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Arch of cricoid cartilage

The arch of the cricoid cartilage is the anterior, narrow portion of the cricoid, a complete ring of hyaline cartilage forming the subglottic framework of the larynx. Shaped like a signet ring, the cricoid cartilage consists of a broad posterior lamina and a thin anterior arch, which encircles the airway and connects to the thyroid cartilage superiorly and the tracheal rings inferiorly. The arch provides anterior structural support to the subglottic airway, maintains airway patency, and serves as an attachment point for several laryngeal muscles and ligaments. The anterior arch is palpable in some individuals and acts as a critical landmark for airway procedures and radiologic assessment.

Synonyms

  • Anterior cricoid arch

  • Cricoid anterior ring

  • Subglottic cricoid cartilage

Function

  • Provides anterior structural support to the subglottic airway

  • Maintains airway patency at the subglottic level

  • Serves as an attachment site for cricothyroid muscles, cricotracheal ligament, and other intrinsic laryngeal muscles

  • Contributes to laryngeal stability during phonation and respiration

MRI Appearance
T1-weighted images:

  • The arch appears as a low-signal (hypointense) curved structure anterior to the airway lumen

  • Surrounded by hyperintense fat and soft tissue, which delineates the cartilage clearly

  • Pathology such as fracture, edema, or cartilage invasion appears as abnormal signal disruption

T2-weighted images:

  • Normal cartilage remains low to intermediate signal, while surrounding soft tissue edema or fluid appears hyperintense

  • Helps identify inflammatory changes, trauma, or neoplastic invasion

STIR (Short Tau Inversion Recovery):

  • Suppresses surrounding fat, highlighting cartilage edema or adjacent soft tissue pathology

  • Normal arch remains hypointense, whereas inflammation or tumor appears bright

CT Appearance

  • The arch of cricoid cartilage appears as a hyperdense, C-shaped bony-like structure surrounding the hypodense air-filled subglottic lumen

  • The posterior lamina is broader and thicker, while the anterior arch is thin and curves around the airway

  • CT is optimal for evaluating fractures, calcification, congenital anomalies, and subglottic narrowing

  • Air within the lumen appears black, providing natural contrast against the cartilage

MRI images

Arch of cricoid cartilage mri axial image -img-00000-00000