CT and MRI characteristics and differential diagnosis of pineal region tumors

Abstract

Objective To analyze the CT and MRI characteristics of the pineal region tumors (PRTs) to improve the accuracy of diagnosis and differential diagnosis.Methods The MRI and CT findings of 28 patients with PRTs proved by operation and pathology were retrospectively analyzed.Eight of them were performed preoperative 1H-MRS and DWI examination and thier data were analyzed too.Results of these 28 patients,11 were diagnosed as having germinoma,4 teratoma,3 astrocytoma,3 meningioma,2 pinealocytoma and 1 epidermoid cyst,1 pineoblastoma,1 hamartoma and 1 dermoidcyst.The main imaging characteristics were cystic tumors in the pineal region,variational density/signal intensity with few tumors having their specified morphology,density/signal intensity and enhancement style.The germinomas and the pineoblastomas were mainly homogeneous solid masses with symmetrical density/signal.The astrocytoma was cystic-solid,mostly,with changing shapes and odds density/signal.The mature teratoma showed blending density/signal.The 1H-MRS showed typical high Cho peak and low NAA peak in the astrocytoma; no NAA peak was found in the meningeoma; high Cho peak and no Lip peak were found in the pineoblastoma; the germinoma was noted having Lip peak.Conclusion Observation on the changes of the morphologic features,density/signal intensity and enhancement style can help in the differential diagnosis of PRTs.DWI and 1H-MRS examinations can improve the accuracy of differential diagnosis to some extent,but some PRTs remain to be non-differentiable. Key words: Pineal region tumors; Magnetic resonance imaging; Magnetic resonance spectroscopy; Diffusion-weighted imaging; Computed tomography