Diffusion MR imaging features of skull base osteomyelitis compared with skull base malignancy.

Area of Science:

• Radiology
• Infectious Diseases
• Oncology

Background:

• Skull base osteomyelitis (SBO) presents with radiologic findings similar to neoplastic conditions.
• Accurate differentiation is crucial for timely and appropriate patient management.

Purpose of the Study:

• To evaluate diffusion-weighted imaging (DWI) findings in SBO.
• To facilitate the differential diagnosis of SBO from skull base neoplasms.

Main Methods:

• Retrospective analysis of MR imaging in 9 SBO patients.
• Comparison with 9 patients each of nasopharyngeal carcinoma (NPC), lymphoma, and metastatic disease.
• Apparent diffusion coefficient (ADC) measurements (ADC(ST) and ADC(NST)) were performed for all groups.

Main Results:

• Mean ADC(ST) values were significantly higher in SBO (1.26 ± 0.19 × 10(-3) mm(2)/s) compared to NPC (0.74 ± 0.18 × 10(-3) mm(2)/s) and lymphoma (0.59 ± 0.11 × 10(-3) mm(2)/s).
• No significant difference was observed between SBO and metastatic disease.
• An ADC value ≥ 1.08 × 10(-3) mm(2)/s achieved 96% accuracy in ruling out lymphoma and NPC.

Conclusions:

• ADC values derived from DWI can aid in distinguishing SBO from malignant skull base lesions.
• Prompt differential diagnosis is essential for initiating appropriate treatment for SBO.