Signs Coil Spring

Coil Spring Sign

Etymology: The term “coil spring sign” is derived from the radiologic appearance of contrast material outlining multiple concentric loops of bowel, resembling a coiled spring, commonly seen in intussusception.

AKA:

  • Coiled Spring Appearance

What is it? The coil spring sign refers to a radiologic finding typically seen in intussusception, where contrast outlines the intussusceptum and the surrounding intussuscipiens, creating a layered or coiled appearance.

Caused by:

  • Intussusception (most common)
  • Bowel telescoping within itself
  • Barium trapped between layers of bowel

Resulting in:

  • Telescoping of bowel loops
  • Concentric layering of the bowel wall

Structural Changes:

  • Invagination of the bowel
  • Barium or contrast filling in the layered bowel segments

Pathophysiology: Intussusception occurs when a segment of bowel (intussusceptum) telescopes into an adjacent segment (intussuscipiens), causing bowel wall thickening and compromised blood flow. The trapped contrast in the bowel layers produces the coil spring appearance. The contrast accumulates between the mucosal surfaces of both the intussuscipiens and intussusceptum, outlining the interfaces and creating the classic coiled appearance, with the intussuscipiens forming the outermost layer. (Radiopaedia)

Pathology:

  • Invagination of bowel
  • Thickened bowel wall
  • Possible vascular compromise

Diagnosis:

  • Radiologic Criteria: Characteristic coiled spring appearance seen on barium enema or fluoroscopy.
  • Clinical Correlation: Often associated with symptoms of bowel obstruction or abdominal pain.

Clinical:

  • Colicky abdominal pain
  • Vomiting
  • Palpable abdominal mass
  • Currant jelly stools

Radiology:

  • KUB (Abdominal X-Ray): May show nonspecific signs of bowel obstruction.
  • CT:
    • Parts: Intussusceptum telescoping into intussuscipiens
    • Size: Concentric, thickened bowel loops
    • Shape: Concentric rings resembling a spring
    • Position: Typically involves ileocecal junction
    • Character: Contrast outlining multiple bowel loops
    • Time: Acute presentation
  • Barium Studies:
    • Classic coiled spring appearance with contrast collecting between the intussuscipiens and intussusceptum

Differentiation from Stack of Coins Sign and Thumbprinting:

  • Coil Spring Sign: Multiple concentric loops from bowel telescoping
  • Stack of Coins Sign: Closely apposed thickened bowel folds
  • Thumbprinting: Broad-based submucosal edema projecting into the lumen

Labs:

  • Not diagnostic but may show leukocytosis if associated with inflammation

Management:

  • Non-surgical reduction with barium or air enema (for pediatric intussusception)
  • Surgery if non-reducible or complications arise

Radiology Detail:

  • KUB (Abdominal X-Ray): Often nonspecific
  • CT: Described by parts, size, shape, position, character, and time
  • Barium Enema: Gold standard with coiled spring appearance

Pulmonary Function Tests (PFTs):

  • Not applicable

Recommendations:

  • Consider barium or air enema for pediatric cases
  • Prompt surgical consultation for adults with intussusception

Key Points and Pearls:

  • The coil spring sign is highly specific for intussusception.
  • Contrast studies are key for visualization.
  • Early diagnosis can often prevent surgical intervention.
  • The contrast collects in both the intussuscipiens and intussusceptum, but the intussuscipiens forms the outermost loop.

References:

  1. Radiopaedia – Coil Spring Sign: https://radiopaedia.org/articles/coil-spring-sign
  2. Radiology Key – Intussusception Imaging: https://radiologykey.com/intussusception/
  3. Radiographics – Pediatric Abdominal Imaging: https://pubs.rsna.org/doi/full/10.1148/rg.312105205
  4. American Journal of Roentgenology – Intussusception Imaging: https://www.ajronline.org/doi/full/10.2214/AJR.09.2971