This document defines and describes several radiographic signs seen on chest x-rays. It defines signs such as the air bronchogram, silhouette sign, spine sign, and bulging fissure sign. For each sign, it provides a brief definition and examples of medical conditions in which the sign may occur, such as pneumonia, lung tumors, and pulmonary embolism. The document aims to inform radiologists and doctors about important signs seen on chest x-rays and their potential medical implications.

2. By
Dr Ahmed mahmoud fayed
Master degree in chest diseases and TB
Mansora chest hospital
July 2013

3. Definition: lucency of bronchus or bronchiole ( linear, tubular or
branching) passing through airless lung parenchyma.
Importance: indicates that opacity is pulmonary parenchyma not pleural
or mediastinal
Occure in: • Pneumonia
• Alveolar He
• Alveolar edema
• Alveolar proteiniosis
• Br.alveolar cell carcinoma
• Others lymphoma
infarction
non obst.
atelectasis
Air Bronchogram

4. Silhouette sign
Definition: obliteration of the border of Diaphragm or Mediastinum
Occure in: Rt Ht border middle lobe process
Lt Ht border Lingula process
Diaphragm LL process

5. Spine sign
Definition: interruption of the progressive increase in lucency of the
vertebral bodies from above downward
Occure in: LLL pneumonia

6. Bulging Fissure sign
Definition: consolidation spreading rapidly, causing lobar expansion and
bulging of the adjacent fissure inferiorly.
Occure in: Klebsiella pneumoniae involving the right upper lobe

7. Deep sulcus sign
Definition: deep fingure like costophrenic angle in supine CXR
Occure in: Pneumothorax

8. Golden S sign
Definition: Lobe collapse around central mass (Resembles a reverse S shape also referred as
reverse S sign of Golden)
Occure in: highly suspicious of Mg

9. Halo sign
Definition: ground glass attenuation surround a denser nodule or area of
consolidation
Occure in: 1- Hge pulmonary nodule
2- invasive BPA (specially in acute leukaemia)
Reversed halo sign focal rounded GG surrounded by ring of consolidation
occure in cryptogenic organizing pneumonia and para coccidiodomycosis

10. Reverse Halo Sign
Definition: focal rounded GG surrounded by ring of consolidation.
Also in: sarcoidosis,
para coccidiodomycosis
Wgener’s granulomatosis
lymphomatoid granulomatosis
Occur in: relatively specific to a diagnosis of cryptogenic organizing pneumonia

11. Signet ring sign
Definition: Ring opacity(dilated Br) with adjacent nodular opacity (Pul. A)
Occure in: Bronchiectasis
also in reduced pul. Flow as in ch thromb. embolism

12. Westermark sign
Definition: focal area of oligaemia
Occure in: Pulmonary Embolism

13. Humpton hump sign
Definition: area of opacity in contact with pleura
Occure in: Pulmonary infarction due to Pulmonary Embolism

14. Melting ice cube sign
Definition: ice cube melting peripherally to internally
Occure in: Resolving pulm. infarction
CT scan obtained 2 weeks later shows bilateral peripheral opacities (arrows), an appearance typical of resolving pulmonary infarcts. Note that the opacities are not wedge shaped or rounded, as expected with acute infarcts. Infarcts resolve from the periphery inward, like a melting ice cube

15. Air crecent (“meniscus”)
sign
Definition: mass growing in pre excisting cavity or pneumonia undergoes
necrosis and cavitation
Occure in: 1- mycetoma
2- infarction
3- others TB
Cx
W.G
(when occure in immunocompromized invasive BPA patient indicates recovery of the immune sysytem and response of WBCs to infection)

16. Finger in glove sign
Definition: impaction of the bronchi by mucus, cellular depris, esinophils
or fungal hyphae
Occure in: BPA
also in bronchiectasis

17. Continuous diaphragm sign
Definition: continuous lucency outlined Ht base
Occure in: pneumo-mediastinum

18. Juxta phrenic peak
Definition: triangular shadow obsecure a dome of hemidiaphragm
Occure in: UL collapse

19. Flat waist sign
Definition: flattening of the contour of aortic knob and main P.A due to Lt
ward displacement and rotation of the Ht
Occure in: sever LLL collapse
loss of the medial contour of the left hemidiaphragm, which is known as the silhouette sign. The left lower lobe bronchus has a more vertical course than normal (arrowheads). Leftward displacement and rotation of the heart in left lower lobe collapse results in flattening of the contours of the aortic knob and adjacent main pulmonary artery (arrows),

20. Luftsichel sign
Definition: hyperlucent sickle surrounds aortic arch on frontal CXR
Occure in: LUL collapse “probably Cx”
German for sickle of air (luft: air sichel: crescent)

21. CT Angiogram
Definition: blood vessels with in portion of Airless lung on contrast
enhanced CT
Occure in:
• Lymphoma
• Br.alveolar cell carcinoma
• infectious Pneumonia

22. Definition: separation of the visceral and parietal pleura
Occure in: empyema
Split Pleura Sign

23. Characterized by bilateral hilar and right paratracheal lymphadenopathy
Occure in:
Suggestive of sarcoidosis
also called Garland triad

24. Double Density Sign
Right side of the left atrium pushes into adjacent lung Splaying of the carina
•Superior displacement of left main stem bronchus on frontal view
Posterior displacement of left main stem bronchus on lateral view
•Posterior displacement of esophagus on barium study
Indicates left atrial enlargement

25. Fleischner Sign
Enlargement proximal pulmonary arteries on plain film or angiography due to
embolus
Commonly in the setting of massive PE

26. Ring Around Artery Sign
Definition: Lucency along or surrounding RPA Visualized on lateral chest radiographs
Occur in: pneumomediastinum

27. Occure in: Pneumomediastinum in a neonate.
Definition: normal thymus surrounded by mediastinal air.
Angel wing sign

28. Well-defined, black line around one or both lateral margins of the heart.
This is an optical illusion resulting from overlap of superimposed normal
structures
Mach effect