Role of MR Spectroscopy and Diffusion Weighted Techniques in Discrimination between Capsular Stage Brain Abscesses, Necrotic and Cystic Brain Lesions

Purpose: The aim of this study was to compare MRS findings and those of DWI with biopsy results to determine which technique is more effective in discriminating between abscesses, cystic and necrotic brain lesions.Patients and Methods: Fifty patients (33 males 17 females) having intracranial marginally enhancing cystic space occupying lesions on CT or conventional MRI, were further evaluated with DWI and MRS.Results: This study included 18 patients with abscess and 32 patients with cystic or necrotic tumours. The correct diagnosis of brain abscess were made in 15 patients by DWI while the correct diagnosis were made in 14 patients by MRS. On the other hand, the correct diagnosis of cystic or necrotic tumour were made in 31 patients by DWI while the correct diagnosis were made in 30 patients by MRS. The sensitivity, specificity, PPV and NPV for DWI were 96.88%, 83.33%, 91.18%, 93.75% respectively, while they were 93.75%, 77.78%, 88.24%, 87.5% for MRS.Conclusion: Comparing DWI and MRS to differentiate brain abscesses from cystic or necrotic brain tumours show that DWI is more accurate, requires less imaging time and is also easier to interpret.