More black sign

The more black sign is a normal finding in lateral chest x-ray, and refers to the gradual increased apparent radiolucency (blackness) of the vertebral bodies, when proceeding from upper to lower chest. This is due to the increased proportion of the chest comprised of air containing lungs over distal dorsal spine compared to the upper parts. 

When the air is displaced by higher attenuation material, such as consolidation, fluid or a mass (e.g. bronchogenic carcinoma, paraspinal neurogenic tumour) then the lower dorsal vertebral bodies become more radiodense; this is referred to as the loss of the more back sign and is also known as the spine sign


Chest x-ray
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Article Information

rID: 10579
System: Chest
Section: Signs
Tag: refs
Synonyms or Alternate Spellings:
  • Loss of more black sign
  • Spine sign

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Cases and Figures

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    Normal chest x-ray
    Case 1: normal chest x-ray
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    Case 2: left lower lobe consolidation
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    Case 3: right pleural effusion
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    Case 4: colorectal metastases
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    Case 5: Bochdalek hernia
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