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Topic

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Nasal septum

The nasal septum is a midline structure dividing the nasal cavity into right and left halves, composed of both bony and cartilaginous components. Superiorly, it is formed by the perpendicular plate of the ethmoid bone, while posteriorly it includes the vomer. Anteriorly, the septum is supported by the quadrangular cartilage, which connects to the anterior nasal spine of the maxilla. The septum is covered by mucoperichondrium and mucoperiosteum, which house blood vessels, nerves, and minor glands. Its integrity is essential for airflow regulation, structural support of the nose, and even distribution of inhaled air across the nasal cavities. Variations in size, shape, or alignment (e.g., septal deviation) can affect respiration, sinus ventilation, and olfaction.

Synonyms

  • Nasal septal plate

  • Cartilaginous and bony septum

  • Midline nasal partition

Function

  • Divides the nasal cavity into right and left passages

  • Provides structural support for the nose and nasal cartilages

  • Regulates airflow and directs inspired air toward the olfactory region

  • Contributes to facial symmetry and midline skeletal support

MRI Appearance

T1-weighted images:

  • Bony septum (perpendicular plate of ethmoid, vomer) appears hypointense

  • Cartilaginous septum also appears low to intermediate signal

  • Surrounded by hyperintense nasal mucosa and subcutaneous fat, providing contrast

  • Septal hematomas or masses may appear intermediate to hyperintense, altering normal low-signal continuity

T2-weighted images:

  • Air within the nasal cavity appears as signal void (black), sharply outlining the septum

  • Soft tissues and mucosa are intermediate to hyperintense, highlighting edema or inflammation

  • Useful for identifying septal deviations, mucosal thickening, or inflammation

STIR (Short Tau Inversion Recovery):

  • Fat suppression emphasizes pathologic changes in cartilage or bone marrow

  • Normal septum remains low signal, while edema, hematoma, or inflammatory lesions appear hyperintense

  • Particularly valuable in trauma or postoperative evaluation

CT Appearance

  • Nasal septum appears as a thin, hyperdense bony and cartilaginous midline structure

  • Air within the nasal cavities appears hypodense (black), providing high contrast with the septum

  • Axial, coronal, and sagittal planes allow evaluation of septal deviation, fractures, or perforations

  • CT clearly demonstrates bony septum (vomer, perpendicular plate) and anterior cartilaginous septum, as well as calcifications or ossification within cartilage

MRI images

Nasal septum mri axial image -img-00000-00000