Orbitale Raumforderungen. Praktische Aspekte zur Bildgebung

Abstract

During the period 1992-1998,we diagnosed orbital tumors in 23 cases at the MLU Halle-Wittenberg. In the intraconal compartment we mostly saw cavernous hemangiomas and neurogenic tumors. Lymphomas and a primary meningioma were located in the extraconal space. Beneath the periosteum, bony processes, tumors of the sinuses, dermoid-and epidermoid-cysts normally occur, but we only observed metastases and hematomas. Furthermore,tumors of the lacrimal gland and inflammatory lesions were diagnosed. Orbital tumors are uncommon lesions, whose location in the orbit gives an important hint to differential diagnosis, because a high percentage of various pathologies is located in special compartments of the orbit. According to our results,the MRI-scan is usually sufficient for differentiation and for preoperative planning in order to reduce the X-ray dose of the lens. CT-scans with contrast are sometimes necessary for examining bone destroying processes and for planning the surgical approach to removing the tumor. X-rays of the skull widely lost their importance in the exact diagnostic of orbital tumors. B-scan ultrasonic imaging is reserved for screening and follow-up examination. Despite the use of MRI and CT scanning, the histological examination remains necessary.

Assessment of ultrasonography and computed tomography for the evaluation of unilateral orbital disease in dogs

“…Determining the exact location of a lesion may be easier by use of CT than by ultrasonography because of constant scanning planes and better anatomic landmarks on CT images. The compartmental approach to orbital CT imaging, which is used in humans to guide differential diagnoses, 10,36,37 had limited value to differentiate neoplastic from nonneoplastic disease in dogs.…”

“…Computed tomography was used as the criterion-referenced standard to assess the value of ultrasonography because confirmation of bone involvement during surgery or necropsy was available only in a limited number of dogs and CT was intuitively believed to be better than ultrasonography for evaluation of bone involvement. Furthermore, CT has been used in studies 9,20,36,37,39 in humans. Unfortunately, the sensitivity of CT for use in detecting invasion of the orbital bone in human patients with invasive periorbital carcinomas is not reliable, and bone invasion may be visible histologically, even though destruction cannot be seen on CT images in patients without clinical signs of orbital disease.…”

Diagnostic difficulties and treatment of non-Hodgkin lymphoma of the orbit

“…On the basis of CT and MRI, non-Hodgkin lymphomas of the orbit are described as abnormal, homogenous masses with relatively high density, subject to poor contrast amplification. In T2-dependent MRI images, lymphomas give a high signal, which is stronger than in T1-dependent images (Bloching et al, 2001). But these are not characteristic clinico-radiological features, differentiating nonHodgkin lymphomas from other orbital tumours (Coupland, 2004).…”

“…waves into deep tissues (Bloching et al, 2001;Neudorfer et al, 2004). On the basis of CT and MRI, non-Hodgkin lymphomas of the orbit are described as abnormal, homogenous masses with relatively high density, subject to poor contrast amplification.…”

Diagnostische Wertigkeit der Farbdopplersonographie

“…Gerade im Kindesalter lassen sich hier Befunde in der Gl. parotidea oder auch in der Orbita [3,17] nicht-invasiv erfassen und im Verlauf gut beurteilen (Abb. 9).…”