Classical Radiological Appearances 

1. Boot shaped heart (Coeur-en-sabot) in Chest x-ray - Fallot's tetralogy 

2. Box shaped heart - Ebstein anomaly (Lithium)

3. Jug handle appearance - Primary pulmonary artery hypertension

4. Pruned tree appearance of Pulmonary vasculature (Vascular pruning/ Tapering)- Pulmonary artery hypertension

5. Egg and Banana sign on axial CT/MRI - Pulmonary arterial hypertension

6. Flask shaped / pear shaped / Money bag shaped / Leather bottle shaped heart in Chest x-ray - Pericardial effusion

7. Pear shaped bladder / Tear drop shaped bladder - Pelvic hematoma

8. Gooseneck sign - Endocardial cushion defect

9. Egg on side / Egg on string appearance - Transposition of great arteries (TGA)

10. Egg in cup appearance - Constrictive pericarditis

11. Egg in cup appearance  ( Ball on tee sign) - Medullary form of renal papillary necrosis

12. Snowman's heart / Figure of 8 appearance / Cottage loaf appearance in Chest x-ray - Supracardiac TAPC

13. Cloverleaf skull - Kleeblattschadel syndrome (Craniosynostosis)

14. Scimitar Turkish sword sign - Partial anomalous pulmonary venous return

15. "3" like appearance of aorta in Chest x-ray - Coarctation of aorta

16. Reverse figure 3 sign / Figure E sign in Barium esophagogram - Coarctation of aorta

17. Hilar dance on fluoroscopy - Atrial septal defect

18. Batwing appearance - Pulmonary edema

19. Angelwing appearance (Spinnaker sign) in neonates - Pediatric thymus in Pneumomediastinum

20. Coca-Cola bottle sign in axial CT - Grave's ophthalmopathy

21. Tiger eye sign in T2W MRI (Marked low signal intensity of globus pallidus due to abnormal iron accumulation) - Hallervorden-Spatz disease (Pantothenate kinase associated neurodegeneration with brain iron accumulation)

22. Leopard skin sign / Tigroid pattern / Stripe sign on T2W MRI (Dark spots/stripes due to sparing of Perivascular white matter within Bright Demyelinated periventricular white matter) - Metachromatic leukodystrophy

23. Bagel sign (Blob sign / Tubal ring sign) in ultrasound - Unruptured tubal ectopic pregnancy

24. Ring of fire sign (Ring of vascularity) on color doppler - Hypervascular ring with low impedence (Placental blood flow) Tubal ectopic pregnancy ; Corpus luteum cyst (more common)

25. Puff of smoke appearance in cerebral angiography - Moya Moya disease

26. Popcorn calcification in Mammogram - Fibroadenoma

27. Bone within bone sign in x-ray ; Sandwich vertebrae in x-ray- Osteopetrosis 

28. Rugger jersey spine in x-ray - Renal osteodystrophy

29. Winking owl sign / Absent pedicle sign - Vertebral metastases , congenital absence / hypoplasia of pedicle

30. Hot cross bun sign in MRI - Multisystem atrophy ,Spinocerebellar ataxia , Creutzfeldt jakob disease

31. Champagne glass pelvis in x-ray ; Trident hand appearance in x-ray - Achondroplasia

32. Hummingbird sign / Penguin sign in MRI - Progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome)

33. Molar tooth sign in MRI - Joubert syndrome

34. Micky mouse sign in USG - Normal anatomy of Common femoral artery , Common femoral vein and Great saphenous vein meeting at saphenofemoral junction

35. Salt and pepper sign / Pepper pot skull - Hyperparathyroidism

36. Raindrop skull , Moth eaten bone - Multiple myeloma

37. Robert's sign(Gas shadow in cardiac chambers) , Spalding sign (Overlapping skull bones) , Deuel's Halo sign (increased pericranial fat) - Intrauterine fetal death

38. Twin peak sign / Lambda sign - Dichorionic diamniotic twins

39. 'T' Sign in USG - Monochorionic twins

40. Sunray appearance , Codman's triangle - Osteosarcoma

41. Onion peel appearance - Ewing's sarcoma

42. Soap bubble appearance - Gaint cell tumor , Adamantinoma , Aneurysmal bone cyst

43. Shepherd's crook deformity - Fibrous dysplasia

44. Fallen fragment / Trap door sign - Simple bone cyst

45. Polka dot sign / corduroy / jail house sign - Vertebral hemangioma

46. Apple core sign / Napkin ring sign (bowel) - Stenosing annular colorectal carcinoma

47. Apple core sign (Femur) - Synovial chondromatosis

48. Apple peel sign - Apple peel intestinal atresia / Christmas tree intestinal atresia / type 3b ( small bowel atresia )

49. Cashew nut sign on CT - Juxtacortical intracerebral hemorrhage due to cerebral venous thrombosis

50. Strawberry skull (Fetal trigonocephaly) - Trisomy 18 (Edward's syndrome)

51. Watermelon skin sign MRI - Tuberculous Prostatitis

52. Double decidual sign - Normal usg appearance of Intrauterine gestational sac

53. Bunch of grapes sign - Hydatidiform mole 

54. Bunch of grapes sign - Botryoid Rhabdomyosarcoma

55. Bunch of grapes sign - Bronchiectasis

56. Bunch of grapes sign -  Intraductal papillary mucinous neoplasia (IPMN) of pancreas

57. Bunch of grapes sign - Intracranial tuberculoma

58. Empty amnion sign - Pregnancy failure

59. Banana sign & Lemon sign - Arnold chiari 2 malformation ---- spina bifida

60. Butterfly sign - Normal appearance of choroid plexus on axial imaging of fetal brain on USG . Its absence suggests Holoprosencephaly

61. Shenton's line - Imaginary curved line drawn along inferior border of superior pubic ramus and along inferomedial border of neck of femur . Significance - To detect superior femoral head subluxation indicative of acetabular dysplasia

62. Split pleura sign on CT - Pleural empyemas

63. Holman-Miller sign / Antral sign in CECT of Head and Neck (Anterior bowing of Posterior wall of Maxillary sinus)  - Nasopharyngeal angiofibroma

64. Subdiaphragmatic free gas - Pneumoperitoneum

Signs in Pneumoperitoneum :-

1) Right upper quadrant signs :-

• Cupola / saddlebag / Mustache sign - Air accumulation underneath central tendon of diaphragm in midline seen in supine radiograph

• Fissure for ligamentum teres sign - Extraluminal air in fissure for ligamentum teres

• Hepatic edge sign - Cigar shaped pocket of free air in subhepatic region

• Lucent liver sign - Reduction of liver opacity due to air located anterior to liver

• Morison pouch sign (doge cap sign) - Triangular collection of gas in morrison pouch

• Periportal free gas sign

2) Peritoneal ligament related signs :-

• Football sign - Abdominal cavity outlined by gas , seen in massive pneumoperitoneum

• Falciform ligament sign (Silver's sign) - Air outlines falciform ligament

• Lateral umbilical ligament sign (Inverted v sign) - Air outlining lateral umbilical ligaments (Inferior epigastric vessels)

• Urachus sign - Outline of middle umbilical ligament

3) Bowel related signs :-

• Double wall sign (Rigler's sign / bas-relief sign) - Air outlining both sides of bowel wall (outer and inner bowel wall)

• Telltale triangle sign (Triangle sign) - Triangular air pocket between 3 loops of bowel wall

65. Tram track sign - Optic nerve sheath meningiomas

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