MRI Maxillofacial: What It Involves
MRI of the maxillofacial region involves multiplanar imaging without and with IV contrast to characterize soft tissue components, distinguish tumor from inflammation, identify intracranial and perineural involvement, and detect osseous marrow invasion—capabilities that complement CT's superior osseous detail 1.
Technical Components
The examination typically includes:
- T1-weighted sequences (with and without contrast) to assess anatomical detail and enhancement patterns
- T2-weighted sequences to differentiate tumor from hyperintense inflammatory changes and retained secretions
- Fat-suppressed sequences (STIR, SPAIR) for improved lesion detection
- Specialized sequences including diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) mapping to assess cellularity 1, 2
Advanced protocols may incorporate UTE (ultra-short echo time) and VIBE-Dixon sequences, which provide CT-like bone visualization while maintaining soft tissue contrast 3.
Clinical Applications
MRI maxillofacial excels at:
- Soft tissue characterization: Identifying specific pathology patterns such as the cerebriform appearance of inverted papillomas, intrinsic T1 hyperintensity of melanotic melanomas, and peritumoral intracranial cysts suggesting esthesioneuroblastoma 1
- Tumor mapping: Superior to CT for distinguishing actual tumor from surrounding inflammation and secretions
- Intracranial extension: Best modality for detecting skull base involvement and intracranial complications
- Perineural spread: Critical for staging and surgical planning 1
- Osseous marrow invasion: More sensitive than CT for detecting marrow involvement despite CT's superiority for cortical bone detail 1
Anatomical Coverage
The scan encompasses:
- Paranasal sinuses and nasal cavity
- Orbits and periorbital structures
- Temporomandibular joints 4, 5
- Salivary glands
- Mandible and maxilla
- Soft tissues of the face and neck
- Skull base when evaluating masses with potential intracranial extension 1
Complementary Role with CT
CT and MRI function as complementary modalities rather than alternatives 1. CT provides superior osseous detail for surgical planning and can be performed without contrast when MRI is also planned, since CT's primary role becomes evaluating bone involvement while MRI handles soft tissue assessment. This combined approach optimizes treatment planning by leveraging each modality's strengths.
Specialized Applications
Beyond static imaging, emerging applications include:
- Real-time MRI (70 frames/second) for assessing oral and facial function, particularly valuable for procedure planning and rehabilitation monitoring 6
- Perfusion MRI for diagnostic characterization of sinonasal masses 1
- Dynamic contrast-enhanced MRI for evaluating odontogenic lesions 2
- Black Bone sequences for radiation-free trauma assessment, particularly beneficial for pediatric and young adult patients requiring repeated imaging 3, 7
Important Caveats
The examination requires dedicated coils (such as 15-channel mandibular coils) for optimal image quality in specific regions 3. Sequence selection should be tailored to the clinical question—UTE excels for naso-orbito-ethmoidal and Le Fort regions, while VIBE-Dixon performs best for mandibular and orbital imaging 3.