Magnetic resonance spectroscopy in posterior fossa tumours: the tumour spectroscopic signature may improve discrimination in adults among haemangioblastoma, ependymal tumours, medulloblastoma, and metastasis.

Objectives: Assessing a posterior fossa tumour in an adult can be challenging. Metastasis, haemangioblastoma, ependymal tumours, and medulloblastoma are the most common diagnostic possibilities. Our aim was to evaluate the contribution of magnetic resonance spectroscopy (MRS) in the diagnosis of these entities.

(1)H-MRS is useful to reinforce the suspicion of primary central nervous system lymphoma prior to surgery.

Objectives: To assess whether (1)H-MRS may be useful to reinforce the radiological suspicion of PCNSL.

Methods: In this retrospective study, we included 546 patients with untreated brain tumours in which single-voxel spectroscopy at TE 30 ms and 136 ms had been performed. The patients were split into two subgroups: "training set" and "test set.

Orbital lymphoma: imaging features and differential diagnosis.

Purpose: Patterns of orbital lymphoma at diagnosis and follow-up are described. We also discuss differential diagnosis of orbital masses.

Materials And Methods: This pictorial review contains 19 cases of orbital lymphoma before and after treatment.