<s>[INST] context: (Complicated hydatid disease) (400 Grainger's diagnostic radiology 4th)Hydatid disease of lung - lower lobes affected in 60% cases* Calcification of cyst wall is rare and seen only in 0.7% cases* When a mediastinum, vertebral erosion in addition to rib erosion may occur with posterior mediastinum being affected in 65% cases. May be complicated by bacterial infection after cyst rupturesRadio logical signs* Meniscus / double arch / moon/ cresent sign due to thin radiolucent in upper most part of cyst* Combo sign due to air fluid level inside endocyst and air between pcricyst and endocyst* Collapsed membranes inside the cyst outlined by air causing "serpent' sign"* Completely collapsed crumpled cyst** membrane floating on the cyst produces or Water- Lilly" sign of camalotte* Cyst in cyst sign * *Radiological sign in pulmonary embolism (1562- H16th)* Wester mark sign (unilateral oligemia)* Hampton's hump*** Fleischner lines - long curxilinear densities* Felson's sign (Pleural effusion greater on the left than right side)** - Calcification in "Popcorn" craggy or punctate in Hamartoma [/INST] question: Water -lily sign is seen in | options: A: Hamartoma B: Complicated hydatid disease C: Cavitatory lesion in metastasis of the lung D: Aspergillosis | answer: B </s>