Vacuum phenomenon in shoulder

Vacuum phenomenon in the shoulder refers to the presence of intra-articular gas in the shoulder joint. It is a very common occurrence, particularly in external rotation. This can cause circular or linear areas of low signal intensity on GRE MR images of the shoulder obtained with external rotation of the arm and represent small foci of intra-articular gas. Awareness of this potential pitfall and an understanding of the characteristic appearance and location of this collection of intra-articular gas may help prevent misdiagnosis of intra-articular loose bodies or chondrocalcinosis.

The presence of gas in a joint can occur in almost any joint, such as the SCJ where it may outline the intra-articular disc (see case 4).

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Article information

rID: 2251
Section: Signs
Tag: cases
Synonyms or Alternate Spellings:
  • Vacuum phenomena in shoulder
  • Vacuum phenomenon in shoulder joint
  • Vacuum phenomenon in the shoulder joint
  • Vacuum phenomenon in the shoulder
  • Intra-articular gas in shoulder joint

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Cases and figures

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    Case 1: vacuum phenomenon in shoulder
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    Case 2: in left shoulder
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    Case 3
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    Case 4: vacuum phenomenon in the SCJ
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