Diffusion-weighted imaging for differentiating benign from malignant skull lesions and correlation with cell density.

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Skull lesions present diagnostic challenges, often requiring advanced imaging techniques.
• Differentiating benign from malignant lesions is crucial for appropriate patient management.

Purpose of the Study:

• To evaluate the utility of diffusion-weighted imaging (DWI) and cell density in distinguishing benign from malignant skull lesions.
• To establish apparent diffusion coefficient (ADC) values and normalized ADC thresholds for lesion characterization.

Main Methods:

• Retrospective review of 24 skull lesions (12 malignant, 12 benign) in 18 patients.
• Measurement of minimum apparent diffusion coefficient (ADC) values, normalized to white matter (normalized ADC).
• Correlation of ADC values with measured cell densities in 15 cases.

Main Results:

• Malignant tumors showed significantly lower average minimum ADC (0.70 × 10⁻³ mm²/s) and normalized ADC (1.03) compared to benign tumors (1.11 × 10⁻³ mm²/s and 1.65, respectively).
• Optimal normalized ADC and ADC thresholds were identified with high accuracy, sensitivity, and specificity.
• A significant inverse correlation was found between cell density and normalized ADC (r = -0.58, p = 0.023).

Conclusions:

• Apparent diffusion coefficient (ADC) values in skull lesions correlate with tumor cell density.
• DWI, particularly normalized ADC, can aid in narrowing the differential diagnosis of indeterminate skull lesions.
• Integrating histopathologic features with DWI findings enhances the interpretation of skull lesions.