranes (arrows) in a patient presented with jaundice

Figure 11

Magnetic resonance imaging axial T2-weighted (a and b) and magnetic resonance cholangiopancreatography (c) images show communication between ruptured hydatid cyst and biliary radicle (arrow) with air-foci within the cyst (arrow head) and biliary radicles. Right lobe of liver atrophy is noted

Figure 12

Contrast-enhanced computed tomography of abdomen shows infected hydatid cyst with peripheral enhancement and perilesional inflammatory changes

Figure 13

Contrast-enhanced computed tomography of abdomen: Sequential axial images (a and b) show liver hydatid cyst leading to secondary Budd-Chiari syndrome due to compression of inferior vena cava and hepatic veins

Figure 14

Contrast-enhanced computed tomography of abdomen in two different patients shows splenic hydatid cysts (a) well-defined lesion with peripheral wall calcification and membranes appear as lamellated calcification (arrow head) and (b) well-defined multivesicular mass with daughter cysts (arrow)

Figure 15

Contrast-enhanced computed tomography of abdomen (a and b) shows rupture of splenic hydatid causing left pleural effusion

Figure 16

Contrast-enhanced computed tomography of abdomen shows calcified splenic hydatid cyst with peritoneal seedling (arrow)

Figure 17

Ultrasonography abdomen shows well-capsulated multivesicular cystic lesion at upper pole of right kidney with multiple daughter cysts (arrows)

Figure 18

Contrast-enhanced computed tomography of abdomen shows peritoneal seeding of liver hydatid with daughter cysts and rim like mural calcification

Figure 19

Contrast-enhanced computed tomography of abdomen: serial axial images (a-c) show liver hydatidosis with peritoneal seeding

Figure 20

Contrast-enhanced computed tomography of pelvis shows isolated retrovesical multivesicular hydatid cyst with daughter cysts (arrows) and rim like mural calcification (arrow head)

Figure 21

Computed tomography (a) and magnetic resonance imaging T1-weighted (b) and T2-weighted (c) images of brain show a well-circumscribed cystic lesion in left cerebral hemisphere with peripheral daughter cysts (arrows) sugg

Figure 22

Magnetic resonance imaging axial T2-weighted (a and b), T1-weighted (c) and diffusion-weighted (d) images of brain show a well-circumscribed cystic lesion in right cerebral hemisphere with detached germinal membrane (arrow heads) and intraventricular rupture (black arrow) causing mass effect and multiple brain infarcts (white arrow)

Figure 23

Non-contrast computed tomography of thorax shows a cystic lesion with air-fluid level (arrow) and collapsed endocyst (arrow head) lying in the dependent part of the cyst ("Water-lily sign")

Figure 24

Contrast-enhanced computed tomography of chest (mediastinal window) shows hypodense lesion in left lower lobe with thick-enhancing wall with air bubbles and surrounding infection- The “air bubble” sign

Figure 25

Contrast-enhanced computed tomography of chest shows thin walled air-filled cavitary lesion in left lower lobe during the course of pulmonary hydatid disease

Figure 26

Contrast-enhanced computed tomography of thorax shows mediastinal (a – arrow) and pleural (a and b – arrow heads) dissemination of (c) splenic hydatid cyst

Figure 27

Contrast-enhanced computed tomography of chest: Serial axial images (a and b) show pleural dissemination of liver hydatid cyst

Figure 28

Contrast-enhanced computed tomography of chest: axial (a) and coronal reconstructed (b) images show well capsulated multivesicular cystic lesion in myocardium of left ventricle with multiple daughter cysts

Figure 29

Contrast-enhanced computed tomography of thorax shows Type II hydatid cysts with multiple daughter cysts in right cardiophrenic angle that connects to the pericardium (arrow) and a unilocular pleural-based cyst (arrow head)

Figure 30

Magnetic resonance imaging of shoulder, axial T2-weighted (a) sagittal T2-weighted (b) and fat-suppressed Short tau inversion recovery (c) images of a patient with painless swelling in shoulder region showing multiple hydatid cysts with internal daughter cysts and membrane