The pineal region: thin sectional anatomy with MR correlation in the coronal plane

This study was undertaken to explore the anatomic features and adjacent relationships of the pineal region in thin coronal sections. After CT and MR examination verifying no brain lesions, one normal cadaver head was selected for this study from three Chinese adult male cadavers. After being embedded and frozen, the head was sliced into serial sections at 0.1 mm intervals in the coronal plane with SKC 500 computerized freezing milling machine. Then the serial coronal sections were photographed by a high-resolution digital camera and saved in the computer. Subsequently, the anatomic structures of the pineal region on the thin coronal sections were investigated and correlated with in vivo MR images, which were obtained from ten normal Chinese male adult volunteers by a 3.0 T GE scanner. The base lines of the sectioning and the MR scan were all perpendicular to the AC-PC line. A total of 355 coronal sections and 21-23 in vivo coronal MR images related with the pineal region were obtained, respectively. From anterior to posterior, the shape of the pineal region changed from an inverted triangle to a trapezoid and a triangle gradually, and the anatomic details could be depicted clearly in the thin sectional anatomy images in sub-millimeter. Via the comparison, some micro-anatomic structures of the pineal region that cannot be discriminated clearly or missed in the thick sections or MR images were identified. The contrast of the computerized freezing milling technique with the MRI enhanced our ability to comprehend the complex anatomy of the pineal region and to improve the imaging diagnosis and surgical treatments of minute diseases in this region.