[Differentiation of lacrimal gland tumors with high resolution computerized tomography in comparison with magnetic resonance tomography].

In a retrospective study of 15 patients with epithelial and non-epithelial masses of the lacrimal gland, the value of high-resolution computed tomography (CT) with multiplanar and three-dimensional reconstructions was compared to magnetic resonance imaging (MRI). For the differential diagnosis of lacrimal gland lesions the following parameters are important: shape of the lacrimal gland, internal structure, degree of contrast enhancement and integrity of adjacent bony structures. In evaluation of the extent of lacrimal gland lesions, thin-section CT with multiplanar and three-dimensional reconstruction is equal to MRI, while spiral CT with 1-mm slices is superior to standard CT with 2-mm slices. However, internal structure and contrast enhancement of lacrimal glands, integrity of adjacent bones and intracranial infiltration are better visualized with MRI than with CT. Only inhomogeneous mixed tissue tumors can be differentiated from homogeneous tumors by CT due to density differences. In conclusion, MRI is the method of choice if lacrimal gland tumors are suspected, while CT is only useful in doubtful cases concerning the bony structures as an additional method. Using modern imaging modalities, differentiation between epithelial and non-epithelial masses is possible for further diagnosis and therapeutic decisions. Both pleomorphic adenoma due to its different dense components and malignant masses due to bony destruction and intracranial attachment can be differentiated and treated in a specific way. Differentiation between non-epithelial masses (lymphoma and inflammatory pseudotumor) is only possible with a combination of imaging, clinical appearance and in some cases biopsy.