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Lambdoid suture

The lambdoid suture is a fibrous cranial suture located at the posterior aspect of the skull, separating the occipital bone from the paired parietal bones. It is named for its resemblance to the Greek letter lambda (Λ) and forms a major component of the posterior cranial vault.

The lambdoid suture is an important anatomical landmark in skull development, pediatric imaging, trauma assessment, and differentiation between normal sutures and skull fractures.

Synonyms

  • Lambdoidal suture

  • Posterior cranial suture

Location

  • Situated at the posterior aspect of the skull

  • Extends transversely and obliquely across the occipital region

  • Separates the occipital bone inferiorly from the parietal bones superiorly

  • Meets the sagittal suture at the lambda

  • Meets the occipitomastoid suture laterally

Anatomical components

  • Parietal bones (paired)

  • Occipital bone (squamous part)

  • Serrated fibrous suture line

  • Adjacent landmarks:

    • Lambda

    • Occipitomastoid suture

    • Parietomastoid region

Relations

Superiorly:

  • Parietal bones

Inferiorly:

  • Occipital bone

Medially:

  • Sagittal suture

  • Lambda

Laterally:

  • Occipitomastoid suture

  • Mastoid region of temporal bone

Deep (intracranial):

  • Occipital lobes of the cerebral hemispheres

  • Dural venous sinuses (nearby transverse sinus region)

Structures related to the lambdoid suture

  • Lambda (junction of sagittal and lambdoid sutures)

  • Posterior cranial fossa contents (indirectly)

  • Occipital lobes

  • Transverse sinus (deep and inferior relationship)

X-ray appearance

Skull radiographs (AP / lateral / Towne views):

  • Suture line: Serrated, zigzag radiolucent line

  • Symmetry: Typically symmetric on both sides

  • Margins: Interdigitated appearance distinguishing it from fractures

  • Age-related changes: Progressive narrowing and partial fusion with age

CT appearance

Non-contrast CT:

  • Suture morphology: Well-defined, interdigitated low-density line

  • Cortical margins: Smooth edges without displacement

  • Adjacent bones: Normal alignment of parietal and occipital bones

Post-contrast CT:

  • Suture line: No enhancement

  • Adjacent venous structures: Possible visualization of transverse sinus nearby

3D CT VRT appearance

Volume-rendered technique (VRT):

  • Suture configuration: Clearly visualized zigzag pattern

  • Extent: Curves across posterior skull from one side to the other

  • Lambda: Easily identified junction with sagittal suture

  • Utility: Excellent for evaluating cranial shape and suture patency

MRI appearance

T1-weighted images:

  • Suture: Low-signal linear gap between bones

  • Diploic marrow: Intermediate signal on either side

  • Scalp: High-signal subcutaneous fat

T2-weighted images:

  • Suture: Low-signal fibrous band

  • Adjacent bone: Low signal cortex with intermediate diploë

CT VRT 3D image

Lambdoid suture

X-Ray image

X ray Lambdoid Suture anatomy image -img-00000-00000