Differentiating mega cisterna magna from cisterna magna arachnoid cysts: The diagnostic utility of quantitative diffusion-weighted imaging parameters.

OBJECTIVE

To explore the utility of diffusion-weighted imaging (DWI)-derived apparent diffusion coefficient (ADC) and exponential apparent diffusion coefficient (eADC) parameters in differentiating mega cisterna magna (MCM) from cisterna magna arachnoid cysts (CMAC).

METHODS

Retrospective analysis of MRI data from 40 MCM patients, 46 CMAC patients (confirmed via clinical follow-up and imaging criteria), and 36 temporal arachnoid cysts (TAC) as controls was performed. Independent sample t-tests were used to compare ADC and eADC values among the three groups.

RESULTS

The eADC values of MCM, CMAC, and TAC were (3.75 ± 0.27) × 10-2, (4.53 ± 0.54)×10-2, and (4.35 ± 0.30) ×10-2 mm2/s, respectively. There was no significant difference in the eADC value between CMAC and TAC (p = 0.191). However, the eADC value of MCM was significantly different from the two groups (p = 0.000). The ADC values of MCM, CMAC, and TAC were (3.30 ± 0.08) × 10-3, (3.11 ± 0.12) ×10-3, and (2.97 ± 0.71) × 10-3 mm2/s, respectively. Significant differences in ADC were observed between MCM and both CMAC and TAC (p = 0.000/0.003).

CONCLUSION

DWI-derived ADC and eADC parameters can effectively differentiate mega cisterna magna from cisterna magna arachnoid cysts.