Double signs

Double bleb sign-intrauterine pregnancy
Double delta sign - bucket handle meniscal tear
Double diaphragm sign-pneumothorax in a supine patient
Double disc sign- both thickening of the LATERAL pterygoid inferior belly insertion and an anteriorly displaced TMJ disc are present
Double rim sign-early capsule stage of brain abscess
Double track sign-PYLORIC STENOSIS on barium study and pylorospasm on USG
Double wall sign-pneumoperitoneum with air outlining both sides of the bowel wall. It is seen when large amount of free air, > 1000 ml, is present.
Double oreo cookie sign-SLAP TEAR