Cribra orbitalia visualized in computed tomography.

Abstract

Cribra orbitalia are sieve-like lesions of the orbital roof. While common in historic skulls, they have long been absent in those examined in the last decades. Only recently we found low-grade cribra orbitalia in some contemporary cases. Though of unknown origin, this lesion is often attributed to anemia and deficiency diseases. It is theoretically possible to visualize cribra orbitalia in living subjects by computed tomography and thus study their etiology. The aim of our study was to investigate the possibilities of computed tomography for visualizing cribra orbitalia. We used multislice computed tomography (MSCT) in the spiral and sequential mode to image medium-grade cribra orbitalia of moderate severity in a human skull. Virtual endoscopic and 3-D images were produced by post-processing. The best results were obtained by the sequential mode and 3-D reconstruction. Given a thin slice thickness and a wide slice angle between slice plane and the orbital roof, the threshold level seems to be the most important factor influencing realistic reproduction and should be finely adjusted according to bone density. Clinical research may now begin by examining relevant patients undergoing CT.