The purpose was to analyze characteristic magnetic resonance (MR) imaging of pineal region tumors and to explore the value of diffusion-weighted imaging (DWI) and (1)H-MR spectroscopy ((1)H-MRS) in differential diagnosis among four common solid diseases: germinoma, teratoma, pineoblastoma, and glioma.

Thirty-three patients with pineal region tumors proven by pathology were prospectively studied. All of them underwent MRI SE-T1WI, FSE-T2WI, fluid-attenuated inversion recovery (FLAIR), and postcontrasted MR scan. Minimum apparent diffusion coefficient (ADC) value, and maximum MRS choline/N-acetyl-aspartate (Cho/NAA) and lipid/creatine (Lip/Cr) metabolic peak-height ratios were quantified within each lesion.

Most pineal region diseases have their typical morphology, signal intensity, and enhancement style. ADC values were lower in germinoma [(6.98±0.35)*10(-4)] and pineoblastoma [(9.14±0.79)*10(-4)] than in teratoma [(2.80±0.18)*10(-3)] and pineal glioma [(1.63±0.66)*10(-3)] (P< .05). Cho/NAA ratios were higher in germinoma (2.09±0.39), pineoblastoma (4.70±0.82), and pineal glioma (3.54±0.38) than in teratoma (1.52±0.91) (P< .05). Lip/Cr ratios were lower in germinoma (2.52±0.41) than in teratoma (8.47±1.16) (P< .05).

Changes in morphologic features, signal intensity, and enhancement style are the most helpful variables for the differential diagnosis of pineal region tumors. To some extent, DWI and (1)H-MRS imaging enable distinction among them.