The role of diffusion-weighted MRI in characterization of intracranial cystic lesions

Background Diffusion-weighted imaging (DWI) is reliable in diagnosing intracranial cysts. However, sometimes, it could not give satisfactory diagnostic confidence. Objective To study the role of DWI in differentiation between intracranial cysts and the usefulness of apparent diffusion coefficient. Patients and methods This study included 40 patients of different age groups with intracranial cysts. All patients included were subjected to full history taking, clinical examination, laboratory investigations, routine MRI examination, DWI, and apparent diffusion coefficient map. Results Receiver operating characteristic curve was generated to identify inflammatory intra-axial lesions and to obtain the best sensitivity (80%), specificity (83.3%), positive predictive value (80%), and negative predictive value (83.3%). The relationship was significant (P<0.028). Receiver operating characteristic curve to identify epidermoid and arachnoid cysts and to obtain the best sensitivity (100%), specificity (100%), positive predictive value (100%), and negative predictive value (100%). The relationship was significant (P=0.013). Conclusion DWI is perfect in differentiating between necrotic tumors and abscesses, benign and malignant intracranial cysts, and between arachnoid and epidermoid cysts. But it failed in differentiating between lower-grade and high-grade glioma.